IWACA'94
Advance Reservation of Network Resources for
Multimedia Applications
Wilko Reinhardt
Technical University of Aachen (RWTH Aachen), Dept. of Computer Science (Informatik IV)
Ahornstr. 55, 52056 Aachen, Germany
email: wilko@informatik.rwth-aachen.de
Abstract. To guarantee Quality of Services for continuous media like audio and
video, intermediate nodes in networks must be able to reserve resources like buffer
capacity, CPU time and bandwidth. Several methods have been introduced to
verify that new connections can be accepted by the network without violating
guarantees made for already established connections. One drawback of all pro-
posed admission control algorithms is that they accept the reservation only at
connection establishment time. It is not possible to reserve resources in advance.
This paper introduces an algorithm that allows the user to reserve the desired QOS
in advance. The paper further describes how the signalling of advance reservation
can be realized using the Internet Stream Protocol ST-2.
1Introduction
Communication support of distributed multimedia applications imposes several chal-lenges on today's communication systems. The requirements of these applications reveal a lack of performance of traditional protocol stacks. Major reasons are contradictory demands made by the various media types. On one hand, isochronous data streams from live video and audio sources request high bandwidth, timely delivery of the data and low delay variation (jitter). On the other hand, asynchronous streams resulting e.g. from the transfer of still images or textual documents need a reliable transmission but can accept some delays and are insensitive to jitter. Broadband networks (e.g. B-ISDN, DQDB, FDDI, FDDI II, etc.) were developed in recent years, providing sufficient bandwidth to support the various requirements. Thus, the problem lies within the functionality and performance characteristics of the network and transport layers [5]. A new generation of protocols is necessary to bridge the functional and performance gap within these layers. XTP [10] and ST-2 [8] are two of the very promising approaches besides experimental approaches from several research laboratories [3,9]. The common part of all these protocols is the extended support of Quality of Service (QOS) parameters, allowing the user processes to define their exact requirements for the requested connection. In accordance with the QOS values the protocol functionality is configured and/or resources are reserved to provide a guaranteed service.
The 'real' support of QOS, i.e.. not just OSI's 'request and pray' approach is a key issue for sufficient communication support of multimedia applications. Currently, several ex-tended QOS semantics are under discussion:
?Threshold QOS: The service user specifies 'worst case' values which are accept-able as the lowest quality. If values fall below these thresholds the user process will be informed so that it can decide to accept the lower quality or abort the connection. The QOS concept introduced by the OSI 95 project [1] proposes a more rigorous semantics, called compulsory QOS: If only one of the 'worst case' values is exceeded the connection will be aborted immediately.
?Guaranteed QOS: [2] introduced the guaranteed QOS semantics which has a rather strong legal flavour. When a service provider guarantees a performance value to the service user, it commits itself to provide that performance and to pay
a penalty if the negotiated value can not be achieved. On the other hand the service
user is obliged not to exceed the negotiated value.
Guaranteed QOS assumes that all intermediate nodes from the source to the destination allocate appropriate resources like bandwidth, buffer space and CPU time. These resources are exclusively used by the data streams the reservation was made for. A protocol for the negotiation of the QOS values and the corresponding reservations is needed. Examples of resource reservation protocols are ST-2 or RSVP [11]. The reservation protocol is a vehicle to transmit the user demands to the several network nodes. In general, it works independently from the routing and the admission control algorithms. The admission control algorithm is responsible to check if sufficient resources are available to serve the desired new connection without violating agreed performance parameters for already established connections.
A common drawback of all resource reservation protocols is that there is no possibility to reserve the resources in advance. This paper introduces an approach to solve this problem by presenting the necessary changes in the admission control procedure and the resource reservation protocol. Chapter 2 gives a brief introduction to ST-2 as an example for a reservation protocol. Chapter 3 describes an extension of intermediate nodes to manage the advance resource reservation. The necessary extensions of the resource reservation protocol are explained on the basis of ST-2 in chapter 4. The paper closes with a discussion of the approach in chapter 5.
2ST-2: A Brief Overview
The experimental Internet stream protocol, version 2 (ST-2) as defined in RFC 1190 [8] is a revised version of the Internet stream protocol introduced in IEN-119 [4]. It provides especially realtime applications with guaranteed and predictable end-to-end level of performance across networks. Thus, multimedia applications are enabled to communi-cate on existing infrastructures and request QOS parameters according to their demands. Within the OSI reference model, ST-2 can be classified as a network layer protocol, and according to the ARPANET reference model as an Internet protocol. The main tasks performed are routing and signalling of data streams as well as the fast forwarding of data packets from the source host (called origin in the ST-2 terminology) to one or many remote hosts (called targets). Multicast communication is supported at the network layer by setting up a static routing tree from the origin to all targets, with the origin representing
the root of the tree and the targets representing the leaves. Each intermediate node is an ST-2 router, forwarding the data downstream on the routing tree to the targets.Data is transported over the tree as streams . RFC 1190 defines a stream as ?
the set of paths that data generated by an application entity traverses on its way to its peer application entities,?
the resources allocated to support that transmission of data and ?the state information that is maintained describing the transmission of data.The principle of ST-2 is to split connection management from data transfer. The stream set-up, maintenance and release are performed by the ST Control Message Protocol (SCMP). During connection establishment paths to all targets are installed. All interme-diate nodes allocate, if possible, resources for the requested stream characteristics and establish connections to the next hops on the way to the targets. During the data transfer phase the data follow the established paths. In the header of each data packet the next intermediate node is identified by a hop identification number negotiated at connection set-up time, but it includes no control information. This leads to an efficient forwarding of all data packets since no control packets disturb the information flow along the path.
