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  1. 1. Cisco Education CDN Caching and Content Delivery Networking – Delivering Content to the Learner. Delivering exciting, interactive and media rich content and communication is the primary objective of the National Grid for Learning. Cisco’s Content Delivery Networking (CDN) technology allows RBCs and LEAs to deliver tightly integrated network services that will seamlessly delivery curriculum online and interactive services such as IP Video Conferencing, IP Telephony and collaboration tools Cisco CDN Solution Cisco’s CDN solution provides high performance, scalable and reliable content caching and distribution. It can create and deliver media rich curriculum content and be used to distribute software, documents, virus updates, executive announcements and INSET. Crucially a Cisco CDN can integrate with your Portal, Managed Learning Environment (MLE) or Virtual Learning Environment (VLE). The Cisco solution offers far superior performance, scalability, reliability and ease of use and management than basic caching only solutions. Solution Component Description Content Engines (CE) A range of Cisco appliances that provide transparent caching and when used in conjunction with a CDM provide centrally managed content distribution • NM-CE – Content Engine network module that may be installed inside Cisco 2600, 3600 and 3700 routers it is suitable for school use • CE-510 – Content Engine suitable for school use • CE-565 – Content Engine suitable for use at a small/medium LEA data centre • CE-7305 – Content Engine suitable for use at a medium/large LEA data centre • CE-7325 – Content Engine suitable for use within the core of an RBC network Content Engines may also be placed in front of web servers to provide server acceleration Content Distribution Manager A Cisco appliance that manages a whole network of 1000’s of Content Engines via an easy to use Web (CDM) interface or API to your portal/VLE/MLE. The CDM enables system administrators to manage the infrastructure and enables individual content providers, schools, LEAs and RBCs to manage the distribution of content Content Router (CR) An optional Cisco appliance that provides enhanced intelligence to the CDN that is particularly valuable in large scale deployments Content Switch A standalone switch or module for the Cisco Catalyst 6500 switch that is used in data centres to provide load balancing and resiliency for multiple servers IP/TV Server An optional Cisco appliance with video encoding capability that delivers TV or DVD quality live video streaming with audience interaction (question manager) from virtually any video source. IP/TV enables large scale events such as training, remote teaching and conferences © 2003 Cisco Systems, Inc. All right reserved. Important notices, privacy statements, and trademarks of Cisco Systems, Inc. can be found on Page 1 of 12
  2. 2. Transparent Caching Cisco Content Engines provide automatic caching of Web and streamed video content. Unlike proxy caches Cisco’s Content Engines are transparent to the user, requiring no browser re-configuration. Transparency is provided using the Cisco developed WCCPv2 protocol supported on Cisco routers and Catalyst Layer 3 switches. The Cisco router automatically and transparently redirects traffic to the Content Engine. This reduces the management overhead of installing the solution and provides superior performance and availability compared to proxy caches: • The router will load share over multiple Content Engines providing cost effective scalability • In the event of failure or planned Content Engine outage the router will transparently by-pass the Content Engine • If a Content Engine becomes temporarily overloaded the router will reduce the offered load ensuring consistent performance, compared to a proxy cache that would degrade performance for ALL users and cause break-up of streaming video Note: A Cisco CDN can be installed on a non-Cisco infrastructure. WCCPv2 transparent redirect will not be possible in this case. Therefore either Layer 4 transparent switch redirect can be used or the Content Engines can be configured in proxy cache mode. Cache Pre-Load A list of URLs can be used to instruct individual Content Engines to pre-load web, FTP and streaming content. The URL list specifies the content to acquire, time of day / day of week to fetch the content and the maximum volume (MB/GB) of content to be fetch from a particular site. Bandwidth controls prevent pre-load traffic from overloading the network. This ensures content is fetched out of hours rather than consuming bandwidth when others are using the network and means the first user of the content does not experience poor response performance. Cache pre-load is a per Content Engine managed process suited to smaller deployments. For larger deployments we strongly recommend the fully managed content distributed solution (see below) Content Distribution Caching alone is not sufficient to support the diverse requirement of education users. Cisco’s