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IPv6演进技术要求第2部分：基于IPv6段路由(SRv6)的IP承载网络1 范围本文件规定了基于SRv6的IP承载网络总体架构、基于SRv6的设备层技术要求及基于SRv6的管控层技术要求。
本文件适用于支持SRv6的IP承载网络。
2 规范性引用文件下列文件中的内容通过文中的规范性引用而构成本文件必不可少的条款。
其中，注日期的引用文件，仅该日期对应的版本适用于本文件；不注日期的引用文件，其最新版本（包括所有的修改单）适用于本文件。
IETF RFC2493 IPv6规范中的通用报文隧道（Generic Packet Tunneling in IPv6 Specification）IETF RFC4659 IPv6 VPN场景中的BGP-MPLS IP虚拟私有网络扩展（BGP-MPLS IP Virtual Private Network (VPN) Extension for IPv6 VPN）IETF RFC5549 通告带有IPv6下一跳地址的IPv4网络层可达性信息（Advertising IPv4 Network Layer Reachability Information with an IPv6 Next Hop）IETF RFC6437 IPv6流标签规范（IPv6 Flow Label Specification）IETF RFC6514 MPLS/BGP IP VPN中提供组播服务的BGP编码与处理（BGP Encodings and Procedures for Multicast in MPLS/BGP IP VPNs）IETF RFC7432 基于BGP MPLS的EVPN（BGP MPLS-Based Ethernet VPN）IETF RFC7606 改进的BGP更新消息的错误处理（Revised Error Handling for BGP UPDATE Messages）IETF RFC8200 互联网协议第六版规范（Internet Protocol, Version 6 (IPv6) Specification）IETF RFC8402 分段路由架构（Segment Routing Architecure）IETF RFC8754 IPv6段路由报头(IPv6 Segment Routing Header)IETF RFC8986 SRv6网络编程（Segment Routing over IPv6 (SRv6) Network Programming）IETF RFC9252 基于SRv6的BGP overlay业务(BGP Overlay Services Based on Segment Routing over IPv6 (SRv6))IETF RFC9352 支持SRv6的ISIS扩展(IS-IS Extensions to Support Segment Routing over the IPv6 Data Plane）GB/T XXXXX IPv6演进技术要求第4部分：基于IPv6段路由(SRv6)的网络编程GB/T XXXXX IPv6演进技术要求第7部分：基于IPv6段路由(SRv6)的业务链GB/T XXXXX IPv6演进技术要求第8部分：基于IPv6段路由(SRv6)的报文头压缩GB/T XXXXX IPv6演进技术要求第9部分：基于IPv6段路由(SRv6)的网络故障保护3 术语、定义和缩略语3.1 术语和定义下列术语和定义适用于本文件。
中国移动通信企业标准家庭网关终端技术规范版本号：3.0.0 中国移动通信集团公司发布 ╳╳╳╳-╳╳-╳╳发布 ╳╳╳╳-╳╳-╳╳实施 QB-╳╳-╳╳╳-╳╳╳╳T e c h n i c a l S p e c i f i c a t i o n f o r H o m e G a t e w a y目录2.规范性引用文件...............................................................................................................................3.术语、定义和缩略语 .......................................................................................................................4.设备总体定义...................................................................................................................................4.1.设备在网络中的位置 ....................................................................................................................4.2.接口定义........................................................................................................................................4.3.设备类型........................................................................................................................................5.接入型家庭网关...............................................................................................................................5.1.接口要求........................................................................................................................................网络侧接口........................................................................................................................................网络侧接口描述............................................................................................................................................网络侧以太网接口要求................................................................................................................................PON接口要求.................................................................................................................................................TD-SCDMA接口要求.......................................................................................................................................TD-LTE接口要求...........................................................................................................................................用户侧接口........................................................................................................................................用户侧以太网接口要求................................................................................................................................WLAN接口 ......................................................................................................................................................USB接口（可选）.........................................................................................................................................5.2.功能要求........................................................................................................................................数据通信要求....................................................................................................................................IP协议要求 ..................................................................................................................................................数据转发功能要求........................................................................................................................................DNS功能要求.................................................................................................................................................IPv4地址管理及拨号管理功能要求 ...........................................................................................................IPv6地址管理及拨号管理功能要求 ...........................................................................................................IPv4NAT要求.................................................................................................................................................ALG要求 ........................................................................................................................................................组播要求 .......................................................................................................................................................其他功能要求................................................................................................................................................安全要求............................................................................................................................................防火墙 ...........................................................................................................................................................登陆WEB页面的安全要求............................................................................................................................设备安全性 ...................................................................................................................................................QoS要求.............................................................................................................................................VLAN功能要求...................................................................................................................................USB扩展及管理（可选）.................................................................................................................设备发现要求....................................................................................................................................UPnP ...............................................................................................................................................................DLNA（可选）................................................................................................................................................支持WLAN的开启和禁用..............................................................................................................................基本要求 .......................................................................................................................................................多SSID要求 .................................................................................................................................................WLAN安全要求...............................................................................................................................................5WLANQoS要求...............................................................................................................................................WPS要求 ........................................................................................................................................................ 基本应用要求.....................................................................................................................................WLAN共享 ....................................................................................................................................................家庭存储（可选）........................................................................................................................................5.3.性能要求........................................................................................................................................ 路由转发性能要求............................................................................................................................吞吐量 ...........................................................................................................................................................地址学习 .......................................................................................................................................................缓存大小 .......................................................................................................................................................连接数量要求................................................................................................................................................ WLAN无线性能要求...........................................................................................................................WLAN吞吐量性能要求...................................................................................................................................WLAN覆盖性能要求.......................................................................................................................................WLAN接收灵敏度要求...................................................................................................................................5.4.管理和维护要求............................................................................................................................ 本地管理和配置要求........................................................................................................................本地管理基本要求........................................................................................................................................用户分级管理................................................................................................................................................系统信息管理................................................................................................................................................基本配置 .......................................................................................................................................................高级配置 .......................................................................................................................................................设备管理 .......................................................................................................................................................网络诊断 .......................................................................................................................................................设备认证注册功能........................................................................................................................................ 远程管理要求....................................................................................................................................远程管理基本要求........................................................................................................................................远程参数配置和性能监测............................................................................................................................远程故障诊断功能........................................................................................................................................设备告警功能................................................................................................................................................远程链路维持功能........................................................................................................................................软件远程管理................................................................................................................................................业务部署和控制............................................................................................................................................PON上行家庭网关远程管理实现方式 ......................................................................................................... 日志功能要求....................................................................................................................................5.5.预配置要求.................................................................................................................................... 预配置要求........................................................................................................................................5.6.硬件要求........................................................................................................................................ 基本要求............................................................................................................................................硬件基本框图示例............................................................................................................................5.7.软件要求........................................................................................................................................基本要求............................................................................................................................................软件基本架构....................................................................................................................................