2.1The Stream Protocol (ST)
The task of the stream protocol is to forward the data down the routing tree. ST provides a connection oriented but unreliable data transfer. Each ST header is 8 Bytes long,carrying 8 fields (Figure 1).HID ST=5Ver=2Pri T Bits
TotalBytes Header Checksum
Timestamp
01531Figure 1: ST Header
ST operates as an extension of the IP protocol. Therefore, the first field in the header contains a special IP version number to indicate an ST packet. The current version number of IP is 4, therefore the RFC 1190 proposes the version number 5 for the ST protocol. The second field contains the ST version number. The priority field (PRI ) is used to indicate packets that can be dropped by an intermediate node if a stream is exceeding its resource allocations. During connection set-up the ST agents negotiate whether or not the header contains a timestamp and its semantics. If the timestamp is included in the header, the T bit is set. The TotalBytes field contains the complete length of the ST packet including header, optional timestamp and user data. The HID field is the hop identifier. Each hop within the stream is identified by a unique identifier. The HID represents a stream and how the packet will be forwarded to the next hop. When the packet leaves the station, the HID will be updated with the HID that indicates the stream at the next node. All HIDs related
to a stream are negotiated during connection set-up. For the calculation of the HeaderChecksum field which covers only the ST header the standard Internet checksum algorithm is used.
2.2The ST Control Message Protocol
SCMP is responsible for the stream control. Within the telecommunication world's terminology SCMP would be called a signalling protocol. Its task is to create, maintain and release the routing trees used by ST. SCMP messages are encapsulated in ST packets and are distinguished from data packets by a HID that is zero. SCMP messages are sent from one ST agent to a single other in a reliable mode. Each message must be acknowledged immediately, otherwise the sender of the message re-transmits several times until a timer expires.
Connection set-up is handled as follows: The origin ST agent receives a list of targets from the application that are destinations of the stream. The desired QOS parameters of this stream are described in the flow specification (called Flow Spec). The ST Flow Spec structure contains, among other parameters, values for the average and minimum acceptable bandwidth, acceptable and maximum values for delay, delay jitter and error rate. After receiving a connect request the agent calls the routing function that returns a set of next-hop ST agents and the parameters of the intervening networks. Using these results the ST agent is able to decide whether the selected networks will support the requested Flow Spec parameters. After the routing decision the ST agent sends connect messages to all determined next-hop agents, containing a proposal for the HID, link references, the updated Flow Spec in accordance to the reservation at the node, and an updated target list (all target lists together will deliver the original list). This procedure is repeated until all targets are reached. The target agent requests an acknowledgement for the modified Flow Spec parameters from the application, and sends back an acknowledgement message to the origin.
3Advance Resource Reservation
Most of the work in the area of resource reservation at the network layer has been done on reservation at connection establishment time. If the resources are available at that time they are reserved in accordance to the user demands. The word 'if' describes an element of uncertainty, which means that the resources are only reserved when they are available and not used by other connections. In the worst case, the connection request must be rejected or the connection will be established only with extremely reduced QOS parameters. Today, this is a common situation if we consider e.g. wide area data links. Users are not always guaranteed a suitable connection upon their request. In this situation users have to try again later or they need a lot of patience since the offered performance of the network is not sufficient. However, if we consider new applications providing e.g. video conferencing with several participants this situation is not satisfying. A date for the meeting has to be arranged so that all participant are available at the scheduled time. What happens if they are not able to set up a conference due to the fact that not enough resources
are available from the network? If the users wait for better conditions on the network, a new date will have to be arranged with all problems of setting up a time schedule between several partners and the risk that it is not sure that the resources are available at the new date.
This paper proposes to integrate an advance resource booking mechanism into the reservation procedure. [7] states that it would be a helpful feature for the users if they were able to reserve the requested resources a certain time in advance. The initiator of a conference could set-up the data streams for the time the conference is scheduled. At that time the necessary resources are guaranteed from the network.
To realize this concept an adequate signalling protocol must be responsible for the negotiation of the requested resources between the source, intermediate nodes and all targets. Within the network nodes some more work has to be performed. Not only the resources used by currently active connections have to be managed but also requests for future reservations have to be examined. It has to be decided if the resources are available at the desired time and if so, the agreed performance values and the dates must be stored and managed. This work can be performed by a resource manager.
Figure 2: Scheme of the resource manager
Before a router reserves the resources, it has to check if sufficient resources are available to guarantee the desired QOS parameters. The router has to make sure that the guaranteed service parameters for existing connections are not violated. Therefore, an admission control algorithm is executed to determine whether already agreed parameters from existing connections and the requested performance values from the new connection can be guaranteed. Only in this case the new connection is accepted with the desired values.
If a new connection will violate the guarantees of other flows the desired QOS has to be reduced, or the connection request must be rejected.
The same procedure has to be performed if resources are allocated in advance. In this case the admission control algorithm must check if the new request can be accepted for the desired time without violating already confirmed reservations. Therefore, the function-ality of a router has to be extended by a resource manager responsible for monitoring the available resources, the resources in use and the already allocated resources for the future. To remember the future allocation states, a calendar is needed that stores already confirmed reservations and their related parameters. These parameters include the date when the connection will be in place, their duration, a pointer to the name descriptor of the stream and a pointer to its agreed Flow Spec (Figure 2). All confirmed reservations are sorted in relation to their starting time. This makes it easier for the admission control algorithm to verify the situation at the particular time the new connection wishes to reserve resources in advance. The resource manager has to consider the situation at the starting time of the planed connection. It has to make sure that none of the performance guarantees for already confirmed future active connections are violated. Furthermore, it has to verify the connection request against all reservations that are made in the time period the new connection will be active. To make this verification process more efficient, connections should only be allowed to pre-reserve at certain times.
For the determination of this certain times the following considerations can be made: The starting time of a conference and its duration is determined by the user. In general, dates are made in steps of five or up to fifteen minutes. A date at e.g. 11:00:00 h is much more likely than a date at e.g. 11:02:34 h. Since the resource manager has to control all starting times of reserved connections the overhead can be reduced significantly when only a small number of possible starting times are allowed. Consider for an example a time period of two days within which advance reservations are possible. The necessary number of comparisons can be calculated as a function of the interval size. Time intervals in steps of 1 second cause 172.800 time periods within 48 hours, whereas an interval size of 5 minutes lead to 576 time periods. A further increase of the interval size up to 15 minutes reduces the number of time periods down to 192 periods.
