Chapter 5: Provisioning SS7-Based POPs

POPs that must support the signaling provided by the PSTN require a different implementation. The progress and alerting tones that we are familiar with in traditional telephone services, such as dial or busy tones, are produced by the PSTN. In addition, telecommunications switches, such as the Class 4 and Class 5, communicate with each other through standards-based signaling. This signaling is essential to providing interconnections among carrier, cellular, and wireless networks, because it is the means by which calls are set up and torn down.

A major breakthrough in signaling networks was the separation of the signaling path from the voice or data path. This new data network, called common channel interoffice signaling, or CCS (also known as out-of-band signaling), overlays the carrier's switching network. CCS increases network intelligence, efficiency, automation, and functionality.

CCS has evolved into a standard called Signaling System 7, or SS7, a protocol that lowered costs and increased network reliability even further. With SS7, all carriers can interoperate as a consistent, seamless network. Services such as global billing, wireless roaming, and 800 number calling rely on the SS7 protocol to exchange messages reliably.

Where these services exist they must be maintained, although traffic now traverses the Internet instead of the traditional switched network. This is why Cisco developed the Cisco H.323 VoIP with SS7 Solution, to provide interconnection between SS7-based carriers and IP-based networks. H.323 is an ITU-T standard that is really a set of standards that define real-time multimedia communications for packet-based networks, otherwise known as IP telephony. Of particular interest are the call setup and control features provided by H.323.

Note Where SS7 must be supported, the Cisco Wholesale Voice Solution relies on the Cisco SS7 Interconnect for Voice Gateways Solution. That solution is a distributed system that provides SS7 connectivity for H.323 VoIP access gateways, by using the Cisco Signaling Controller (also known as the Cisco SC2200) and access gateways as a bridge from the H.323 IP network to the PSTN. The Cisco SS7 Interconnect for Voice Gateways Solution interacts over the IP network with other Cisco H.323 VoIP access gateways; it can also interoperate with H.323 endpoints by using non-SS7 signaling, as in ISDN PRI and channelized T1.

For the most current information about SS7 connectivity as it relates to the Cisco Wholesale Voice Solution, see the discussion of the Cisco SS7 Interconnect for Voice Gateways Solution, Release 1.1. That solution is described in detail at the following URL:

http://www.cisco.com/univercd/cc/td/doc/product/access/sc/rel7/soln/voip11/index.htm

A variety of topics are discussed at the above site, among them the following:

An introduction to the Cisco SS7 Interconnect for Voice Gateways Solution, and its options
How to install, provision, and configure required components
How to use the features of the related software

Note The cross connections (channel assignments) in a Cisco SS7 Interconnect for Voice Gateways Solution are nailed up. That is, there is no dynamic assignment of cross connections on the basis of number prefix, hunt group, and so on.

This chapter does not attempt to recreate the substantial background information available at the Cisco SS7 Interconnect for Voice Gateways Solution website, although it does introduce the required components (see Cisco SC2200 Node Components). Although this chapter introduces the fundamentals of installing hardware and software, its main purpose is to focus on the provisioning details that are specific to Cisco SC2200 Signaling Link Controllers, Cisco Signaling Link Terminals (SLTs), and Cisco GWs in the Cisco Wholesale Voice Solution.

This chapter presents the following major topics:

Architecture

The Cisco SC2200 logical entity consists of various components, and is referred to as a Cisco SC2200 node. This node, which appears as a Signaling Service Point (SSP) to the SS7 network, consists of an active and standby SC host, as well as a redundant pair of Cisco SLTs. The latter support SS7 A or F links, through redundant A and B link sets.

A links (access links) are used between the SSP and the STP, to provide access into the network and to databases (through the STP). With rare exceptions, there are always at least two A links, one to each of the STP pairs. F links (fully associated links) are used when a large amount of traffic must be handled between two SSPs, or when an SSP cannot be connected directly to an STP. F links allow SSPs to use the SS7 protocol to access SS7 databases even when it is not economical to provide a direct connection to an STP pair. Figure 5-1 illustrates the architecture of a Cisco SC2200 node.

Checkpointing monitors the states of the active and standby SC hosts, to enable switching from active to standby as needed. In the PSTN cloud, links are terminated by Service Switching Points (SSPs) or Signal Transfer Points (STPs). An SSP is the local exchange, and provides communication with a voice switch or SS7 switch. It also sends database queries throughout the SS7 network. An STP is essentially a router in the SS7 network, allowing SS7 message packets to travel from one SSP to another. An STP can be adjunct to a voice switch, although ideally it is a standalone function.

To provide SS7 connectivity for access gateways, the Cisco H.323 VoIP system architecture uses the SC2200 as a protocol translator, with SS7 signaling provided through the ISDN Q.931+ protocol (which in turn is tunneled through IP).

Table 5-1 lists the components, both required and optional, of the Cisco H.323 system architecture in support of SS7.

Figure 5-1 Architecture of a Cisco SC2200 Node

Table 5-1 Components of the Cisco H.323 VoIP System Architecture

Component	Description
Cisco Signaling Controller (SC)	Required. The Cisco SC2200, running MGC (SC) Software Release 7.4, operates as an SS7-to-ISDN protocol converter, a front end to the access gateways. The Cisco SC2200 is a Sun Netra series host that runs the Solaris operating system.
Cisco Signaling Link Terminal (SLT)	Required. The Cisco 2611 SLT terminates the physical SS7 links.
Cisco Access Gateway	Required. Cisco AS5300, Cisco AS5350, and Cisco AS5400 access gateways terminate voice and data ISUP (ISDN User Part) trunks.
Cisco H.323 Gatekeeper	Optional. Cisco 3600s and 7200s are used to manage other nodes in an H.323 network.
Cisco LAN Switch	Optional. When necessary, switches from the Catalyst switch family are used to extend VLANs across platforms through backbone Fast Ethernet, Gigabit Ethernet, or ATM connections.

The Cisco SC2200 Signaling Controller is based on Sun Netra t 1120/1125 and t 1140/1145 series host computers (the "5" indicates AC-only operation); the Cisco SLT is based on the Cisco 2600 series routers. The combination of the Cisco SC and SLT in support of SS7 signaling over voice gateways form what is known as the Cisco SS7 Interconnect for Voice Gateways Solution.

Note The terms "SC" and "signaling controller" refer to the function of the Cisco SC2200 product as well as to the computers that perform the signaling conversion, the SC hosts. The term "MGC" (media gateway controller) is also used refer to the SC products and components when they are used in other solutions. MGC documents are later referred to with respect to the installation of SC node components.

Cisco SC2200 Node Components

The hardware components of the Cisco SC2200 node consist at the most fundamental level of a Cisco SC2200 Signaling Controller and Cisco Signaling Link Controller. Two sets of these are paired in a fault-tolerant SS7 signaling environment.

Note LAN switches, typically Catalyst 5000 and 6000 series switches, are optional, not mandatory, components of the Cisco Wholesale Voice Solution. For information about these switches, see Multilayer LAN Switches at the following URL:

http://www.cisco.com/univercd/cc/td/doc/product/lan/index.htm

The node components are described briefly below.