软件接口要求....................................................................................................................................用户登录要求....................................................................................................................................系统升级要求....................................................................................................................................5.8.配置界面要求................................................................................................................................配置界面要求....................................................................................................................................配置界面用户权限要求....................................................................................................................5.9.设备标识要求................................................................................................................................5.10.外观及附件要求..........................................................................................................................运营商Logo要求..............................................................................................................................设备标签要求....................................................................................................................................网关指示灯要求................................................................................................................................开关与按键要求................................................................................................................................设备面板标识要求............................................................................................................................设备接口要求....................................................................................................................................附件要求............................................................................................................................................5.11.运行环境要求..............................................................................................................................供电要求............................................................................................................................................环境要求............................................................................................................................................抗电磁干扰能力................................................................................................................................设备本身产生的电磁干扰要求........................................................................................................过压过流保护....................................................................................................................................5.12.认证要求......................................................................................................................................6.接入型家庭网关支持物联网功能 ....................................................................................................6.1.接入型家庭网关支持宜居通的功能要求（内置433M模块）...................................................433M模块要求...................................................................................................................................外围设备要求....................................................................................................................................业务功能描述....................................................................................................................................安防功能要求................................................................................................................................................家电控制功能................................................................................................................................................接入型家庭网关配置界面要求........................................................................................................配置界面要求................................................................................................................................................配置界面用户权限要求................................................................................................................................6.2.接入型家庭网关支持基于低功耗W I F I的物联网功能要求..........................................................设备接入功能要求............................................................................................................................WiFi接入.......................................................................................................................................................接入型家庭网关要求 ...............................................................................................................................外设要求...................................................................................................................................................DHCP流程要求 .............................................................................................................................................7.宽带应用型家庭网关 .......................................................................................................................7.1.类型描述..........................................................................................................................................7.2.分体机接入设备要求......................................................................................................................7.3.分体机应用设备（机顶盒）要求 ..................................................................................................硬件要求............................................................................................................................................硬件、接口及按键要求................................................................................................................................遥控器要求及参考设计................................................................................................................................电源要求 .......................................................................................................................................................配件要求 .......................................................................................................................................................设备标识要求................................................................................................................................................网络侧接口要求................................................................................................................................业务功能要求....................................................................................................................................互联网电视应用............................................................................................................................................多屏互动功能................................................................................................................................................概述...........................................................................................................................................................镜像功能...................................................................................................................................................分享功能...................................................................................................................................................家庭高清视频通话（可选）........................................................................................................................家庭卡拉OK功能（可选） .........................................................................................................................语音交互功能................................................................................................................................................软件要求............................................................................................................................................操作系统要求................................................................................................................................................软件协议要求................................................................................................................................................编码及解码能力要求....................................................................................................................................编解码能力要求 .......................................................................................................................................音视频播放质量要求 ...............................................................................................................................屏幕管理要求................................................................................................................................................防刷机要求 ...................................................................................................................................................管理要求............................................................................................................................................操作管理 .......................................................................................................................................................软件管理 .......................................................................................................................................................文件管理 .......................................................................................................................................................4.配置管理 ....................................................................................................................................................其他要求............................................................................................................................................供电要求 .......................................................................................................................................................环境要求 .......................................................................................................................................................噪声要求 .......................................................................................................................................................7.4.一体机设备要求............................................................................................................................网络侧接口要求................................................................................................................................网络接入功能要求............................................................................................................................业务功能要求....................................................................................................................................软件要求............................................................................................................................................管理要求............................................................................................................................................硬件要求............................................................................................................................................其他要求............................................................................................................................................供电要求 .......................................................................................................................................................环境要求 .......................................................................................................................................................噪声要求 .......................................................................................................................................................8.编制历史 .......................................................................................................................................... 附录A省公司代码.......................................................................................................................... 附录B设备故障消息（标准性附录） ...........................................................................................B.1告警编号规则 ...............................................................................................................................B.2设备告警信息列表 ....................................................................................................................... 附录C WIMO协议说明.....................................................................................................................C.1设备类型和功能流程 .....................................................................................................................C.2网络连接.........................................................................................................................................C.3设备连接.........................................................................................................................................C.4媒体格式要求.................................................................................................................................C.4.1视频编解码流程.....................................................................................................................C.4.2M-JPEG视频编解码方案.........................................................................................................C.4.3H.264视频编解码方案...........................................................................................................C.4.4音频编解码流程..................................................................................................................... 附录D手机遥控接口说明 ..............................................................................................................D.1设备发现.........................................................................................................................................D.2配对请求接口.................................................................................................................................D.3配对连接接口.................................................................................................................................D.4发送遥控器键值接口 .....................................................................................................................D.5发送文本接口.................................................................................................................................D.6发送心跳接口.................................................................................................................................D.7断开连接接口.................................................................................................................................D.8配对成功广播发送接口 .................................................................................................................D.9配对断开广播发送接口 ................................................................................................................. 附录E宽带应用型家庭网关牌照合作注册机制............................................................................ 附录F家庭网关命名规则 ..............................................................................................................。