content distribution solution addresses the following shortcomings. Caching Issues • Personalised learning offers one of the great potential benefits of on-line curriculum. Rather than present all users with exactly the same set of content, personalised learning links the assessment and curriculum. A personalised learning environment will create a customised, dynamic route through the curriculum based on the individual learner’s current assessment and their learning style. This will significantly reduce the “hit rate” of caching and makes cache pre-load redundant since there is no specific set of web pages to fetch • Caching performance is optimised for delivering the many small objects associated with Internet Web pages, while on-line curriculum will have a structured content with very large objects such as streamed video, applets, animations, etc. • The caching philosophy of “slow for the first user, fast for others” forces teachers to adapt to and be frustrated by the technology • Content may be “too broad” to get into the cache, for example the very high quality videos used by Espresso and Pearson Broadband would be unlikely to play successfully for the first user over a 2Mbps connection with other traffic flowing • The “first view” traffic will normally pass over the network during the day slowing other users © 2003 Cisco Systems, Inc. All right reserved. Important notices, privacy statements, and trademarks of Cisco Systems, Inc. can be found on Page 2 of 12
  3. 3. • Inefficient use of network and server resources with each cache fetching content from the origin • No integration with other network services such as QoS and multicast and potential interference with other applications • Caches are managed as single devices, creating a huge management overhead in a large LEA or RBC deployment and making it impossible to apply quick pro-active changes Management The whole Cisco CDN is managed centrally via the Content Distribution Manager (CDM), this is important because an RBC could be managing thousands of Content Engines and hundreds of content provides while an LEA could be managing hundreds of Content Engines. There are two types of CDM manager, although there may be many individual manager accounts. • Systems administrators manage the CDN system as a whole configuring the individual components, such as all the Content Engines in the network, content replication controls, content administrator accounts, etc. • Content administrators manage the content in one of more content channels (see below), they are focussed on the content and do not need to understand the administration of the CDN as a whole, or the network infrastructure User account information can either be held within the CDM as a self-contained system or interface to your own user directory. Content Distribution Management Content is segmented into channels, which are analogous to TV channels. Channels can be defined each with their own unique content administrator or one user can administer multiple channels. The content administrators are responsible for defining what content is in their channel, they may be commercial content providers, or users within an RBC, LEA or school. Channels may be defined however is most suitable, for example BBC Key Stage 3 Maths could be a channel, individual schools could have their own channels into which they place content relevant to them. At its most basic level content can be individual files (e.g. software, videos, virus scan updates, etc). Where a suite of content is to be distributed, such as a particular curriculum package an XML standards based manifest list defines what content to place in the channel. It includes: • Host name (web or FTP server) to fetch the content from, together with any username/password information required • Optional specific file name(s) • Optional crawler level to follow HTML links down a specified number of levels or down an FTP directory structure • Optional filters to only fetch certain types of content, for example particular file types or sizes. This can be used to control storage requirements by only fetching larger “chunks” of content that will have a significant impact on user performance by being distributed • Optional content access controls that define the date/time when content can be accessed and date/time when it can no longer be accessed. This has a number of uses, for example a content provider can grant temporary access for a free trial, or an important announcement can be distributed ahead of time but only made viewable when public • Optional origin server authentication can be used to force individual users to authenticate with the origin server before they can view the content. Authentication can be used by content providers for tracking and rights management, since they can still © 2003 Cisco Systems, Inc. All right reserved. Important notices, privacy statements, and trademarks of Cisco Systems, Inc. can be found on Page 3 of 12