Cisco SC2200 Signaling Controller

The Cisco SC2200 host platform is essential to a Cisco Wholesale Voice Solution network that needs to support SS7 signaling. The Cisco SC2200 product is a signaling controller (SC) that converts telephony signals from one protocol variant to another. For example, it converts SS7 variants, such as ANSI SS7, to an IP-based variant required to establish calls between the PSTN and a packet data network. For detailed information about the Cisco SC2200, see the following URL:

http://www.cisco.com/univercd/cc/td/doc/product/access/sc/rel7/index.htm

Cisco SLT

The Cisco SLT provides termination of the SS7 signaling. Based on the Cisco 2611 modular access router, the Cisco SLT terminates the lower layers of the SS7 protocol (MTP1 and MTP2), encapsulating the higher SS7 layers and reliably passing (backhauling) the IP packets (MTP layer 3) back to the Cisco SC2200 for interpretation and processing. By offloading the MTP1 and MTP2 layers from the Cisco SC2200, improvements are realized in both MTP2 performance and Cisco SC2200 system reliability and fault tolerance. For detailed information about the Cisco SLT, see the following URL:

http://www.cisco.com/univercd/cc/td/doc/product/access/sc/slt/index.htm

Four MTP2 variants are supported or complied with:

Telcordia (formerly Bellcore)/ANSI
ITU-White, ITU-Blue
Japan-NTT
Japan Telecom TTC

Note The Cisco 2611 provides dual Ethernet interfaces. However, currently only a single Ethernet port is supported in the SLT configuration. Network modules are not supported, and only two SS7 links can be used.

Note Each Cisco SLT consists of a custom Cisco IOS image running on a Cisco 2611 router. However, the SLT itself does not function as a router. It is designed to offload signaling at layers MTP1 and MTP2 from the signaling controller. It is not designed to transport or tunnel SS7 over IP protocols other than RUDP (Reliable User Datagram Protocol).

The Cisco 2611 only has SS7 functionality when used as a Cisco SLT. All standard Cisco 2611 software features are disabled when the system is running the Cisco SLT image.

The Cisco SLT uses RUDP, a Cisco proprietary protocol that makes UDP reliable. RUDP connections are established by the RUDP client, which, in the case of the SLT, is the Session Manager. The SLT Session Manager maintains the connection between the SC and the SLT. Based on standard UDP functions, RUDP becomes reliable through the addition of the following TCP/IP features:

The establishment and maintenance of reliable connections between client and server
Flow control
Congestion control
The establishment of a reliable connection between an SLT and an SC by means of a TCP/IP address and a specified UDP port

Configuring the Cisco SC2200 Node Components

The following discussion assumes that the necessary hardware have already been installed. For installation instructions, see Installing Cisco SC2200 Node Hardware and Software.

Figure 5-2 illustrates our example Cisco SC2200 node and its components for the following example configuration. (This figure is essentially the same as Figure 5-1, except for being rotated 90 degrees.) The addresses required for signaling in a redundant configuration are discussed in Edit the File XECfgParm.dat. Point codes are discussed in Create the File config.mml.

Caution For purposes of illustration, only a few examples of the network entities are illustrated in the discussion that follows. To facilitate provisioning, research your network needs carefully, and record all entities, their IP addresses, and SS7 point codes on a network map before continuing.

Figure 5-2 Example Cisco SC2200 Node and Components

Configuring the Cisco Signaling Controllers

You must configure both a designated active (primary) and designated standby (secondary) Cisco Signaling Controller (the Cisco SC2200), as in the procedures below:

You must do the following on both machines:

Refer to Figure 5-2 for the following discussion.

Note If the necessary hardware and software have not yet been installed, proceed first to
Installing Cisco SC2200 Hardware and Software.

Configuring the Designated Active Cisco SC2200

The example below illustrates the configuration on the designated active SC. With respect to network addresses, the configurations are essentially mirrors of each other, as each is the (failover) peer of the other.

Assign User mgcuser to User Group mgcgroup

To enable the software to be used by a regular user other than the superuser, you must log in on completion of the last reboot and assign the Signaling Controller users to belong to the group mgcgroup.

Step 1 Go to the directory /etc and use a text editor such as vi to edit the file group, adding user mgcuser to user group mgcgroup as follows:

 
nobody::60001: 

 
noaccess::60002: 

 
nogroup::65534: 

 
mgcuser::20000:mgcgroup

Note In the above example, we simply assign user mgcuser to group mgcgroup. The username mgcuser can be anything.

Step 2 Log out and log in as user mgcgroup to begin provisioning the Cisco SC2200.

Edit the File XECfgParm.dat

The file XECfgParm.dat on the Cisco SC2200 host contains a variety of configuration parameters that you must edit for your system to function. Refer to Figure 5-2 for the following example.

Note For a complete list of parameters, including their functions, definitions, and sample values, see XECfgParm.dat File Parameters at the following URL:
http://www.cisco.com/univercd/cc/td/doc/product/access/sc/rel7/sw_ref/elparms.htm

The most current release of the SC software (also referred to as MGC, or Media Gateway Controller, software) is Release 7.4. Refer to discussions of the most recent version only.

Then find the file XECfgParm.dat, in /opt/CiscoMGC/etc on the Cisco SC2200 host, then search for and edit the following parameters. Use a text editor such as vi.

Step 1 Edit the first local IP address, *.ipAddrLocalA:

 
*.ipAddrLocalA = 10.10.1.27

This is the first IP address of the designated active, or primary, Cisco SC2200 host.

The local IP address is used for checkpointing and failover heartbeats with active/standby hosts.

Note This address is typically the same as that of *.IP_Addr1 (see below).

Step 2 Edit the second local IP address, *.ipAddrLocalB:

 
*.ipAddrLocalB = 10.10.1.27

This is the second IP address of the designated active, or primary, Cisco SC2200 host. It is the same as that of *.ipAddrLocalA.

Note If your configuration does not use an external card, leave this setting at the default value, 0.0.

Step 3 Edit the first corresponding peer's IP address, *.ipAddrPeerA:

 
*.ipAddrPeerA = 10.10.1.28

The peer IP address is used for checkpointing (the mirroring of call state information on the other SC) and failover heartbeat (regular keep-alive status messages). With two Cisco hosts in a failover configuration, the peer IP address is one of two IP addresses of the second host.

Step 4 Edit the second corresponding peer's IP address, *.ipAddrPeerB:

 
*.ipAddrPeerB = 10.10.2.28

Note If your configuration does not use an external card, leave this setting at the default value, 0.0.

Step 5 Edit the IP address of interface 1:

 
*.IP_Addr1 = 10.10.1.27

This is the same as the local address (*.ipAddrLocalA) of the first interface (used for signaling).

Step 6 Edit the IP address of interface 2:

 
*.IP_Addr2 = 10.10.2.27

This is the same as the local address (*.ipAddrLocalB) of the second interface (used for signaling).

Step 7 Edit the number of the port used between peer components or processes:

 
*.stPort = 7000

This can be the number of any unused port. This is the number of the port that communicates with the Cisco SLT.

Step 8 Edit a variety of additional parameters, as discussed below:

a. Determine the platform state (*.desiredPlatformState). As we have an active and a standby SC host, we select master for the designated active unit:

 
*.desiredPlatformState master

Note We must edit this parameter to slave on the designated standby unit.

b. Enable checkpointing (*.SyscheckpointEnabled). This ensures that calls that are in the talking state are preserved and survive a control switchover. All status checkpointing information is sent to the replicator on the active side.

 
*.SyscheckpointEnabled = true

c. Several connection types are supported, one of which is to the failover daemon (foverd). The daemon must be aware of A and B local and peer ports. Use the following values for the two required connections:

 
# connection 1 parameters

 
foverd.conn1Type = socket

 
foverd.ipLocalPortA = 1050

 
foverd.ipPeerPortA = 1051

 
# connection 2 parameters

 
foverd.conn2Type = socket

 
foverd.ipLocalPortB = 1052

 
foverd.ipPeerPortB = 1053

Note The above commented-out "connection 1" and "connection 2" lines are not required, but are useful in identifying the separate connection types.