Internet Message Access Protocol (IMAP) is an email retrieval protocol. It stores email messages on a mail server and enables the recipient to view and manipulate them as though they were stored locally on their device. IMAP was developed in the late 1980s and has since become one of the most widely used email retrieval protocols.The IMAP standard is defined in RFC 3501, which was published in 2003. This document provides a detailed description of the protocol's functionality, including its data formats, commands, and responses. The standard specifies how IMAP clients and servers should communicate with each other to enable the retrieval and manipulation of email messages.One of the key features of IMAP is its support for multiple clients accessing the same mailbox simultaneously. This is achieved through the use of a "shared" storage model, where all clients see the same set of messages and folders stored on the server. This allows users to access their email from different devices without having to worry about synchronizing their messages manually.Another important aspect of IMAP is its support for message organization and management. Clients can create, delete, and rename folders, as well as move messages between folders. They can also search for specific messages based on various criteria, such as sender, subject, or date.IMAP also provides a range of features for managing individual messages. Clients can mark messages as read or unread, flag them for follow-up, and even move them to a specific folder. They can also reply to messages, forward them to others, and generate replies or forwards with attachments.Overall, the IMAP standard provides a powerful and flexible framework for managing email messages. Its support for shared storage, message organization, and advanced message management features make it a popular choice for both personal and business email users.。
中国移动通信企业标准QB-╳╳-╳╳╳-╳╳╳╳家庭网关终端技术规范T e c h n i c a l S p e c i f i c a t i o n f o r H o m e G a t e w a y版本号：3.0.0╳╳╳╳-╳╳-╳╳发布╳╳╳╳-╳╳-╳╳实施目录1. 范围 (1)2. 规范性引用文件 (1)3. 术语、定义和缩略语 (5)4. 设备总体定义 (9)4.1.设备在网络中的位置 (9)4.2.接口定义 (10)4.3.设备类型 (10)5. 接入型家庭网关 (11)5.1.接口要求 (11)5.1.1. 网络侧接口 (11)5.1.1.1. 网络侧接口描述 (11)5.1.1.2. 网络侧以太网接口要求 (12)5.1.1.3. PON接口要求 (12)5.1.1.4. TD-SCDMA接口要求 (12)5.1.1.5. TD-LTE接口要求 (12)5.1.2. 用户侧接口 (12)5.1.2.1. 用户侧以太网接口要求 (12)5.1.2.2. WLAN接口 (12)5.1.2.3. USB接口（可选） (12)5.2.功能要求 (13)5.2.1. 数据通信要求 (13)5.2.1.1. IP协议要求 (13)5.2.1.2. 数据转发功能要求 (13)5.2.1.3. DNS功能要求 (14)5.2.1.4. IPv4地址管理及拨号管理功能要求 (14)5.2.1.5. IPv6地址管理及拨号管理功能要求 (16)5.2.1.6. IPv4 NAT要求 (16)5.2.1.7. ALG要求 (17)5.2.1.8. 组播要求 (17)5.2.1.9. 其他功能要求 (17)5.2.2. 安全要求 (17)5.2.2.1. 防火墙 (17)5.2.2.2. 登陆WEB页面的安全要求 (17)5.2.2.3. 设备安全性 (18)5.2.3. QoS 要求 (18)5.2.4. VLAN功能要求 (19)5.2.5. USB扩展及管理（可选） (19)5.2.6. 设备发现要求 (19)5.2.6.1. UPnP (19)5.2.6.2. DLNA（可选） (19)5.2.7.1. 支持WLAN的开启和禁用 (20)5.2.7.2. 基本要求 (20)5.2.7.3. 多SSID要求 (20)5.2.7.4. WLAN安全要求 (20)5.2.7.5. WLAN QoS要求 (21)5.2.7.6. WPS要求 (21)5.2.8. 基本应用要求 (22)5.2.8.1. WLAN共享 (22)5.2.8.2. 家庭存储（可选） (23)5.3.性能要求 (23)5.3.1. 路由转发性能要求 (23)5.3.1.1. 吞吐量 (23)5.3.1.2. 地址学习 (23)5.3.1.3. 缓存大小 (23)5.3.1.4. 连接数量要求 (24)5.3.2. WLAN无线性能要求 (24)5.3.2.1. WLAN吞吐量性能要求 (24)5.3.2.2. WLAN覆盖性能要求 (24)5.3.2.3. WLAN接收灵敏度要求 (24)5.4.管理和维护要求 (24)5.4.1. 本地管理和配置要求 (24)5.4.1.1. 本地管理基本要求 (24)5.4.1.2. 用户分级管理 (25)5.4.1.3. 系统信息管理 (25)5.4.1.4. 基本配置 (25)5.4.1.5. 高级配置 (26)5.4.1.6. 设备管理 (27)5.4.1.7. 网络诊断 (27)5.4.1.8. 设备认证注册功能 (27)5.4.2. 远程管理要求 (29)5.4.2.1. 远程管理基本要求 (30)5.4.2.2. 远程参数配置和性能监测 (30)5.4.2.3. 远程故障诊断功能 (30)5.4.2.4. 设备告警功能 (30)5.4.2.5. 远程链路维持功能 (31)5.4.2.6. 软件远程管理 (31)5.4.2.7. 业务部署和控制 (31)5.4.2.8. PON上行家庭网关远程管理实现方式 (31)5.4.3. 日志功能要求 (32)5.5.预配置要求 (33)5.5.1. 预配置要求 (33)5.6.硬件要求 (34)5.6.1. 基本要求 (34)5.6.3. 硬件基本框图示例 (34)5.7.软件要求 (34)5.7.1. 基本要求 (34)5.7.2. 软件基本架构 (35)5.7.3. 软件接口要求 (35)5.7.4. 用户登录要求 (36)5.7.5. 系统升级要求 (36)5.8.配置界面要求 (36)5.8.1. 配置界面要求 (36)5.8.2. 配置界面用户权限要求 (36)5.9.设备标识要求 (38)5.10.外观及附件要求 (39)5.10.1. 运营商Logo要求 (39)5.10.2. 设备标签要求 (39)5.10.3. 网关指示灯要求 (40)5.10.4. 开关与按键要求 (41)5.10.5. 设备面板标识要求 (41)5.10.6. 设备接口要求 (41)5.10.7. 附件要求 (41)5.11.运行环境要求 (42)5.11.1. 供电要求 (42)5.11.2. 环境要求 (42)5.11.3. 抗电磁干扰能力 (42)5.11.4. 设备本身产生的电磁干扰要求 (42)5.11.5. 过压过流保护 (42)5.12.认证要求 (43)6. 接入型家庭网关支持物联网功能 (43)6.1.接入型家庭网关支持宜居通的功能要求（内置433M模块） (43)6.1.1. 433M模块要求 (43)6.1.2. 外围设备要求 (43)6.1.3. 业务功能描述 (43)6.1.3.1. 安防功能要求 (44)6.1.3.2. 家电控制功能 (44)6.1.4. 接入型家庭网关配置界面要求 (45)6.1.4.1.配置界面要求 (45)6.1.4.2. 配置界面用户权限要求 (46)6.2.接入型家庭网关支持基于低功耗W I F I的物联网功能要求 (48)6.2.1. 设备接入功能要求 (48)6.2.1.1. WiFi接入 (48)6.2.1.1.1. 接入型家庭网关要求 (48)6.2.1.1.2. 外设要求 (49)6.2.1.2. DHCP流程要求 (49)7. 宽带应用型家庭网关 (49)7.1.类型描述 (49)7.2.分体机接入设备要求 (49)7.3.分体机应用设备（机顶盒）要求 (50)7.3.1. 硬件要求 (50)7.3.1.1. 硬件、接口及按键要求 (50)7.3.1.2. 遥控器要求及参考设计 (53)7.3.1.3. 电源要求 (53)7.3.1.4. 配件要求 (53)7.3.1.5. 设备标识要求 (53)7.3.2. 网络侧接口要求 (54)7.3.3. 业务功能要求 (54)7.3.3.1. 互联网电视应用 (54)7.3.3.2. 多屏互动功能 (54)7.3.3.2.1. 概述 (54)7.3.3.2.2. 镜像功能 (54)7.3.3.2.3. 分享功能 (55)7.3.3.3. 家庭高清视频通话（可选） (55)7.3.3.4. 家庭卡拉OK功能（可选） (56)7.3.3.5. 语音交互功能 (56)7.3.4. 软件要求 (56)7.3.4.1. 操作系统要求 (56)7.3.4.2. 软件协议要求 (57)7.3.4.3. 编码及解码能力要求 (57)7.3.4.3.1. 编解码能力要求 (57)7.3.4.3.2. 音视频播放质量要求 (58)7.3.4.4. 屏幕管理要求 (58)7.3.4.5. 防刷机要求 (58)7.3.5. 管理要求 (59)7.3.5.1. 操作管理 (59)7.3.5.2. 软件管理 (60)7.3.5.3. 文件管理 (60)7.3.5.4. 配置管理 (60)7.3.6. 其他要求 (61)7.3.6.1. 供电要求 (61)7.3.6.2. 环境要求 (61)7.3.6.3. 噪声要求 (62)7.4.一体机设备要求 (62)7.4.1. 网络侧接口要求 (62)7.4.2. 网络接入功能要求 (62)7.4.3. 业务功能要求 (62)7.4.4. 软件要求 (62)7.4.5. 管理要求 (62)7.4.6. 硬件要求 (62)7.4.7. 其他要求 (62)7.4.7.1. 供电要求 (62)7.4.7.2. 环境要求 (63)7.4.7.3. 噪声要求 (63)8. 编制历史 (63)附录A省公司代码 (64)附录B设备故障消息（标准性附录） (65)B.1 告警编号规则 (65)B.2 设备告警信息列表 (66)附录C WIMO协议说明 (67)C.1设备类型和功能流程 (67)C.2网络连接 (68)C.3设备连接 (69)C.4媒体格式要求 (70)C.4.1视频编解码流程 (70)C.4.2 M-JPEG视频编解码方案 (70)C.4.3 H.264视频编解码方案 (70)C.4.4 音频编解码流程 (70)附录D手机遥控接口说明 .............................................................................. 错误!未定义书签。
rfc相关设置及使用RFC（Request for Comments）是一种用于定义互联网协议、标准和相关问题的文档。
RFC的格式由互联网工程任务组（IETF）统一规定，它们记录了网络技术的发展和演进过程。
在本文中，我们将介绍RFC相关的设置和使用。
1. 了解RFC的作用和历史：RFC是由IETF组织制定的一种标准化文档，它记录了互联网协议的设计、开发和演化过程。
RFC起源于20世纪60年代的ARPANET，是一种社区驱动的文档，通过共享和讨论来推动互联网技术的发展。
RFC文档旨在提供指南、建议和最佳实践，帮助网络技术人员解决问题。
2. 寻找和阅读RFC文档：RFC文档可以在互联网上免费获取，IETF的官方网站和其他资源库都有存档。
这些文档按照顺序编号，并且以RFC开头，比如RFC 791定义了IPv4协议。
通过搜索引擎或在IETF网站上使用关键词搜索，可以找到特定主题的RFC文档。
阅读RFC文档时，应该注意文档的状态，有一些可能已经被更新或废弃。
3. 使用RFC文档：RFC文档在网络技术的发展过程中起着重要的指导作用。
它们提供了协议规范、算法实现、安全性和隐私等方面的建议。
网络管理员、网络工程师和开发人员可以使用RFC文档来了解和理解特定协议或标准的设计原理和要求。
此外，RFC文档还常用于进行互联网协议的实现、编程和配置。
4. 参与RFC的制定过程：RFC并不是静止的文件，而是一个持续演进的过程。
任何人都可以参与到RFC的制定过程中。
要参与RFC的制定，可以加入IETF并参与相关的工作组或邮件列表。
通过这种方式，个人可以提出改进建议，参与讨论和标准化的制定。
5. 遵循RFC的指导原则：在网络技术领域，遵循RFC的指导原则是至关重要的。
这些指导原则包括设计原则、协议分层、安全性和互操作性等要求。
遵循RFC的指导原则可以确保网络协议的正确性、稳定性和可靠性，同时也可以促进网络技术的发展和创新。
总结起来，RFC在互联网技术领域起着重要的作用，它们记录了互联网协议的发展历程和指导原则。
Network Working Group J. Galbraith Request for Comments: 4716 VanDyke Software Category: Informational R. Thayer Canola & Jones November 2006 The Secure Shell (SSH) Public Key File FormatStatus of This MemoThis memo provides information for the Internet community. It doesnot specify an Internet standard of any kind. Distribution of thismemo is unlimited.Copyright NoticeCopyright (C) The IETF Trust (2006).AbstractThis document formally documents an existing public key file formatin use for exchanging public keys between different Secure Shell(SSH) implementations.In addition, this document defines a standard textual representation for SSH public key fingerprints.Table of Contents1. Introduction (2)2. Conventions Used in This Document (2)3. Key File Format (2)3.1. Line Termination Characters (2)3.2. Begin and End Markers (3)3.3. Key File Header (3)3.3.1. Subject Header (3)3.3.2. Comment Header (4)3.3.3. Private Use Headers (4)3.4. Public Key File Body (4)3.5. Differences with RFC 1421 PEM Formats (4)3.6. Examples (5)4. Public Key Fingerprints (6)5. IANA Considerations (6)6. Security Considerations (7)7. References (8)7.1. Normative References (8)7.2. Informative References (8)Galbraith & Thayer Informational [Page 1]1. IntroductionThe SSH protocol supports the use of public/private key pairs inorder to perform authentication based on public key cryptography.However, in order to use public key authentication in the SSHprotocol, public keys must first be exchanged between client andserver.This document formally describes an existing public key file formatthat can be used with any of the common existing file transfermechanisms in order to exchange public keys.The SSH protocol also uses public/private key pairs to authenticatethe server. In this scenario, it is important to verify that thepublic key provided by the server is indeed the server’s public key. This document describes a mechanism for creating a short text string that uniquely represents a particular public key, calledfingerprinting.2. Conventions Used in This DocumentThe key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT","SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119].3. Key File FormatIn order to implement public key authentication, SSH implementations must share public key files between the client and the server inorder to interoperate.A key file is a text file, containing a sequence of lines. Each line in the file MUST NOT be longer than 72 8-bit bytes excluding linetermination characters.3.1. Line Termination CharactersImplementations SHOULD generate public key files using their system’s local text file representation.In the event that public key files are not transferred as text files, implementations SHOULD be prepared to read files using any of thecommon line termination sequence, <CR>, <LF>, or <CR><LF>.Galbraith & Thayer Informational [Page 2]3.2. Begin and End MarkersThe first line of a conforming key file MUST be a begin marker, which is the literal text:---- BEGIN SSH2 PUBLIC KEY ----The last line of a conforming key file MUST be an end marker, whichis the literal text:---- END SSH2 PUBLIC KEY ----3.3. Key File HeaderThe key file header section consists of multiple RFC822-style header fields. Each field is a line of the following format:Header-tag ’:’ ’ ’ Header-valueThe Header-tag MUST NOT be more than 64 8-bit bytes and is case-insensitive. The Header-value MUST NOT be more than 1024 8-bitbytes. Each line in the header MUST NOT be more than 72 8-bit bytes.A line is continued if the last character in the line is a ’\’. Ifthe last character of a line is a ’\’, then the logical contents ofthe line are formed by removing the ’\’ and the line terminationcharacters, and appending the contents of the next line.The Header-tag MUST be encoded in US-ASCII. The Header-value MUST be encoded in UTF-8 [RFC3629].A line that is not a continuation line that has no ’:’ in it is thefirst line of the base64-encoded body. (See Section 3.4.)The space of header-tags is managed as described in Section 5.Compliant implementations MUST ignore headers with unrecognizedheader-tags. Implementations SHOULD preserve such unrecognizedheaders when manipulating the key file.3.3.1. Subject HeaderThis field is used to store the login-name that the key was generated under. For example:Subject: userGalbraith & Thayer Informational [Page 3]3.3.2. Comment HeaderThe comment header contains a user-specified comment. The commentSHOULD be displayed when using the key.It is suggested that this field default to user@hostname for the user and machine used to generate the key. For example:Comment: user@Currently, common practice is to quote the Header-value of theComment by prefixing and suffixing it with ’"’ characters, and someexisting implementations fail if these quotation marks are omitted.Compliant implementations MUST function correctly if the quotationmarks are omitted.Implementations MAY include the quotation marks. If the first andlast characters of the Header-value are matching quotation marks,implementations SHOULD remove them before using the value.3.3.3. Private Use HeadersHeaders with header-tags beginning with "x-" are reserved for private use.3.4. Public Key File BodyThe body of a public key file is the base64 encoded ([RFC2045])public key data as specified by [RFC4253], Section 6.6:string certificate or public key format identifierbyte[n] key/certificate dataAs with all other lines, each line in the body MUST NOT be longerthan 72 8-bit bytes excluding line termination characters.3.5. Differences with RFC 1421 PEM FormatsImplementers should take care to notice that while the format issuperficially similar to those specified by PEM [RFC1421] and OpenPGP [RFC2440], it is not identical; most notably:o The other specifications use different BEGIN/END delimiters (five dashes, no space rather than four dashes and a space).o There is no blank line before the start of the base64-encodedcontents.Galbraith & Thayer Informational [Page 4]o There is no Cyclic Redundancy Check (CRC) at the end of thebase64-encoded block.o Header continuation uses a backslash at the end of the continuedline rather than whitespace at the start of the next line.3.6. ExamplesThe following are some examples of public key files that arecompliant (note that the examples all wrap before 72 bytes to meetIETF document requirements; however, they are still compliant.)