Guest

Cisco Signaling Controllers

Cisco Signaling Link Terminal Interface Card Support

Product Technical Reference

Cisco Signaling Link Terminal Interface Card Support
for Cisco 2611- and 2651-Based Platforms

The Cisco Signaling Link Terminal (SLT), based on the Cisco 2611Multisevice Platform can support up to two Signaling System 7 (SS7) "A" or "F" signaling links. The Cisco SLT, based on the Cisco 2651 Multiservice Platform can support up to four SS7 "A" or "F" signaling links. The ability to support a given number of links depends on the WAN interface cards (WICs) or voice WAN interface cards (VWICs) selected, the number of physical facilities terminated on the interface cards, and the number of signaling links contained within the facility. Table 1 lists all interface cards that are supported on the Cisco SLT, and provides commentary on the number of facilities and signaling links supported per interface card.


Table 1: Interface Cards Supported on the Cisco 2611- and 2651-Based SLTs
Interface cards Description Facilities terminated SS7 Links supported per card1 Comments
WIC-1T

One-port, high-speed serial interface

One

One

Can terminate one 56/64 Kbps facility with the use of an external CSU/DSU.

WIC-2T

Two-port, high-speed serial interface

Up to two

Two

Can terminate two 56/64 Kbps facilities with the use of an external CSU/DSU.

WIC-1DSU-56K4

One-port, serial four-wire 56/64 Kbps card with CSU/DSU

One

One

Can terminate one 56/64 Kbps facility without the use of an external CSU/DSU.

VWIC-1MFT-T1

One-port T1 trunk interface card

One

Up to two

Up to two SS7 signaling links can be groomed from the T1 or E1 facility.

VWIC-1MFT-E1

One-port E1 trunk interface card

One

VWIC-2MFT-T1

Two-port T1 trunk interface card

Up to two

Up to two

Up to two SS7 signaling links can be groomed from each T1 or E1 facility. However, if two SS7 signaling links are groomed from one T1/E1 facility, no SS7 signaling links can be groomed from the other T1/E1 facility.

VWIC-2MFT-E1

Two-port E1 trunk interface card

Up to two

VWIC-2MFT-T1-DI

Two-port T1 trunk interface card with drop-and-insert function

One

Up to two

Up to two SS7 signaling links can be groomed from the T1 or E1 facility on a drop-and-insert card. Only one facility from the PSTN can be terminated on this WIC as the bearers are externally hairpinned out to the gateway on the second port on the drop-and-insert WIC card.

VWIC-2MFT-E1-DI

Two-port E1 trunk interface card with drop-and-insert function

One

1Total number of supported SS7 links depends on the SLT platform used


Network modules or other available interface cards supported on the Cisco 2611 and 2651 are not supported for use with SS7 signaling link termination on the Cisco SLT.

Slot Support Restrictions on the Cisco 2611- and 2651-Based SLTs

Figure 1 depicts the rear panel on the Cisco 2611- and 2651-based SLTs, showing the available ports and slots on the platforms. Any of the SLT-supported WICs and VWICs can be installed in the two available WIC slots (W0 and W1) on the Cisco 2611- and 2651-based SLTs.


Figure 1
View of Rear Panel on Cisco 2611- and 2651-Based SLTs


It is important to note that the only slots available for supporting SS7 signaling link termination on the supported WICs and VWICs are the WIC slots depicted above (W0 and W1). There is no SS7 support available for WICs and VWICs installed in the network module slot, or any other ports or interfaces on either the Cisco 2611- or 2651-based SLTs.

Using the VWIC-2MFT-T1/E1-DI Cards to Terminate Four "F" Links

The Cisco 2651-based SLT 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 2651-based SLT 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 de-multiplexing function, either internal or external to the Cisco SLT. While external de-multiplexing is possible, it is generally more cost-effective to use the drop-and-insert function available on both the VWIC-2MFT-TI-DI and VWIC-2MFT-E1-DI interface cards.

The drop-and-insert, or D/I-enabled VWICs, permit "F" links with bearers to be directly terminated on the Cisco SLT. Each D/I-enabled VWIC can terminate a single T1 or E1 facility on one of the RJ-48C ports on the module. The VWIC can groom up to two SS7 signaling links from the facility and backhaul the signaling information over an IP-based signaling network to the Cisco PGW 2200. The remaining bearer channels are hairpinned on the card and sent to the voice gateways by connecting a cable between an available port on the access server and the second RJ-48C port on the D/I-enabled VWIC.

To terminate four "F" links with bearers on the Cisco 2651-based SLT requires installing two of the D/I-enabled VWICs (the VWIC-2MFT-TI-DI or VWIC-2MFT-E1-DI) in the two available WIC 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 D/I-enabled WICs. Figure 2 illustrates this concept.


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



Note Situations where interconnect regulations permit the provisioning of only one signaling channel per facility on an "F" link restrict the Cisco 2651-based SLT from supporting a maximum of two "F" links.