Step 9 Examine the configuration. In our example configuration, we expect to see the following address assignments at a minimum in the file XECfgParm.dat on the primary host.

 
*.ipAddrLocalA = 10.1.1.27

 
*.ipAddrLocalB = 10.1.2.27

 
*.ipAddrPeerA = 10.1.1.28

 
*.ipAddrPeerB = 10.1.2.28

 
*.IP_Addr1 = 10.1.1.27

 
*.IP_Addr2 = 10.1.2.27

 
*.IP_Addr3 = 0.0.0.0

 
*.IP_Addr4 = 0.0.0.0

 
*.stPort = 7000

Note For the changes to the file XECfgParm.dat to take effect, you must restart the SC. For now, continue with the following step, and restart the SC when you are finished with all required provisioning. You do not need to restart the machine after other provisioning.

Prepare the Designated Standby Cisco SC2200 for Autoprovisioning

The most efficient way to provisioning the designated standby SC host is to enable a data synchronization parameter on both machines. This way, the only configuration required on the designated standby SC host is to edit the file XECfgParm.dat.

Step 1 The synchronization parameter in the file XECfgParm.dat is pom.dataSync, and you simply set it to true on the current machine:

 
pom.dataSync = true

As it comes up, the designated standby SC host will automatically pull the latest MML provisioning information from the active machine.

Step 2 You will need to edit the synchronization parameter on the designated secondary SC host when you edit the file XECfgParm.dat on that machine. (See Configuring the Designated Standby Cisco SC2200.) The only configuration that is required on the designated standby SC host is editing XECfgParm.dat. This will take care of the MML provisioning requirements for that machine.

For now, continue configuring the current machine. Proceed to Create the File config.mml, below.

Note When you are finished configuring the current (designated active) machine, restart the machine for the changes to XECfgParm.dat to take effect, then proceed to Configuring the Designated Standby Cisco SC2200.

Create the File config.mml

See Example Cisco SC2200 Node and Components. The following example steps address the principle components of an MML provisioning session on the designated active (primary) Cisco SC2200. You must also do this for the secondary SC in a fault-tolerant configuration. The result of the session is a file called config.mml. Only the key parameters are discussed. For a more detailed discussion of MML, see "Configuring with MML" at the following URL:

http://www.cisco.com/univercd/cc/td/doc/product/access/sc/rel7/prvplan/02mmlprv.htm

Caution The following is an example only. PSTN switch types and their provisioning requirements will vary. Although optional, descriptions are important for maintenance and troubleshooting.

Define Cards, Interfaces, and Point Codes

Step 1 First invoke MML from a dumb terminal connected to the Cisco SC2200:

 
sc2200>mml

The mml prompt appears.

Step 2 Start a new provisioning session as follows:

 
mml>prov-sta::srcver="new",dstver="new_config"

Note You must enclose value strings in quotes.

Step 3 Using the prov-add command, define and describe Ethernet cards, and assign each a slot.

 
mml>prov-add:CARD:NAME="en-0",DESC="Ethernet Card 0",TYPE="EN",SLOT=0

 
mml>prov-add:CARD:NAME="en-1",DESC="Ethernet Card 1",TYPE="EN",SLOT=1

Note the following parameters and their descriptions:

prov-add:CARD: Defines the Ethernet card
NAME: Name of the card
DESC: Description of the card
TYPE: Type of the card, EN (options are ATM, EN, PTI, V35)
SLOT: Slot number of the card (0 for built-in Ethernet card)

Step 4 Define Ethernet interfaces for the above cards. The CARD values must correspond with those in Step 3.

 
mml>prov-add:ENETIF:NAME="en-0-lif0",DESC="EN LIF 0",CARD="en-0"

 
mml>prov-add:ENETIF:NAME="en-1-lif1",DESC="EN LIF 1",CARD="en-1"

Note the following parameters and their descriptions:

prov-add:ENETIF: Defines the properties of the Ethernet card
NAME: Name of the interface
DESC: Description of the interface
CARD: Ethernet card name defined previously

Step 5 Define and describe a point code for the origination point code (OPC). This is the PSTN network address of both the primary and secondary Cisco SC2200s.

Note You must obtain point codes from Telcordia Technologies (formerly Bellcore) at http://www.telcordia.com, or from a third-party representative that interfaces with Telcordia, such as Illuminet at http://www.illuminet.com.

 
mml>prov-add:PTCODE:NAME="opc",DESC="Own Pointcode 214.110.035",NETADDR="214.110.35",NETIND=2

Note NETIND = 2 is a default value.

Step 6 Define and describe point codes for each destination point code (DPC) with which the SC communicates. DPCs include PSTN switches and SS7 route sets. Here we use the example of a Nortel DMS-100 switch.

 
mml>prov-add:PTCODE:NAME="dpc-dms100",DESC="dms100 point code 214-110-218",NETADDR="214.110.218",NETIND=2

Note the following parameters and their descriptions:

prov-add:PTCODE: Defines the SS7 Point Code of the SC.
NAME: Name of the point code
DESC: Description of the point code
NETIND: Network indicator, 2 in this case. (Options: 1 = CCITT or international, 2 = national)
NETADDR: Network address of the SC.

Define SS7 Paths and Their Properties

Define an SS7 path and assign sigsvsprop (signaling service property) values for communication to each of the PSTN switches. Later we will define the switch entities from which the paths are derived.

Step 1 Define an SS7 path and signaling service properties for the Nortel DMS-100 switch, ss7-dms100.

 
mml>prov-add:SS7PATH:NAME="ss7-dms100",DESC="ss7 ansi standard to dms100",DPC="dpc-dms100",
MDO="ANSISS7_STANDARD",CUSTGRPID="0000",CUSTGRPTBL="0101",SIDE="network"

 
mml>prov-add:sigsvcprop:name="ss7-dms100",BTermStartIndex="2"

 
mml>prov-add:sigsvcprop:name="ss7-dms100",BOrigStartIndex="1"

 
mml>prov-add:sigsvcprop:name="ss7-dms100",CLIPEss="1"

 
mml>prov-add:sigsvcprop:name="ss7-dms100",ReleaseMode="Sync"

Note the following parameters and their descriptions:

prov-add:SS7PATH: Defines a SS7 signaling path to the DMS-100 switch
NAME: Name of the signaling path
DESC: Description of the signaling path
MDO: MDO file name for the ANSI SS7 protocol
DPC: SS7 point code name of the switch
CUSTGRPID: A flag used for dial plan screening (A and B listing)
CUSTGRPTBL: A file that hold CUSTGRPID data; numbers are mapped to dial plan files
prov-add:sigvcprop: Defines signaling service properties, where

BTermStartIndex: 2 is a common default value
BOrigStartIndex: 1 is a common default value
CLIPEss: 1 is a common default value
ReleaseMode: Always use Sync.

Caution Take care to assign ReleaseMode="Sync" throughout. This improves call success rates.

Step 2 Define SS7 paths for all other switches as required. Parameters are as defined previously.

Defining External Nodes

The EXTNODE parameter is used to name the physical entities in the network, both switches and access gateways.

Step 1 The following assigns a name to the switch for which we assigned a point code in Define SS7 Paths and Their Properties.

 
mml>prov-add:PTCODE:NAME="dms100",DESC="Nortel DMS-100 switch",TYPE="DMS"

Note the following parameters and their descriptions:

prov-add:PTCODE: Defines the switch or GW
NAME: Name of the switch or GW
DESC: Description of the switch or GW
TYPE: Type of switch

Step 2 The following assigns a name to our Cisco AS5300 GW in a zone called Zone 1.