---- BEGIN SSH2 PUBLIC KEY ----Comment: "1024-bit RSA, converted from OpenSSH by me@"x-command: /home/me/bin/lock-in-guest.shAAAAB3NzaC1yc2EAAAABIwAAAIEA1on8gxCGJJWSRT4uOrR13mUaUk0hRf4RzxSZ1zRb YYFw8pfGesIFoEuVth4HKyF8k1y4mRUnYHP1XNMNMJl1JcEArC2asV8sHf6zSPVffozZ 5TT4SfsUu/iKy9lUcCfXzwre4WWZSXXcPff+EHtWshahu3WzBdnGxm5Xoi89zcE=---- END SSH2 PUBLIC KEY -------- BEGIN SSH2 PUBLIC KEY ----Comment: This is my public key for use on \servers which I don’t like.AAAAB3NzaC1kc3MAAACBAPY8ZOHY2yFSJA6XYC9HRwNHxaehvx5wOJ0rzZdzoSOXxbET W6ToHv8D1UJ/z+zHo9Fiko5XybZnDIaBDHtblQ+Yp7StxyltHnXF1YLfKD1G4T6JYrdH YI14Om1eg9e4NnCRleaqoZPF3UGfZia6bXrGTQf3gJq2e7Yisk/gF+1VAAAAFQDb8D5c vwHWTZDPfX0D2s9Rd7NBvQAAAIEAlN92+Bb7D4KLYk3IwRbXblwXdkPggA4pfdtW9vGf J0/RHd+NjB4eo1D+0dix6tXwYGN7PKS5R/FXPNwxHPapcj9uL1Jn2AWQ2dsknf+i/FAA vioUPkmdMc0zuWoSOEsSNhVDtX3WdvVcGcBq9cetzrtOKWOocJmJ80qadxTRHtUAAACB AN7CY+KKv1gHpRzFwdQm7HK9bb1LAo2KwaoXnadFgeptNBQeSXG1vO+JsvphVMBJc9HS n24VYtYtsMu74qXviYjziVucWKjjKEb11juqnF0GDlB3VVmxHLmxnAz643WK42Z7dLM5 sY29ouezv4Xz2PuMch5VGPP+CDqzCM4loWgV---- END SSH2 PUBLIC KEY -------- BEGIN SSH2 PUBLIC KEY ----Comment: DSA Public Key for use with MyIspAAAAB3NzaC1kc3MAAACBAPY8ZOHY2yFSJA6XYC9HRwNHxaehvx5wOJ0rzZdzoSOXxbET W6ToHv8D1UJ/z+zHo9Fiko5XybZnDIaBDHtblQ+Yp7StxyltHnXF1YLfKD1G4T6JYrdH YI14Om1eg9e4NnCRleaqoZPF3UGfZia6bXrGTQf3gJq2e7Yisk/gF+1VAAAAFQDb8D5c vwHWTZDPfX0D2s9Rd7NBvQAAAIEAlN92+Bb7D4KLYk3IwRbXblwXdkPggA4pfdtW9vGf J0/RHd+NjB4eo1D+0dix6tXwYGN7PKS5R/FXPNwxHPapcj9uL1Jn2AWQ2dsknf+i/FAA vioUPkmdMc0zuWoSOEsSNhVDtX3WdvVcGcBq9cetzrtOKWOocJmJ80qadxTRHtUAAACB AN7CY+KKv1gHpRzFwdQm7HK9bb1LAo2KwaoXnadFgeptNBQeSXG1vO+JsvphVMBJc9HS n24VYtYtsMu74qXviYjziVucWKjjKEb11juqnF0GDlB3VVmxHLmxnAz643WK42Z7dLM5 sY29ouezv4Xz2PuMch5VGPP+CDqzCM4loWgV---- END SSH2 PUBLIC KEY ----Galbraith & Thayer Informational [Page 5]---- BEGIN SSH2 PUBLIC KEY ----Subject: meComment: 1024-bit rsa, created by me@ Mon Jan 15 \08:31:24 2001AAAAB3NzaC1yc2EAAAABJQAAAIEAiPWx6WM4lhHNedGfBpPJNPpZ7yKu+dnn1SJejgt4 596k6YjzGGphH2TUxwKzxcKDKKezwkpfnxPkSMkuEspGRt/aZZ9wa++Oi7Qkr8prgHc4 soW6NUlfDzpvZK2H5E7eQaSeP3SAwGmQKUFHCddNaP0L+hM7zhFNzjFvpaMgJw0=---- END SSH2 PUBLIC KEY ----4. Public Key FingerprintsThe security of the SSH protocols relies on the verification ofpublic host keys. Since public keys tend to be very large, it isdifficult for a human to verify an entire host key. Even with aPublic Key Infrastructure (PKI) in place, it is useful to have astandard for exchanging short fingerprints of public keys.This section formally describes the method of generating public keyfingerprints that is in common use in the SSH community.The fingerprint of a public key consists of the output of the MD5message-digest algorithm [RFC1321]. The input to the algorithm isthe public key data as specified by [RFC4253]. (This is the samedata that is base64 encoded to form the body of the public key file.)The output of the algorithm is presented to the user as a sequence of 16 octets printed as hexadecimal with lowercase letters and separated by colons.For example: "c1:b1:30:29:d7:b8:de:6c:97:77:10:d7:46:41:63:87"5. IANA ConsiderationsSection 3.3 defines a new namespace of "Header-tags". These areUS-ASCII strings of maximum length 64 characters and arecase-insensitive.IANA has created and maintains a registry of these header-tags. The registry maps each header-tag to a reference defining the header.The initial contents of the registry are as follows:subject defined in Section 3.3.1comment defined in Section 3.3.2Header-tags beginning with "x-" are reserved for private use, asdefined in [RFC2434].Galbraith & Thayer Informational [Page 6]All other allocations are to be made by IETF consensus, as defined in [RFC2434].6. Security ConsiderationsThe file format described by this document provides no mechanism toverify the integrity or otherwise detect tampering with the datastored in such files. Given the potential of adversarial tamperingwith this data, system-specific measures (e.g., Access Control Lists, UNIX permissions, other Discretionary and/or Mandatory AccessControls) SHOULD be used to protect these files. Also, if thecontents of these files are transferred it SHOULD be done over atrusted channel.The header data allowed by this file format could contain anunlimited range of information. While in many environments theinformation conveyed by this header data may be considered innocuous public information, it may constitute a channel through whichinformation about a user, a key, or its use may be disclosedintentionally or otherwise (e.g., "Comment: Mary E. Jones, 123 MainSt, Home Phone:..."). The presence and use of this header dataSHOULD be reviewed by sites that deploy this file format.The public key fingerprint method presented here relies on the MD5one-way hash function, which is known to have certain weaknessesregarding its collision resistance; however, the particular use made of MD5 here depends solely on its 2nd-preimage resistance, not on its collision resistance.MD5 is used here for historical reasons.Galbraith & Thayer Informational [Page 7]7. References7.1. Normative References[RFC1321] Rivest, R., "The MD5 Message-Digest Algorithm", RFC 1321, April 1992.[RFC2045] Freed, N. and N. Borenstein, "Multipurpose Internet MailExtensions (MIME) Part One: Format of Internet MessageBodies", RFC 2045, November 1996.[RFC2119] Bradner, S., "Key words for use in RFCs to IndicateRequirement Levels", BCP 14, RFC 2119, March 1997.[RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO10646", STD 63, RFC 3629, November 2003.[RFC4253] Ylonen, T. and C. Lonvick, "The Secure Shell (SSH)Transport Layer Protocol", RFC 4253, January 2006.[RFC2434] Narten, T. and H. Alvestrand, "Guidelines for Writing anIANA Considerations Section in RFCs", BCP 26, RFC 2434,October 1998.7.2. Informative References[RFC1421] Linn, J., "Privacy Enhancement for Internet ElectronicMail: Part I: Message Encryption and AuthenticationProcedures", RFC 1421, February 1993.[RFC2440] Callas, J., Donnerhacke, L., Finney, H., and R. Thayer,"OpenPGP Message Format", RFC 2440, November 1998.Galbraith & Thayer Informational [Page 8]Authors’ AddressesJoseph GalbraithVanDyke Software4848 Tramway Ridge BlvdSuite 101Albuquerque, NM 87111USPhone: +1 505 332 5700EMail: galb@Rodney ThayerCanola & Jones650 Castro Street Suite 120-205Mountain View CA 94041USPhone: +1 650 704 8389EMail: rodney@Galbraith & Thayer Informational [Page 9]Full Copyright StatementCopyright (C) The IETF Trust (2006).This document is subject to the rights, licenses and restrictionscontained in BCP 78, and except as set forth therein, the authorsretain all their rights.This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST,AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES,EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THATTHE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULARPURPOSE.Intellectual PropertyThe IETF takes no position regarding the validity or scope of anyIntellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described inthis document or the extent to which any license under such rightsmight or might not be available; nor does it represent that it hasmade any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can befound in BCP 78 and BCP 79.Copies of IPR disclosures made to the IETF Secretariat and anyassurances of licenses to be made available, or the result of anattempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of thisspecification can be obtained from the IETF on-line IPR repository at /ipr.The IETF invites any interested party to bring to its attention anycopyrights, patents or patent applications, or other proprietaryrights that may cover technology that may be required to implementthis standard. Please address the information to the IETF atietf-ipr@.AcknowledgementFunding for the RFC Editor function is currently provided by theInternet Society.Galbraith & Thayer Informational [Page 10]。
令牌桶算法版权声明本文截取自internet，不代表本公司见解。
介绍令牌桶算法是目前IP QoS中最常采用的一种流量测量方法，广泛应用于约定访问速率技术、通用流量整形技术以及物理接口总速率限制等技术中。
IETF RFC 建议规范了单速率三色标记和双速率三色标记两种令牌桶算法，在桶的构成、令牌添加和报文处理流程方面前者较后者简单，成为目前业界比较常用的流量标记方式。
在实际应用中，应针对不同的流量特征选择恰当的标记方式。
1.令牌桶算法基本原理RFC中定义了两种令牌桶算法——单速率三色标记算法和双速率三色标记算法，其评估结果都是为报文打上红、黄、绿三色标记。
QoS会根据报文的颜色，设置报文的丢弃优先级，其中单速率三色标记比较关心报文尺寸的突发，而双速率三色标记则关注速率上的突发，两种算法都可工作于色盲模式和非色盲模式。
单速率三色标记算法IETF的RFC文件l2j定义了单速率三色标记算法，评估依据以下3个参数：承诺访问速率( CIR)，即向令牌桶中填充令牌的速率；承诺突发尺寸(CBS)，即令牌桶的容量，每次突发所允许的最大流量尺寸( 注：设置的突发尺寸必须大于最大报文长度)；超额突发尺寸(EBS)。
一般采用双桶结构：C桶和E桶。
表示C桶中的令牌数，表示E桶中令牌数，两桶的总容量分别为CBS 和EBS。
初始状态时两桶是满的，即Tc和初始值分别等于CBS和EBS。
令牌的产生速率是CIR，通常是先往c桶中添加令牌，等c桶满了，再往E桶中添加令牌，当两桶都被填满时，新产生的令牌将会被丢弃。
色盲模式下，假设到达的报文长度为口。
若报文长度口小于c桶中的令牌数，则报文被标记为绿色，且C桶中的令牌数减少B；若Te< B< T e，则标记为黄色，E和c桶中的令牌数均减少口；若B> Te，标记为红色，两桶总令牌数都不减少。
在非色盲模式下，若报文已被标记为绿色或B<TC，则报文被标记为绿色，R，C减少B；若报文已被标记为黄色或TC<BTe，则标记为红色，r，c和都不减少。
华为认证ICT工程师HCIA考试(习题卷10)说明：答案和解析在试卷最后第1部分：单项选择题，共105题，每题只有一个正确答案,多选或少选均不得分。
1.[单选题]通常提供应用运行开发环境的服务属于哪个层面的云服务?A)IaaSB)PaaSC)SaaS2.[单选题]下列关于Adhoc会议描述错误的是()A)在预约Adhoc会议时,需分别设置主席密码和会议激活密码。
B)Adhoc会议是通过终端侧激活会议并加入会议的一种会议方式。
C)使用Adhoc会议前需要新建Adhoc会议模板。
D)Adhoc会议在未激活的情况下,不占用MCU资源。
3.[单选题]以下关于华为Fusion Computer HA描述不正确的是（）A)虚拟机的数据如果保存在共享存储內，发生故障时保存的数据不会失B)该功能支持虚拟机故障后自动重启C)系统周期检测虚拟机状态，当物理服务器故障引|起虚拟机故障时，系统可以将虚拟机迁移到其他物理服务器重新启动，保证虚拟机能够快速恢复D)管理员可以根据虚拟机的重要程度，设置不同的HA策略4.[单选题]以下不属于Tensor Flow 2.0的特点是?A)多核CPU加速B)分布式C)多语言D)多平台5.[单选题]下列RAID级别数据冗余能力最弱的是（）A)RAID 1B)RAID 6C)RAID 0D)RAID 56.[单选题]如果应用层协议为Telnet，那么IPv4首部中Protocol字段取值为？A)17B)67C)53D)67.[单选题]在很多小文件场景下,Spark会起很多Task,当SQL逻辑中存在Shuffle操作时,会大大増加hash分桶数,严重影A)group byB)coalosceC)connectD)join8.[单选题]按华为云服务的划分,哪项云服务不属于计算云服务?A)弹性云服务B)弹性伸缩云服务C)虚拟私有云D)裸金属服务9.[单选题]以下哪项不是链接克隆虚拟机的特点?（）A)当需要对虚拟机的软件进行维护时，必须对每台虚拟机进行操作。
中国金融集成电路(IC)卡与应用无关的非接触式规范中国金融集成电路（IC）卡标准修订工作组二零零四年九月目次1 范围 (1)2 参考资料 (2)3 定义 (3)3.1 集成电路Integrated circuit(s)（IC） (3)3.2 无触点的Contactless (3)3.3 无触点集成电路卡Contactless integrated circuit(s) card (3)3.4 接近式卡Proximity card（PICC） (3)3.5 接近式耦合设备Proximity coupling device（PCD） (3)3.6 位持续时间Bit duration (3)3.7 二进制移相键控Binary phase shift keying (3)3.8 调制指数Modulation index (3)3.9 不归零电平NRZ-L (3)3.10 副载波Subcarrier (3)3.11 防冲突环anticollision loop (3)3.12 比特冲突检测协议bit collision detection protocol (3)3.13 字节byte (3)3.14 冲突collision (3)3.15 基本时间单元（etu）elementary time unit（etu） (3)3.16 帧frame (3)3.17 高层higher layer (4)3.18 时间槽协议time slot protocol (4)3.19 唯一识别符Unique identifier（UID） (4)3.20 块block (4)3.21 无效块invalid block (4)4 缩略语和符号表示 (5)5 物理特性 (8)5.1 一般特性 (8)5.2 尺寸 (8)5.3 附加特性 (8)5.3.1 紫外线 (8)5.3.2 X-射线 (8)5.3.3 动态弯曲应力 (8)5.3.4 动态扭曲应力 (8)5.3.5 交变磁场 (8)5.3.6 交变电场 (8)5.3.7 静电 (8)5.3.8 静态磁场 (8)5.3.9 工作温度 (9)6 射频功率和信号接口 (9)6.1 PICC的初始对话 (9)6.2 功率传送 (9)6.2.1 频率 (9)6.2.2 工作场 (9)6.3 信号接口 (9)6.4 A类通信信号接口 (10)6.4.1 从PCD到PICC的通信 (10)6.4.2 从PICC到PCD的通信 (12)6.5 B类通信信号接口 (13)6.5.1 PCD到PICC的通信 (13)6.5.2 PICC到PCD的通信 (13)6.6 PICC最小耦合区 (14)7 初始化和防冲突 (15)7.1 轮询 (15)7.2 类型A-初始化和防冲突 (15)7.2.1 字节、帧、命令格式和定时 (15)7.2.2 PICC状态 (19)7.2.3 命令集 (20)7.2.4 选择序列 (21)7.3 类型B 初始化和防冲突 (26)7.3.1 比特、字节和帧的定时 (26)7.3.2 CRC_B (28)7.3.3 防冲突序列 (28)7.3.4 PICC状态描述 (29)7.3.5 命令集合 (31)7.3.6 ATQB和Slot-MARKER响应概率规则 (31)7.3.7 REQB命令 (31)7.3.8 Slot-MARKER命令 (33)7.3.9 ATQB（请求应答-类型B）响应 (33)7.3.10 ATTRIB命令 (34)7.3.11 对A TTRIB命令的应答 (36)7.3.12 HALT命令及应答 (36)8 传输协议 (38)8.1 类型A PICC的协议激活 (38)8.1.1 选择应答请求 (40)8.1.2 选择应答 (40)8.1.3 协议和参数选择请求 (43)8.1.4 协议和参数选择响应 (45)8.1.5 激活帧等待时间 (45)8.1.6 差错检测和恢复 (45)8.2 类型B PICC的协议激活 (46)8.3 半双工块传输协议 (46)8.3.1 块格式 (46)8.3.2 帧等待时间（FWT） (49)8.3.3 帧等待时间扩展 (49)8.3.4 功率水平指示 (50)8.3.5 协议操作 (50)8.4 类型A和类型B PICC的协议停活 (52)8.4.1 停活帧等待时间 (53)8.4.2 差错检测和恢复 (53)9 数据元和命令 (54)9.1 关闭非接触通道命令 (54)9.1.1 定义和范围 (54)9.1.2 命令报文 (54)9.1.3 命令报文数据域 (54)9.1.4 响应报文数据域 (54)9.1.5 响应报文状态码 (54)9.2 激活非接触通道命令 (55)9.2.1 定义和范围 (55)9.2.2 命令报文 (55)9.2.3 命令报文数据域 (55)9.2.4 响应报文数据域 (55)9.2.5 响应报文状态码 (55)附录 A：标准兼容性和表面质量 (56)A.1. 标准兼容性 (56)A.2. 印刷的表面质量 (56)附录 B： ISO/IEC其他卡标准参考目录 (57)附录 C：类型A的通信举例 (58)附录 D： CRC_A和CRC_B的编码 (60)D.1. CRC_A编码 (60)D.1.1. 通过标准帧发送的比特模式举例 (60)D.2. CRC_B编码 (60)D.2.1. 通过标准帧传送的比特模式实例 (60)D.2.2. 用C语言写的CRC计算的代码例子 (61)附录 E：类型A_时间槽-初始化和防冲突 (64)E.1. 术语和缩略语 (64)E.2. 比特、字节和帧格式 (64)E.2.1. 定时定义 (64)E.2.2. 帧格式 (64)E.3. PICC状态 (64)E.3.1. POWER-OFF状态 (64)E.3.2. IDLE状态 (65)E.3.3. READY状态 (65)E.3.4. ACTIVE状态 (65)E.3.5. HALT状态 (65)E.4. 命令/响应集合 (65)E.5. 时间槽防冲突序列 (65)附录 F：详细的类型A PICC状态图 (67)附录 G：使用多激活的举例 (69)附录 H：协议说明书 (70)H.1. 记法 (70)H.2. 无差错操作 (70)H.2.1. 块的交换 (70)H.2.2. 等待时间扩展请求 (70)H.2.3. DESELECT (70)H.2.4. 链接 (71)H.3. 差错处理 (71)H.3.1. 块的交换 (71)H.3.2. 等待时间扩展请求 (72)H.3.3. DESELECT (74)H.3.4. 链接 (74)附录 I：块和帧编码概览 (77)1 范围本规范包括以下主要内容：－物理特性：规定了接近式卡（PICC）的物理特性。
