当前位置：文档之家 › rfc2668.Definitions of Managed Objects for IEEE 802.3 Medium Attachment Units (MAUs)

rfc2668.Definitions of Managed Objects for IEEE 802.3 Medium Attachment Units (MAUs)

  • 格式：pdf
  • 大小：63.31 KB
  • 文档页数：56

Network Working Group A. Smith Request for Comments: 2668 Extreme Networks, Inc. Obsoletes: 2239 J. Flick Category: Standards Track Hewlett-Packard Company K. de Graaf Argon Networks D. Romascanu Lucent Technologies D. McMaster Cisco Systems, Inc. K. McCloghrie Cisco Systems, Inc. S. Roberts Farallon Computing, Inc. August 1999 Definitions of Managed Objects forIEEE 802.3 Medium Attachment Units (MAUs)Status of this MemoThis document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions forimprovements. Please refer to the current edition of the "InternetOfficial Protocol Standards" (STD 1) for the standardization stateand status of this protocol. Distribution of this memo is unlimited. Copyright NoticeCopyright (C) The Internet Society (1999). All Rights Reserved. AbstractThis memo defines a portion of the Management Information Base (MIB) for use with network management protocols in the Internet community. This memo obsoletes RFC 2239, "Definitions of Managed Objects forIEEE 802.3 Medium Attachment Units (MAUs) using SMIv2". This memoextends that specification by including management information useful for the management of 1000 Mb/s MAUs.Ethernet technology, as defined by the 802.3 Working Group of theIEEE, continues to evolve, with scalable increases in speed, newtypes of cabling and interfaces, and new features. This evolutionmay require changes in the managed objects in order to reflect thisnew functionality. This document, as with other documents issued by this working group, reflects a certain stage in the evolution ofEthernet technology. In the future, this document might be revised, Smith, et al. Standards Track [Page 1]or new documents might be issued by the Ethernet Interfaces and HubMIB Working Group, in order to reflect the evolution of Ethernettechnology.Table of Contents1. Introduction (2)2. The SNMP Management Framework (3)3. Overview (4)3.1. Relationship to RFC 2239 (4)3.2. Relationship to RFC 1515 (4)3.3. MAU Management (4)3.4. Relationship to Other MIBs (5)3.4.1. Relationship to the Interfaces MIB (5)3.4.2. Relationship to the 802.3 Repeater MIB (5)3.5. Management of Internal MAUs (5)4. Definitions (6)5. Intellectual Property (49)6. Acknowledgements (49)7. References (50)8. Security Considerations (52)9. Authors’ Addresses (53)10. Appendix: Change Log (55)11. Full Copyright Statement (57)1. IntroductionThis memo defines a portion of the Management Information Base (MIB) for use with network management protocols in the Internet community. In particular, it defines objects for managing IEEE 802.3 MediumAttachment Units (MAUs).This memo also includes a MIB module. This MIB module extends thelist of managed objects specified in the earlier version of this MIB: RFC 2239 [21].The 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 [20].Smith, et al. Standards Track [Page 2]2. The SNMP Management FrameworkThe SNMP Management Framework presently consists of five majorcomponents:o An overall architecture, described in RFC 2571 [1].o Mechanisms for describing and naming objects and events for thepurpose of management. The first version of this Structure ofManagement Information (SMI) is called SMIv1 and described inSTD 16, RFC 1155 [2], STD 16, RFC 1212 [3] and RFC 1215 [4]. The second version, called SMIv2, is described in STD 58, RFC 2578[5], STD 58, RFC 2579 [6] and STD 58, RFC 2580 [7].o Message protocols for transferring management information. Thefirst version of the SNMP message protocol is called SNMPv1 anddescribed in STD 15, RFC 1157 [8]. A second version of the SNMPmessage protocol, which is not an Internet standards trackprotocol, is called SNMPv2c and described in RFC 1901 [9] and RFC 1906 [10]. The third version of the message protocol is calledSNMPv3 and described in RFC 1906 [10], RFC 2572 [11] and RFC 2574 [12].o Protocol operations for accessing management information. Thefirst set of protocol operations and associated PDU formats isdescribed in STD 15, RFC 1157 [8]. A second set of protocoloperations and associated PDU formats is described in RFC 1905[13].o A set of fundamental applications described in RFC 2573 [14] and the view-based access control mechanism described in RFC 2575[15].Managed objects are accessed via a virtual information store, termedthe Management Information Base or MIB. Objects in the MIB aredefined using the mechanisms defined in the SMI.This memo specifies a MIB module that is compliant to the SMIv2. AMIB conforming to the SMIv1 can be produced through the appropriatetranslations. The resulting translated MIB must be semanticallyequivalent, except where objects or events are omitted because notranslation is possible (use of Counter64). Some machine readableinformation in SMIv2 will be converted into textual descriptions inSMIv1 during the translation process. However, this loss of machinereadable information is not considered to change the semantics of the MIB.Smith, et al. Standards Track [Page 3]3. Overview3.1. Relationship to RFC 2239This MIB is intended to be a superset of that defined by RFC 2239[21], which will go to historic status. This MIB includes all of the objects contained in that MIB, plus several new ones which provideadditional capabilities. Implementors are encouraged to support all applicable conformance groups in order to make the best use of thenew functionality provided by this MIB. The new objects providemanagement support for:o management of 1000 Mb/s deviceso management of PAUSE negotiationo management of remote fault status3.2. Relationship to RFC 1515RFC 2239 was a replacement for RFC 1515 [22], which is now historic. RFC 2239 defined a superset of RFC 1515 which contained all of theobjects defined in RFC 1515, plus several new ones which providedadditional capabilities. The new objects in RFC 2239 providedmanagement support for:o management of 100 Mb/s deviceso auto-negotiation on interface MAUso jack management3.3. MAU ManagementInstances of these object types represent attributes of an IEEE 802.3 MAU. Several types of