Note Organizing equipment into zones can be useful for management, but is not required. Choose names that are self-explanatory. Conventions can vary.

 
mml>prov-add:EXTNODE:NAME="z1-5300-1",DESC="zone 1 5300-1",TYPE="AS5300"

Define APCs, Linksets, SS7 Routes, and NAS Paths

The following steps define APCs (adjacent point codes), SS7 routes, and NAS paths, respectively.

Step 1 Define APCs to signal transfer points (STPs). STPs provide for signaling redundancy in the SS7 network. The following are for STPs A and B, respectively.

 
mml>prov-add:APC:NAME="apc-stpa",DESC="apc of stpa 214.111.000",NETADDR="214.111.0",NETIND=2

 
mml>prov-add:APC:NAME="apc-stpb",DESC="apc of stpb 214.112.000",NETADDR="214.112.0",NETIND=2

Note the following parameters and their descriptions:

prov-add:APC: Defines the adjacent point code at which the GW terminates
NAME: Name of the point code
DESC: Description of the point code
NETADDR: The adjacent point code
NETIND: Network indicator, 2 in this case. (Options: 1 = CCITT or international, 2 = national)

Note NETADDR is similar but not identical to OPC, APC, or DPC, being an MML parameter.

Step 2 Define linksets. These are communication paths between the Cisco 2611 SLT and the STPs.

 
mml>prov-add:LNKSET:NAME="ls-stpa",DESC="linkset to stpa via 2600",APC="apc-stpa",PROTO="SS7-ANSI",TYPE="IP"

 
mml>prov-add:LNKSET:NAME="ls-stpb",DESC="linkset to stpb via 2600",APC="apc-stpb",PROTO="SS7-ANSI",TYPE="IP"

Note the following parameters and their descriptions:

prov-add:LNKSET: Defines an SS7 linkset to the STP through the Cisco 2611 SLT
NAME: Name of the linkset
DESC: Description of the linkset
APC: The point code at which the linkset terminates
PROTO: The signaling protocol
TYPE: Transport type of the linkset. It is TDM in this case (options: TDM, IP)

Step 3 Define SS7 routes. These are redundant signaling paths that relate the OPC to the DPC.

 
mml>prov-add:SS7ROUTE:NAME="rs-dms100-a",DESC="ss7 routeset to dms100 via the stpa dpc of dms100 214-110-218",OPC="opc",DPC="dpc-dms100",LNKSET="ls-stpa",PRI=1

 
mml>prov-add:SS7ROUTE:NAME="rs-dms100-b",DESC="ss7 routeset to dms100 via the stpb dpc of dms100 214-110-218",OPC="opc",DPC="dpc-dms100",LNKSET="ls-stpb",PRI=1

Note the following parameters and their descriptions:

prov-add:SS7ROUTE: Defines an SS7 route to the switch
NAME: Name of the route
DESC: Description of the route
OPC: Origination SS7 point code; the PC defined in prov-add:PTCODE for the SC. See Define Cards, Interfaces, and Point Codes.
DPC: Destination SS7 point code; the PC defined in prov-add:PTCODE for the associated switch.
LNKSET: The linkset that is associated with this route. It is the SS7 linkset defined in prov-add:LNKSET in this case.

Step 4 Define the ISDN signaling path to the NAS, the links from the SC to the network access servers, or GWs in our case. The key parameter is NASPATH, which includes an (arbitrary) description, an EXTNODE assignment (for the NAS), and a signaling protocol (MDO). There are a variety of protocols; here we use Bell 1268 C3 ISDN protocol.

 
mml>prov-add:NASPATH:NAME="ip-z1-5301",DESC="ISDN PRI over ip to 5300-1 in zone 1",EXTNODE="z1-5300-1",MDO="BELL_1268_C3"

 
mml>prov-add:sigsvcprop:name="ip-z1-5301",BcInitState="OOS"

Note the following parameters and their descriptions:

prov-add:NASPATH: Defines an ISDN signaling path to the gateway
NAME: Name of the signaling path
DESC: Description of the signaling path
EXTNODE: The gateway the signaling path is connected to
MDO: MDO file name for the Bell 1268 ISDN protocol

Caution Recall that this is a nailed-up configuration. The Bell 1268 C3 protocol must be used in nailed-up configurations.

Define C7 IP Links and IP Links

The C7 IP link is used to define SS7 A-links between STPs A and B and the Cisco 2611 (SLT). The IP link is used to define the ISDN signaling paths (A and B, main and standby) between the GW (NAS) and the Cisco SLT. The STPs are redundant and provide load sharing for calls through two SLTs.

Note The Cisco Wholesale Voice Solution supports multiple RLM (Redundant Link Manager) groups for GWs only, not for the SLTs. For information about RLM, see Redundant Link Manager (RLM) at the following URL:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/120newft/120t/120t3/rlm_123.htm

Step 1 Assign C7 IP links. The parameter IPADDR here must map to the same parameter in Step 2, below.

 
mml>prov-add:C7IPLNK:NAME="c7-2601-0a",DESC="ss7 a-link to stpa via 2600-1 slc 0",LNKSET="ls-stpa",IF="en-0-lif0",IPADDR="IP_Addr1",PORT=7000,PEERADDR="10.10.1.26",SLC=0,PRI=1,TIMESLOT=0,NEXTHOP="0.0.0.0",NETMASK="255.255.255.255"

 
mml>prov-add:C7IPLNK:NAME="c7-2601-0b",DESC="ss7 a-link to stpb via 2600-1 slc 0",LNKSET="ls-stpb",IF="en-0-lif0",IPADDR="IP_Addr1",PORT=7000,PEERADDR="10.10.1.26",SLC=0,PRI=1,TIMESLOT=1,NEXTHOP="0.0.0.0",NETMASK="255.255.255.255"

 
mml>prov-add:C7IPLNK:NAME="c7-2602-0a",DESC="ss7 a-link to stpa via 2600-2 slc 1",LNKSET="ls-stpa",IF="en-1-lif1",IPADDR="IP_Addr2",PORT=7000,PEERADDR="10.10.2.26",SLC=1,PRI=1,TIMESLOT=0,NEXTHOP="0.0.0.0",NETMASK="255.255.255.255"

 
mml>prov-add:C7IPLNK:NAME="c7-2602-0b",DESC="ss7 a-link to stpb via 2600-2 slc 1",LNKSET="ls-stpb",IF="en-1-lif1",IPADDR="IP_Addr2",PORT=7000,PEERADDR="10.10.2.26",SLC=1,PRI=1,TIMESLOT=1,NEXTHOP="0.0.0.0",NETMASK="255.255.255.255"

Note the following parameters and their descriptions:

prov-add:C7IPLNK: Defines a C7 IP link to the SLT.
NAME: Name of the link
DESC: Description of the link
IF: Ethernet interface defined in prov-add:ENIF
IPADDR: IP address of the local machine
PORT: UDP port for SS7 backhaul on the local machine (the SC)
PEERADDR: IP address of the SLT
PEERPORT: UDP port for SS7 backhaul on the SLT
PRI: Priority
SLC: Signaling link code
LNKSET: SS7 linkset for this C7 IP link
TIMESLOT: Serial interface number on the SLT. The designation is 0 for serial 0/0, 1 for serial 0/1, 2 for serial 1/0, and 3 for serial 1/1.

Caution The parameter *.stPort in file XECfgParm.dat must also be configured to correspond to the local UDP port. On the primary (designated active) SC, make sure that *.stPort = 7000. Port 7000 is the primary port. A standby port would be assigned 7001. See Edit the File XECfgParm.dat.