Network Working Group G. Van de Velde Request for Comments: 5375 C. Popoviciu Category: Informational Cisco Systems T. Chown University of Southampton O. Bonness C. Hahn T-Systems Enterprise Services GmbH December 2008 IPv6 Unicast Address Assignment ConsiderationsStatus of This MemoThis memo provides information for the Internet community. It doesnot specify an Internet standard of any kind. Distribution of thismemo is unlimited.Copyright NoticeCopyright (c) 2008 IETF Trust and the persons identified as thedocument authors. All rights reserved.This document is subject to BCP 78 and the IETF Trust’s LegalProvisions Relating to IETF Documents (/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document.AbstractOne fundamental aspect of any IP communications infrastructure is its addressing plan. With its new address architecture and allocationpolicies, the introduction of IPv6 into a network means that network designers and operators need to reconsider their existing approaches to network addressing. Lack of guidelines on handling this aspect of network design could slow down the deployment and integration ofIPv6. This document aims to provide the information andrecommendations relevant to planning the addressing aspects of IPv6deployments. The document also provides IPv6 addressing case studies for both an enterprise and an ISP network.Van de Velde, et al. Informational [Page 1]Table of Contents1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 32. Network-Level Addressing Design Considerations . . . . . . . . 4 2.1. Globally Unique Addresses . . . . . . . . . . . . . . . . 4 2.2. Unique Local IPv6 Addresses . . . . . . . . . . . . . . . 5 2.3. 6bone Address Space . . . . . . . . . . . . . . . . . . . 6 2.4. Network-Level Design Considerations . . . . . . . . . . . 6 2.4.1. Sizing the Network Allocation . . . . . . . . . . . . 82.4.2. Address Space Conservation . . . . . . . . . . . . . . 83. Subnet Prefix Considerations . . . . . . . . . . . . . . . . . 83.1. Considerations for /64 Prefixes . . . . . . . . . . . . . 104. Allocation of the IID of an IPv6 Address . . . . . . . . . . . 10 4.1. Automatic EUI-64 Format Option . . . . . . . . . . . . . . 10 4.2. Using Privacy Extensions . . . . . . . . . . . . . . . . . 104.3. Manual/Dynamic Assignment Option . . . . . . . . . . . . . 115. Security Considerations . . . . . . . . . . . . . . . . . . . 116. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 117. Informative References . . . . . . . . . . . . . . . . . . . . 12 Appendix A. Case Studies . . . . . . . . . . . . . . . . . . . . 16 A.1. Enterprise Considerations . . . . . . . . . . . . . . . . 16 A.1.1. Obtaining General IPv6 Network Prefixes . . . . . . . 16 A.1.2. Forming an Address (Subnet) Allocation Plan . . . . . 17 A.1.3. Other Considerations . . . . . . . . . . . . . . . . . 18 A.1.4. Node Configuration Considerations . . . . . . . . . . 18 A.2. Service Provider Considerations . . . . . . . . . . . . . 19 A.2.1. Investigation of Objective Requirements for anIPv6 Addressing Schema of a Service Provider . . . . . 19 A.2.2. Exemplary IPv6 Address Allocation Plan for aService Provider . . . . . . . . . . . . . . . . . . . 23 A.2.3. Additional Remarks . . . . . . . . . . . . . . . . . . 28 Appendix B. Considerations for Subnet Prefixes Different than/64 . . . . . . . . . . . . . . . . . . . . . . . . . 30 B.1. Considerations for Subnet Prefixes Shorter than /64 . . . 30 B.2. Considerations for Subnet Prefixes Longer than /64 . . . . 31 B.2.1. /126 Addresses . . . . . . . . . . . . . . . . . . . . 31 B.2.2. /127 Addresses . . . . . . . . . . . . . . . . . . . . 31 B.2.3. /128 Addresses . . . . . . . . . . . . . . . . . . . . 31 B.2.4. EUI-64 ’u’ and ’g’ Bits . . . . . . . . . . . . . . . 31 B.2.5. Anycast Addresses . . . . . . . . . . . . . . . . . . 32 B.2.6. Addresses Used by Embedded-RP (RFC 3956) . . . . . . . 33 B.2.7. ISATAP Addresses . . . . . . . . . . . . . . . . . . . 34 Van de Velde, et al. Informational [Page 2]1. IntroductionThe Internet Protocol Version 6 (IPv6) Addressing Architecture[RFC4291] defines three main types of addresses: unicast, anycast,and multicast. This document focuses on unicast addresses, for which there are currently two principal allocated types: Globally UniqueAddresses (’globals’) [RFC3587] and Unique Local IPv6 Addresses(ULAs) [RFC4193]. In addition, until recently there has been the’experimental’ 6bone address space [RFC3701], though its use has been deprecated since June 2006 [RFC3701].The document covers aspects that should be considered during IPv6deployment for the design and planning of an addressing scheme for an IPv6 network. The network’s IPv6 addressing plan may be for an IPv6- only network, or for a dual-stack infrastructure where some or alldevices have addresses in both protocols. These considerations will help an IPv6 network designer to efficiently and prudently assign the IPv6 address space that has been allocated to their organization.The address assignment considerations are analyzed separately for the two major components of the IPv6 unicast addresses -- namely,’Network-Level Addressing’ (the allocation of subnets) and the’interface-id’ (the identification of the interface within a subnet). Thus, the document includes a discussion of aspects of addressassignment to nodes and interfaces in an IPv6 network. Finally, the document provides two examples of deployed addressing plans in aservice provider (ISP) and an enterprise network.Parts of this document highlight the differences that an experienced IPv4 network designer should consider when planning an IPv6deployment, for example:o IPv6 devices will more likely be multi-addressed in comparisonwith their IPv4 counterparts.o The practically unlimited size of an IPv6 subnet (2^64 bits)reduces the requirement to size subnets to device counts for thepurposes of (IPv4) address conservation.o The vastly increased subnet size has implications on the threat of address-based host scanning and other scanning techniques, asdiscussed in [RFC5157].We do not discuss here how a site or ISP should proceed withacquiring its globally routable IPv6 address prefix. In each case,the prefix received is either provider assigned (PA) or providerindependent (PI).Van de Velde, et al. Informational [Page 3]We do not discuss PI policy here. The observations andrecommendations of this text are largely independent of the PA or PI nature of the address block being used. At this time, we assume that when an IPv6 network changes provider, typically it will need toundergo a renumbering process, as described in [RFC4192]. A separate document [THINKABOUT] makes recommendations to ease the IPv6renumbering process.This document does not discuss implementation aspects related to the transition from the now obsoleted site-local addresses to ULAs. Some implementations know about site-local addresses even though they are deprecated, and do not know about ULAs even though they representcurrent specification. As a result, transitioning between thesetypes of addresses may cause difficulties.2. Network-Level Addressing Design ConsiderationsThis section discusses the kind of IPv6 addresses used at the network level for the IPv6 infrastructure. The kind of addresses that can be considered are Globally Unique Addresses and ULAs. We also commenthere on the deprecated 6bone address space.2.1. Globally Unique AddressesThe most commonly used unicast addresses will be Globally UniqueAddresses (’globals’). No significant considerations are necessaryif the organization has an address space assignment and a singleprefix is deployed through a single upstream provider.However, a multihomed site may deploy addresses from two or moreservice-provider-assigned IPv6 address ranges. Here, the networkadministrator must have awareness on where and how these ranges areused on the multihomed infrastructure environment. The nature of the usage of multiple prefixes may depend on the reason for multihoming(e.g., resilience failover, load balancing, policy-based routing, or multihoming during an IPv6 renumbering event). IPv6 introducesimproved support for multi-addressed hosts through the IPv6 defaultaddress selection methods described in RFC 3484 [RFC3484]. Amultihomed host may thus have two or more addresses, one per prefix(provider), and select source and destination addresses to use asdescribed in that RFC. However, multihoming also has someoperational and administrative burdens besides choosing multipleaddresses per interface [RFC4218] [RFC4219].Van de Velde, et al. Informational [Page 4]2.2. Unique Local IPv6 AddressesULAs have replaced the originally conceived site-local addresses inthe IPv6 addressing architecture, for reasons described in [RFC3879]. ULAs improve on site-locals by offering a high probability of theglobal uniqueness of the prefix used, which can be beneficial whenthere is (deliberate or accidental) leakage or when networks aremerged. ULAs are akin to the private address space [RFC1918]assigned for IPv4 networks, except that in IPv6 networks we mayexpect to see ULAs used alongside global addresses, with ULAs usedinternally and globals used externally. Thus, use of ULAs does notimply use of NAT for IPv6.The ULA address range allows network administrators to deploy IPv6addresses on their network without asking for a globally uniqueregistered IPv6 address range. A ULA prefix is 48 bits, i.e., a /48, the same as the currently recommended allocation for a site from the globally routable IPv6 address space [RFC3177].A site that wishes to use ULAs can have (a) multiple /48 prefixes(e.g., a /44) (b) one /48, or (c) a less-than-/48 prefix (e.g., a /56 or /64). In all of the above cases, the ULAs can be randomly chosen according to the principles specified in [RFC4193]. However, in case (a) the use of randomly chosen ULAs will provide suboptimalaggregation capabilities.ULAs provide the means to deploy a fixed addressing scheme that isnot affected by a change in service provider and the corresponding PA global addresses. Internal operation of the network is thusunaffected during renumbering events. Nevertheless, this type ofaddress must be used with caution.A site using ULAs may or may not also deploy global addresses. In an isolated network, ULAs may be deployed on their own. In a connected network that also deploys global addresses, both may be deployed,such that hosts become multi-addressed (one global and one ULA), and the IPv6 default address selection algorithm will pick theappropriate source and destination addresses to use, e.g., ULAs will be selected where both the source and destination hosts have ULAs.Because a ULA and a global site prefix are both /48 length, anadministrator can choose to use the same subnetting (and hostaddressing) plan for both prefixes.As an example of the problems ULAs may cause, when using IPv6multicast within the network, the IPv6 default address selectionalgorithm prefers the ULA as the source address for the IPv6multicast streams. This is NOT a valid option when sending an IPv6multicast stream to the IPv6 Internet for two reasons. For one,Van de Velde, et al. Informational [Page 5]these addresses are not globally routable, so Reverse Path Forwarding checks for such traffic will fail outside the internal network. The other reason is that the traffic will likely not cross the networkboundary due to multicast domain control and perimeter securitypolicies.In principle, ULAs allow easier network mergers than RFC 1918addresses do for IPv4 because ULA prefixes have a high probability of uniqueness, if the prefix is chosen as described in the RFC.2.3. 6bone Address SpaceThe 6bone address space was used before the Regional InternetRegistries (RIRs) started to distribute ’production’ IPv6 prefixes.The 6bone prefixes have a common first 16 bits in the IPv6 Prefix of 3FFE::/16. This address range has been deprecated as of 6 June 2006 [RFC3701] and must not be used on any new IPv6 network deployments.Sites using 6bone address space should renumber to production address space using procedures as defined in [RFC4192].2.4. Network-Level Design ConsiderationsIPv6 provides network administrators with a significantly largeraddress space, enabling them to be very creative in how they candefine logical and practical addressing plans. The subnetting ofassigned prefixes can be done based on various logical schemes thatinvolve factors such as:o Using existing systems* translate the existing subnet numbers into IPv6 subnet IDs* translate the VLAN IDs into IPv6 subnet IDso Redesign* allocate according to your needo Aggregation* Geographical Boundaries - by assigning a common prefix to allsubnets within a geographical area.* Organizational Boundaries - by assigning a common prefix to an entire organization or group within a corporate infrastructure. Van de Velde, et al. Informational [Page 6]* Service Type - by reserving certain prefixes for predefinedservices such as: VoIP, content distribution, wirelessservices, Internet access, security areas, etc. This type ofaddressing may create dependencies on IP addresses that canmake renumbering harder if the nodes or interfaces supportingthose services on the network are sparse within the topology.Such logical addressing plans have the potential to simplify network operations and service offerings, and to simplify network management and troubleshooting. A very large network would not need to consider using private address space for its infrastructure devices, therebysimplifying network management.The network designer must however keep in mind several factors whendeveloping these new addressing schemes for networks with and without global connectivity:o Prefix aggregation - The larger IPv6 addresses can lead to larger routing tables unless network designers are actively pursuingaggregation. While prefix aggregation will be enforced by theservice provider, it is beneficial for the individualorganizations to observe the same principles in their networkdesign process.o Network growth - The allocation mechanism for flexible growth of a network prefix, documented in RFC 3531 [RFC3531] can be used toallow the network infrastructure to grow and be numbered in a way that is likely to preserve aggregation (the plan leaves ’holes’for growth).o ULA usage in large networks - Networks that have a large number of ’sites’ that each deploy a ULA prefix that will by default be a’random’ /48 under fc00::/7 will have no aggregation of thoseprefixes. Thus, the end result may be cumbersome because thenetwork will have large amounts of non-aggregated ULA prefixes.However, there is no rule to disallow large networks from using a single ULA prefix for all ’sites’, as a ULA still provides 16 bits for subnetting to be used internally.o Compact numbering of small sites - It is possible that as registry policies evolve, a small site may experience an increase in prefix length when renumbering, e.g., from /48 to /56. For this reason, the best practice is to number subnets compactly rather thansparsely, and to use low-order bits as much as possible whennumbering subnets. In other words, even if a /48 is allocated,act as though only a /56 is available. Clearly, this advice does not apply to large sites and enterprises that have an intrinsicneed for a /48 prefix.Van de Velde, et al. Informational [Page 7]o Consider assigning more than one /64 to a site - A small site may want to enable routing amongst interfaces connected to a gatewaydevice. For example, a residential gateway that receives a /48and