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Cisco Signaling Controllers

Cisco Signaling Link Terminal

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Data Sheet

The Cisco® Signaling Link Terminal (SLT) is an integral part of the Cisco PGW 2200 Softswitch node, designed for terminating Signaling System 7 (SS7) signaling traffic and backhauling MTP3, ISUP, and higher layers over IP to Cisco Media Gateway Controller hosts. The special-purpose Cisco IOS Software® image can run on Cisco 2611/2651XM multiservice routers as a standalone product or on Cisco AS5350/5400 universal gateways in conjunction with voice traffic (integrated SLT).

The Cisco SLT provides one of the two available methods for terminating SS7 signaling on the Cisco PGW 2200 Softswitch. Another product that provides SS7 link termination is the Cisco IP Transfer Point (ITP), which can act as both an IP-enabled STP and a signaling gateway.

CISCO PGW 2200 SOFTSWITCH NODE ARCHITECTURE

A Cisco PGW 2200 Softswitch node consists of the Cisco SLTs and redundant Cisco Media Gateway Controller (MGC) hosts, interconnected through an IP signaling control network.

Figure 1. Cisco PGW 2200 Softswitch Node Architecture

In Figure 1, access ("A") links or fully associated ("F") links from the SS7 network are physically connected on the Cisco SLT through one of several supported interface cards. The Cisco SLT terminates Message Transfer Part (MTP) Layers 1 and 2 of the SS7 protocol stack. Because MTP 2 is a message- and processor-intensive layer of SS7 signaling, terminating it on the Cisco SLT frees the Cisco PGW 2200 Softswitch from wasting cycles on lower-layer functions.
The Cisco SLT uses Reliable User Datagram Protocol (RUDP) to backhaul the upper-layer SS7 protocols across an IP signaling control network to the Cisco MGC. Cisco RUDP is a simple, connection-oriented, packet-based, transport protocol based on RFC 908 (Reliable Data Protocol) and RFC 1151 (Version 2 of the Reliable Data Protocol).
Upper layers forwarded include:

• Message Transfer Part Layer 3 (MTP3)

• Integrated Services Digital Network User Part (ISUP)

• Signal Connection Control Part (SCCP)

• Transactions Capabilities Applications Part (TCAP)

• Advanced Intelligent Network (AIN)

• Intelligent Network Application Part (INAP)

The Cisco SLTs use the Cisco IOS Software SS7 Signaling Link Terminal feature set, providing reliable interoperability within the Cisco PGW 2200 Softswitch node.
Cisco Session Manager software manages the communication sessions with the Cisco Media Gateway Controller. When the Cisco SLT feature is used with a redundant pair of controllers, the Cisco Session Manager software maintains separate communication sessions with each controller in the pair. The session between the Cisco SLT and the active controller transports the SS7 traffic, while the session between the Cisco SLT and the standby controller provides backup. Cisco Session Manager software uses Cisco RUDP to communicate between the Cisco SLT and the Cisco Media Gateway Controller. Figure 2 illustrates this concept.

Figure 2. SS7 Signaling Backhaul Architecture

STANDALONE AND INTEGRATED SLT OPTIONS

Designed to meet the individual needs of customers, the Cisco SLT is available in both standalone and integrated configurations. The standalone product runs a special-purpose Cisco IOS Software image on the Cisco 2611XM and Cisco 2651XM multiservice platforms specifically designed to terminate SS7 signaling links. When used with one of the many supported WAN interface cards (WICs) or voice WAN interface cards (VWICs), the standalone Cisco SLT provides a high-performance, economical product with which to terminate SS7 facilities. Figure 3 illustrates the standalone Cisco SLT architecture.

Figure 3. Standalone SLT Architecture

The Cisco AS5350, Cisco AS5400, and Cisco AS5400HPX universal gateways offer, as an option, an integrated version of the Cisco SLT. In this case, the universal gateways function as network access servers, voice gateways, or both and SLTs. SS7 signaling links are terminated directly on the universal gateway as well as with IMTs from the PSTN. Figure 4 illustrates the Cisco integrated SLT architecture.
The integrated SLT option is appropriate for any voice-over-IP (VoIP) network deployment, but is well suited for smaller, highly distributed networks requiring many small points of presence (POPs) or local interconnect points. Combined with low-end Sun platforms such as Netra 120s as the Cisco Media Gateway Controller active and standby hosts and a Cisco AS5350 acting as the universal gateway and SLT, it is possible to build a "micro-POP" that can be deployed in as little as three rack units (3 RUs). Figure 4 illustrates this concept.