  4. 4. centrally control who accesses their content. For example to enforce licences that are based on maximum simultaneous users or to grant temporary access for a trial Content Replication Curriculum content together with the other applications for a CDN means there will be many Gigabytes of data to distribute to hundreds or thousands of sites. Therefore it is vital the replication of the content from the source to all the Content Engines is as efficient as possible to minimise its impact on both the network and the origin servers. A Cisco CDN uses a number of features to achieve this: Replication Controls The CDM controls when content is replicated by time-of-day / day-of-week and the amount of bandwidth used. For example overnight all available bandwidth is used. Weekday evening 50% is used since there are evening classes and daytime is limited to 5% to trickle feed important updates with minimal impact to users. System wide changes can be made with the click of a mouse on the CDM, so if there is an urgent requirement to push out content the normal bandwidth restrictions can be changed. For example if there were a major virus infection software patches and virus scan updates could be rapidly pushed out, or if the director of education wanted to make an important announcement their video could be pushed immediately. Replication Priority Replication of content can be prioritised by a combination of prioritising individual channels or even specific content within a channel. Therefore important content (e.g. a software patch) would be delivered first. Content Fetch Rather than having every cache fetch the same content from the origin server the Cisco solution only fetches the same content once. This can have a huge saving on bandwidth and server load for the content provider in large education networks where hundreds or thousands of caches could be fetching content simultaneously. With a Cisco CDN one Content Engine is designated the “Route CE”, it is responsible for fetching the content from the origin servers. “Route CEs” can be unique per channel, for example if a school is producing content that others wish to use that school’s Content Engine can be designated as the “Route CE” for that school’s channel. Channel Subscription Each Content Engine can be uniquely subscribed to any mix of channels. Content in a channel is only replicated to Content Engines that are subscribed to it, saving bandwidth and storage. Channel subscription is managed from the CDM, either per Content Engine or using groups of Content Engines. Multicast Replication This is the most efficient way of distributing the content, the “Route CE” sends out a single multicast stream per channel with all Content Engines subscribed to that channel receiving the same single stream. Therefore the content is only sent once over any part of the network no matter how many Content Engines. Hierarchical Replication Where multicast replication is not used, for example the network is not yet multicast enabled, hierarchical replication distributes the content down a tree from the “Route CE”. For example the “Route CE” in the RBC core would replicate to each LEA Content Engine, these in turn © 2003 Cisco Systems, Inc. All right reserved. Important notices, privacy statements, and trademarks of Cisco Systems, Inc. can be found on Page 4 of 12
  5. 5. replicate to the Content Engines in schools. Cisco’s patented SODA (Self Organising Distribution Architecture) technology ensures the most efficient replication based on available bandwidth and Content Engine responsiveness. Streaming Video Streaming video is an increasingly important and powerful medium. Many content providers are creating media rich curriculum. It can also enable other applications such as live conferences and specialist distance teaching. Video content can be delivered as basic video files that are downloaded and played on a PC. However streaming video offers a number of significant advantages • Enable large scale live events • Better interactivity, streamed video can be treated like a CD or DVD, it is can be fast forwarded, rewound and the user can jump directly to any point in the video without having to wait for the whole video to download • Can be synchronised with other content, for example click on a particular piece of content and the accompanying video will jump to the matching point • Digital rights management and tracking enables the content provides to control who has access to their content and gather statistics on how it is used • Integrates with network Quality of Service for reliable delivery Cisco supports all the major streaming media formats: Streaming System Description Cisco Streaming Engine Supports caching and content distribution of any standards based streaming video that uses the Real Time Streaming Protocol (RTSP – RFC2326) Real Proxy Supports caching of Real encoded content Real Subscriber/Server Supports full content distribution of Real encoded content (Content Engines effectively become Real Video Servers) Microsoft Windows Media Supports caching and content distribution of WMT encoded content Technologies (WMT) Apple