MAUs are defined in the IEEE 802.3 CSMA/CDstandard [16]. These MAUs may be connected to IEEE 802.3 repeatersor to 802.3 (Ethernet-like) interfaces. For convenience this document refers to these devices as "repeater MAUs" and "interface MAUs."The definitions presented here are based on Section 30.5, "LayerManagement for 10, 100 & 1000 Mb/s Medium Attachment Units (MAUs)",and Annex 30A, "GDMO Specifications for 802.3 managed object classes" of IEEE Std. 802.3, 1998 edition [16]. That specification includesdefinitions for 10Mb/s, 100Mb/s and 1000Mb/s devices. Thisspecification is intended to serve the same purpose: to provide formanagement of all types of Ethernet/802.3 MAUs.Smith, et al. Standards Track [Page 4]3.4. Relationship to Other MIBsIt is assumed that an agent implementing this MIB will also implement (at least) the ’system’ group defined in MIB-II [18]. The following sections identify other MIBs that such an agent should implement.3.4.1. Relationship to the Interfaces MIB.The sections of this document that define interface MAU-relatedobjects specify an extension to the Interfaces MIB [19]. An agentimplementing these interface-MAU related objects MUST also implement the relevant groups of Interface MIB. The value of the objectifMauIfIndex is the same as the value of ’ifIndex’ used toinstantiate the interface to which the given MAU is connected.It is expected that an agent implementing the interface-MAU relatedobjects in this MIB will also implement the Ethernet-like Interfaces MIB, [23].(Note that repeater ports are not represented as interfaces in theInterface MIB.)3.4.2. Relationship to the 802.3 Repeater MIBThe section of this document that defines repeater MAU-relatedobjects specifies an extension to the 802.3 Repeater MIB defined in[17]. An agent implementing these repeater-MAU related objects MUST also implement the 802.3 Repeater MIB.The values of ’rpMauGroupIndex’ and ’rpMauPortIndex’ used toinstantiate a repeater MAU variable SHALL be the same as the valuesof ’rptrPortGroupIndex’ and ’rptrPortIndex’ used to instantiate theport to which the given MAU is connected.3.5. Management of Internal MAUsIn some situations, a MAU can be "internal" -- i.e., itsfunctionality is implemented entirely within a device. For example, a managed repeater may contain an internal repeater-MAU and/or aninternal interface-MAU through which management communicationsoriginating on one of the repeater’s external ports pass in order to reach the management agent associated with the repeater. Suchinternal MAUs may or may not be managed. If they are managed,objects describing their attributes should appear in the appropriate MIB subtree: dot3RpMauBasicGroup for internal repeater-MAUs anddot3IfMauBasicGroup for internal interface-MAUs.Smith, et al. Standards Track [Page 5]4. DefinitionsMAU-MIB DEFINITIONS ::= BEGINIMPORTSCounter32, Integer32,OBJECT-TYPE, MODULE-IDENTITY, NOTIFICATION-TYPE,OBJECT-IDENTITY, mib-2FROM SNMPv2-SMITruthValue, TEXTUAL-CONVENTIONFROM SNMPv2-TCOBJECT-GROUP, MODULE-COMPLIANCE, NOTIFICATION-GROUPFROM SNMPv2-CONF;mauMod MODULE-IDENTITYLAST-UPDATED "9908240400Z" -- August 24, 1999ORGANIZATION "IETF Ethernet Interfaces and Hub MIBWorking Group"CONTACT-INFO"WG E-mail: hubmib@To subscribe: hubmib-request@Chair: Dan RomascanuPostal: Lucent TechnologiesAtidim Technology Park, Bldg. 3Tel Aviv 61131IsraelTel: +972 3 645 8414, 6458458Fax: +972 3 648 7146E-mail: dromasca@Editors: Andrew SmithPostal: Extreme Networks, Inc.10460 Bandley DriveCupertino, CA 95014USATel: +1 408 579-2821E-mail: andrew@John FlickPostal: Hewlett-Packard Company8000 Foothills Blvd. M/S 5557Roseville, CA 95747-5557USATel: +1 916 785 4018Fax: +1 916 785 1199E-mail: johnf@Smith, et al. Standards Track [Page 6]Kathryn de GraafPostal: Argon Networks25 Porter RoadLittleton, MA 01460USATel: +1 978 486 0665 x163Fax: +1 978 486 9379E-mail: kdegraaf@"DESCRIPTION "Management information for 802.3 MAUs.The following reference is used throughoutthis MIB module:[IEEE 802.3 Std] refers toIEEE Std 802.3, 1998 Edition: ’Informationtechnology - Telecommunications andinformation exchange between systems -Local and metropolitan area networks -Specific requirements - Part 3: Carriersense multiple access with collisiondetection (CSMA/CD) access method andphysical layer specifications’,September 1998.Of particular interest is Clause 30, ’10Mb/s,100Mb/s and 1000Mb/s Management’."REVISION "9908240400Z" -- August 24, 1999DESCRIPTION "This version published as RFC 2668. Updatedto include support for 1000 Mb/secMAUs and flow control negotiation."REVISION "9710310000Z" -- October 31, 1997DESCRIPTION "This version published as RFC 2239."REVISION "9309300000Z" -- September 30, 1993DESCRIPTION "Initial version, published as RFC 1515."::= { snmpDot3MauMgt 6 }snmpDot3MauMgt OBJECT IDENTIFIER ::= { mib-2 26 }-- textual conventionsJackType ::= TEXTUAL-CONVENTIONSTATUS currentDESCRIPTION "Common enumeration values for repeaterand interface MAU jack types."Smith, et al. Standards Track [Page 7]SYNTAX INTEGER {other(1),rj45(2),rj45S(3), -- rj45 shieldeddb9(4),bnc(5),fAUI(6), -- female auimAUI(7), -- male auifiberSC(8),fiberMIC(9),fiberST(10),telco(11),mtrj(12), -- fiber MT-RJhssdc(13) -- fiber channel style-2}dot3RpMauBasicGroupOBJECT IDENTIFIER ::= { snmpDot3MauMgt 1 }dot3IfMauBasicGroupOBJECT IDENTIFIER ::= { snmpDot3MauMgt 2 }dot3BroadMauBasicGroupOBJECT IDENTIFIER ::= { snmpDot3MauMgt 3 }dot3IfMauAutoNegGroupOBJECT IDENTIFIER ::= { snmpDot3MauMgt 5 }-- object identities for MAU types-- (see rpMauType and ifMauType for usage)dot3MauTypeOBJECT IDENTIFIER ::= { snmpDot3MauMgt 4 }dot3MauTypeAUI OBJECT-IDENTITYSTATUS currentDESCRIPTION "no internal MAU, view from AUI"::= { dot3MauType 1 }dot3MauType10Base5 OBJECT-IDENTITYSTATUS currentDESCRIPTION "thick coax MAU (per 802.3 section 8)"::= { dot3MauType 2 }dot3MauTypeFoirl OBJECT-IDENTITYSTATUS currentDESCRIPTION "FOIRL MAU (per 802.3 section 9.9)"::= { dot3MauType 3 }dot3MauType10Base2 OBJECT-IDENTITYSTATUS currentSmith, et al. Standards Track [Page 8]DESCRIPTION "thin coax MAU (per 802.3 section 10)"::= { dot3MauType 4 }dot3MauType10BaseT OBJECT-IDENTITYSTATUS currentDESCRIPTION "UTP MAU (per 802.3 section 14).Note that it is strongly recommended