If we further consider the already mentioned user behaviour, an interval size of five or fifteen minutes should be acceptable for advance reservations. This leads to the consequence that the resource manager should only accept starting times for reservation which are in accordance to these time steps. With this smaller amount of possible starting points it is possible to store the complete traffic situation for all time intervals. Therefore, the admission control algorithm is able to consider the traffic situation over the time period in question, without recalculating the reservations at the beginning of all time intervals. The number of comparisons is further reduced because the tests are only necessary within the duration of the connection. The duration of a video conference will for example be two hours. If we assume possible starting points in steps of five minutes the admission control must be called twenty-four times. Since this effort will not disturb the data transfer through the intermediate agents we can assume that the additional processing overhead is acceptable.
For the signalling of the advance resource reservation a protocol is needed that transmits the user request to all involved network nodes. Existing reservation protocols can be used if they are extended by adequate features. To realise the advance booking the connection setup of the reservation protocol can be used, since all negotiations are identical to the negotiations during the immediate connection establishment. The resource allocation within the intermediate nodes is generally independent from the reservation protocol. The existing signalling protocols can easily be enhanced to provide the signalling for advance resource allocation. Two additional parameters have to be added to the respective FlowSpec of the reservation protocol:
?The starting time of the data flow across the connection and
?the duration of the connection from the starting event.
The starting time is only used for advance resource reservation, to indicate the date and time the new connection will start. The duration parameter is needed for all requested connections to evaluate if the required resources conflict with already reserved resources in the near future. The starting time can further be used to indicate the immediate connection setup. If the value is set to zero the path is established for immediate use. 4Signalling of Advance Resource Reservation with ST-2
Only a few changes have to be made to use the ST-2 protocol for resource reservation. First the duration and starting time parameters as described above need to be integrated in the Flow Spec. The routing path is established immediately through a connect message, and all parameters (e.g. the HIDs, Flow Spec values, etc.) and resource requests are negotiated as in the conventional ST-2 version. (Figure 3) The only difference is, that all reservations are stored within the resource manager of each ST agent if the starting time parameter is not zero. The reservations are not performed immediately, but the resources are reserved for the time the connection will be used by the applications.
Agent A Agent B
Intermediate ST-Agent I
When the connection is to be activated by the users, a FlowStart PDU is sent from the origin to all targets. This PDU-type has to be integrated into SCMP. The FlowStart message indicates all intermediate ST agents at which resources allocated in advance for this connection that they will be used within the agreed duration (Figure 4). If the FlowStart message is not be received from the involved agents at the agreed time, the pre-allocated resources are released within a specified time interval and are available for other connections.
Intermediate ST-Agent I
Agent A Agent B
Figure 4: Processing of a FlowStart message at intermediate nodes
The FlowStart message should be integrated into the SCMP protocol since all SCMP messages are transferred in a reliable mode. An ST-2 agent that receives a FlowStart message immediately generates an ACK message to the previous hop. If the previous hop does not receive an ACK within a fixed time period it has to re-send the FlowStart message. Just to set a flag in the first packet of the data flow, indicating its start is not suitable since the transmission of ST packets is unreliable. If the first packet is lost or corrupted the intermediate agents will not be informed that the reserved resources will be used and release the reservation.
OpCode Options Total Bytes
RVLId SVLId
Reference LnkReference
SenderIPAddress
Checksum
DetectorIPAddress
Name Parameter
UserData Parameter 0
01531 Figure 5: FlowStart PDU
Figure 5 depicts the structure of the FlowStart message. In addition to the mandatory SCMP parameters (OpCode, Options, TotalBytes, RVLId, SVLId, Reference, LinkReference, SenderIPAddress and Checksum) the DetectorIPAddress, Name and UserData Parameter are added. The DetectorIPAddress Parameter identifies the agent originating the message (in general the origin). It is copied from hop to hop and is primarily used for control purposes. The name data structure identifies the stream. It contains the origin's IP address, a unique stream identifier issued by the origin and a timestamp. The combination of the three parameters guarantees an globally unique identification of the stream. The origin is able to transmit messages from upper layer protocols with the UserData parameter. All additional parameters are also used in other SCMP PDUs and their structure is already defined in the RFC 1190. Each parameter contains a parameter ID, the length of the parameter data structure and some parameter specific values.
5Discussion
The advance resource reservation mechanism causes additional overhead for connection set-up and resource management at the ST agents. Data streams requiring this feature, are typically long term connections transmitting video and audio streams for multimedia conferences. These streams require high bandwidth and real time delivery of data packets. New network technologies provide this high bandwidth, but we have to take into account that a lot of data streams with identical characteristics are transmitted, over several links, thus reducing the available capacity for a single stream. If we further consider that generally more than two partners are participating in a video conference an agreement for the date of this conference has to be arranged. If the connection can not be set-up due to limited available network resources this situation leads to a new time schedule for the meeting. A mechanism that provides the possibility for the users to define their requirement in advance seems to be a useful service provided by the network.
The overhead of the newly introduced advance resource reservation is limited to the connection establishment procedure. Most of the management PDUs for connection maintenance have to be exchanged anyway. Only one additional PDU that indicates the start of the data flow has to be added. Within the intermediate agent a calendar function has to monitor all reservations. The advantage of this proposal is that the data transfer is not disturbed by these negotiation, since all negotiations will be finished at the time the applications start transmitting their data.
The amount of memory that is needed to store information about all confirmed resources is another issue. It should be clear that there will be more 'intelligence' within future routers. In normal network nodes only the determination of the routes to the next hop are performed, while in future systems the nodes will be aware of the characteristics of data flows. An overhead for the processing of advance reservation should not influence the decision, whether or not it will be supported. In the end users should pay for the additional service.
The advance reservation mechanism causes several problems that have to be solved. Within this paper these problems can only be mentioned. They are described briefly with an idea how a solution may look like.