QuickTime Supports caching and distribution of QuicktTime encoded content – supported when Real proxy or server is enabled The Cisco Streaming Engine is standard on all Cisco Content Engines. Support for Real, WMT and QuickTime require an optional licence key to activate the built in software – no software update is required to enable. Certified and Supported Cisco’s streaming implementations are fully certified and supported by Real (therefore QuickTime) and Microsoft, rather than reverse engineered implementations. Digital Rights Management (DRM) The Cisco solution is fully integrated with Real’s, Microsoft’s and Apple’s DRM solutions. Viewing of streamed video that has been cached or distributed is controlled and tracked by the origin video server. True Video Distribution © 2003 Cisco Systems, Inc. All right reserved. Important notices, privacy statements, and trademarks of Cisco Systems, Inc. can be found on Page 5 of 12
  6. 6. The Cisco solution distributes the native streaming files for playback by the server element of the appropriate streaming system. Some caching solutions emulate this by pre-fetching the video, this simulates a user viewing a video causing it to be cached. This is far less reliable and efficient that true distribution. Stream Splitting Many web sites offer live video streaming (e.g. BBC, ITN, CNN, etc), the same technology can be used privately to enable live events such as conferences. However viewing such content creates a unique stream per viewer. This can rapidly overload a broadband connection, for example only 6 people could watch a typical 300Kbps broadband stream within a school on a 2Mbps line and even this would starve other users of bandwidth. It also puts major stress on the rest of the network and the origin server limiting the scale of live events. Stream splitting in Cisco Content Engines ensure only one stream is required from the origin video server and only one stream transverses the network. The Content Engine delivers multiple streams to its local users. This can either be separate individual streams or if the local network is multicast enabled it can be a single multicast stream. In a hierarchy of Content Engines (e.g. RBC, LEAs and schools) stream splitting occurs at each level. This also provides many of the scalability benefits of multicast to networks that are not multicast enabled, for example public IP VPN services. Cisco API – Portal, VLE & MLE Integration Cisco’s open standards based (HTTPS and XML) Application Program Interface (API) enables the CDN to be controlled and monitored directly from a Web Portal, Virtual Learning Environment (VLE) or Managed Learning Environment (MLE). This enables a highly integrated solution to be built. For example a teacher could construct a lesson plan using the MLE. The MLE would then automatically instruct the CDN to distribute the content in the lesson plan ready for use before the lesson. Security The Cisco CDN solution is designed to be highly secure itself and to provide advanced security services. Cisco’s appliance approach makes the solution highly resistant to attack. Separate accounts for overall system administration and content distribution management limit risk of accidental or intentional service disruption. Optional user authentication can be used to both authenticate users before they can access any content within the CDN system and force origin server authentication to allow content providers to authenticate and track users of their content. Content Filtering Many RBCs and LEAs use differential filtering policies, for example staff have a different content filtering policy than pupils. Where differential filtering is used it is vital that the Content Engine participates in the system. Otherwise content could be cached due to a member of staff viewing material that is permitted within their filtering policy and subsequently delivered from the cache to a pupil who should be denied access. The Cisco solutions support three major content filtering solutions: Secure Computing’s SMARTfilter ( is an “on box” solution requiring no additional hardware or software. Activated by licence key the Content Engines fetch regular filter list updates from Secure Computing © 2003 Cisco Systems, Inc. All right reserved. Important notices, privacy statements, and trademarks of Cisco Systems, Inc. can be found on Page 6 of 12