thatagents return either dot3MauType10BaseTHD ordot3MauType10BaseTFD if the duplex mode isknown. However, management applications shouldbe prepared to receive this MAU type value fromolder agent implementations."::= { dot3MauType 5 }dot3MauType10BaseFP OBJECT-IDENTITYSTATUS currentDESCRIPTION "passive fiber MAU (per 802.3 section 16)"::= { dot3MauType 6 }dot3MauType10BaseFB OBJECT-IDENTITYSTATUS currentDESCRIPTION "sync fiber MAU (per 802.3 section 17)"::= { dot3MauType 7 }dot3MauType10BaseFL OBJECT-IDENTITYSTATUS currentDESCRIPTION "async fiber MAU (per 802.3 section 18)Note that it is strongly recommended thatagents return either dot3MauType10BaseFLHD ordot3MauType10BaseFLFD if the duplex mode isknown. However, management applications shouldbe prepared to receive this MAU type value fromolder agent implementations."::= { dot3MauType 8 }dot3MauType10Broad36 OBJECT-IDENTITYSTATUS currentDESCRIPTION "broadband DTE MAU (per 802.3 section 11).Note that 10BROAD36 MAUs can be attached tointerfaces but not to repeaters."::= { dot3MauType 9 }------ new since RFC 1515:dot3MauType10BaseTHD OBJECT-IDENTITYSTATUS currentDESCRIPTION "UTP MAU (per 802.3 section 14), half duplexmode"::= { dot3MauType 10 }Smith, et al. Standards Track [Page 9]dot3MauType10BaseTFD OBJECT-IDENTITYSTATUS currentDESCRIPTION "UTP MAU (per 802.3 section 14), full duplexmode"::= { dot3MauType 11 }dot3MauType10BaseFLHD OBJECT-IDENTITYSTATUS currentDESCRIPTION "async fiber MAU (per 802.3 section 18), halfduplex mode"::= { dot3MauType 12 }dot3MauType10BaseFLFD OBJECT-IDENTITYSTATUS currentDESCRIPTION "async fiber MAU (per 802.3 section 18), fullduplex mode"::= { dot3MauType 13 }dot3MauType100BaseT4 OBJECT-IDENTITYSTATUS currentDESCRIPTION "4 pair categ. 3 UTP (per 802.3 section 23)"::= { dot3MauType 14 }dot3MauType100BaseTXHD OBJECT-IDENTITYSTATUS currentDESCRIPTION "2 pair categ. 5 UTP (per 802.3 section 25),half duplex mode"::= { dot3MauType 15 }dot3MauType100BaseTXFD OBJECT-IDENTITYSTATUS currentDESCRIPTION "2 pair categ. 5 UTP (per 802.3 section 25),full duplex mode"::= { dot3MauType 16 }dot3MauType100BaseFXHD OBJECT-IDENTITYSTATUS currentDESCRIPTION "X fiber over PMT (per 802.3 section 26), halfduplex mode"::= { dot3MauType 17 }dot3MauType100BaseFXFD OBJECT-IDENTITYSTATUS currentDESCRIPTION "X fiber over PMT (per 802.3 section 26), fullduplex mode"::= { dot3MauType 18 }dot3MauType100BaseT2HD OBJECT-IDENTITYSTATUS currentSmith, et al. Standards Track [Page 10]DESCRIPTION "2 pair categ. 3 UTP (per 802.3 section 32),half duplex mode"::= { dot3MauType 19 }dot3MauType100BaseT2FD OBJECT-IDENTITYSTATUS currentDESCRIPTION "2 pair categ. 3 UTP (per 802.3 section 32),full duplex mode"::= { dot3MauType 20 }------ new since RFC 2239:dot3MauType1000BaseXHD OBJECT-IDENTITYSTATUS currentDESCRIPTION "PCS/PMA (per 802.3 section 36), unknown PMD,half duplex mode"::= { dot3MauType 21 }dot3MauType1000BaseXFD OBJECT-IDENTITYSTATUS currentDESCRIPTION "PCS/PMA (per 802.3 section 36), unknown PMD,full duplex mode"::= { dot3MauType 22 }dot3MauType1000BaseLXHD OBJECT-IDENTITYSTATUS currentDESCRIPTION "Fiber over long-wavelength laser (per 802.3section 38), half duplex mode"::= { dot3MauType 23 }dot3MauType1000BaseLXFD OBJECT-IDENTITYSTATUS currentDESCRIPTION "Fiber over long-wavelength laser (per 802.3section 38), full duplex mode"::= { dot3MauType 24 }dot3MauType1000BaseSXHD OBJECT-IDENTITYSTATUS currentDESCRIPTION "Fiber over short-wavelength laser (per 802.3section 38), half duplex mode"::= { dot3MauType 25 }dot3MauType1000BaseSXFD OBJECT-IDENTITYSTATUS currentDESCRIPTION "Fiber over short-wavelength laser (per 802.3section 38), full duplex mode"::= { dot3MauType 26 }Smith, et al. Standards Track [Page 11]dot3MauType1000BaseCXHD OBJECT-IDENTITYSTATUS currentDESCRIPTION "Copper over 150-Ohm balanced cable (per 802.3section 39), half duplex mode"::= { dot3MauType 27 }dot3MauType1000BaseCXFD OBJECT-IDENTITYSTATUS currentDESCRIPTION "Copper over 150-Ohm balanced cable (per 802.3section 39), full duplex mode"::= { dot3MauType 28 }dot3MauType1000BaseTHD OBJECT-IDENTITYSTATUS currentDESCRIPTION "Four-pair Category 5 UTP (per 802.3 section40), half duplex mode"::= { dot3MauType 29 }dot3MauType1000BaseTFD OBJECT-IDENTITYSTATUS currentDESCRIPTION "Four-pair Category 5 UTP (per 802.3 section40), full duplex mode"::= { dot3MauType 30 }---- The Basic Repeater MAU Table--rpMauTable OBJECT-TYPESYNTAX SEQUENCE OF RpMauEntryMAX-ACCESS not-accessibleSTATUS currentDESCRIPTION "Table of descriptive and status informationabout the MAU(s) attached to the ports of arepeater."::= { dot3RpMauBasicGroup 1 }rpMauEntry OBJECT-TYPESYNTAX RpMauEntryMAX-ACCESS not-accessibleSTATUS currentDESCRIPTION "An entry in the table, containing informationabout a single MAU."INDEX { rpMauGroupIndex,rpMauPortIndex,rpMauIndex}::= { rpMauTable 1 }Smith, et al. Standards Track [Page 12]RpMauEntry ::=SEQUENCE {rpMauGroupIndex Integer32,rpMauPortIndex Integer32,rpMauIndex Integer32,rpMauType OBJECT IDENTIFIER,rpMauStatus INTEGER,rpMauMediaAvailable INTEGER,rpMauMediaAvailableStateExits Counter32,rpMauJabberState INTEGER,rpMauJabberingStateEnters Counter32,rpMauFalseCarriers Counter32}rpMauGroupIndex OBJECT-TYPESYNTAX Integer32 (1..2147483647)MAX-ACCESS read-onlySTATUS currentDESCRIPTION "This variable uniquely identifies the groupcontaining the port to which the MAU describedby this entry is connected.Note: In practice, a group will generally bea field-replaceable unit (i.e., module, card,or board) that can fit in the physical systemenclosure, and the group number will correspondto a number marked on the physical enclosure.The group denoted by a particular value of thisobject is the same as the group denoted by thesame value of rptrGroupIndex."REFERENCE "Reference RFC 2108, rptrGroupIndex."::= { rpMauEntry 1 }rpMauPortIndex OBJECT-TYPESYNTAX Integer32 (1..2147483647)MAX-ACCESS read-onlySTATUS currentDESCRIPTION "This variable uniquely identifies the repeaterport within group rpMauGroupIndex to which theMAU described by this entry is connected."REFERENCE "Reference RFC 2108, rptrPortIndex."::= { rpMauEntry 2 }rpMauIndex OBJECT-TYPESYNTAX Integer32 (1..2147483647)MAX-ACCESS read-onlySTATUS currentSmith, et al. Standards Track [Page 