?Time synchronisation: All clocks within the involved nodes have to be synchro-nized with a central time so that the reserved resources are available at all nodes at the same time. A possible solution is the use of the Network Time Protocol [6].
?Cancellation of the conference: How long must the resources be reserved without use after a scheduled time? A delay has to be agreed within which the reservation is still valid. Within this time period the resource may be used by other connec-tions, but with the proviso that the resources may be re-allocated when the delayed connection is activated. From my point of view users have to be charged for the effort this new feature causes. Therefore, the users have to pay a fee, if they don't use already reserved resources. The signalling of the cancellation could be performed with the disconnect message like a normal disconnect request in the original ST-2 version.
?Failure within an intermediate agent: In the time between advance resource allocation and the actual start of the data flow one or more intermediate agents may crash, thus corrupting advance booking within this node. This will interrupt the complete routing path. The intermediate agents should inform each other about their status as usual. ST-2 provides several protocol functions that allow the interchange of status information between intermediate nodes. The notify mes-sage e.g. is used if the routing function causes problems or if the resource allocation changes. The intermediate node that receives a notify messages decides whether to solve the problem locally, or to forward the message to the previous node or the origin.
?Exceed of reservation duration: The proposed mechanism requires the users to define the duration of the reservation. This is also a problem for traditional meetings that are not support by communication systems. Meeting room have to be reserved and a time schedule is agreed for the agenda. For the reservation of network resources it has to be investigated whether the connection is aborted immediately or the connection is further support with best effort QOS.
6Conclusion
Within this paper an algorithm for advance reservation of network resources was introduced. It has been considered which extension are necessary for the common reservation procedures, and how they can be integrated into existing environments. An enhancement of the reservation protocol ST-2 was presented that allows to support advance reservation. As a result of the final discussion it can be stated that such a mechanism is a desirable feature for multimedia conference applications, but there are still problems to be solved.
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办理入住酒店英语口语对话 【篇一】办理入住酒店英语口语对话 (A：Receptionist/the waitress B：Guest) A： Good afternoon. Welcome to Qingdao Sea-view Garden Hotel. Can I help you, sir? B：Well, I’m~~~ from `````. I’d like to check in, please. A： All right. Do you have a reservation with us, sir? B：Sorry, I didn’t book any room before. I would like to know which standard room do you have ? A： Wait a moment, please。 We have triple room, standard double room, and standard single room. What kind of room do you need? B ：what’s the price for standard double room? A：oh，sir。the price for standard double room is 288 Yuan。 B： What! Why is so expensive? A：yes，sir。Our hotel is an international 5-star chain hotel，and adopts international standard price。triple room is 476 yuan, is 288 yuan, and standard single room is 136 yuan. all the room has TV, AC (air conditioner), free internet access and breakfast. Oh, excuse me ，the dinning room locates at 6th floor, between 7am to 9am.
日常用语（句子）： 酒店常用英语 Restaurant 酒店里面的称为餐厅，酒店外的可以叫饭馆或者餐馆都可以 B&B 家庭式酒店 Boutique hotel 精品酒店 Resort 度假村 King-size 特大号床 Queen-size 大号床 Twin beds 双床房 Single bed 单床房 Double room 双人间 Single room 单人间 Suite 套房 Studio suite 公寓套房 Adjoining room 相邻房 Connecting room 连通房 Executive Floor 行政楼层 Bellboy 行李员 Concierge 礼宾 Receptionist 前台接待 Reception/Front desk 前台 Coach 旅游大巴 Reservation 预订（不是预定） Doorman 门房门童 Housekeeping staff 客房清洁人员 Room service 客房服务，有时特指客房送餐服务 Ground 花园 Tip 小费 Service charge 服务费 Turn down 开夜床服务（指的是傍晚的时候再次整理房间，使客人晚上睡的舒服） Executive room 商务房 Shuttle bus 班车 Do Not Disturb Sign /DND sign请勿打扰牌 Please Make Up sign /PMU sign 请收拾房间牌 check-out 退房 check-in 登记入住 lobby 大堂 Owner response: 业主回复 基本信息 23．May I have your name, please? 请问您贵姓？ 10．Which dates would you like to book? When will you check in and check out? 请问您需要订哪一天？什么时候入住及退房？ 59．What time do you expect to arrive, Sir? 请问大概什么时候到酒店，先生？ 46．What time will the guest be arriving? 客人大概什么到达酒店？ 11．How long will you stay in our hotel? 请问您打算逗留多长时间？ 36．Could you h old the line, please? I’ll check our room availabilities for those days. 麻烦请您稍等，我们查询那段时间的房态。 37．Just a minute, please I’ll check our booking situation. 麻烦请您稍等，我需要查询我们的房态。 73．Just a moment, please. I’ll check the availability for you. 麻烦请您稍等，我查询能否可以提供给您。 41．Could you hold on for a moment please? I’ll check our reservation record. 麻烦请您稍等，让我查询我们的预订纪录。 72．How many people are there in your party? 与您同行有多少人？ 50．I’ll arrive one day early. Is that OK? 我那天早点到，可以吗？