Figure 4. Cisco Integrated SLT Architecture

SUPPORTED SS7 NETWORK INTERCONNECT METHODS USING THE CISCO SLT

When the Cisco PGW 2200 Softswitch is used in Cisco VoIP networks, the solution will support common signaling interconnect methods as well as features that exploit the power and savings of transporting SS7 signaling over IP-based networks.

"A" Links

Access or "A" links are used between the service switching point (SSP), served by the Cisco PGW 2200 Softswitch, and the signaling transfer point (STP) to connect the VoIP network to the PSTN. These links are dedicated to signaling, meaning that no bearer traffic is provisioned on the facility, even if there are available time slots not being used by signaling. For reliability, there are generally, at a minimum, two "A" links provisioned between the SLTs and the home STPs. While most commonly seen in North America, "A" links are used in other geographic areas such as Asia and South America, depending on availability of facilities.

"F" Links

Fully associated or "F" links are generally deployed when a large volume of traffic exists between two SSPs (between the Cisco PGW 2200 Softswitch and a PSTN switch, for example) or when it is not feasible to connect directly to an STP. "F" links are not commonly used in North America, but they are widely deployed in Europe, Asia, and South America. While "F" links can be provisioned with only signaling on the facility, the most common configuration includes the provisioning of bearer channels on time slots not used by SS7 signaling.

Drop-and-Insert Option

The "drop-and-insert" application feature, also known as time-division multiplexing (TDM) cross-connect, allows customers to deploy "F" links with both signaling and bearer traffic on the same facility. The drop-and-insert feature grooms the SS7 signaling channels from the facility and backhauls the signaling to a Cisco Media Gateway Controller for processing. Bearer channels are "hairpinned" on the Cisco SLT interface card and sent to a voice gateway by connecting a cable between the egress port on the Cisco SLT voice WAN interface card (VWIC) and an available T1 or E1 port on a gateway.
The integrated SLT offers internal drop-and-insert, which requires no external cabling. All bearer channels are internally hairpinned on the gateway and sent to the VoIP network. Figure 5 depicts both the Cisco SLT and integrated SLT drop-and-insert architectures.

Figure 5. Drop and Insert Architectures

Using the VWIC "Drop-and-Insert" Cards to Terminate Four "F" Links

The Cisco SLT that is based on the Cisco 2651XM Multiservice Platform can terminate up to four SS7 "A" or "F" signaling links. The exact configuration used to support four links is determined by the WICs chosen to terminate the physical facilities and the SS7 signaling links within those facilities.
While configuring four links on most of the available WICs and VWICs is intuitive, terminating four "F" links on the Cisco SLT based on the Cisco 2651XM requires careful consideration. Generally, "F" links are provisioned with bearers on the available channels not being used by SS7 signaling. Separating the bearer channels from the SS7 signaling channels requires a demultiplexing function, either internal or external to the Cisco SLT. While external demultiplexing is possible, it is generally more cost-effective to use the drop-and-insert function available on the interface cards with part numbers VWIC-2MFT-TI-DI and VWIC-2MFT-E1-DI.
To terminate four "F" links with bearers on the Cisco SLT based on the Cisco 2651XM requires installing two of the WICs enabled with the drop-and-insert function (the VWIC-2MFT-TI-DI or VWIC-2MFT-E1-DI) in the two available WIC slots (card slots W0 and W1) on the Cisco SLT. Two "F" links, configured with two signaling channels per facility, are terminated on the SLT on each of the WICs. Figure 6 illustrates this concept.

Figure 6. Terminating Four "F" Links with VWIC-2MFT-T1/E1 DI Cards

In situations where interconnect regulations permit the provisioning of only one signaling channel per facility on an "F" link, the Cisco SLT based on the Cisco 2651XM is restricted to supporting a maximum of two "F" links.

Remote SS7 Signaling Backhaul

The Cisco SLT supports both collocated and remote termination of SS7 signaling links. With colocated configurations, the Cisco SLTs are physically located with the Cisco Media Gateway Controller hosts, and are connected to the host through a LAN. Remote configurations are defined as deployments where the SS7 signaling is backhauled over an IP-based WAN from an SSP or STP to the Cisco PGW 2200 Softswitch. Figure 7 illustrates this concept.