13]DESCRIPTION "This variable uniquely identifies the MAUdescribed by this entry from among otherMAUs connected to the same port(rpMauPortIndex)."REFERENCE "[IEEE 802.3 Std], 30.5.1.1.1, aMAUID."::= { rpMauEntry 3 }rpMauType OBJECT-TYPESYNTAX OBJECT IDENTIFIERMAX-ACCESS read-onlySTATUS currentDESCRIPTION "This object identifies the MAU type. Aninitial set of MAU types are defined above. Theassignment of OBJECT IDENTIFIERs to new types ofMAUs is managed by the IANA. If the MAU type isunknown, the object identifierunknownMauType OBJECT IDENTIFIER ::= { 0 0 }is returned. Note that unknownMauType is asyntactically valid object identifier, and anyconformant implementation of ASN.1 and the BERmust be able to generate and recognize thisvalue."REFERENCE "[IEEE 802.3 Std], 30.5.1.1.2, aMAUType."::= { rpMauEntry 4 }rpMauStatus OBJECT-TYPESYNTAX INTEGER {other(1),unknown(2),operational(3),standby(4),shutdown(5),reset(6)}MAX-ACCESS read-writeSTATUS currentDESCRIPTION "The current state of the MAU. This object MAYbe implemented as a read-only object by thoseagents and MAUs that do not implement softwarecontrol of the MAU state. Some agents may notsupport setting the value of this object to someof the enumerated values.The value other(1) is returned if the MAU is ina state other than one of the states 2 through6.Smith, et al. Standards Track [Page 14]The value unknown(2) is returned when the MAU’strue state is unknown; for example, when it isbeing initialized.A MAU in the operational(3) state is fullyfunctional, operates, and passes signals to itsattached DTE or repeater port in accordance toits specification.A MAU in standby(4) state forces DI and CI toidle and the media transmitter to idle or fault,if supported. Standby(4) mode only applies tolink type MAUs. The state ofrpMauMediaAvailable is unaffected.A MAU in shutdown(5) state assumes the samecondition on DI, CI, and the media transmitteras though it were powered down or not connected.The MAU MAY return other(1) value for therpMauJabberState and rpMauMediaAvailable objectswhen it is in this state. For an AUI, thisstate will remove power from the AUI.Setting this variable to the value reset(6)resets the MAU in the same manner as apower-off, power-on cycle of at least one-halfsecond would. The agent is not required toreturn the value reset (6).Setting this variable to the valueoperational(3), standby(4), or shutdown(5)causes the MAU to assume the respective stateexcept that setting a mixing-type MAU or an AUIto standby(4) will cause the MAU to enter theshutdown state."REFERENCE "[IEEE 802.3 Std], 30.5.1.1.7, aMAUAdminState,30.5.1.2.2, acMAUAdminControl, and 30.5.1.2.1, acResetMAU."::= { rpMauEntry 5 }rpMauMediaAvailable OBJECT-TYPESYNTAX INTEGER {other(1),unknown(2),available(3),notAvailable(4),remoteFault(5),invalidSignal(6),Smith, et al. Standards Track [Page 15]remoteJabber(7),remoteLinkLoss(8),remoteTest(9),offline(10),autoNegError(11)}MAX-ACCESS read-onlySTATUS currentDESCRIPTION "If the MAU is a link or fiber type (FOIRL,10BASE-T, 10BASE-F) then this is equivalent tothe link test fail state/low light function.For an AUI or a coax (including broadband) MAUthis indicates whether or not loopback isdetected on the DI circuit. The value of thisattribute persists between packets for MAU typesAUI, 10BASE5, 10BASE2, 10BROAD36, and 10BASE-FP.The value other(1) is returned if themediaAvailable state is not one of 2 through 11.The value unknown(2) is returned when the MAU’strue state is unknown; for example, when it isbeing initialized. At power-up or following areset, the value of this attribute will beunknown for AUI, coax, and 10BASE-FP MAUs. Forthese MAUs loopback will be tested on eachtransmission during which no collision isdetected. If DI is receiving input when DOreturns to IDL after a transmission and therehas been no collision during the transmissionthen loopback will be detected. The value ofthis attribute will only change duringnon-collided transmissions for AUI, coax, and10BASE-FP MAUs.For 100Mbps and 1000Mbps MAUs, the enumerationsmatch the states within the respective linkintegrity state diagrams, fig 32-16, 23-12 and24-15 of sections 32, 23 and 24 of [16]. AnyMAU which implements management ofauto-negotiation will map remote faultindication to remote fault.The value available(3) indicates that the link,light, or loopback is normal. The valuenotAvailable(4) indicates link loss, low light,or no loopback.Smith, et al. Standards Track [Page 16]The value remoteFault(5) indicates that a faulthas been detected at the remote end of the link.This value applies to 10BASE-FB, 100BASE-T4 FarEnd Fault Indication and non-specified remotefaults from a system running auto-negotiation.The values remoteJabber(7), remoteLinkLoss(8),and remoteTest(9) SHOULD be used instead ofremoteFault(5) where the reason for remote faultis identified in the remote signaling protocol.The value invalidSignal(6) indicates that aninvalid signal has been received from the otherend of the link. InvalidSignal(6) applies onlyto MAUs of type 10BASE-FB.Where an IEEE Std 802.3u-1995 clause 22 MIIis present, a logic one in the remote fault bit(reference section 22.2.4.2.8 of that document)maps to the value remoteFault(5), and a logiczero in the link status bit (reference section22.2.4.2.10 of that document) maps to the valuenotAvailable(4). The value notAvailable(4)takes precedence over the value remoteFault(5).Any MAU that implements management of clause 37Auto-Negotiation will map the received RemoteFault (RF1 and RF2) bit values for Offline tooffline(10), Link Failure to remoteFault(5) andAuto-Negotiation Error to autoNegError(11)."REFERENCE "[IEEE 802.3 Std], 30.5.1.1.4, aMediaAvailable."::= { rpMauEntry 6 }rpMauMediaAvailableStateExits OBJECT-TYPESYNTAX Counter32MAX-ACCESS read-onlySTATUS currentDESCRIPTION "A count of the number of times thatrpMauMediaAvailable for this MAU instance leavesthe state available(3).Discontinuities in the value of this counter canoccur at re-initialization of the managementsystem, and at other times as indicated by thevalue of rptrMonitorPortLastChange."REFERENCE "[IEEE 802.3 Std], 30.5.1.1.5,aLoseMediaCounter.RFC 2108, rptrMonitorPortLastChange"Smith, et al. Standards Track [Page 17]。