文件夹同步就是将两个文件夹内的文件内容进行分析，可选择性的让两个文件夹内容保存一直。文件夹同步软件相当有用，虽然大多数人没用过，但它确实能够为你节省很多时间和操作。比如说：同步U盘上的数据和软件设置，查找软件版本区别和更新，同步FTP上的数据。我认为，很多情况下使用同步软件可以极大提高计算机操作效率。 高效文件同步工具GoodSync 在多种驱动设备之间自动同步和备份，（个人电脑、移动设备、网络设备）支持任何文件类型，支持多任务、多语言。人性化的界面，可自由选择部分单向双向同步，有强大的过滤系统，有完整的日志记录及更改内容报表。 注意：GoodSync分析之后会在任务文件夹生成“_gsdata_”的隐藏文件夹，里面存放在任务日志和备份文件。GoodSync有免费版和专业版之分。免费版在30天内没有任何限制，仅仅是不能可用于商业用途和政府机构。过来三十天依然可以免费使用，但是仅支持3个任务（相比很多单任务的还是强大不少）和每次100文件夹的同步工作（一般情况下够）。下载 开源同步软件FreeFileSync 界面简洁，操作简单。虽然是单任务，但是可以保存和加载配置。最重要的是，作为一款开源如软件，它没有任何限制。下载
多文件夹同步器Allway Sync Allway Sync 是一个非常容易使用的 Windows 文件同步软件。同样支持在多种设备进行同步、多向同步（1个文件夹到N个）、自动同步。有极其强大的过滤规则、错误管理，可以压缩备份、加密备份。可导出导入xml格式配置文件和任务。免费版有文件大小和数量限制。当然，有着强大功能的同时，体积和资源占用也偏大。下载
酒店实用英语口语，如何用英语订房、办理入住？ 安格英语导读：外出旅游、商务出差都离不开“住”的问题。在国内还好，要是到了外国，你能够用英语流利地完成订房、入住整个过程吗？相信这对许多职场白领来说还是有些困难的，今天就和安格英语老师一起从酒店客房口语到各种酒店客房说法以及订房、办理入住需要用到的实用英语口语！ 在入住酒店的时候，我们首先需要与前台沟通订房适宜，以及办理入住等步骤。在这个步骤中我们首先要学会的是如何选择房型： What kind/type of room do you like/prefer? 请问你要订哪种房间？ We have single rooms, double rooms and suites and deluxe suites and Presidential suites. 我们旅馆里有单人间、双人间、套房、豪华套房及总统套房。 I want to reserve a single room with shower. 我想预订一间有淋浴的单人房间。 Could I book a double room with bath? 我可以预订一间有浴缸的双人客房吗？ I'd like to make a reservation for a suite with both shower and bath. 我想预订一个既带淋浴又带浴缸的套房。 I'd like a room with a view. 我想要一个风景较好的房间。
I'd prefer a quiet room. 我想要一个安静点的房间。 I'd like a room facing the sea/the mountains. 我喜欢朝向大海/群山的房间。 在预定房间的时候，前台工作人员还会询问你关于逗留时间、早餐、叫醒服务及一些基本的个人信息，以下的句子是安格英语老师认为你必须听得懂，最好还能说得出来的句子：工作人员： What name is the reservation under? 您预订时用的名字是？ May I see your passport, please?请出示你的护照。 How long will you be staying here?你在这儿停留多久？ Are you planning on checking out tomorrow? 您打算明天就离开吗？ I'm afraid you can't check in until after 4:00 pm. 恐怕您只能在下午四点以后才能入住。 Complimentary breakfast is served in the lobby between 8 and 10 am. 您可以在早晨8点到10点到大厅享受住宿附送的早餐。 I'll give you two room keys. 我会给您两套房间钥匙。 The dining room is on the main floor at the end of the hall. 餐厅在一层大厅最里面。 The weight room and sauna are on the top floor.
汇博通文档借阅管理系统使用说明书 汇博通知识管理系统的属性管理，实际上已提供了借阅与归还功能，但那是针对每一份文件 或档案而言的。 这里，为客户提供一款专门用于文档的借阅与归还的软件，不但可办理一份文件的借阅或归 还手续，只要有需要，也可批量办理借阅与归还，另外，还提供了与借阅有关的一系列统计 报表。 发放功能与借阅类似，所不同的只是发放不必归还，如将购买的资料、图书发放给职员学习 等。 注：借阅与归还模块的操作，需要获得以下三种权限中的一种： 系统管理员 归档授权（档案管理员） 编号授权（文件管理员） 与借阅与归还模块相关的系统参数的设置说明如下：
首页 汇博通主页的模块工具条上，有一个借阅与归还的按钮，单击它即进入借阅与归还首页。 借阅（发放） 前面已经介绍过，借阅与发放的区别在于，借阅需要归还，发放则不必归还，从某种意义上 来说，发放实际上已将所有权（或有条件的所有权）转移给接收者。 借阅界面包括左右两个子窗体，左侧子窗体用于显示可供借阅（发放）的文档，其上部有搜 索关键词输入框，输入相应关键词即可查找出可供借阅的相应文档，如果要借阅的文档已经 在操作者手上，并且，标注有条形码或电子标签，操作者可直接通过条码阅读器或电子标签
阅读器读取相应编码直接获取到该文档。 根据实际需要，通过点选左侧的复选框，选择具体文档，然后，通过点击两个子窗体中间的箭头，即可将选中的文档添加到右侧子窗体的列表中，即可直接办理借阅或发放手续。 可供借阅（发放）检索列表待选区。借阅（发放）选择勾选列表区。 可供借阅（发放） 输入文件名称、编号、责任者或主题词等属性，点击【检索】按钮进行查找，如下图： 勾选确定后点击该按钮，即可添加到已 选择列表区中。
酒店英语情景对话;唤醒服务 句型： 1．I'm going to Tianjln early tomorrow morning． 我明天一大早要去天津。 2．So I would like to request an early morning call． 因此我想让你们明天早上叫醒我。 3．At what time would you like us to call you tomorrow morning？ 您想让我们明天早上什么时候叫醒您？ 4．But I have to be at the conference room of the Garden Hotel in Tianjin by 10 o'clock．但我是10点钟必须赶到天津花园宾馆会议室。 5．That means that I'll have to be on the road by 7 o'clock at the latest． 就是说我明天早晨最迟也要7点钟上路。 6．In that case，I would like you to call me at 5∶45？ 那样的话，你们明早5点45分叫醒我好吗？ 7．OK．So we will wake you up at 5∶45 tomorrow morning． 好，那么我们明早5点45分叫醒您。 8．Will you do me a favour，Miss？ 小姐，能帮个忙吗？ 9．I wonder if your hotel has the morning call service． 不知道你们饭店是否有叫早服务。 10．Would you like a morning call？ 您要叫醒服务吗？ 11．I want to go to the Bund to enjoy the morning scenery there． 我想到外滩去欣赏那儿的景色。
如何使用群晖备份、同步文件？通过群晖管家安装好NAS之后，想要实现备份、同步还要随时随地查看所有的文件？只需要一个Drive，就能把你的需求统统搞定。让你轻松的掌握文件同步和备份。 Drive既是备份盘、同步盘、网盘，还可以是协作盘。集中管理所有文件，还能够同步不同电脑上的数据。团队脑风暴时，可以多人在同一个文档上实时协同编辑，还能够备份电脑上的文件并且提供多版本保护。 安装及设置drive套件 1、打开群晖DSM界面，在套件中心安装Drive套件。 2、安装Drive套件会一并安装Drive管理控制台——顾名思义，就是可以设置Drive 相关功能、管理所有备份和同步的设备、查看历史版本等。 3、建议你在Drive管理控制台启用深度搜索，就可以在Drive里面查找内文关键字还有照片各种原始信息，步骤如图。
设置备份盘 1、首先进入群晖官网的下载中心，根据NAS机型，选择下载“Drive Client”PC客户端，Windows、Mac、Ubuntu一应俱全，系统兼容妥妥的。 2、PC客户端安装完成后，根据需求修改Drive服务器（NAS端）和电脑（本地端）的不同文件夹。 3、设置完成后，进入Drive PC客户端的控制面板，将同步模式改成“单向上传”，点击应用，然后就开始备份啦。 同步盘如何实现 1、同步盘很简单，设置步骤跟上面的备份盘一样，在需要同步的电脑上安装Drive PC客户端，并且选择双向同步。 2、如果在办公场景，希望把他人分享给你的共享文件夹同步到电脑本地，在PC客户 端控制面板点击“创建>启用同步与我共享”，这么一来，别人与你分享的文件也会同步到本地。