is situated in a home with multiple LANs of different mediatypes (sensor network, wired, Wi-Fi, etc.), or has a need fortraffic segmentation (home, work, kids, etc.), could benefitgreatly from multiple subnets and routing in IPv6. Ideally,residential networks would be given an address range of a /48 or/56 [RIPE_Nov07] such that multiple /64 subnets could be usedwithin the residence.2.4.1. Sizing the Network AllocationWe do not discuss here how a network designer sizes their application for address space. By default, a site will receive a /48 prefix[RFC3177]; however, different RIR service regions policies maysuggest alternative default assignments or let the ISPs decide onwhat they believe is more appropriate for their specific case (seeSection 6.5.4, "Assignments from LIRs/ISPs", of [ARIN]). The default provider allocation via the RIRs is currently a /32 [RIPE_Nov07].These allocations are indicators for a first allocation for anetwork. Different sizes may be obtained based on the anticipatedaddress usage [RIPE_Nov07]. At the time of writing, there areexamples of allocations as large as /19 having been made from RIRs to providers.2.4.2. Address Space ConservationDespite the large IPv6 address space, which enables easiersubnetting, it still is important to ensure an efficient use of this resource. Some addressing schemes, while facilitating aggregationand management, could lead to significant numbers of addresses being unused. Address conservation requirements are less stringent inIPv6, but they should still be observed.The proposed Host-Density (HD) value [RFC3194] for IPv6 is 0.94compared to the current value of 0.96 for IPv4. Note that with IPv6, HD is calculated for sites (e.g., on a basis of /56), instead of for addresses as with IPv4.3. Subnet Prefix ConsiderationsAn important part of an IPv4 addressing plan is deciding the lengthof each subnet prefix. Unlike in IPv4, the IPv6 addressingarchitecture [RFC4291] specifies that all subnets using GloballyUnique Addresses and ULAs always have the same prefix length of 64bits. (This also applies to the deprecated 6bone and site-localaddresses.)Van de Velde, et al. Informational [Page 8]The only exception to this rule are special addresses starting withthe binary value 000, such as IPv4-compatible IPv6 addresses. These exceptions are largely beyond the scope of this document.Using a subnet prefix length other than a /64 will break manyfeatures of IPv6, including Neighbor Discovery (ND), Secure Neighbor Discovery (SEND) [RFC3971], privacy extensions [RFC4941], parts ofMobile IPv6 [RFC4866], Protocol Independent Multicast - Sparse Mode(PIM-SM) with Embedded-RP [RFC3956], and Site Multihoming by IPv6Intermediation (SHIM6) [SHIM6], among others. A number of otherfeatures currently in development, or being proposed, also rely on/64 subnet prefixes.Nevertheless, many IPv6 implementations do not prevent theadministrator from configuring a subnet prefix length shorter orlonger than 64 bits. Using subnet prefixes shorter than /64 wouldrarely be useful; see Appendix B.1 for discussion.However, some network administrators have used prefixes longer than/64 for links connecting routers, usually just two routers on apoint-to-point link. On links where all the addresses are assignedby manual configuration, and all nodes on the link are routers (notend hosts) that are known by the network, administrators do not need any of the IPv6 features that rely on /64 subnet prefixes, this canwork. Using subnet prefixes longer than /64 is not recommended forgeneral use, and using them for links containing end hosts would bean especially bad idea, as it is difficult to predict what IPv6features the hosts will use in the future.Appendix B.2 describes some practical considerations that need to be taken into account when using prefixes longer than /64 in limitedcases. In particular, a number of IPv6 features use interfaceidentifiers that have a special form (such as a certain fixed valuein some bit positions). When using prefixes longer than /64, it isprudent to avoid certain subnet prefix values so that nodes whoassume that the prefix is /64 will not incorrectly identify theaddresses in that subnet as having a special form. Appendix B.2describes the subnet prefix values that are currently believed to be potentially problematic; however, the list is not exhaustive and can be expected to grow in the future.Using /64 subnets is strongly recommended, also for links connecting only routers. A deployment compliant with the current IPv6specifications cannot use other prefix lengths. However, the V6OPSWG believes that despite the drawbacks (and a potentially expensivenetwork redesign, if IPv6 features relying on /64 subnets are needed in the future), some networks administrators will use prefixes longer than /64.Van de Velde, et al. Informational [Page 9]3.1. Considerations for /64 PrefixesBased on RFC 3177 [RFC3177], 64 bits is the prescribed subnet prefix length to allocate to interfaces and nodes.When using a /64 subnet length, the address assignment for theseaddresses can be made either by manual configuration, by a DynamicHost Configuration Protocol [RFC3315], by stateless autoconfiguration [RFC4862], or by a combination thereof [RFC3736].Note that RFC 3177 strongly prescribes 64-bit subnets for generalusage, and that stateless autoconfiguration on most link layers(including Ethernet) is only defined for 64-bit subnets. While intheory it might be possible that some future autoconfigurationmechanisms would allow longer than 64-bit prefix lengths to be used, the use of such prefixes is not recommended at this time.4. Allocation of the IID of an IPv6 AddressIn order to have a complete IPv6 address, an interface must beassociated with a prefix and an Interface Identifier (IID). Section 3 of this document analyzed the prefix selection considerations.This section discusses the elements that should be considered whenassigning the IID portion of the IPv6 address.There are various ways to allocate an IPv6 address to a device orinterface. The option with the least amount of caveats for thenetwork administrator is that of EUI-64 [RFC4862] based addresses.For the manual or dynamic options, the overlap with well-known IPv6addresses should be avoided.4.1. Automatic EUI-64 Format OptionWhen using this method, the network administrator has to allocate avalid 64-bit subnet prefix. Once that allocation has been made, the EUI-64 [RFC4862] allocation procedure can assign the remaining 64 IID bits in a stateless manner. All the considerations for selecting avalid IID have been incorporated into the EUI-64 methodology.4.2. Using Privacy ExtensionsThe main purpose of IIDs generated based on RFC 4941 [RFC4941] is to provide privacy to the entity using an IPv6 address. While there are no particular constraints in the usage of IPv6 addresses with IIDs as defined in [RFC4941], there are some implications to be aware of when using privacy addresses as documented in Section 4 of RFC 4941[RFC4941]Van de Velde, et al. Informational [Page 10]4.3. Manual/Dynamic Assignment OptionThis section discusses those IID allocations that are not implemented through stateless address configuration (Section 4.1). They areapplicable regardless of the prefix length used on the link. It isout of scope for this section to discuss the various assignmentmethods (e.g., manual configuration, DHCPv6, etc).In this situation, the actual allocation is done by humanintervention, and consideration needs to be given to the completeIPv6 address so that it does not result in overlaps with any of thewell-known IPv6 addresses:o Subnet Router Anycast Address (Appendix B.2.5.1)o Reserved Subnet Anycast Address (Appendix B.2.5.2)o Addresses used by Embedded-RP (Appendix B.2.6)o Intra-Site Automatic Tunnel Addressing Protocol (ISATAP) Addresses (Appendix B.2.7)When using an address assigned by human intervention, it isrecommended to choose IPv6 addresses that are not obvious to guessand/or to avoid any IPv6 addresses that embed IPv4 addresses used in the current infrastructure. Following these two recommendations will make it more difficult for malicious third parties to guess targetsfor attack, and thus reduce security threats to a certain extent.5. Security ConsiderationsThis document doesn’t add any new security considerations that aren’t already outlined in the security considerations of the references.It must be noted that using subnet prefixes other than /64 breakssecurity mechanisms such as Cryptographically Generated Addresses(CGAs) and Hash-Based Addresses (HBAs), and thus makes it impossible to use protocols that depend on them.6. AcknowledgementsConstructive feedback and contributions have been received duringIESG review cycle and from Marla Azinger, Stig Venaas, Pekka Savola, John Spence, Patrick Grossetete, Carlos Garcia Braschi, BrianCarpenter, Mark Smith, Janos Mohacsi, Jim Bound, Fred Templin, Ginny Listman, Salman Assadullah, Krishnan Thirukonda, and the IESG.Van de Velde, et al. Informational [Page 11]7. Informative References[RFC1918] Rekhter, Y., Moskowitz, R., Karrenberg, D., Groot,G., and E. Lear, "Address Allocation for PrivateInternets", BCP 5, RFC 1918, February 1996.[RFC2526] Johnson, D. and S. Deering, "Reserved IPv6 SubnetAnycast Addresses", RFC 2526, March 1999.[RFC3021] Retana, A., White, R., Fuller, V., and D. McPherson, "Using 31-Bit Prefixes on IPv4 Point-to-Point Links", RFC 3021, December 2000.[RFC3053] Durand, A., Fasano, P., Guardini, I., and D. Lento,"IPv6 Tunnel Broker", RFC 3053, January 2001.[RFC3056] Carpenter, B. and K. Moore, "Connection of IPv6Domains via IPv4 Clouds", RFC 3056, February 2001.[RFC3177] IAB and IESG, "IAB/IESG Recommendations on IPv6Address Allocations to Sites", RFC 3177,September 2001.[RFC3180] Meyer, D. and P. Lothberg, "GLOP Addressing in233/8", BCP 53, RFC 3180, September 2001.[RFC3194] Durand, A. and C. Huitema, "The H-Density Ratio forAddress Assignment Efficiency An Update on the Hratio", RFC 3194, November 2001.[RFC3315] Droms, R., Bound, J., Volz, B., Lemon, T., Perkins,C., and M. Carney, "Dynamic Host ConfigurationProtocol for IPv6 (DHCPv6)", RFC 3315, July 2003.[RFC3484] Draves, R., "Default Address Selection for InternetProtocol version 6 (IPv6)", RFC 3484, February 2003. [RFC3531] Blanchet, M., "A Flexible Method for Managing theAssignment of Bits of an IPv6 Address Block",RFC 3531, April 2003.[RFC3587] Hinden, R., Deering, S., and E. Nordmark, "IPv6Global Unicast Address Format", RFC 3587,August 2003.[RFC3627] Savola, P., "Use of /127 Prefix Length BetweenRouters Considered Harmful", RFC 3627,September 2003.Van de Velde, et al. Informational [Page 12][RFC3633] Troan, O. and R. Droms, "IPv6 Prefix Options forDynamic Host Configuration Protocol (DHCP) version6", RFC 3633, December 2003.[RFC3701] Fink, R. and R. Hinden, "6bone (IPv6 Testing Address Allocation) Phaseout", RFC 3701, March 2004.[RFC3736] Droms, R., "Stateless Dynamic Host ConfigurationProtocol (DHCP) Service for IPv6", RFC 3736,April 2004.[RFC3879] Huitema, C. and B. Carpenter, "Deprecating Site Local Addresses", RFC 3879, September 2004.[RFC3956] Savola, P. and B. Haberman, "Embedding the Rendezvous Point (RP) Address in an IPv6 Multicast Address",RFC 3956, November 2004.[RFC3971] Arkko, J., Kempf, J., Zill, B., and P. Nikander,"SEcure Neighbor Discovery (SEND)", RFC 3971,March 2005.[RFC4192] Baker, F., Lear, E., and R. Droms, "Procedures forRenumbering an IPv6 Network without a Flag Day",RFC 4192, September 2005.[RFC4193] Hinden, R. and B. Haberman, "Unique Local IPv6Unicast Addresses", RFC 4193, October 2005.[RFC4218] Nordmark, E. and T. Li, "Threats Relating to IPv6Multihoming Solutions", RFC 4218, October 2005.[RFC4219] Lear, E., "Things Multihoming in IPv6 (MULTI6)Developers Should Think About", RFC 4219,October 2005.[RFC4271] Rekhter, Y., Li, T., and S. Hares, "A Border Gateway Protocol 4 (BGP-4)", RFC 4271, January 2006.[RFC4291] Hinden, R. and S. Deering, "IP Version 6 AddressingArchitecture", RFC 4291, February 2006.[RFC4477] Chown, T., Venaas, S., and C. Strauf, "Dynamic HostConfiguration Protocol (DHCP): IPv4 and IPv6 Dual-Stack Issues", RFC 4477, May 2006.Van de Velde, et al. Informational [Page 13]。
IPv6全球因特网至今为止还在使用许多基于IPv4的隧道。
这些隧道在大环境下难以配置和维护。
6bone已经证实大型的站点和ISP可以建立前述的隧道，但是这样做的程序对于那些想要连入IPv6世界的IPv4终端用户来说太复杂了。
开发隧道代理模型的动机是为了帮助早期的IPv6站点链接在现存的IPv6网络（例如6bone）以获得稳定永久的IPv6地址和DNS 域名。
隧道代理的概念最早是在1998年11月Orlando IETF年会上提出的。
1999年二月法国Grenoble IPng & NGtrans临时会议上实现两个工具。
1. 介绍IPv6网络初始的增长主要使用现在的因特网提供的传输设备。
这使得几种管理IPv6 over IPv4隧道的技术发展起来。
现在大多数的6bone的网络是由手工配置建立穿越因特网的隧道的。
这种方法的主要缺点是对网络管理员的压倒性的手工配置，他不得不对每一条隧道都手动配置。
几种减轻这种配置负担的尝试已经被提出并且表现得很有优势，而且解决了隧道代理没有解决得问题或者是避免隧道代理中存在得缺点：- 使用IPv4兼容地址的自动配置隧道是一种简单的IPv6连接双栈终端主机或路由器自动配置方法。
这种方法的问题在于不能解决IPv4地址的枯竭问题。
更大的问题是这会使路由表过大问题5倍的恶化；- 6over4 是基于使用IPv4组播的站点本地转换机制就像虚拟链路层。
他并没有解决终端用户连入IPv6因特网的问题；- 6to4 被设计为用来允许终端IPv6域在没有本地IPv6支持的情况下通过最少的配置就可以与IPv6站点通讯。
想法是把IPv4隧道地址嵌入IPv6前缀使得任何外部的域的路由对IPv6通信自动发现隧道的端点。
隧道代理的概念是一个可以选择使用的基于叫做Tunnel Brokers的专用服务器的自动管理来自用户请求的隧道。
这个方法是期望有助于IPv6连接主机数的增长和使得早期的IPv6网络提供者提供简单的IPv6接入方式。
PTN专业考试(试卷编号221)1.[单选题]IPV6的邻居发现机制要用到IPV6的_____地址A)节点链路地址B)节点链路地址本地链路地址C)全球可聚合单播地址答案:B解析:2.[单选题]针对南北向业务，在SRTP隧道上部署CC/CV检测机制，CV报文发送的时间间隔分别为A)3.3msB)10msC)100ms答案:B解析:3.[单选题]R860设备最大支持本地会话的ID为（）A)1200B)1800C)1000答案:B解析:4.[单选题]C类地址最大可能子网位数是（ ）A)6B)7C)12D)14答案:A解析:5.[单选题]下列关于IP-FRR说法正确的是 （1.5分）A)A . IP-FRR保护是网间保护B)B . IP-FRR保护的原理的主用节点保护备用节点C)C . IP-FRR保护不能和VRRP保护同时使用D)D . IP-FRR保护的原理和VRRP保护原理一样答案:A解析:6.[单选题]IP地址190.233.27.13/16所在的网段地址是？B)190.233.0.0C)190.233.27.0D)190.233.27.1答案:B解析:7.[单选题]MPLS的标签可以嵌套多少层？A)1B)3C)10D)理论上无限答案:D解析:8.[单选题]在路由器中，如果去往同一目的地有多条路由，则决定最佳路由的因素有( )。
A)路由的优先级B)路由的发布者C)路由的cost值D)路由的生存时间答案:A解析:9.[单选题]为了满足子网寻径的需要，路由表中应包含的元素有A)源地址、子网掩码、目的网络地址B)源地址、目的网络地址、下一跳地址C)源地址、子网掩码、目的网络地址D)目的网络地址、子网掩码、下一跳地址答案:B解析:10.[单选题]在评估660的高阶槽位的UNILSP标签资源时，下面说法正确的是A)每个槽位的可用资源都一样B)UNI可用资源不受本槽位NNI接口上的串通资源影响C)因LSP一般是双向且对称的，因此评估时考察单项LSP资源即可D)单个槽位LSP单向标签资源最大为1024答案:C解析:11.[单选题]在PTN保护中的APS字节长度为A)2B)4D)8答案:B解析:12.[单选题]在MPLS VPN的连接模型中，VPN的构建、连接和管理工作是在________。