合集下载

IEEE 802.3af Isolation

IEEE 802.3af Isolation

IEEE 802_3 Isolation.docSummary:Spec Isolation10BASE-T MAU Frame ground and all leads: 2250VDC,1500Vrms, 2400V pulsesTP-PMD(100BASE-TX PMD) Frame ground and all leads: 2250VDC, 1500Vrms, 2400V pulsesRepeaterEnvironment ASegment and protective ground: 500VrmsRepeater Environment B Segment and other segment(s) or protective ground: 1500VrmsRepeaterport to portLocal isolation requirements.IEEEPart 3: Carrier sense multiple access with collision detection (CSMA/CD) access method and physical layer specifications9.Repeater unit for 10 Mb/s baseband networks9.5.7 Electrical isolationNetwork segments that have different isolation and grounding requirements shall have those requirements provided by the port-to-port isolation of the repeater set.9.7 Electrical isolationThere are two electrical power distribution environments to be considered that require different electrical isolation properties.Environment A—When a LAN or LAN segment, with all its associated interconnected equipment, is entirely contained within a single low- voltage power distribution system and within a single building.Environment B—When a LAN crosses the boundary between separate power distribution systems or the boundaries of a single building.The repeater unit shall comply with applicable local and national codes related to safety. See [B21].9.7.1 Environment A requirementsAttachment of network segments via repeaters (sets) possessing internal MAUs requires electrical isolation of 500 Vrms, 1 min withstand, between the segment and the protective ground of the repeater unit. For repeater ports that connect to external MAUs via an AUI Interface, the requirement for isolation is encompassed within the isolation requirements of the basic MAU/medium standard. (See 8.3.2.1, 9.9.3.1, 10.4.2.1, 14.3.1.1, and 15.3.4.) The repeater unit shall not require any electrical isolation between exposed AUI Interfaces or between exposed AUI Interfaces and chassis ground of the repeater unit. No isolation boundary need therefore exist at any AUI compatible interface (that is, “D”connector) provided by a repeater unit.9.7.2 Environment B requirementsThe attachment of network segments, which cross environment A boundaries, requires electrical isolation of 1500 Vrms, 1 min withstand, between each segment and all otherattached segments and also the protective ground of the repeater unit. If segments are of an electrically conductive medium, it is recommended that this isolation be provided by the use of external MAUs connected by AUI Interfaces. If internal MAUs are used for attachment to conductive media segments, then the segments shall be installed such that it is not possible for an equipment user to touch the trunk cable screen or signal conductor.A repeater of this variety requires professional installation. The requirements for interconnected electrically conducting LAN segments that are partially or fully external to a single building environment may require additional protection against lightning strike hazards. Such requirements are beyond the scope of this standard. It is recommended that the above situation be handled by the use of a nonelectrically conducting LAN segment (see 9.9 or Clause 15).14.Twisted-pair medium attachment unit (MAU) and baseband medium, type10BASE-T14.3.1.1 Isolation requirementThe MAU shall provide isolation between the DTE Physical Layer circuits including frame ground and all MDI leads including those not used by 10BASE-T. This electrical separation shall withstand at least one of the following electrical strength tests.a)1500 Vrms at 50 Hz to 60 Hz for 60 s, applied as specified in Section 5.3.2 of IEC 60950: 1991.b)2250 Vdc for 60 s, applied as specified in Section 5.3.2 of IEC 60950: 1991.c)A sequence of ten 2400 V impulses of alternating polarity, applied at intervals of not less than 1 s. The shape of the impulses shall be 1.2/50 µs (1.2 µs virtual front time, 50µs virtual time of half value), as defined in IEC 60060.There shall be no insulation breakdown, as defined in Section 5.3.2 of IEC 60950: 1991, during the test. The resistance after the test shall be at least 2 M , measured at 500 Vdc.25.Physical Medium Dependent (PMD) sublayer and baseband medium, type100BASE-TX25.2 Functional specificationsThe 100BASE-TX PMD (and MDI) is specified by incorporating the FDDI TP-PMD standard, ANSI X3.263: 1995 (TP-PMD), by reference, with the modifications noted below. This standard provides support for Category 5 unshielded twisted pair (UTP) and shielded twisted pair (STP). For improved legibility in this clause, ANSI X3.263: 1995 (TP-PMD), will henceforth be referred to as TP-PMD.27.Repeater for 100 Mb/s baseband networks27.4.1 Electrical isolationNetwork segments that have different isolation and grounding requirements shall have those requirements provided by the port-to-port isolation of the repeater set.27.5.2.2 GroundingThe safety ground, or chassis ground for the repeater set, shall be provided through the main ac power cord via the third wire ground as defined by applicable local codes andregulations. It is recommended that an external PHY to the repeater should also be mechanically grounded to the repeater unit through the power and ground signals in the MII connection and via the metal shell and shield of the MII connector if available.If the MDI connector should provide a shield connection, the shield may be connected to the repeater safety ground. A network segment connected to the repeater set through the MDI may use a shield. If both ends of the network segment have a shielded MDI connector available, then the shield may be grounded at both ends according to local regulations and ISO/IEC 11801: 1995, and as long as the ground potential difference between both ends of the network segment is less than 1 V rms. The same rules apply towards an inter-repeater link between two repeaters. Multiple repeaters should reside on the same power main; if not, then it is highly recommended that the repeaters be connected via fiber.27.5.3 Electrical isolationThere are two electrical power distribution environments to be considered that require different electrical isolation properties:a)Environment A. When a LAN or LAN segment, with all its associated interconnected equipment, is entirely contained within a single low-voltage power distribution system and within a single building.b)Environment B. When a LAN crosses the boundary between separate power distribution systems or the boundary of a single building.27.5.3.1 Environment A requirementsAttachment of network segments via repeater sets requires electrical isolation of 500 Vrms, one-minute withstand, between the segment and the protective ground of the repeater unit.27.5.3.2 Environment B requirementsThe attachment of network segments that cross Environment B boundaries requires electrical isolation of 1500 Vrms, one-minute withstand, between each segment and all other attached segments and also the protective ground of the repeater unit. The requirements for interconnected electrically conducting LAN segments that are partiallyor fully external to a single building environment may require additional protection against lightning strike hazards. Such requirements are beyond the scope of this standard. It is recommended that the above situation be handled by the use of nonelectrically conducting segments (e.g., fiber optic). It is assumed that any nonelectrically conducting segments will provide sufficient isolation within that media to satisfy the isolation requirements of Environment B.ANSI X3.263:199XFDDI TP-PMD8.4.1 UTP isolation requirementsThe UTP-PMD shall provide isolation between frame ground and all leads of the UTP-MIC, including those not used by the AOI and AII. This electrical separation shall withstand at least one of the following electrical strength tests.1.1500 Vrms at 50 to 60 Hz for 60 s, applied as specified in subclause 5.3.2 of IEC 950:1991.2.2250 VDC for 60 s, applied as specified in subclause 5.3.2 of IEC 950:1991.3.A sequence of ten 2400 V impulses of alternating polarity, applied at intervals of not less than 1 s. The shape of these impulses shall be 1,2/50 ms (1,2 ms virtual front time, 50 ms virtual time of half value), as defined in IEC 60.There shall be no insulation breakdown, as defined in subclause 5.3.2 of IEC 950:1991, during the test. The resistance after the test shall be at least 2 MW, measured at 500 VDC.。