  7. 7. The Cisco Content Engines query a central WebSense ( server that maintains the filter lists and checks users and policy information. Effectively the Content Engine is doing a remote database query in a client-server module The Cisco Content Engines query a central N2H2 server using N2H2’s Internet Filtering Protocol (IFP) - Support for other filtering solutions Cisco plans to support the ICAP standard in the next major software release. This should enable integration with any content filtering solution that also supports the ICAP standard. Filtering Streaming Content Content Filtering products generally do not filter streaming video. Specific undesirable streaming content can be added to a block list on the CDN system. Performance Cisco’s approach is to provide the maximum possible consistent performance to the user. From the user’s perspective they should all see rapid response times, fast data transfers and experience consistency – variation in performance can be as frustrating as poor performance. The user’s experience will be based on the performance of the solution as a whole. Therefore Cisco takes a system wide approach to performance that encompasses not just high performance optimised components but also integration with the rest of the network. Qualify of Service (QoS) QoS enables the network to identify, classify and prioritise the different application streams that transverse it. UKERNA have proposed a UK education QoS policy through the work of the QoS Think tank ( and coordinated with Europe wide education QoS initiatives. In essence this defines four classes of service: • Premium IP – For highly interactive applications such as IP videoconferencing, IP Telephony and VoIP that require low latency and jitter • IP+ - For applications such as video streaming that require consistent bandwidth delivery but are not as sensitive as interactive applications to latency and jitter • Best Effort – Standard Internet like service suitable for applications such as web browsing (although critical web applications could be prioritised to the IP+ service) • Less than Best Effort – For applications such as content distribution where short-term variation in speed of delivery is not critical. This class of service leaves more bandwidth for Best Effort traffic giving users a more responsive experience QoS can be used to prioritise interactive traffic that impacts the performance of the CDN solution, notably: • Interaction between the end user and the central VLE or MLE. This is typically small volume control traffic but must be delivered with minimum delay © 2003 Cisco Systems, Inc. All right reserved. Important notices, privacy statements, and trademarks of Cisco Systems, Inc. can be found on Page 7 of 12
  8. 8. • Interaction between the Content Engine and content filtering server. This is effectively database queries that the Content Engine must receive quick responses to so it does not delay delivery of content. The Cisco CDN solution itself supports QoS in both distribution and delivery of content: • Content that is being replicated can be tagged (at IP packet level) for forwarding by the network as Less than Best Effort • Content delivered to the user by a Content Engine can be tagged (at IP packet level) appropriately based on rules configured by the system administrator. For example streamed video would be tagged for forwarding as IP+ service. This can extend down to URL level so content from critical web sites/applications can be given priority Content Engine Performance Cisco Content Engines are appliances that are purpose designed for maximum performance delivery of a wide range of content types, by optimising them for high speed I/O. A major challenge in delivering high performance is meeting the differing requirements of different content types. Rather than compromising performance for one type of content over another the Content Engines have four different file systems each optimised for different types of content: • Operating file system contains the operating system software, configuration files and system logs. This ensures the operating system software performs at optimum rate • Caching file system is optimised for delivering web content that is characterized by many small files (e.g. a web page may be made of many small objects such as text, .gif files, etc) • Pre-positioned content file system is optimised for delivering the larger files that are characteristic of pre-positioned content (e.g. Java applications, Shockwave, software, etc). Since pre-positioned content can also consist of standard web content the Content Engine monitors pre-positioned content and automatically moves small objects (e.g. .gif files) to the caching file system which is optimise for their delivery • Streaming content file system is optimised for delivery of large streaming video files Because disk performance has such a major impact on overall system performance the Cisco solution is designed for scalable performance as well as scalable capacity storage. In addition to the high performance internal disk store Cisco Content Engines can utilise external storage. For example SCSI and Fibre Channel disk arrays and in future network attached storage via iSCSI support. This not only gives much great storage scalability compared to internal storage only solutions but also provides far more effective performance scalability compared to folk lift upgrade to larger higher performance cache boxes. Adding external disk arrays in future can increase performance very significantly and is a simple field upgrade. Transparent caching provides further performance benefits: • Performance remains consistent since a temporarily overloaded Content Engine will be presented with less load, preventing major performance degradation to all users that would be seen otherwise • Performance can be increased by adding an additional Content Engine and take advantage of transparent load sharing, rather than a folk lift replacement of the existing cache. This also increases availability These features make a Cisco Content Engine far superior for delivering media rich on-line curriculum compared to a basic cache that is designed for accelerating Internet web pages only. © 2003 Cisco Systems, Inc. All right reserved. Important notices, privacy statements, and trademarks of Cisco Systems, Inc. can be found on Page 8 of 12