2021LTE华为认证初级题库及答案12考号姓名分数一、单选题(每题1分,共100分)1、Linux系统中，启动监听服务的命令是:A.listenerstartB.listenerstartupC.lsnrctlstartD.lsnrctlstartup答案：C2、以下哪个信道用于寻呼和用户数据的资源分配（）A.PDSCHB.PDCCHC.PBCHD.PCFICH答案：B3、S1AP和Diameter协议最好使用哪种协议作为传输层协议（）A.TCPB.UDPC.SCTPD.MTP2答案：C4、哪个信道用来指示PDCCH所用的符号数目( ）A.PHICHB.PDCCHD.PCFICH答案：D5、LTE NR的过程中，UE通过（）信道获得邻区的GCI信息。
A.CHB.HC.MIBD.SIB答案：A6、下列哪一项命令不能重启Linux系统:A.haltB.init6C.shutdown-rD.reboot答案：A7、LTE OMC前后台建链成功时，建链消息EV_CONNECTION_ SNMP_ ASK_SUCCESS中，第21和22字节数据(前后台的建链消息号)为:A.16212B.16213C.16214D.16215答案：B8、TDLTE中，要将每个CQI（宽频带或子频带）转换成一个SINR值（dB），cQIToSINRLookUpTable 需要设置（）个值A.32B.29C.16D.15答案：D9、用于上行调度的控制信息是哪个？B.BDI0I1AD.DDCI2B答案：B10、TDLTE中，以下（）是下行FSS调度可用的条件A.fdsOnly=TrueB.QCI=1C.UE步行D.只报告宽带CQI答案：C11、定时器T302的作用是:A.UE监测无线链路失败的等待时间B.UE监测到无线链路失败后转入RRC_IDLE状态的等待时间C.UE收到RRC连接拒绝后等待RRC连接请求重试的定时器D.UE等待因发起呼叫而等待RRC连接建立的定时器答案：C12、关于随机接入描叙正确的是A.随机接入分为基于竞争与基于非竞争两种，根据网络配置，初始接入及切换过程中都可以是基于竞争接入或基于非竞争接入B.随机接入分为基于竞争与基于非竞争两种，根据网络配置，初始接入可以为基于竞争接入或基于非竞争接入，切换过程只能是基于非竞争接入C.随机接入分为基于竞争与基于非竞争两种，根据网络配置，初始接入可以为基于竞争接入或基于非竞争接入，切换过程中无随机接入D.随机接入分为基于竞争与基于非竞争两种，根据网络配置，初始接入只能是基于竞争接入，切换过程中的随机接入可以是基于竞争也可以是基于非竞争接入答案：D13、以下哪个功能不属于SGW的功能（）A.eNodeB之间的切换的本地锚点B.数据包路由和转发D.PGW的选择答案：D14、UE收到RRC连接拒绝后等待RRC连接请求重试的定时器是:A.T300B.T301C.T302D.T304答案：C15、TD-LTE系统中，以下哪项可以认为测试无线环境为好点（）A.RSRP=-90dB，SINR=11B.RSRP=-95dB，SINR=17C.RSRP=-85dB，SINR=3D.RSRP=-75dB，SINR=25答案：B16、S1接口的用户面终止在什么上？A.SGWB.MMEC.MMHD.SAW答案：A17、完成测量报告文件存储与管理的单元是（）A.应用服务器B.CDG服务器C.FTP服务器D.MR服务器答案：D18、CQT测试在什么地方A.车内B.车外D.无信号的地方答案：B19、为保证MIMO性能，双路室内分布系统应通过合理的设计确保两路分布系统的功率差控制在( )dB以内。
Network Working Group IAB Advisory Committee Request for Comments: 3716 IETF Category: Informational March 2004 The IETF in the Large: Administration and ExecutionStatus of this MemoThis memo provides information for the Internet community. It doesnot specify an Internet standard of any kind. Distribution of thismemo is unlimited.Copyright NoticeCopyright (C) The Internet Society (2004). All Rights Reserved. AbstractIn the fall of 2003, the IETF Chair and the IAB Chair formed an IABAdvisory Committee (AdvComm), with a mandate to review the existingIETF administrative structure and relationships (RFC Editor, IETFSecretariat, IANA) and to propose changes to the IETF managementprocess or structure to improve the overall functioning of the IETF. The AdvComm mandate did not include the standards process itself.This memo documents the AdvComm’s findings and proposals.Table of Contents1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 21.1. Overview of the AdvComm Work Process and Output. . . . 31.2. Scope. . . . . . . . . . . . . . . . . . . . . . . . . 31.3. Next Steps . . . . . . . . . . . . . . . . . . . . . . 42. Observations . . . . . . . . . . . . . . . . . . . . . . . . 42.1. Current IETF Support Structure . . . . . . . . . . . . 42.1.1. What the Term IETF Includes in this Document . 42.1.2. Functions. . . . . . . . . . . . . . . . . . . 42.1.3. Support. . . . . . . . . . . . . . . . . . . . 62.2. Observed Stress Points . . . . . . . . . . . . . . . . 82.2.1. Stress Points Observed by IETF Leadership. . . 82.2.2. Stress Points Observed by OrganizationsSupporting the IETF. . . . . . . . . . . . . . 102.3. A final Observation. . . . . . . . . . . . . . . . . . 103. Stand Facing the Future: Requirements for a SuccessfulIETF Administration. . . . . . . . . . . . . . . . . . . . . 103.1. Resource Management. . . . . . . . . . . . . . . . . . 103.1.1. Uniform Budgetary Responsibility . . . . . . . 10 IAB Advisory Committee Informational [Page 1]3.1.2. Revenue Source Equivalence . . . . . . . . . . 113.1.3. Clarity in Relationship with SupportingOrganizations. . . . . . . . . . . . . . . . . 113.1.4. Flexibility in Service Provisioning. . . . . . 113.1.5. Administrative Efficiency. . . . . . . . . . . 113.2. Stewardship. . . . . . . . . . . . . . . . . . . . . . 123.2.1. Accountability for Change. . . . . . . . . . . 123.2.2. Persistence and Accessibility of Records . . . 123.3. Working Environment. . . . . . . . . . . . . . . . . . 123.3.1. Service Automation . . . . . . . . . . . . . . 123.3.2. Tools. . . . . . . . . . . . . . . . . . . . . 134. Advisory Committee Advice . . . . . . . . . . . . . . . . . 134.1. Proposed: (Single) Formalized IETF OrganizationalEntity . . . . . . . . . . . . . . . . . . . . . . . . 134.1.1. Comments on the Necessity of thisFormalization. . . . . . . . . . . . . . . . . 144.2. Possible Structures. . . . . . . . . . . . . . . . . . 144.2.1. ISOC . . . . . . . . . . . . . . . . . . . . . 154.2.2. ISOC Subsidiary. . . . . . . . . . . . . . . . 154.2.3. Completely Autonomous Organizational Entity. . 164.3. Who Can Decide . . . . . . . . . . . . . . . . . . . . 175. Security Considerations. . . . . . . . . . . . . . . . . . . 176. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 177. Informative References . . . . . . . . . . . . . . . . . . . 18A. IAB Advisory Committee Charter . . . . . . . . . . . . . . . 19B. Input from the current IETF and IAB Chairs . . . . . . . . . 20C. Consultation with ISI: RFC Editor . . . . . . . . . . . . . 21D. Consultation with Foretec/CNRI: Secretariat and MeetingPlanning . . . . . . . . . . . . . . . . . . . . . . . . . . 32E. Consultation with ICANN: IANA Protocol ParameterAssignment . . . . . . . . . . . . . . . . . . . . . . . . . 35Author’s Address . . . . . . . . . . . . . . . . . . . . . . 39Full Copyright Statement . . . . . . . . . . . . . . . . . . 40 1. IntroductionIn the fall of 2003, the IETF Chair and the IAB Chair formed an IABAdvisory Committee (AdvComm), with a mandate to review the existingIETF administrative structure and relationships (RFC Editor, IETFSecretariat, IANA) and to propose changes to the IETF managementprocess or structure to improve the overall functioning of the IETF. This purpose was defined in the IAB Advisory Committee (AdvComm)charter, copied in Appendix A. The AdvComm mandate did not includethe standards process itself.IAB Advisory Committee Informational [Page 2]The tangible output of this committee is a set of observations andrecommendations for the IETF’s executive structure - how the IETFmight be organizationally (re)structured so that it can effectivelyand efficiently carry out its administrative activities. As anecessary preamble to that, a description of the current issues andfuture requirements is presented. The output does not represent any decision-making or implementation -- see Section 1.3 for a discussion of follow-on steps.1.1. Overview of the AdvComm Work Process and OutputThe AdvComm was formed in September 2003, and carried out its workover the course of the following 2 months, prior to the IETF58 inNovember of 2003.The AdvComm’s membership included many of the individuals who are, or have been, volunteered to manage the IETF’s inter-organizationadministrative relationships in recent years. The first phase of the committee’s work, therefore, included sharing and discussing the body of tacit knowledge about those relationships. This included theinput from the current IETF and IAB Chairs in Appendix B, and yielded the IETF organizational structure information in Section 2.1.The committee also sought input from the other end of the keyexisting administrative relationships (RFC Editor, Secretariat, andIANA). The output of those efforts is included in Appendix C,Appendix D, and Appendix E, and these were also used as the basis for the observations in Section 2.From these inputs, the committee drew together a list of requirements for successful future IETF administration, documented in Section 3.Finally, the committee put together some advice for how the IETFmight consider reorganizing its administrative structure to meetthose requirements moving forward -- Section 4.1.2. ScopeThe AdvComm endeavored to stay focused on the IETF executivestructure -- the collection of organizations that work together tobring the IETF’s work to reality. However, by virtue of the veryfact that those relationships exist to get the work done, it wasimportant to bear in mind the work being done in the IETF PROBLEMworking group and IESG proposals for change, even as the committeeendeavored not to infringe on the scope of those efforts. Theobjective is that these observations and proposals should be relevant for today’s IETF and any near-term evolutions that are deemedappropriate.IAB Advisory Committee Informational [Page 3]1.3. Next StepsThis documents the state of the AdvComm’s thinking at the end of atwo month process, and brings the currently-chartered work of theAdvComm to a close.Next steps include review of this material by the community, andspecific proposals for action that will be put forward by the IAB and IETF Chairs.2. Observations2.1. Current IETF Support Structure2.1.1. What the Term IETF Includes in this DocumentRFC 3233 ([1]) provides a definition of the IETF, in terms of itswork and its participation.This document discusses the collection of organizations that worktogether to support the effort described in RFC 3233. In thisdocument, the term "IETF" explicitly includes the IESG, WGs, IAB,IRTF, and RGs. This inclusive sense accords with considerable common usage of the term "IETF". Formally, the IAB and IRTF are charteredindependently of the IETF. However, rather than coming up with a new term to encompass "the IETF and all its friends", the common usage is followed here.2.1.2. FunctionsThe work of the IETF is supported by a specific set of functions. It is useful to distinguish between the functions and the organizations which provide those services, as outlined in the table below. Insome cases a single organization provides multiple services, but the functions are logically distinct.IAB Advisory Committee Informational [Page 4]Function Known as Organization(within the IETF)--------- ---------------- ------------IESG Support Secretariat Foretec/CNRIIAB Support ISOC/Secretariat ISOC, Foretec/CNRI WG Support Secretariat Foretec/CNRICommunity Support Secretariat Foretec/CNRIIETF Meetings Secretariat Foretec/CNRIRFC Publication RFC Editor USC/ISIStandards Status Record RFC Editor USC/ISIParameter Reg. IANA ICANNLegal, insurance, etc. (largely invisible) Provided by ISOCTable 1. IETF functions, labels and organizationsIn more detail, the functions can be broken down as follows:IESG SupportTelechatsCommunicationsIETF document trackingWorking document management (mailing list, website, repository)IAB supportTelechatsCommunicationsWorking document management (mailing list, website, repository)WG supportChartersMilestone trackingWorkspace (website, mailing list)Working document archive (mailing list archives, documentrepository)Community SupportWebsiteIETF mailing listAnnouncementsI-D repositoryIAB Advisory Committee Informational [Page 5]RFC PublicationWebsiteRFC editorialDocument publicationRFC repository managementOfficial standards status recordIETF MeetingsPlanningMeeting ProceedingsProtocol parameter registrationCreation of registriesAssignment of protocol parametersManagement of accessible registry repositoryLegal, insurance, etc.Legal supportLiability insurance for IAB, IESG, WG chairs, etc.Miscellaneous2.1.3. SupportA presentation of the scope and depth of support that created theIETF and has allowed it to continue to contribute would require adiscussion of history that is rich, vibrant, and completely beyondthe scope of this document. However, a very brief introduction tosome of the current pillars is needed to understand where the IETF is today.ISOC: Since 1992, ISOC has been the organizational home of theIETF. This activity is part of its more general mission ofserving as the international organization for global coordination and cooperation on the Internet, promoting and maintaining a broad spectrum of activities focused on the Internet’s development,availability, and associated technologies.Foretec/CNRI: The Corporation for National Research Initiatives(CNRI) was founded in 1986, and since 1987, CNRI has served thecommunity by providing IETF Secretariat services. Until the early 1990s, CNRI provided legal assistance to the IETF and the IETFSecretariat. After ISOC was founded, ISOC assumed overall legalresponsibility for the substantive workings of the IETF including the efforts of the IETF chair, the IESG, the IAB, the areaIAB Advisory Committee Informational [Page 6]directors and the working group chairs. CNRI assumed operational responsibility for the substantive workings of the IETFSecretariat. In 1998, in order to decrease overhead costs on the activities, the Secretariat was reorganized placing Secretariatemployees including the IETF Executive Director in a CNRI for-profit subsidiary (Foretec Seminars, Inc.). Foretec was foundedin 1997, in anticipation of the Secretariat becoming self-supporting. CNRI and its subsidiary have continued to improve the operation of the Secretariat, as appropriate, and maintain atrained staff.USC/ISI: The role of the RFC Editor, and USC/ISI, is detailed in RFC 2555. The RFC document series is a set of technical andorganizational notes about the Internet (originally the ARPANET), beginning in 1969. For 30 years, the RFC Editor was Jon Postel, a research scientist and manager in the Networking Division of theUSC Information Sciences Institute (ISI), with the functiongradually evolving into a team headed by him. The RFC Editoractivity is currently organized as a project within ISI, using the ISI infrastructure, and supported by a contract with ISOC. TheRFC Editor is the publisher of RFCs and is responsible for thefinal editorial review of the documents, as well as themaintenance of the online repository and index of those documents. ICANN: The Internet Corporation for Assigned Names and Numbers(ICANN) is the non-profit corporation that was formed in 1998 toassume responsibility for the IP address space allocation,protocol parameter assignment, domain name system management, and root server system management functions previously performed under U.S. Government contract by IANA (at ISI) and other entities.The support picture (who does what) can be described as follows:Secretariat at Foretec/CNRIIESG SupportIAB Support (working document management)WG SupportCommunity SupportIETF meetingsRFC Editor at USC/ISI[Supported by ISOC, based on a contract between