Step 2 Assign IP links.

 
mml>prov-add:IPLNK:NAME="z1-531-10",DESC="ip link for nas service to z1 5300-1 10",SVC="ip-z1-5301",IF="en-0-lif0",IPADDR="IP_Addr1",PORT=3001,PEERADDR="10.10.1.25",
PEERPORT=3001,PRI=1,SIGSLOT=0,SIGPORT=0,NEXTHOP="0.0.0.0",NETMASK="255.255.255.255"

 
mml>prov-add:IPLNK:NAME="z1-531-100",DESC="ip link for nas service to z1 5300-1 100",SVC="ip-z1-5301",IF="en-1-lif1",IPADDR="IP_Addr2",PORT=3001,PEERADDR="10.10.2.25",
PEERPORT=3001,PRI=1,SIGSLOT=0,SIGPORT=0,NEXTHOP="0.0.0.0",NETMASK="255.255.255.255"

Note the following parameters and their descriptions:

prov-add:IPLNK: Defines an IP link for the ISDN signaling path defined in prov-add:path
NAME: Name of the link
DESC: Description of the link
IF: Ethernet interface for the link defined in prov-add:ENETIF
IPADDR: IP address of the Ethernet interface
PORT: UDP port number for ISDN over IP
PEERADDR: IP address of the Ethernet interface for ISDN over IP on the gateway
PEERPORT: UDP port number for ISDN over IP on the gateway

Caution You must assign either 3001, 3003, 3005, or 3007 to PEERPORT. The default for a NAS (network access server, or GW) is 3001.

Importing a Trunk File

After defining all the signaling components in the previous steps, you must define the mapping between the CICs (Carrier Identification Codes) on the SS7 side and the bearer channels on the GW (ISDN over IP) side. There are two methods to accomplish this task: using the MML prov-add:files command or the prov-add:nailtrnk command. These are presented below.

Note By default, the trunk file is assumed to be stored on the Cisco SC2200 in /opt/CiscoMGC/etc/cust_specific.

Option 1: Using the prov-add:files Command

Step 1 Use the command prov-add:files to import a trunk group file for use by the system. In the following example, a trunk mapping file named export_trunk.dat is referenced.

 
mml>prov-add:files:name="bcfile",file="cfg-mar17/export_trunk.dat",action="IMPORT"

The file to be imported looks like the following file for an example GW:

Note The keyword #format2 must be present on the first line of a trunk group file.

 
#format2 - 0   <---this line is required

 
1  ss7-dms100 ffff  1  ip-z1-5301  0  1

 
2  ss7-dms100 ffff  2  ip-z1-5301  0  2

 
3  ss7-dms100 ffff  3  ip-z1-5301  0  3

 
4  ss7-dms100 ffff  4  ip-z1-5301  0  4

 
<---snip--->

 
21  ss7-dms100 ffff  21  ip-z1-5301  0  21

 
22  ss7-dms100 ffff  22  ip-z1-5301  0  22

 
23  ss7-dms100 ffff  23  ip-z1-5301  0  23

 
24  ss7-dms100 ffff  24  ip-z1-5301  0  24

The seven columns of the above file (in an order that is unique to a Cisco SC) are defined as follows:

Column 1: Order number
Column 2: SS7 signaling path as defined in prov-add:ss7path
Column 3: Source span ID. Always enter ffff.
Column 4: SS7 CIC number.

Caution Ensure that the CIC here matches the CIC on the SC side, and also that it falls within the CIC range supported by the serving IXC (interexchange carrier) switch. You must confirm this with your telecommunications service provider.

Column 5: ISDN/IP signaling path as defined in prov-add:naspath
Column 6: Destination span ID. Range is an integer from 1 through 65535 or ffff (the default). This value is converted from decimal to hexadecimal, except when the value is ffff.

Note The above number for Column 6 must correspond with the value of nfas-int (Non-Facility Associated Signaling interface number) on the associated GW, as set by the command isdn service. It must match the number of interfaces that are defined on the GW. Multiple spans that are assigned to a GW will have multiple destination span IDs. However, the destination span is always 0 because the GW (NAS) is using NFAS, and Controller 0 is where the D-channel is located. For a detailed discussion of the parameter nfas-int and other dial-related commands and parameters, refer to the Cisco IOS Dial Technologies Command Reference, Release 12.2, at the following URL:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fdial_r/

Column 7: ISDN time slot number. These are DS0 bearer time slots. The series begins with 1 for each span.

Note See the note and reference immediately preceding. The above number must correspond with the value for b_channel (set by the command isdn service) on the associated GW.

Note the following parameters and their descriptions:

prov-add:files: Imports a file
name: Type of file to be imported. It is a trunk group with the keyword BCFile in this case.
file: Name of file to be imported.
action: "Import," which instructs MML to import the file

Option 2: Using the prov-add:nailtrnk command

Step 2 The second method is to use the regular MML prov-add:nailtrnk command, as in the following example:

 
mml>prov-add:nailtrnk:name="1",srcsvc="ss7-svc-sc1",srcspan="ffff",srctimeslot=101,dstsvc="nassvc-gw2, dstspan="0000",dsttimeslot=1

Note the following parameters and their descriptions:

prov-add:nailtrnk: Provisions an individual nailed-up bearer channel
name: Trunk identifier. It must be an integer > 0.
srcsvc: SS7 signaling path as defined in prov-add:ss7path
srcspan: Source span ID. Set it to ffff for SS7.
srctimeslot: SS7 CIC. Ensure that it matches with the CIC on the SC.
dstsvc: ISDN signaling path as defined in prov-add:naspath
dstspan: Destination span ID. Set it to 0 for ISDN over IP.
dsttimeslot: ISDN bearer channel number. It begins with 1.

TimeSaver The former method, Option 1, is highly recommended, because it reduces typing and introduces fewer errors.

Step 3 Whatever option you choose, copy the provisioning data to the production area (/opt/CiscoMGC/etc):

 
mml>prov-cpy

This command copies all the provisioning data and closes the provisioning session.

A copy of this configuration, except for the file XECfgParm.dat, is backed up and stored in /opt/CiscoMGC/etc/CONFIG_LIB/CFG_<dstver>

where <dstver> is the destination version, and CFG_ is prepended automatically.

Configuring the Designated Standby Cisco SC2200

Now provision the designated standby (secondary) host. The only provisioning required on this machine is to edit the file XECfgParm.dat. The MML provisioning is taken care of by the synchronization parameter. (See Prepare the Designated Standby Cisco SC2200 for Autoprovisioning.)

Step 1 Refer to Configuring the Designated Active Cisco SC2200.

Step 2 Assign user mgcuser to user group mgcgroup, as in Assign User mgcuser to User Group mgcgroup.

Step 3 See Edit the File XECfgParm.dat. Edit the file XECfgParm.dat on the secondary host with the same parameters, with the following exceptions:

a. Change the value of the parameter *.stPort.

Note With two Cisco hosts in a failover configuration, you must enter a different value (for example, 7001) for *.stPort in the file XECfgParm.dat on the secondary host.

b. Because this is the designated standby unit, we make it the slave unit, with the parameter *.desiredPlatformState:

 
*.desiredPlatformState = slave

Step 4 Examine the configuration. In our example configuration, we expect to see the following address assignments at a minimum in the file XECfgParm.dat on the designated standby host.