Figure 7. Remote SLT Architecture

Remote SS7 signaling backhaul is well suited for customers who:

• Want to deploy a centralized Cisco Media Gateway Controller controlling multiple POPs

• Have many SS7-enabled POPs distributed over a wide area

• Need to connect to distributed STPs or SSPs

• Need to deploy and run multiple SS7 ISUP variants on a single Cisco Media Gateway Controller

The ability to backhaul SS7 signaling over a wide-area, IP-based network offers cost-savings benefits, including:

• Lowering the overall, upfront cost of deploying VoIP networks by reducing equipment costs, especially for rollouts of multiple or distributed POPs over a wide geographic area

• Dramatically reducing recurring telecommunications costs by eliminating dedicated, point-to-point SS7 signaling links

In many countries, the cost of dedicated signaling links can be prohibitive. Dedicated signaling links may also be unavailable because of facilities shortages. With the Cisco PGW 2200 Softswitch and its SLT-based architecture, customers can now take advantage of IP-based WANs to backhaul SS7 signaling from STPs and SSPs to the Cisco Media Gateway Controller for call processing.

PCR Support

SS7 offers two methods of error checking: basic and Preventive Cyclic Redundancy (PCR). Basic error detection and correction is used when SS7 is carried over terrestrial signaling links. When an error is detected using basic error detection and correction, a retransmission is requested. The sequence number is provided for the last known signaling unit that was good, permitting the originator of the errored signaling unit to determine which signaling units to retransmit.
Because of the inherent propagation delay when using satellite transmission, PCR is the error detection method used when SS7 is transmitted over satellite links. When using PCR, all of the transmitted signaling units are continually retransmitted until they are acknowledged by the distant end. Once acknowledged, the signaling units are dropped from the transmission buffer.
PCR is only applicable to the serial-side interfaces of the Cisco SLT (the serial interfaces between the STP and the Cisco SLT). It cannot be applied to the IP-side interfaces between the Cisco SLT and the Cisco Media Gateway Controller. See Figure 8.

Figure 8. PCR Support for the Cisco SLT

Cisco SLT Feature Set

Table 1 summarizes the feature set available on both the standalone and integrated SLT.