雅思口语Part2答案：住过的酒店 参考答案： The hotel that I stayed in 2 years back while my visit to India is Westin. I had an official tour to Pune, India and my office arranged the stay in Westin. The reason I stayed in this particular hotel is mostly because my office arranged our stay there. But that was a really great experience. Since Westin is a renowned hotel chain and I have experienced their superb service in our country, I was excited to be in Westin in Pune as well. The hotel has been placed in a distinctive location in the beautiful Koregaon Park along the Mula Mutha River, and is just five kilometers from the airport. Westin is also in the vicinity is Magarpatta and Hadapsar, an information technology hotspot. Industrial parks lie within a 25-kilometer radius of this hotel. The staying rooms are subtly designed and give comfort to be there. The hotel includes club rooms, attractive and heavenly spa and workout gym, meeting room and exclusive restaurant. The rooms feature soft and comfortable bed and a eye-catching views overlooking green surroundings Mula Mutha River. The Westin is a renowned hotel chain that offers exclusive customer experience. The view, the stay, the foods and facilities makes the hotel a different experience. Tips for answering this cue card topic： You need to describe a hotel where you have stayed. If you pick a famous hotel, your description should be close to
XX集团—人力资源管理系统操作手册 目录 常用操作（新人必读） (2) 1.基础数据管理 ................................................................................................................... - 5 - 1.1组织架构 (5) 1.2职位体系 (8) 1.3职员维护 (11) 1.4结束初始化.................................................................................. 错误！未定义书签。 2.组织管理业务 ................................................................................................................. - 27 - 2.1组织规划 (27) 2.2人力规划 (33) 2.3组织报表 (38) 3.员工管理业务 ................................................................................................................. - 41 - 3.1员工状态管理 (41) 3.2合同管理 (41) 3.3后备人才管理 .............................................................................. 错误！未定义书签。 3.4人事事务 (52) 3.5人事报表 (59) 4.薪酬管理 ......................................................................................................................... - 69 - 4.1基础数据准备 (69) 4.2薪酬管理日常业务 (92) 4.3薪酬管理期末业务 (107) 4.4薪酬报表 (108)
English Drama of Hotel Management English英语话剧酒店管理英语 Service Counter （A：Receptionist/the waitress B：Guest） A: Good afternoon. Welcome to Qingdao Sea-view Garden Hotel. Can I help you, sir? B: Well, I’m~~~ from `````. I’d like to check in, please. A: All right. Do you have a reservation with us, sir? B: Sorry, I didn’t book any room before. I would like to know which standard room do you have ？ A: Wait a moment, please。 We have triple room, standard double room, and standard single room. What kind of room do you need? B ：what’s the price for standard double room？ A：oh，sir。the price for standard double room is 288 Yuan。 B: What! Why is so expensive？ A：yes，sir。Our hotel is an international 5-star chain hotel，and adopts international standard price。triple room is 476 yuan, is 288 yuan, and standard single room is 136 yuan. all the room has TV, AC (air conditioner), free internet access and breakfast. Oh, excuse me ，the dinning room locates at 6th floor, between 7am to 9am. B：OK， I know now。i’d like to check in a standard double room. A: All right. how many days are you planning to stay? B: oh, I want to stay here for 3 days. A: one moment, please. Sir，please show your ID ，just like driver's license, passport or ID card。 B：here you are。 A：wait a moment ，please。 Could you please fill in the registration card? B: Sure. Here it is. Is it all right? A: Yes, thanks. Your room number is 202. Here is your key. The room bellman will show you to your room. I hope you will enjoy your stay. the check-out time is 1pm of forth day later。 B: Thank you. A：you’re welcome。Good luck。
饭店服务员常用英语口语 1、What kind of rooms(foods)would you like to have?您需要什么样的房间（吃什么样的菜）？ 2、Here is a brochure of our hotel and tariff. 这是介绍我们饭店的小册子和价目表。 3、We'll give you a10%(ten percent)discount. 我们给您九折优惠。 4、We'll offer tour guides complimentary breakfasts.我们给陪同提供免费早餐。 5、We accept your terms. 我们接受您的条件。 6、May I introduce myself? 让我介绍我自己。 7、May I present you a litter souvenir? 请接受我们的一点小纪念品。 8、Let's drink to our friendship! 为我们的友谊干杯！ 9、Let me propose a toast to the health of our guests!建议为在座客人的健康干杯！ 10、Cheers!(Bottoms!) 干杯！ 11、How do you like Chinese food? 您喜欢中国菜吗？ 12、What do you think of our service? 您对我们的服务有什么意见？ 13、 Thank you for your comments(compliment,suggestion s). 谢谢您给我们提的意见（赞扬、建议） 14、I'm afraid it's against the hotel's regulations. 这是违反饭店规章制度的。 15、In our hotel we don't accept tips. 我们饭店是不收小费的。 16、It's our pleasure to serve our guests well.