 
*.ipAddrLocalA = 10.1.1.28

 
*.ipAddrLocalB = 10.1.2.28

 
*.ipAddrPeerA = 10.1.1.27

 
*.ipAddrPeerB = 10.1.2.27

 
*.IP_Addr1 = 10.1.1.28

 
*.IP_Addr2 = 10.1.2.28

 
*.IP_Addr3 = 0.0.0.0

 
*.IP_Addr4 = 0.0.0.0

 
*.stPort = 7001 <--- port number must be different from that on primary host

Step 5 Enable the synchronization parameter. This is as you set it in Prepare the Designated Standby Cisco SC2200 for Autoprovisioning.

 
pom.dataSync = true

As it comes up, the designated standby SC host will automatically pull the latest MML provisioning information from the active machine.

Step 6 Restart the machine to enable the changes to the file XECfgParm.dat.

Configuring the Cisco Signaling Link Terminals

This section presents the following major topics:

Overview
Configuring Basic Parameters on Both Cisco SLTs
Configuring SLT1
Configuring SLT2

Note If the necessary hardware and software have not yet been installed, proceed first to Installing Cisco SLT Hardware and Software.

Overview

Because the Cisco SLTs communicate with both to the SS7 network as well as the SC host, there are two fundamental aspects of provisioning the SLTs:

Configuring the SS7 interface side
Configuring the IP interface side

Figure 5-3 illustrates these two aspects. The SS7 cloud contains STPs and SSPs, among other entities.

Figure 5-3 Two Aspects of Configuring the Cisco SLTs

With both SLTs set up to provide load sharing, they can both send calls to an active SC for call processing. In a fault-tolerant configuration, with both SLTs active simultaneously, we will refer to them simply as SLT1 and SLT2. A Session Manager facilitates the SS7 backhaul between the SLT and the SC. On each SLT, two sessions (maximum) can be configured:

1. The first session, session-0, is for SS7 backhaul to the standalone in a non-fault-tolerant case (not recommended) and to the active SC in our fault-tolerant case.

2. The second session, session-1, is for SS7 backhaul to the standby SC in our fault-tolerant case.

See our example in Figure 5-2. We begin with the configuration of SLT1, then highlight the simple difference in the configuration of SLT2.

Caution Note the following exceptions and caveats:

With the Cisco SLT, the SS7 MTP2 protocol is the only serial protocol supported. Therefore, you cannot configure serial interfaces for other protocols, such as HDLC, PPP, X.25, LAPB, and Frame Relay.
The encapsulation interface configuration command is not supported on the Cisco SLT image. Also, all other commands related to non-SS7 serial protocols are not supported.
Cisco recommends that you take MTP2 links out of service (OOS) at the Cisco SC2200 host before issuing Cisco SLT commands.

Configuring Basic Parameters on Both Cisco SLTs

This section applies to both SLTs. We use the example of SLT1 in Figure 5-2.

Configuring a Cisco SLT is not quite the same as configuring a router. To configure the basic parameters of the Cisco SLT, complete the following steps:

Step 1 Power on the Cisco SLT.

Caution Do not press any keys until the system messages stop. Any keys pressed during this time are interpreted as the first command, which may cause the Cisco SLT to power off and start over. It will take a few minutes for these messages to stop.

Step 2 When you are asked if you would like to configure the initial configuration dialog, enter y (yes) to begin the configuration.

 
Would you like to enter the initial configuration dialog? [yes/no]: y

At any point you may enter a question mark for help. Use Ctrl-c to abort configuration dialog at any prompt. Default settings are in square brackets.

Basic management setup provides only enough connectivity for management of the system. Extended setup will ask you to configure each interface on the system.

Step 3 Enter y (yes) to enter basic management setup.

 
Would you like to enter basic management setup? [yes/no]: y

 
Configuring global parameters:

Step 4 Enter the host name for the Cisco 2611 router.

 
Enter host name [Router]: 2600-1

Step 5 Enter the enable secret password. This password is encrypted (more secure) and cannot be seen when viewing the configuration. The enable secret is a password used to protect access to privileged EXEC and configuration modes. This password, after entered, becomes encrypted in the configuration.

 
Enter enable secret: enable_secret

Step 6 Enter an enable password that is different from the enable secret password. This password is not encrypted (less secure) and can be seen when viewing the configuration. The enable password is used when you do not specify an enable secret password, with some older software versions, and with some boot images.

 
Enter enable password: enable_password

Step 7 Enter the virtual terminal password, which prevents unauthenticated access to the Cisco SLT through ports other than the console port. The virtual terminal password is used to protect access to the router over a network interface.

 
Enter virtual terminal password: vt_password

Step 8 Configure the SNMP parameters.

 
Configure SNMP Network Management? [yes]: no

 
Community string [public]: 

Note We are not enabling SNMP in this example. SNMP is required to enable network management applications that use SNMP traps. See Enabling SNMP.

Step 9 Enter the interface name used to connect to the management network:

 
Current interface summary

 
Controller Timeslots D-Channel Configurable modes Status

 
T1 0/2     24        23        pri/channelized    Administratively up

 
T1 0/3     24        23        pri/channelized    Administratively up

 
Any interface listed with OK? value "NO" does not have a valid configuration

 
Interface                  IP-Address      OK? Method Status Protocol

 
Ethernet0/0                unassigned      NO  unset  up                    up      

 
Serial0/0                  unassigned      NO  unset  down                  down    

 
Ethernet0/1                unassigned      NO  unset  up                    down    

 
Serial0/1                  unassigned      NO  unset  down                  down    

 
Enter interface name used to connect to the management network from the above interface summary: Ethernet0/0

Step 10 Configure the Ethernet interface:

 
Configuring interface Ethernet0/0:

 
Configure IP on this interface? [yes]: y

Step 11 Specify the IP address and the subnet mask for the interface:

 
IP address for this interface: 10.1.1.26 

 
Subnet mask for this interface [255.0.0.0]: 255.255.255.0

 
Class A network is 10.0.0.0, 24 subnet bits; mask is /24

Step 12 Save configuration to NVRAM and exit the initial configuration mode.

 
The following configuration command script was created:

 
hostname 2600-1

 
enable secret 5 $1$0gLU$vLK1YHrMcianH5oVWFJNP/

 
enable password lablab

 
line vty 0 4

 
password lab

 
no snmp-server

!

 
no ip routing

!

 
interface Ethernet0/0

 
no shutdown

 
ip address 10.10.1.26 255.255.255.0

!

 
interface Serial0/0

 
shutdown

 
no ip address

!

 
interface Ethernet0/1

 
shutdown

 
no ip address

!

 
interface Serial0/1

 
shutdown

 
no ip address

!

end

 
[0] Go to the IOS command prompt without saving this config.

 
[1] Return back to the setup without saving this config.

 
[2] Save this configuration to nvram and exit.

 
Enter your selection [2]: 2

 
Building configuration...

 
Use the enabled mode 'configure' command to modify this configuration.

 
Press RETURN to get started!

This completes the basic configuration of SLT1.

Step 13 Repeat the above steps on SLT2, taking care to choose a different host name for the machine.

Configuring the Session Manager and RUDP

The Session Manager and the Reliable User Datagram Protocol (RUDP) are responsible for managing the communication sessions between the Cisco SLTs and the Cisco Signaling Controllers. Regardless of the number of SS7 links that the SC activates on the Cisco 2611, the SLT maintains only one Session Manager session with each of the Cisco SC2200s.

Caution You must reboot the SLT after setting a new session configuration or after changing existing session configuration. Do not change session timers unless instructed to do so by Cisco technical support. Changing timers may result in service interruption or outage.

Configuring the MTP2 Variant

As noted in Cisco SLT, SS7 MTP2 supports four variants. The parameters under one variant have different meanings, purposes, and ranges in another.

Note Note the following considerations:

Parameters that are not configured will remain at the default values.
The channel to be configured must be out of service at the Cisco SC2200 before the variant or the variant configuration can be changed.
After the variant configuration changes have been made, the router must be reloaded to apply the changes.