Table 1. Feature Set for the Cisco Signaling Link Terminal

Feature

Description

Physical Layer Interfaces (MTP Layer 1)
• Cisco SLT (Cisco 2611XM-based)
· Terminate up to two 64-Kbps or 56-Kbps SS7 signaling links
· T1, E1, V.35, RS-449, or RS-530 physical interfaces to the SS7 network
· Up to two SS7 signaling links can be supported per T1 or E1 port
• Cisco SLT (2651XM-based)
· Terminate up to four 64-Kbps or 56-Kbps SS7 signaling links
· T1, E1, V.35, RS-449, or RS-530 physical interfaces to the SS7 network
· Up to two SS7 signaling links can be supported per T1 or E1 port
• Integrated SLT (Cisco AS5350, Cisco AS5400, and Cisco AS5400HPX)
· Terminate up to four 64-Kbps or 56-Kbps SS7 signaling links
· CT-3, T1, E1, and V.35 physical interfaces to the network
· Up to four SS7 signaling links can be supported per CT-3, T1, or E1 port
Terminates Processor-Intensive MTP Layer 2 Functions
• Link-state control (LSC) provides the overall coordination of the session
• Initial alignment control (IAC) provides the link alignment processing
• Transmit control provides transmit flow control and processing
• Receive control provides receive flow control and processing
• Congestion control provides congestion onset and abatement processing
• Signal unit error rate monitor (SUERM) provides monitoring of signal unit events
• Signal unit delimitation detects individual signal units
• Signal unit alignment enforces signal unit encoding rules and bit patterns
• Error detection detects bit errors in signal units by using the cyclic redundancy check (CRC) field
• Error correction uses positive and negative acknowledgments and retransmits errored signal units
• Support for both basic error detection and correction and Preventive Cyclic Redundancy (PCR)
• Alignment error rate monitor (AERM) monitors link alignment errors
Standalone Cisco SLT Supports Multiple Serial Interface Cards (Multiflex Serial Interface Cards)
• Channelized T1 interface cards
· 1-port T1 multiflex interface (VWIC-1MFT-T1)
· 2-port T1 multiflex interface (VWIC-2MFT-T1)
· 2-port T1 multiflex trunk interface with drop-and-insert (VWIC-2MFT-T1-DI)
• Channelized E1 interface cards
· 1-port E1 multiflex interface (VWIC-1MFT-E1)
· 2-port E1 multiflex interface (VWIC-2MFT-E1)
· 2-port E1 multiflex trunk interface with drop-and-insert (VWIC-2MFT-E1-DI)
• V.35, EIA/TIA-449, EIA/TIA-530 Cards
· 1-port high-speed serial interface (WIC-1T)
· 2-port high-speed serial interface (WIC-2T)
• 1-port serial with 4-wire 56/64-Kbps data service unit/channel service unit (DSU/CSU) interface card (WIC-1DSU-56K4)
Feature-Rich Multiflex Interface Cards
• Single or dual port, T1 or E1 capability
• E1 versions support both balanced and unbalanced modes
• Physical-layer alarm-forwarding feature between the two T1/E1 ports on dual-port cards
• Drop-and-insert (also called TDM cross-connect) between the T1/E1 ports on dual-port cards, used to hairpin bearer channels to a media gateway device and allow the interchange of TDM slots between the ports on a 2-port card
• Shared between Cisco 2600 and 3600 series for common inventory sparing for various network applications
Integrated SLT
• Cisco AS5350 and AS5350XM universal gateways
· 2-port T1 or E1 PRI card
· 4-port T1 or E1 PRI card
· 8-port T1 or E1 PRI card
· CT-3 card
• Cisco AS5400, AS5400HPX, and AS5400XM universal gateways
· 2-port T1 or E1 PRI card
· 4-port T1 or E1 PRI card
· 8-port T1 or E1 PRI card
· CT-3 card
Platform Support
• Standalone SLT
· Cisco 2611XM and 2651XM multiservice platforms
• Integrated SLT
· Cisco AS5350, AS5350XM, AS5400, AS5400HPX, and AS5400XM universal gateways
Protocol Compliance
• MTP 1 and 2
· ITU-T Q.701-709, including G.732 support
· ANSI T1-111 1996
· Japan TTC
· Japan NTT
• MTP 3 and higher are backhauled to MGC over IP
Deployment Configurations
• Colocated-The Cisco SLT is physically located with the Cisco Media Gateway Controller hosts and is connected through a LAN
• Remote-The Cisco SLT is physically located somewhere other than with the Cisco Media Gateway Controller hosts (generally with the STP or SSP), and SS7 signaling is backhauled to the node through an IP-based WAN
Remote SLT General Deployment Guidelines
• End-to-end delay (one way) must be less than 150 ms
• Packet loss must not exceed one percent (preferably below 0.5 percent)
• Less than one E-6 line error
• The CiscoWorks Internetwork Performance Monitor (IPM) is recommended to measure the quality of IP-based, wide-area backhaul networks
Cisco IOS Software Release
• Standalone SLT
· 12.3(7)M or later release
· Available at www.cisco.com
• Integrated SLT
· 12.3(7)M or later release
· Available at www.cisco.com

Note: A feature license is required when using the SLT or Integrated SLT functionality on a Cisco IOS Gateway

Memory Requirements
• Standalone SLT
· Minimum required DRAM and flash to support the standalone Cisco SLT feature set are 64-MB DRAM and 16-MB flash
• Integrated SLT
· Minimum required DRAM and flash to support the integrated Cisco SLT feature set are 256-MB DRAM and 32-MB Flash
Certification
• Standalone SLT
• Network Eq uipment Building Systems (NEBS) Level 3 and European Telecommunication Standards Institute (ETSI) compliance kit including 23- or 24-in. rack mounts, grounding lug kit, shielded LAN cables, and bezel removal kit (for additional unit depth reduction)
• Integrated SLT
· NEBS Level 3
· ETSI

CISCO SLT PLATFORM INFORMATION

Cisco 2600XM Series Multiservice Platforms

In combination with this application-specific version of Cisco IOS Software, the Cisco SLT hardware component uses the widely deployed Cisco 2600XM Series multiservice platforms. The Cisco 2600XM Series, powered by a robust Reduced Instruction Set Computer (RISC) processor, provides the high-performance routing required in today's networking infrastructures.