前言 本《操作手册》内容是按该软件主界面上第一横排从左至右的顺序对各个功能加以介绍的，建议初学者先对第一章系统设置作初步了解，从第二章基础资料读起，回头再读第一章。该管理软件的重点与难点是第二章，望读者详读。 第一章系统设置 打开此管理软件，在主界面上的左上方第一栏就是【系统设置】，如下图所示： 点击【系统设置】，在系统设置下方会显示【系统设置】的内容，包括操作员管理、数据初始化、修改我的登录密码、切换用户、选项设置、单据报表设置、导入数据、数据库备份、数据库恢复、压缩和修复数据库、退出程序。下面分别将这些功能作简要介绍： 1.1操作员管理 新建、删除使用本软件的操作员，授权他们可以使用哪些功能。此功能只有系统管理员可以使用。 1.1.1 进入界面 单击【系统设置】，选择其中的【操作员管理】，画面如下：
1.1.2、增加操作员 单击【新建】按钮，画面如下： 输入用户名称、初始密码、选择用户权限，可对用户进行适当描述，按【保存】后就点【退出】，就完成了新操作员的添加，效果如下图。
1.1.3 删除操作员 选择要删除的操作员，单击【删除】按钮。 1.1.4 修改操作员 选择要修改的操作员，单击【修改】按钮，可对操作员作相应修改，修改后需保存。 1.1.5 用户操作权限 选择要修改的操作员，单击【修改】按钮，出现以下画面，点击【用户权限】栏下的编辑框，出现对号后点【保存】，该操作员就有了此权限。 1.2数据初始化 1.2.1进入界面 单击【系统设置】，选择其中的【数据初始化】，画面如下：
1.2.2数据清除 选择要清除的数据，即数据前出现对号，按【确定】后点【退出】，就可清除相应数据。 1.3 修改我的登录密码 1.3.1进入界面 单击【系统设置】，选择其中的【修改我的登录密码】，画面如下： 1.3.2密码修改 输入原密码、现密码，然后对新密码进行验证，按【确定】后关闭此窗口，就可完成密码修改。 1.4 切换用户 1.4.1进入界面 单击【系统设置】，选择其中的【切换用户】，画面如下：
酒店常用英语对话 1、Good morning/afternoon/evening, sir/madam. 早上/下午/晚上好，先生/女士。 2、Good night. 晚安。 3、Have a good time! 祝您过得愉快！ 4、Wish you a most pleasant stay in our hotel. 愿您在我们酒店过得愉快！ 5、I’m sorry. 对不起，很抱歉。 6、Excuse me. 打扰一下，对不起。 7、Sorry to have kept you waiting. 对不起，让您久等了。 8、Just a moment, please. 请稍等一下。 9、I apologize for this. 我为此道歉。 10、Can I help you. 我能帮您吗？ 11、It’s very kind of you. 您真客气。 12、Thank you. 谢谢您。 13、You are welcome. 不用谢。 14、I am at your service. 乐意为您效劳。 15、Turn left/right. 往左/右转。 16、 This way, please. 请这边走。 17、 It’s on the second floor. 在二楼。 18、 Happy birthday! 生日快乐！ Happy New Year! 新年快乐！ Merry Christmas! 圣诞快乐！ 19、 May I come in? 我可以进来吗？
20、 May I know your room number and name? 我能知道您的房间号码和姓名吗？ 总台 基本句型 一、预订服务 Good morning. This is Room reservation. May I help you? 早上好，客房预订处，我能为您做什么？ What kind of room would you like to reserve ? 您想订哪种类型的房间? A single room or a double room ? 要单人间还是双人房间？ For which dates do you want to book the rooms ? 您想订哪几天的房间呢？ What time will you be arriving? 您将在何时到达？ May I know your name ? 您能告诉我您的名字吗？ How long will you be staying? 您将要住多久？ I’d like to confirm your reservation. 我要确认一下您的预订。 I’ll check the room availability. 我查查客房预订情况。
多文件夹的自动同步和各向同步工具 出处：小建の软件园作者：佚名日期：2008-06-25 关键字：同步 对于经常需要备份文件，同步文件的网友，Allway Sync 可谓不可多得，虽然不能激活其专业版，对文件数量多和经常性的同步操作可能会超过免费版的限制，不过对于一般文件数量不多同步操作可以完全满足，Allway Sync 使用相当简单，多种同步方式能满足你不同需求。对重要文件进行备份是文件恢复最好的方法，而 Allway Sync 可以简化你许多备份的过程，能实现自动备份，如果你“胃口”不大，免费版应当已经可以满足。 下载地址：https://www.doczj.com/doc/b511372757.html,/soft/23495.html Allway Sync 可以进行自动同步，可以对的文件/文件夹进行筛选，只备份需要的东东。
Allway Sync 备份方式介绍 - 同步方式有源文件夹同步和各向同步两种方式： 1、源文件夹同步方式将以一个文件夹为基准，删除或覆盖其余文件夹与源文件相比较不相同的文件。 2、各向同步方式则自动将更新的文件覆盖几个同步文件夹中的旧文件。软件带有一个小型数据库，监视每次更新后的文件状态。如果在一次同步之后，你删除了同步文件夹中某些文件，它在同步的时候将其它的几个文件夹的副本也删除，而不会将不需要的未删除文件重复拷贝到已更新的文件夹。由于软件自己会对文件进行删除和覆盖，它提供了使用回收站进行文件备份的措施，使用者可以在不慎执行错误的同步动作之后，从回收站将错误删除或覆盖的文件找回来（默认禁用该功能，请到软件选项处激活相应设置）。 主程序在 AllwaySync＼Bin＼里面，此为多国语言版，在语音选项那里选择中文即可。不过退出的时候会有错误提示（貌似没影响？）
酒店英语情景对话 1.Have you used any hotel services this morning or had breakfast at the hotel dining room，Mr.Green?格林先生，今天早晨您是否用过旅馆服务设施，或在旅馆餐厅用过早餐? 2.Yes，my friend and I just had breakfast at the dining room，but we didn't use any services.是的，我的朋友与我在餐厅刚用过早餐，但是我们没有使用过任何服务设施。 3.The total for the eight days is five hundred sixty yuan and eighty fen.8天来总计是560元8角。 4.I think I'll take the one with a front view then.我想我还是要阳面的吧。 5.How long will you be staying?您打算住多久? 6.We'll be leaving Sunday morning.我们将在星期天上午离开。 7.And we look forward to seeing you next Tuesday.我们盼望下周二见到您。
8.I'd like to book a single room with bath from the after-noon of October 4 to the morning of October 10.我想订一个带洗澡间的单人房间，10月4日下午 到10月10日上午用。 9.We do have a single room available for those dates.我们确实有一个单间，在这段时间可以用。 10. What is the rate， please?请问房费多少? 11.The current rate is$ 50 per night.现行房费是50美元一天。 12. What services e with that?这个价格包括哪些服务项目呢? 13.That sounds not bad at all. I'll take it.听起来还不 错。这个房间我要了。