Do the following in global configuration mode to establish the appropriate SS7 MTP2 variant.

Step 1 Set the amount of DRAM to be used for I/O memory to 40 percent.

Note If you do not set the I/O memory to at least 40 percent, there will not be enough memory for the SS7 MTP2 signaling.

 
2600-1(config)# mem iomem 40

Step 2 Configure the MTP2 Telcordia variant (formerly Bellcore) for channel 2.

 
2600-1(config)# ss7 mtp2-variant Bellcore 2

Note The term "Bellcore" is still used to represent the Telcordia Technologies variant.

The router prompt will change to config-Bellcore.

Step 3 Set the aligned timer to 30,000 milliseconds.

 
2600-1(config-Bellcore)# T3 30000

Step 4 Set the maximum number of MSUs waiting for acknowledgment to 16.

 
2600-1(config-Bellcore)# unacked-MSUs 16

Step 5 Set the excessive delay timer to 50,000 milliseconds.

 
2600-1(config-Bellcore)# T7 50000

Step 6 Exit Bellcore variant configuration mode.

 
2600-1(config-Bellcore)# exit

Step 7 Exit configuration mode.

 
2600-1(config)# end

Step 8 Save the running configuration to the startup configuration.

 
2600-1# copy running-config startup-config

Configuring SLT1

Configure I/O Memory Size

To provide sufficient memory to process SS7 messages, you must set the I/O memory size to at least 40%:

 
slt1(config)# memory-size iomem 40

Configure the Session Manager Session

For each session, the first IP address and UDP port are for the SC host, and the second address and port are for the SLT itself.

Step 1 Establish session-0, which communicates with the designated active Cisco SC2200. The first address and port are those of the designated active SC, followed by those of this SLT.

 
slt1(config)# ss7 session-0 address 10.10.1.27 7000

 
10.10.1.26 7000

 
REBOOT the router after saving new configuration

Note Note the reboot message above.

Step 2 Establish session-1 on the active SLT. The first address and port are those of the designated standby SC, followed by the address and failover port of this SLT.

 
slt1(config)# ss7 session-1 address 10.10.1.28 7000

 
10.10.1.26 7001

 
REBOOT the router after saving new configuration 

Caution Make sure that these configurations match with those on both the Cisco SC2200s, or the sessions will never come up:

In the fault-tolerant case, the remote UDP ports in both sessions must be the same value.
Also in the fault-tolerant case, the local IP address in both sessions must be the same, because the SLT must support one Ethernet port for SS7 backhaul only. However, the local UDP port must be different.

Step 3 Reboot the SLT for the configuration to take effect.

Verify the Configuration

Do the following to ensure that the configuration is properly established.

Step 1 Verify the serial controllers, making sure both controllers are set to DTE.

 
slt1# show controller serial 0/0

 
Interface Serial0/0

 
Hardware is PowerQUICC MPC860

 
DTE V.35 TX and RX clocks detected.

 
idb at 0x80CA395C, driver data structure at 0x80CA98F0

 
<--- snip --->

 
slt1# show controller serial 0/1

 
Interface Serial0/1

 
Hardware is PowerQUICC MPC860

 
DTE V.35 TX and RX clocks detected.

 
idb at 0x80CB16D8, driver data structure at 0x80CB766C

 
<--- snip --->

Step 2 Verifying the serial interfaces, making sure the lines and protocols are up.

 
slt1# show interface serial 0/0

 
Serial0/0 is up, line protocol is up

 
Hardware is PowerQUICC Serial

 
MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec,

 
reliability 255/255, txload 5/255, rxload 1/255

 
Encapsulation SS7 MTP2, loopback not set

 
Keepalive set (10 sec)

 
Last input never, output 00:00:00, output hang never

 
<--- snip --->

 
slt1# show interface serial 0/1

 
Serial0/1 is up, line protocol is up

 
Hardware is PowerQUICC Serial

 
MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec,

 
reliability 255/255, txload 5/255, rxload 1/255

 
Encapsulation SS7 MTP2, loopback not set

 
Keepalive set (10 sec)

 
Last input never, output 00:00:00, output hang never

 
<--- snip --->

Step 3 Verify the Session Manager configuration. This command verifies the Session Manager sessions, including the IP addresses and UDP ports. Ensure that the addresses of the remote hosts (Cisco SC2200s) correspond with your network design.

 
slt1# show ss7 sm session

 
Session[0]: Remote Host 10.10.1.27:7000, Local Host

 
10.10.1.26:7000

 
retrans_t = 600

 
cumack_t = 300

 
kp_t = 2000

 
m_retrans = 2

 
m_cumack = 3

 
m_outseq = 3

 
m_rcvnum = 32

 
Session[1]: Remote Host 10.10.1.28:7000, Local Host

 
10.10.1.26:7001 <---the standby port on this host

 
retrans_t = 600

 
cumack_t = 300

 
kp_t = 2000

 
m_retrans = 2

 
m_cumack = 3

 
m_outseq = 3

 
m_rcvnum = 32 

Step 4 When you have completed the configuration, remember to reboot the SLT for the configuration to take effect.

Step 5 Display the Session Manager statistics.

The show ss7 sm stats command provides you statistics of each Session Manager session, including the state. The following is a typical successful report. Errors will be flagged as nonzero.

 
slt1# show ss7 sm stats

 
-------------------- Session Manager --------------------

 
Session Manager state = SESSION SET STATE-ACTIVE

 
Session Manager Up count = 7

 
Session Manager Down count = 6

 
lost control packet count = 0

 
lost PDU count = 0

 
failover timer expire count = 5

 
invalid_connection_id_count = 0

 
Session[0] statistics SM SESSION STATE-ACTIVE:

 
Session Down count = 0

 
Open Retry count = 0

 
Total Pkts receive count = 9

 
Active Pkts receive count = 1

 
Standby Pkts receive count = 0

 
PDU Pkts receive count = 8

 
Unknown Pkts receive count = 0

 
Pkts send count = 9

 
Pkts requeue count = 0

 
-Pkts window full count = 0

 
-Pkts resource unavail count = 0

 
-Pkts enqueue fail count = 0

 
PDUs dropped (Large) = 0

 
PDUs dropped (Empty) = 0

 
RUDP Not Ready Errs = 0

 
RUDP Connection Not Open = 0

 
RUDP Invalid Conn Handle = 0

 
RUDP Unknown Errors = 0

 
RUDP Unknown Signal = 0

 
NonActive Receive count = 0 

 
Session[1] statistics SM SESSION STATE-STANDBY: <---in a fault-tolerant application only

 
Session Down count = 0

 
Open Retry count = 86352 

 
Total Pkts receive count = 0

 
Active Pkts receive count = 0

 
Standby Pkts receive count = 0

 
PDU Pkts receive count = 0

 
Unknown Pkts receive count = 0

 
Pkts send count = 0

 
Pkts requeue count = 0

 
-Pkts window full count = 0

 
-Pkts resource unavail count = 0

 
-Pkts enqueue fail count = 0

 
PDUs dropped (Large) = 0

 
PDUs dropped (Empty) = 0

 
RUDP Not Ready Errs = 0

 
RUDP Connection Not Open = 0

 
RUDP Invalid Conn Handle = 0

 
RUDP Unknown Errors = 0

 
RUDP Unknown Signal = 0

 
NonActive Receive count = 0

Step 6 To see the overall configuration, see An Overall Configuration: SLT1, below.

Step 7 Proceed to Configuring SLT2.