  9. 9. Network Efficiency The content replication bandwidth controls and efficiency of multicast or hierarchical replication ensure the replication of content has minimum impact on the performance of the overall network. Scalability The whole Cisco CDN solution has been designed from the outset to be deployed as a large-scale solution, rather than an individual cache box: • Up to 2,000 Content Engines can be managed centrally from one CDM. This is expected to increase further in future allowing even the largest RBC to manage a complete system • Content from hundreds of different content providers can be managed and distribution separately and again future software developments will scale this even further • Storage capacity can grow via both internal and external storage options. Cisco is currently testing and certifying additional internal and external storage options • A complete range of Content Engines allows a hierarchy to be build all the way from the RBC core to the individual school as a single system • Transparent Content Engine load share provides easy performance scalability that protects investment Availability Cisco’s appliance approach ensures very high availability of the individual components. Cisco fully regression tests the complete system including any imbedded software such as streaming video and content filtering. System availability is increased due to transparent caching and load sharing. If a loan Content Engine fails it will be transparently by-passed, users will experience a decrease in performance but unlike with a proxy cache they will not lose access to the network. If a Content Engine fails that is part of a cluster the load will simply be redistributed across the remaining Content Engine(s) Overall solution availability is increased by Cisco’s qualification program for content, portal, VLE & MLE providers. Cisco works with these provides in our qualification lab to test interoperation, integration and optimal configuration. When Cisco issues major new software releases this allows us to re-test against these providers and it allows these providers to re-test their content, portal, VLE or MLE when they make significant changes. This provides customers of a Cisco CDN solution a high confidence level that the solution will work with their chosen content, portal, VLE and MLE now and in the future. Cisco and Cisco partners can provide 24 x 7 x 365 support with people who know not only how to support the CDN solution but also the underlying network on which it runs to support an overall solution. Our dedicated team of education Systems Engineers can provide high level consultancy support to customers and Cisco partners in creating an overall integrated high availability solution. Installation & Management Installation uses advanced auto-discovery techniques than enable a Content Engine to be installed at a remote site without any on-site configuration. The Content Engine is simple plugged into power and the LAN and can then be set-up remotely from the CDM. © 2003 Cisco Systems, Inc. All right reserved. Important notices, privacy statements, and trademarks of Cisco Systems, Inc. can be found on Page 9 of 12
  10. 10. The CDM provides full system wide configuration. It also provides advanced monitoring and reporting facilities. Reports can be output in stand or enhanced Squid Log or Apache format for analysis by a wide range of 3rd party tools. The whole systems is SNMPv1, v2 and v3 manageable and is supported within the CiscoWorks overall management system. Total Cost of Ownership (TCO) Capital purchase cost is just one element of the TCO of a CDN solution. Many aspects of a Cisco CDN reduce the TCO of the solution: • Cisco Capital financing can spread the cost of the solution so rather than a capital purchase it becomes like a broadband service that has an annual rental. Financing can also offer technology refresh and reduces the overall cost since Cisco provides a retrained value for the equipment at the end of the lease • Management of the whole solution via the central CDM rather than box-by-box significantly reduces management costs, while CiscoWorks integration can help further reduce management costs by integrating network and CDN management • Installation and maintenance costs are lower since the Content Engines don’t require any onsite configuration to install the first time or to replace in case of