Figure 9. Cisco 2600XM Series

The Cisco 2600XM Series meets service providers' critical physical requirements for equipment depth that fits next to transmission equipment on a standard 12-inch-deep rack with a one-rack-unit (1-RU) height. NEBS compliance is assured by using the NEBS/ETSI kit included with the Cisco SLT. Common Language Equipment Identifier (CLEI) coding is provided for easy identification and tracking of central-office (CO) equipment. Options for either AC or DC power are available.
It is important to note that the standalone Cisco SLT supports only the SS7 MTP 2 Serial Protocol. Therefore, the serial interfaces cannot be configured for other protocols. It is also important to note that the Cisco SLT is not an SS7-over-IP router. It can only be used as a part of the Cisco PGW 2200 Softswitch node to backhaul higher-layer SS7 protocols over the node IP signaling control network.

Cisco AS5350, AS5400, and AS5400 HPX Platform Specifications

The Cisco AS5350 Universal Gateway is the only one-RU gateway supporting two, four, and eight T1/E1 configurations providing universal port access for voice, data, and fax services on any port at any time. The Cisco AS5350 takes advantage of the full-feature richness and strong routing capabilities of Cisco IOS Software. The Cisco AS5350 can be deployed in a variety of network architectures from corporate to service provider networks.

Figure 10. Cisco AS5350 Universal Gateway

The Cisco AS5350 offers hot-swap capability on all cards and the fan tray, allowing hardware maintenance to be performed on active access servers with little or no service interruption. During a hot swap, any card may be removed, inserted, or replaced, affecting only calls on the card being removed.
The Cisco AS5350 complies with NEBS Level 3 requirements, as defined by Telcordia SR-3580, and also complies with European requirements as defined by the ETSI.
The Cisco AS5400 and Cisco AS5400HPX universal gateways are high-density, carrier-class access servers on the market, offering superior capacity in only two RUs. Their high density (up to one CT3 or 14,112 ports in a 7-foot rack), low power consumption (6.6A at 48 volts DC per CT3), and Universal Port readiness make them ideal for many network deployment architectures, especially collocations environments and "mega-POPs."