Polycom VVX 501业务媒体电话说明书

Polycom VVX 501业务媒体电话说明书

DATA SHEETPolycom® VVX® 501Business Media Phones Performance business media phones that deliver best-in-class desktop productivity and unified communications for busy professionalsThe Polycom® VVX® 501 performance business media phones unify superior voice capabilities and applications into a simple-to-use, yet high-performance unified communications (UC) solution. It is the ideal, all-in-one knowledge worker productivity tool, built to integrate seamlessly into a wide range of UC environments.Simplicity and ease of useThe Polycom VVX 501 Business Media Phone is built for today’s busy managers and knowledge workers who need a powerful, expandable office phone that keeps up withtheir multitasking and schedule-juggling. Building on the behavior common to mobile phones, the multitouch, gesture-based user interface of the Polycom VVX 501 makes navigation intuitive and easy.Maximize productivityDesigned for a broad range of environments from small and medium businesses to large enterprises, the Polycom VVX 501 performance business media phone improves productivity by complementing the workplace applications on the user’s computer. Users benefit from such capabilities as viewing their Outlook calendar on the phone and receiving meeting reminders while still having access to their corporate directory—all while waiting for their PCs to boot. Users can also extend their PC desktop to include the Polycom VVX 501’s screen, helping to enable simplified interactions and dialing using their PC’s mouse and keyboard. Training and multipoint communication applications are complemented by the Polycom VVX 501 video playback capability for streaming content.Best-in-class deployment and administrationThe Polycom VVX 501 is easy to deploy and simple to manage. Its enterprise-grade, Web-based, intuitive configuration method gives administrators the ability to easily set up and maintain a large number of phones throughout the entire enterprise. The built-in, broad interoperability capabilities allow IT departments to leverage previous IT infrastructure investments and achieve easy integration with third-party UC and productivity applications.Highly customizable and expandableThe Polycom VVX 501 provides personalized information at a glance, through built-in Web applications and even a digital photo frame. Polycom’s “My Info Portal” serves up stocks, news, sports, weather and other streamed content directly to the phone screen. The Polycom VVX 501 is ready for future expansion modules and accessories for applications such as videoconferencing and even wireless networking.Market-leading open standards interoperabilityDesigned for enhanced interoperability, leveraging and complementing the other existingIT investments of any enterprise, the Polycom VVX 501 delivers HD Voice™, a superior UC experience bundled with business applications. With the broadest call server interoperabilityin the industry, the Polycom VVX 501 business media phone is a flexible foundation for any organization’s UC strategy.Benefits• Improves knowledge-worker productivity• Reduces training time through superior calling features in a sleek design and simple-to-use phone • Cuts telephony administration and maintenance costs• Leverages previous IT infrastructure investments• Easy to deploy, administer, upgrade and maintain• Delivers easy integrationwith third-party UC andproductivity applicationsProduct specificationsUser interface features• Gesture-based, multitouch-capable, capacitive touch-screen• 3.5-in TFT LCD display at QVGA(320 x 240 pixel) resolution,4:3 aspect ratio• Screensaver and digital picture frame mode • On-screen virtual keyboard• Voicemail and videomail support1• Dual USB ports (2.0 compliant) for media and storage applications• WebKit-based browser• Adjustable base height• Unicode UTF-8 character support. Multilingual user interface including Chinese, Danish, Dutch, English (Canada/US/UK), French, German, Italian, Japanese, Korean, Norwegian, Polish, Portuguese, Russian, Slovenian, Spanish and SwedishAudio features• Polycom® HD Voice™ technology delivers lifelike voice quality for each audio path-handset, the hands-free speakerphone and the optional headset• Polycom® Acoustic Clarity™ technology, providing full-duplex conversations, acoustic echo cancellation and background noise suppression-Type 1 compliant (IEEE 1329 full duplex)• Frequency response: 100 Hz–20 kHz for handset, optional headset and hands-free speakerphone modes• Codecs: G.711 (A-law and μ-law), G.729AB, G.722, G.722.1, G.722.1C• Individual volume settings with visual feedback