failure. This reduces engineering costs and makes customer self-installation possible • Overall operational overhead is reduced by Cisco’s qualification program (described in the availability section) which will reduce the time required to ensure full operation with a range increasingly complex content, portal, VLE and MLE products • The advanced content distribution system, especially when integrated with the content, portal, VLE or MLE, can control and optimise the consumption of storage reducing storage requirements and therefore costs • Deploying a CDN solution requires close integration with the underlying network, this can be a significant cost in the overall solution deployment and an area where Cisco and its partners have strong expertise • In the current IT industry economic environment, long term support and development is a real concern when selecting a vendor. Since mid-2002 three companies have either shutdown their caching solution business or strongly refocused their solution. Curriculum online is a rapidly evolving area that will require CDN solutions to track its evolution, providing closer integration and more advanced functionality and performance. Cisco invests over $3M a year in R&D to meet these evolving requirements • Scaling the performance and storage of the solution does not require folk lift upgrades compared to basic caching solutions. External storage can be added to increase performance and capacity and transparent load balancing can be used to add performance and availability • Cisco has gained many years experience of not only developing networking and CDN products but also as a online curriculum content provider with the Cisco Networking Academy Programme (CNAP). CNAP is believed to be the world’s largest eLearning program, with ~300,000 students currently enrolled, 100’s of hours of curriculum being delivered in over 10,000 education institutions in 11 languages and 140 countries. The assessment system alone conducts over 25,000 online tests per day. Cisco has created the Global Learning Network (GLN) to support CNAP. This includes integrated Content Distribution, portal, assessment and managed learning environment. This gives Cisco unique, highly valuable, best practice experience to share with customers “Cisco has continued to grow its content networking solutions for service providers and enterprises into a market leading position” Source: Stratecast Partners © 2003 Cisco Systems, Inc. All right reserved. Important notices, privacy statements, and trademarks of Cisco Systems, Inc. can be found on Page 10 of 12
  11. 11. © 2003 Cisco Systems, Inc. All right reserved. Important notices, privacy statements, and trademarks of Cisco Systems, Inc. can be found on Page 11 of 12
  12. 12. Further Information • UK Education portal: • Cisco Networking Academies • Content Delivery Networking • IP/TV • IP Video conferencing • IP Telephony • Security • Wireless • LAN Switches • UK Education video on demand presentations, including CDN • Education Blueprint for Schools • Contact the UK education team Corporate Headquarters UK Headquarters Americas Headquarters Asia Pacific Headquarters Cisco Systems, Inc. Cisco Systems Ltd Cisco Systems, Inc. Cisco Systems, Inc. 170 West Tasman Drive 9-11 New Square 170 West Tasman Drive Capital Tower San Jose, CA 95134-1706 Bedfont Lakes San Jose, CA 95134-1706 168 Robinson Road USA Feltham USA #22-01 to #29-01 Middlesex, TW14 8HA Singapore 068912 Tel: 408 526-4000 Tel: 408 526-7660 800 553-NETS (6387) TEL: +44 (0)20 8824 1000 Fax: 408 527-0883 Tel: +65 317 7777 Fax: 408 526-4100 Fax: +44 (0)20 8824 1001 Fax: +65 317 7799 Cisco Systems has more than 200 offices in the following countries and regions. Addresses, phone numbers, and fax numbers are listed on the Cisco Web site at Argentina • Australia • Austria • Belgium • Brazil • Bulgaria • Canada • Chile • China PRC • Colombia • Costa Rica • Croatia • Czech Republic • Denmark • Dubai, UAE • Finland • France • Germany • Greece • Hong Kong SAR • Hungary • India • Indonesia • Ireland • Israel • Italy • Japan • Korea • Luxembourg • Malaysia • Mexico• The Netherlands • New Zealand • Norway • Peru • Philippines • Poland • Portugal • Puerto Rico • Romania • Russia • Saudi Arabia • Scotland • Singapore • Slovakia • Slovenia • South Africa • Spain • Sweden • Switzerland • Taiwan • Thailand • Turkey Ukraine • United Kingdom • United States • Venezuela • Vietnam • Zimbabwe Copyright © 2003, Cisco Systems, Inc. All rights reserved. Cisco, Cisco Systems, and the Cisco Systems logo are trademarks or registered trademarks of Cisco Systems, Inc. and/or its affiliates in the U.S. or certain other countries. All other trademarks mentioned in this document or Web site are the property of their respective owners. The use of the word partner does not imply a partnership relationship between Cisco and any other company. (0206R) © 2003 Cisco Systems, Inc. All right reserved. Important notices, privacy statements, and trademarks of Cisco Systems, Inc. can be found on Printed in the UK Page 12 of 12