Figure 11. Cisco AS5400 and Cisco AS5400HPX Universal Gateways

As carrier-class access servers, the Cisco AS5400 and Cisco AS5400HPX have hot-swappable cards, an internal redundant power supply, and environmental monitoring. Their rich set of Cisco IOS Software features enables Internet service providers (ISPs) and enterprise network managers to meet traditional dial-in needs, while supporting the migration to newer technologies.
The Cisco AS5400 and Cisco AS5400HPX comply with NEBS Level 3 requirements, as defined by Telcordia SR-3580, and also comply with European requirements as defined by the ETSI.
When used with the Integrated SLT option, the Cisco AS5350, Cisco AS5400, and Cisco AS5400HPX universal gateways function as both an SS7 signaling link termination point and universal gateway. The SLT option on these gateways is not an SS7-over-IP router. It can only be used as a part of the Cisco PGW 2200 Softswitch node to backhaul higher-layer SS7 protocols over the node IP signaling control network.
Text Box:  Corporate HeadquartersCisco Systems, Inc.170 West Tasman DriveSan Jose, CA 95134-1706USAwww.cisco.comTel:	408 526-4000	800 553-NETS (6387)Fax:	408 526-4100	European HeadquartersCisco Systems International BVHaarlerbergparkHaarlerbergweg 13-191101 CH AmsterdamThe Netherlandswww-europe.cisco.comTel:	31 0 20 357 1000Fax:	31 0 20 357 1100	Americas HeadquartersCisco Systems, Inc.170 West Tasman DriveSan Jose, CA 95134-1706USAwww.cisco.comTel:	408 526-7660Fax:	408 527-0883	Asia Pacific HeadquartersCisco Systems, Inc.168 Robinson Road#28-01 Capital TowerSingapore 068912www.cisco.comTel: +65 6317 7777Fax: +65 6317 7799Cisco Systems has more than 200 offices in the following countries and regions. Addresses, phone numbers, and fax numbers are listed onthe Cisco Website at www.cisco.com/go/offices.Argentina · Australia · Austria · Belgium · Brazil · Bulgaria · Canada · Chile · China PRC · Colombia · Costa Rica · Croatia · Cyprus 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 · ZimbabweCopyright  2006 Cisco Systems, Inc. All rights reserved. CCSP, CCVP, the Cisco Square Bridge logo, Follow Me Browsing, and StackWise are trademarks of Cisco Systems, Inc.; Changing the Way We Work, Live, Play, and Learn, and iQuick Study are service marks of Cisco Systems, Inc.; and Access Registrar, Aironet, BPX, Catalyst, CCDA, CCDP, CCIE, CCIP, CCNA, CCNP, Cisco, the Cisco Certified Internetwork Expert logo, Cisco IOS, Cisco Press, Cisco Systems, Cisco Systems Capital, the Cisco Systems logo, Cisco Unity, Enterprise/Solver, EtherChannel, EtherFast, EtherSwitch, Fast Step, FormShare, GigaDrive, GigaStack, HomeLink, Internet Quotient, IOS, IP/TV, iQ Expertise, the iQ logo, iQ Net Readiness Scorecard, LightStream, Linksys, MeetingPlace, MGX, the Networkers logo, Networking Academy, Network Registrar, Packet, PIX, Post-Routing, Pre-Routing, ProConnect, RateMUX, ScriptShare, SlideCast, SMARTnet, The Fastest Way to Increase Your Internet Quotient, and TransPath are registered trademarks of Cisco Systems, Inc. and/or its affiliates in the United States and certain other countries.All other trademarks mentioned in this document or Website 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. (0601R)Printed in the USA	C78-335026-00 02/06 Text Box:  Corporate HeadquartersCisco Systems, Inc.170 West Tasman DriveSan Jose, CA 95134-1706USAwww.cisco.comTel:	408 526-4000	800 553-NETS (6387)Fax:	408 526-4100	European HeadquartersCisco Systems International BVHaarlerbergparkHaarlerbergweg 13-191101 CH AmsterdamThe Netherlandswww-europe.cisco.comTel:	31 0 20 357 1000Fax:	31 0 20 357 1100	Americas HeadquartersCisco Systems, Inc.170 West Tasman DriveSan Jose, CA 95134-1706USAwww.cisco.comTel:	408 526-7660Fax:	408 527-0883	Asia Pacific HeadquartersCisco Systems, Inc.168 Robinson Road#28-01 Capital TowerSingapore 068912www.cisco.comTel: +65 6317 7777Fax: +65 6317 7799Cisco Systems has more than 200 offices in the following countries and regions. Addresses, phone numbers, and fax numbers are listed onthe Cisco Website at www.cisco.com/go/offices.Argentina · Australia · Austria · Belgium · Brazil · Bulgaria · Canada · Chile · China PRC · Colombia · Costa Rica · Croatia · Cyprus 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 · ZimbabweCopyright  2006 Cisco Systems, Inc. All rights reserved. CCSP, CCVP, the Cisco Square Bridge logo, Follow Me Browsing, and StackWise are trademarks of Cisco Systems, Inc.; Changing the Way We Work, Live, Play, and Learn, and iQuick Study are service marks of Cisco Systems, Inc.; and Access Registrar, Aironet, BPX, Catalyst, CCDA, CCDP, CCIE, CCIP, CCNA, CCNP, Cisco, the Cisco Certified Internetwork Expert logo, Cisco IOS, Cisco Press, Cisco Systems, Cisco Systems Capital, the Cisco Systems logo, Cisco Unity, Enterprise/Solver, EtherChannel, EtherFast, EtherSwitch, Fast Step, FormShare, GigaDrive, GigaStack, HomeLink, Internet Quotient, IOS, IP/TV, iQ Expertise, the iQ logo, iQ Net Readiness Scorecard, LightStream, Linksys, MeetingPlace, MGX, the Networkers logo, Networking Academy, Network Registrar, Packet, PIX, Post-Routing, Pre-Routing, ProConnect, RateMUX, ScriptShare, SlideCast, SMARTnet, The Fastest Way to Increase Your Internet Quotient, and TransPath are registered trademarks of Cisco Systems, Inc. and/or its affiliates in the United States and certain other countries.All other trademarks mentioned in this document or Website 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. (0601R)Printed in the USA	C78-335026-00 02/06