备份软件使用方法 一Bestsync2012使用说明 1 软件运行 点击BestSync2012运行软件 2 设置任务 在编辑菜单下点击追加任务（如果任务列表下没有任务可以在文件菜单下选择新建任务选项） 软件会弹出任务窗口，用来设置同步任务
以其中一个任务为例
选择好同步的文件夹和同步方向，点击下一步，按照要求设置任务即可。 3 查看任务 在以有任务中点击设置任务（任务必须是未在同步状态，否者不能点击设置任务选项）
点击后软件会弹出设置同步任务窗口，在这里可以在里面进行任务修改和设置
目前我们设置的同步任务只需要修改一般和日程两个窗口下的内容，其他暂时不需要修改。 BestSync2012这款同步软件目前还不是很稳定，需要不定期检查一下软件是否运行正常，如果发现软件出错，就关闭软件后在打开BestSync2012软件，因为打开软件后软件不会自动启动同步功能，所有需要手动启动所有任务 注意： 1 在修改任务在开启后，必须将修改的任务停止一下在开启，不然同步任务不能正常同步。 2 现有BestSync2012同步软件在16.15和151.247这两台机器上。
二Backup Exec 2010 R2 SP1使用说明 1 软件运行 点击Backup Exec 2010运行软件 2 设置任务 在作业设置选项中可以看到作业的作业名称、策略名称和备份选这项列表。 其中作业名称里放有现有作业，双击其中一个作业就可以看到作业属性。作业属性默认显示设备和介质窗口，在设备和介质窗口下可以选择设备和介质集。目前设备选项中因为只有一台磁带机工作，所有只有一个选项，而介质集一般选择永久保留数据-不允许覆盖选项。
酒店餐饮常用英语口语 酒店英语情景对话：安排就坐 Seating Guests 安排就坐 Waiter (W): Good evening, madam and sir, welcome to our restaurant.晚上好，先生女士，欢迎光临。 Have you a reservation, sir? 请问有预订吗？ Guest(G):I’m afraid I haven’t. Have you a table for two?没有，有没有两个人的桌。 W: I’m sorry to say that we haven’t got any vacant seat at present. Would you please wait in the lounge for about five minutes? I’ll seat you if the table is ready. 很抱歉，现在没有座位了。请你在休息室等5分钟，可以吗？如果桌子准备好了，我会通知你。 G:It sounds nice.Nancy,let’s go to the lounge then.(Five minutes later.) 听起来不错NANCY。我们去休息室吧。（5分钟后） W:I am sorry to have kept you waiting,madam and sir.Now we have a table for you.Would you step this way,please? 抱歉让您久等了，先生女士们，现在有一张桌子给你们了。 G：(Mr.Smith suddenly catches sight of a table near the window.)May we sit there a table by the window? （突然间有一张靠窗的桌子进入了SMITH先生的视线）我们可以坐那张靠窗的桌子吗？ W:Oh,that table has been reserved.那後桌子已经被订了。 G:It’s a pit y.太可惜了。 W:Well,the table in the corner is quite good.It’s near the band platform.There will be a performance during the meal time.You could enjoy it comfortably. 那张角落的桌子真的很好，靠近条形讲台的那张。用餐期间会有表演看的，你会觉得很
目录 1 软件介绍...................................................... １ 2 软件运行环境 ................................................. １ 3 软件安装步骤 ................................................. １ 4 软件卸载步骤 ................................................. ４ 5 软件使用...................................................... ４5.1、创建数据库.............................................................................................................................. ４ 5.2、创建数据数据表................................................................................................................... ６ 5.3、历史数据读取 ........................................................................................................................ ７ 5.4、查看历史数据、通道信息.............................................................................................. ８ 5.5、打印数据、曲线或图片输出 .................................................................................... １３ 5.6、数据实时采集 .................................................................................................................... １５ 6 软件使用中可能出现的问题与解决方法.................. １８6.1、不出现对话框 .................................................................................................................... １８ 6.2、数据库不能建立............................................................................................................... １８ 6.3、U盘不能数据转存........................................................................................................... １８ 6.4、U盘上没有文件 ................................................................................................................ １８ 6.5、U盘数据不能导入计算机；...................................................................................... １８