for each audio path• Voice activity detection• Comfort noise generation• DTMF tone generation (RFC 2833and in-band)• Low-delay audio packet transmission• Adaptive jitter buffers• Packet loss concealmentHeadset and handset compatibility• Dedicated RJ-9 headset port• Hearing aid compatibility to ITU-T P.370 and TIA• 504A standards• Compliant with ADA Section 508Subpart B 1194.23 (all)• Hearing aid compatible handset for magnetic coupling to hearing aids• Compatible with commercially available TTY adapter equipment• Supports compatible USB headsets Call handling features1• 12 lines (registrations)• Up to 24 simultaneous calls• Shared call/bridged line appearance• Flexible line appearance (1 or moreline keys can be assigned for eachline extension)• Distinctive incoming call treatment/call waiting• Call timer and call waiting• Call transfer, hold, divert (forward), pickup• Called, calling, connectedparty information• Local 3-way audio conferencing• 1-touch speed dial, redial• Remote missed call notification• Do not disturb function• Electronic hook switch capable• Local configurable digit map/dial planOpen application platform• WebKit-enabled full browser that supportsHTML5, CSS, SSL security and JavaScript• Supports Polycom Apps SDK and APIfor third-party business and personalapplications• Bundled with Polycom Productivity Suite:-Corporate directory access using LDAP-Local voice call recording on USBflash drive-Visual conference managementNetwork and provisioning• Network (LAN) cable - CAT-5E• SIP protocol support• SDP• IETF SIP (RFC 3261 and companion RFCs)• Two-port gigabit Ethernet switch-10/100/1000Base-TX across LANand PC ports-Conforms to IEEE802.3-2005 (Clause 40)for physical media attachment-Conforms to IEEE802.3-2002(Clause 28) for link• Partner auto-negotiation• Manual or dynamic hostconfiguration protocol (DHCP)• DHCP network setup• Time and date synchronizationusing SNTP• FTP/TFTP/HTTP/HTTPS server-basedcentral provisioning for mass deployments• Provisioning and call serverredundancy supported1• QoS Support—IEEE 802.1p/Q tagging(VLAN), Layer 3 TOS and Diffserv/DSCP• VLAN—CDP, DHCP VLAN discovery, LLDP-MED for VLAN discovery-Network address translation supportfor static configuration and “Keep-Alive”SIP signaling• RTCP and RTP support• Event logging• Syslog• Local configurable digit map/dial plan• Hardware diagnostics• Status and statistics reporting• IPv4 and IPv6• TCP• UDP• DNS-SRVSecurity• 802.1X authentication and EAPOL• Media encryption via SRTP• Transport layer security• Encrypted configuration files• Digest authentication• Password login• Support for URL syntax with password forboot server address• HTTPS secure provisioning• Support for signed software executablesPower• Built-in auto-sensing IEEE 802.3 at Powerover Ethernet (Class 4)• External universal AC adaptor (optional, 48V0.52A DC)Approvals• FCC Part 15 (CFR 47) Class B• ICES-003 Class B• EN55022 Class B• CISPR22 Class B• VCCI Class B• EN55024• EN61000-3-2; EN61000-3-3• NZ Telepermit• Korea KC• UAE TRA• Russia CU• Brazil ANATEL• Australia RCM• South Africa ICASA• China CCC• Saudi Arabia CITCSafety• UL 60950-1• CE Mark• CAN/CSA-C22.2 No. 60950-1-03• EN 60950-1• IEC 60950-1• AS/NZS 60950-1Operating conditions• Temperature: +32 to 104°F (0 to 40°C)• Relative humidity: 5% to 95%,noncondensingStorage temperature• -40 to +160°F (-40 to +70°C) Polycom® VVX® 501 comes with• Polycom VVX 501 console• Handset with handset cord• Network (LAN) cable—CAT-5E• Quick start guideSize• 7.5 x 6 x 7 in (19 x 15 x 18 cm) (W x H x D) Part numbers• 2200-48500-025—VVX 501 WW PoE • 2200-48500-019—VVX 501 Skype for Business, POE Weight• Unit weight: 2.0 lbs (0.9 kg)Unit box dimensions/weight• 11.46 x 7.9 x 3.82 in (29.1 x 20 x 9.7 cm)• 3.1 lbs (1.4 kg)Master carton quantity• 5Warranty• 1 year1. Most software-enabled features and capabilitiesmust be supported by the server. Please contactyour IP PBXsoftswitch vendor or service provider fora list of supported features.2. T o enjoy all the benefits of Polycom HD Voice whenusing the phone in the headset mode, you must usea wideband headset.Learn moreTo learn more about VVX, visit/voice-conferencing-solutions/desktop-ip-phones.html©2019 Plantronics, Inc. All rights reserved. Poly and the propeller design are trademarks of Plantronics, Inc. All other trademarks are the property of their respective owners. 7.19 475695。

IEEE802.3标准：CSMA CD

IEEE802.3标准：CSMA CD

5.3 IEEE 802.3标准：CSMA/CD更详细内容5.3.1 802.3局域网概述部件（见图）*同轴电缆*收发器*收发器电缆*网卡收发器内部结构及与电缆连接（见图）*收发器的功能：从计算机经收发器电缆得到数据向同轴电缆发送，或反过来，从同轴电缆接收数据经收发器电缆送给计算机；检测在同轴电缆上发生的数据帧的冲突；在同轴电缆和电缆接口的电子设备之间进行电气隔离；当收发器或所连接的计算机出故障时，保护同轴电缆不受其影响。