USC/ISI and ISOC] RFC publication Maintenance of standards status recordIAB Advisory Committee Informational [Page 7]IANA/ICANN[Relationship defined by Memorandum of Understanding: RFC 2860]Protocol parameter registryISOCIAB Support (Telechats)Funds RFC EditorMisc IAB/IESG expensesProvides insurance for IAB, IESG, WG chairs, etc.The available resources to support these activities are:Meeting fees -- through ForetecISOC members’ contributions for standardsICANN for IANAVolunteers/their employers (where applicable):IETF participantsWG chairsDocument editorsIETF NomComIESGIABIAB ExecDir2.2. Observed Stress PointsThe AdvComm noted several properties of the current IETForganizational environment that cause stress in the system. Thesehave been noted both from the point of view of the IETF leadership as well as that of organizations supporting the IETF.2.2.1. Stress Points Observed by IETF LeadershipThe current IETF funding and operational structure is dependent onIETF meeting attendance. Therefore, the most obvious stressor thathas emerged within the last two years is the decline in thatattendance. This trend, which has continued unabated, has resultedin a decline in IETF revenue (detailed in the IETF chair presentation at IETF 56 [2]), even as the requirements of the IETF operation areremaining constant or increasing.IAB Advisory Committee Informational [Page 8]The result has been a budget deficit for operations which began in2002, and is forecasted to continue until at least 2004, even after a substantial increase in meeting fees. The continuing deficits havedepleted working capital, making the IETF less robust againstpotential future budgetary disappointments.The financial stress is real, but the IETF leadership has notedseveral other stressors that are impediments to finding andimplementing solutions to the fiscal issues. Some obvious solutions are not implementable in the current IETF structure.The rest of the stressors listed in this section should be understood as issues for which relief is necessary, particularly in the light of needing to properly address and implement solutions to the financial stress.The current documentation of IETF processes and structure is, inplaces, vague about the distribution of responsibility for management and oversight of the IETF administrative relationships. This makesit opaque to the IETF community, and sometimes leaves the leadership in a poor position to manage effectively.Additionally, the informality of the relationships with some of theorganizations that are carrying out key IETF functions compounds the problem of determining who has responsibility, and how IETF community consensus and desires are reflected in the activity.As a separate issue, important IETF institutional memory is recorded nowhere other than peoples’ minds in many cases -- which requiressignificant transmission of oral history for IETF leadershiptransition to be effective.Apart from the institutional memory, other important IETFinstitutional records are spread across various organizations, andsearching for the set of relevant documentation (especially when this is necessary long after the recording) can be challenging.Another stressor relates to the need to scale support processes interms of reducing latency for mechanical processes. That is, adecrease in the amount of manual labor required for the simpler tasks between the organizations, would make more resources available tofocus on the special cases. Lack of automation in the basic request services has been known to cause undue delay or failure in processing simple, routine tasks. However, automation also requires resourcesand significant management in order to make sure it fulfills thecommunity’s requirements.IAB Advisory Committee Informational [Page 9]2.2.2. Stress Points Observed by Organizations Supporting the IETFSupporting organizations report difficulties in determiningauthoritative channels for directions -- either too many inputs, orno clear authority for resolution of change requests.In the absence of written agreements, supporting organizations maynot be clear from whom to take direction. Even where agreementsexist, the authority to provide direction may not be clear. Thegenesis of both problems is that the IETF relies on external bodiesfor support, but does not have sufficiently clear externalrelationships to allow it to provide input as to its requirements or direction on what services it desires.2.3. A Final ObservationThis section attempts to capture a snapshot of the current state ofthe IETF organization, without undue fixation on the causes forarriving at the current state. However, it seems clear from theobservations that the current state does not provide an adequatestructure from which to reach into the future: some changes areneeded within the IETF administrative and executive structure.3. Stand Facing the Future: Requirements for a Successful IETFAdministrationThis section follows the set of observations with a set ofrequirements for a properly-functioning IETF administrativestructure. These requirements are offered as the AdvComm’sdescription of what the IETF needs, without addressing immediatelythe degree to which they are available with the current environment. That is, these are "requirements", not "requirements for change".3.1. Resource Management3.1.1. Uniform Budgetary ResponsibilityThe IETF has operated in times of financial wealth and times ofeconomic cutbacks in the industry. It is reasonable to expect thatthe future holds similarly variable trends. Therefore, it isimportant that the IETF organization has the ability to make thedecisions to match its needs at a given point in time, i.e.,budgetary autonomy. At this particular moment, there are hardchoices to make, and the AdvComm believes that it is the IETFleadership, with the advice and consent of the IETF community, thatneeds to make them.IAB Advisory Committee Informational [Page 10]3.1.2. Revenue Source EquivalenceThe IETF is currently supported by money from multiple sources,including meeting fees, donations from interested corporate and non- corporate entities, and donations in kind of equipment or manpower.The IETF needs to be able to consider all sources of income, and all expenses involved in running the IETF, as pieces of one budget, to be free to adjust all items on the occasions when the income from thedifferent sources varies, and to allocate funds as reasonablyrequired.The usual caveats apply: that donations not threaten theindependence of the IETF, and that donations are easier when they are tax deductible.3.1.3. Clarity in Relationship with Supporting OrganizationsWhile the IETF needs to be able to manage its revenue streams against its expense expectations, it also needs to respect the needs ofsupporting organizations to manage their own affairs. That is, thetext above does not suggest that the IETF should micro-manage thefinancial affairs of supporting organizations.However, the very clear requirement is for clarity in thedistribution of rights, responsibilities, and accountability in those relationships. The usual mechanism for documenting such clarity isin contract form. Thus, the IETF needs to have clear contractualrelationships with the organizations supporting basic services,including meeting organization, secretarial services, IT services,etc.3.1.4. Flexibility in Service ProvisioningThe IETF needs to be able to raise money for, and fund thedevelopment of, additional services as appropriate. This includesthe development of tools for participants, repository management,etc.3.1.5. Administrative EfficiencyThe IETF’s needs should be met with the minimum of overhead. Thisimplies that there needs to be the possibility of combining workefforts where appropriate, and generally avoiding duplication ofeffort.IAB Advisory Committee Informational [Page 11]3.2. StewardshipThe requirements described below focus primarily on the needs of the IETF administration on a day-to-day basis. However, responsiblemanagement includes stewardship for future IETF work.3.2.1. Accountability for ChangeThe IETF needs to be responsible for changing its administrativestructure to meet the community’s evolving needs. As such, theadministration needs to remain uniquely accountable to the IETFcommunity.This also means that the distribution of responsibilities must beclear to the IETF community, in order to permit it to comment oncurrent actions or future plans, and also to allow it to take action when its needs are not being adequately addressed.An implication of this is that responsibility for financialmanagement within the IETF needs to sit with individuals who areaccountable within the IETF organizational structure.3.2.2. Persistence and Accessibility of RecordsMuch of the work of the IETF is focused on reaching decisions anddeclaring closure. However, responsibility does not stop with thedeclaration of completion. There are any number of reasons thathistory must be adequately documented so that future work can review substantive records, and not rely on oral history.Therefore, the IETF needs to maintain and support the archiving ofall of its working documents in a way that continues to beaccessible, for all current and future IETF workers.3.3. Working EnvironmentPart of the job of administering the IETF is identifying and ensuring the continued support of the tools and working environment necessary to support the ongoing activity.3.3.1. Service AutomationWherever human judgment is not required in order to complete anaction, services should be automated to provide the most friction-free path and minimal delay in completing the action.IAB Advisory Committee Informational [Page 12]More processes could be accomplished without requiring humanjudgment. Wherever possible, these processes should be identified,clarified, and automated.Note that this is not intended to imply ALL processes should beautomated! Rather, by reducing the friction incurred in steps thatare truly mechanical, more time and energy will be available toproperly treat those that require individual judgment.3.3.2. ToolsWhether housed in an IETF-supported location or offered by individual contribution, the PROBLEM WG has identified the need for more toolsupport for working groups and specification development. The IETFneeds to be able to identify, develop and support an adequately rich, consistent set of tools for getting the standards work done.4. Advisory Committee AdviceThe Advisory Committee discussed the material and observations,described in this document, at great length. To the AdvComm, itappeared clear that some level of IETF administration organizational change is needed to address the stressors and meet all of therequirements outlined in Section 3.4.1. Proposed: (Single) Formalized IETF Organizational EntityIn order to ensure an IETF structure that is capable of meeting therequirements outlined above, the AdvComm recommends that the IETF be more formally organized. This would allow the IETF to take fullresponsibility for, and management of, the resources required toaccomplish its work (as described in Section 3.1), provide andmaintain the necessary work environment for current work (asdescribed in Section 3.3), and provide appropriate stewardship of the institutional information required for all aspects of current andfuture work of the organization (as described in Section 3.2).Some proposed models for establishing such a formalized effort aredescribed in the following sections. Some of the key expectations,irrespective of the final implementation of formalism, are:o the administration of the IETF would remain accountable to theIETF leadership and community; the goal would be to ensure thatlines of responsibility and accountability were clearer;o this formalized IETF would be responsible for managing financialresources (revenue and expenses) directly;IAB Advisory Committee Informational [Page 13]o this formalized IETF would be directly signatory to agreementswith other organizations, and would therefore be able to negotiate and administer any appropriate contracts;o however implemented, this would require a small staff complement(e.g., one full-time person) responsible to no other organization than the one chartered with the IETF’s mission;o nevertheless, it remains a non-goal to create an organizationalentity that exists simply for the purpose of continuing to exist. This should be executed with the minimum formality needed in order to address the identified requirements.4.1.1. Comments on the Necessity of this FormalizationAn important question is: what does this proposed formalizationprovide that cannot be provided by the status quo? The AdvCommbelieves that an appropriately implemented formalization of the IETF would permit the unification of the resource management, decisionmaking and stewardship that is imperative to providing clarity andensuring a viable future for the IETF. The AdvComm further believes that this is simply not possible to implement within the existingdistributed and informal arrangement of responsibilities.Naturally, the act of forming such an organization does notimmediately satisfy the requirements outlined in Section 3. It isnot a silver bullet. Changing the formal structure will not, forexample, change the financial status of the IETF. However, theAdvComm believes it would provide the necessary basis from which the required decisions could be made and acted upon.In short, the AdvComm believes that we first have to place theresponsibility for defining the IETF’s administrative environmentwith specific people who are accountable to the IETF community. Then these people can take the detailed decisions that will change theIETF’s administrative environment to fulfill its requirements.4.2. Possible StructuresSection 4.1 was deliberately vague on the nature of the formalorganizational entity that might provide the proper environment,focusing instead on the key components of any implementation of such a formalization, and how the formalization activity would address the requirements laid out in Section 3.IAB Advisory Committee Informational [Page 14]。