* 收发器电缆——5对双绞线，距离小于50米。

* 网卡实现MAC子层及物理层的功能，主要有以下三个：数据的封装与解封发送时将LLC 子层交下来的LLC PDU 加上MAC 子层的首部和尾部，成为MAC 帧。

接收时将MAC 帧剥去首部和尾部，然后送交LLC 子层；链路管理主要是CSMA/CD 协议的实现；编码与译码即曼彻斯特编码与泽码。

（网卡常将收发器集成在一起，电缆通过T 头接入）可将物理层进一步分解为PLS子层和PMA子层∙PLS——物理信令，向MAC提供服务，有收发、编解码及监听等功能。

∙PMA——物理媒体连接件，向PLS提供服务，有冲突检测、超长控制、收发比特流等功能。

∙两种体系a)分开体系—— PLS与PMA分离，两者间用AUI连接件单元接口连接。

b)合成体系—— PLS与PMA在一个设备中。

两种体系都用MDI与电缆连接。

转发器的作用：——放大与重复驱动集线器的一些特点如下：使用集线器的局域网在物理上是一个星型网，但整个系统仍然像一个传统的以太网那样运行。

集线器有许多端口，每个端口通过RJ-45 插座用两对双绞线与一个工作站上的网卡相连（这种插座可连接4对双绞线，实际上只用2 对，即发送和接收各使用一对双绞线）。

集线器的每个端口都具有发送和接收数据的功能。

图5-9 是具有三个端口的集线器的示意图。

集线器采用了专门的芯片，进行自适应串音回波抵消。

可以把多个集线器连成多级星型结构的网络，可以使更多的工作站连接成一个较大的局域网。

Cisco SGE2010P 48-Port Gigabit Switch PoE 产品介绍说明书

Cisco SGE2010P 48-Port Gigabit Switch PoE 产品介绍说明书

Data Sheet Cisco SGE2010P 48-Port Gigabit Switch: PoECisco Small Business Managed SwitchesPerformance and Reliability to Support Small Business NetworksHighlights●48 high-speed ports optimized for the network core or to support bandwidth-intensive applications●Power over Ethernet easily and cost-effectively powers wireless access points, video cameras, and othernetwork-connected endpoints●Resilient clustering provides the ability to manage several switches as a single switch to support growingbusinesses●Strong security protects network traffic to keep unauthorized users off the network●Simplified, web-based management for easy installation and configuration●Limited lifetime warrantyFigure 1. Cisco SGE2010P 48-Port Gigabit Switch: PoEProduct OverviewThe Cisco® SGE2010P 48-Port Gigabit Switch (Figure 1) allows you to expand your network securely. Web-based configuration of the switch is secured using SSL. The Cisco SGE2010P is optimized for maximum system availability, with fully redundant stacking, redundant power options, and dual images for resilient firmware upgrades. The switch helps secure the network through IEEE 802.1Q VLANs, IEEE 802.1X port authentication, access control lists (ACLs), denial-of-service (DoS) prevention, and MAC-based filtering. The enhanced quality of service (QoS) and traffic-management features help ensure clear and reliable voice and video communications.For wireless or voice over IP (VoIP) deployments, the Cisco SGE2010P supports the IEEE 802.3af standard for Power over Ethernet (PoE). Automatic load sensing enables the circuitry to detect PoE on the end device before providing power. For safety, each port has independent overload and short-circuit protection, along with LED indicators to show power status. It provides 15W of available PoE power on up to 24 of the Gigabit Ethernet ports for powering PoE-enabled wireless access points or VoIP handsets. The maximum PoE available per device for all ports is 360W.The Cisco SGE2010P provides resilient stacking for up to four units, or 192 ports. A stack of units is managed as a single switch with one web management interface. The Cisco SGE2010P can coexist in a stack with the Cisco SGE2000 and SGE2000P 24-Port Gigabit Switches, and the Cisco SGE2010 48-Port Gigabit Switch, for a maximum of 192 ports in astack. The stacking capability includes master/backup unit behavior, ring and chain architecture, and hot insertion and removal of units.Software running on the Cisco SGE2010P interacts with provisioning, management, and security software on both the site’s services router and the service provider’s equipment. This interaction provides a simple, one-step installation and access to web-administered features for the administrator and users. Simple, affordable network operations throughout the netwo rk’s lifetime are the result.Features●Forty-eight 10/100/1000 Ethernet ports● 4 mini Gigabit Interface Converter (mini-GBIC) slots (shared with 4 Ethernet ports) for fiber Gigabit Ethernetexpansion●IEEE 802.3af PoE delivered over any of the forty-eight 10/100/1000 ports●15.4W available power to a Gigabit Ethernet port for PoE-enabled wireless access point or VoIP handsets(maximum per-device PoE delivery of 360W available for all ports)●Dual images for resilient firmware upgrades●96 Gbps nonblocking, store-and-forward switching capacity●Simplified QoS management using 802.1p, differentiated services (DiffServ) or type of service (ToS) trafficprioritization●Power redundancy when used with the Cisco RPS1000 380W Redundant Power Supply Unit●Fully resilient stacking provides optimized growth with simplified management●ACLs for granular security and QoS implementation●Configuration and monitoring from a standard web browser●Secure remote management of the switch via Secure Shell (SSH) and SSL encryption●802.1Q-based VLANs enable segmentation of networks for improved performanceSpecificationsTable 1 contains the specifications, package contents, and minimum requirements for the Cisco SGE2010P 48-Port Gigabit Switch.Table 1. Specifications for the Cisco SGE2010P 48-Port Gigabit Switch: PoEService & SupportCisco Small Business switches are backed by the Cisco Small Business Support Service, which provides affordable peace-of-mind coverage. This subscription-based service helps you protect your investment and derive maximum value from Cisco Small Business products. Delivered by Cisco and backed by your trusted partner, this comprehensive service includes software updates, access to the Cisco Small Business Support Center, and expedited hardware replacement.Cisco Small Business products are supported by professionals in Cisco Small Business Support Center locations worldwide who are specifically trained to understand your needs. The Cisco Small Business Support Community, anonline forum, enables you to collaborate with your peers and reach Cisco technical experts for support information.Cisco Limited Lifetime Hardware WarrantyThis Cisco Small Business product offers a limited lifetime hardware warranty with return to factory replacement and a 1-year limited warranty for fans and power supplies. In addition, Cisco offers telephone technical support at no charge for the first 12 months following the date of purchase and software bug fixes for the warranty term. To download software updates, go to: /cisco/web/download/index.html.Product warranty terms and other information applicable to Cisco products are available at/go/warranty.For More InformationFor more information on Cisco Small Business products and solutions, visit: /smallbusiness.。