An Overall Configuration: SLT1

 
slt1# show start

 
Using 951 out of 29688 bytes

!

 
version 12.0

 
service timestamps debug datetime msec localtime

 
service timestamps log datetime msec localtime

 
no service password-encryption

!

 
hostname slt1

!

 
enable password cisco123

!

!

!

!

!

 
memory-size iomem 40

 
ip subnet-zero

!

!

!

!

 
interface Ethernet0/0

 
ip address 10.10.1.26 255.255.255.0

 
no ip directed-broadcast

 
full-duplex

!

 
interface Serial0/0

 
no ip address

 
no ip directed-broadcast

 
no ip mroute-cache

!

 
interface Ethernet0/1

 
no ip address

 
no ip directed-broadcast

 
shutdown

!

 
interface Serial0/1

 
no ip address

 
no ip directed-broadcast

!

 
ip classless

 
no ip http server

!

 
tftp-server flash

 
ss7 session-0 address 10.10.1.27 7000 10.10.1.26 7000

 
ss7 session-1 address 10.10.1.28 7000 10.10.1.26 7001 <---required for fault tolerance

 
ss7 mtp2-variant Bellcore 0

 
ss7 mtp2-variant Bellcore 1

 
ss7 mtp2-variant Bellcore 2

 
ss7 mtp2-variant Bellcore 3

!

 
line con 0

 
exec-timeout 0 0

 
transport input none

 
line aux 0

 
line vty 0 4

 
exec-timeout 0 0

 
no login

!

end

Configuring SLT2

See Figure 5-2. The configuration of SLT2 is essentially identical to the configuration presented in Configuring SLT1, except for the address of the current SLT.

Configure the Session Manager Session

Step 1 Establish session-0 on SLT2.

 
slt2(config)# ss7 session-0 address 10.10.2.27 7000

 
10.10.2.26 7000

 
REBOOT the router after saving new configuration

Step 2 Establish session-1 on SLT2.

 
slt2(config)# ss7 session-1 address 10.10.2.28 7000

 
10.10.2.26 7001

 
REBOOT the router after saving new configuration 

Step 3 When you have completed the configuration, remember to reboot the SLT for the configuration to take effect.

Step 4 To see the overall configuration, see An Overall Configuration: SLT2, below.

An Overall Configuration: SLT2

 
slt2# show start

 
Using 951 out of 29688 bytes

!

 
version 12.0

 
service timestamps debug datetime msec localtime

 
service timestamps log datetime msec localtime

 
no service password-encryption

!

 
hostname slt1

!

 
enable password cisco123

!

!

!

!

!

 
memory-size iomem 40

 
ip subnet-zero

!

!

!

!

 
interface Ethernet0/0

 
ip address 10.10.2.26 255.255.255.0

 
no ip directed-broadcast

 
full-duplex

!

 
interface Serial0/0

 
no ip address

 
no ip directed-broadcast

 
no ip mroute-cache

!

 
interface Ethernet0/1

 
no ip address

 
no ip directed-broadcast

 
shutdown

!

 
interface Serial0/1

 
no ip address

 
no ip directed-broadcast

!

 
ip classless

 
no ip http server

!

 
tftp-server flash

 
ss7 session-0 address 10.10.1.27 7000 10.10.1.23 7000

 
ss7 session-1 address 10.10.1.28 7000 10.10.1.23 7001 <---required for fault tolerance

 
ss7 mtp2-variant Bellcore 0

 
ss7 mtp2-variant Bellcore 1

 
ss7 mtp2-variant Bellcore 2

 
ss7 mtp2-variant Bellcore 3

!

 
line con 0

 
exec-timeout 0 0

 
transport input none

 
line aux 0

 
line vty 0 4

 
exec-timeout 0 0

 
no login

!

end

Installing Cisco SC2200 Node Hardware and Software

The following discussion addresses the Cisco SC2200 host server and the Cisco SLT.

Note The online documents referred to use the term "Media Gateway Controller" (MGC) in place of "SC" or "Cisco SC2200 node." In any case, the role and function of the two entities is essentially the same. The following discussion concerns only the use of similar hardware and software.

Installing Cisco SC2200 Hardware and Software

Introduction

Table 5-3 lists the minimum hardware and software requirements for the Cisco SC2200 (simplex system).

Note Double hardware quantities for redundant systems, as required in SS7 environments.

The following is an abbreviated discussion that focuses on system-specific provisioning parameters with relation to a specific network-configuration example. For detailed information, refer to Cisco MGC Release 7 Provisioning Guide, at the following URL:

http://www.cisco.com/univercd/cc/td/doc/product/access/sc/rel7/swinst/index.htm

Note in particular the following chapters in the above document:

"Installing the Operating System Software" (Chapter 1)
(Installing the Sun Solaris 2.6 Operating System)
"Installing the Cisco Media Gateway Controller Software Release 7.4" (Chapter 4)

Table 5-2 Minimum Hardware and Software Requirements for the Cisco SC2200

Hardware	Software
One Sun Ultra 5 SPARC workstation, with a minimum of 2048MB¹ of RAM and a 4 GB hard disk	Sun Solaris 2.6 Cisco Media Gateway Controller software Release 7.4

1The install.sh script will fail without this minimum of RAM.

Installing Cisco SC2200 Hardware

Step 1 Refer to the following Web site:

Cisco SS7 Interconnect for Voice Gateways Solution, Release 1.1, at the following URL:

http://www.cisco.com/univercd/cc/td/doc/product/access/sc/rel7/soln/voip11/index.htm

Note The following steps refer to documents at the above URL.

Step 2 Refer to the following online document at the Cisco SS7 Interconnect for Voice Gateways Solution, Release 1.1 site:

Cisco Media Gateway Controller Hardware Installation Guide

Step 3 Refer to the following chapter in the above document:

"Cisco Media Gateway Controller Product Introduction"

a. In the section "Cisco SC2200 Product Overview," note the host platforms that support the Cisco SC2200, and select the appropriate host for your application.

b. In the section "Cisco MGC Product Configurations," note the host configuration options and select the appropriate option for your application.

Step 4 Refer to the following chapter in the Cisco Media Gateway Controller Hardware Installation Guide:

"Preparing the Installation Site"

Note the instructions that are specific to the hardware you have selected.

Step 5 Refer to the following chapter in the Cisco Media Gateway Controller Hardware Installation Guide:

"Hardware Installation Instructions"

a. Read the section "Installation Preview," and note the instructions that are specific to the hardware you have selected.

b. Read the section "Installing Host Hardware," and note the instructions that are specific to the hardware you have selected.

Step 6 Refer to the following chapter in the Cisco Media Gateway Controller Hardware Installation Guide:

"Cabling and Connections"

Connect your hardware components to the network as appropriate for your installation.

Step 7 Refer to the following chapter in the Cisco Media Gateway Controller Hardware Installation Guide:

"Power and Grounding"

Read the section "Connecting" for the host platform you have selected, and ensure that you observe the appropriate power and grounding requirements.

Installing Cisco SC2200 Software

Step 1 Refer to the following Web site:

Cisco SS7 Interconnect for Voice Gateways Solution, Release 1.1, at the following URL:

http://www.cisco.com/univercd/cc/td/doc/product/access/sc/rel7/soln/voip11/index.htm

Note The following steps refer to documents at the above URL.

Step 2 Refer to the following online document at the Cisco SS7 Interconnect for Voice Gateways Solution, Release 1.1 website:

Cisco MGC Software Release 7 Installation & Configuration Guide

Step 3 Refer to the following chapter in the above document:

"Installing the Sun Solaris 2.6 Operating System"

Follow the instructions in the above chapter to install the required software.

Caution For the most current information, including the latest patches, always refer to the release notes for the software provided for your host platform.

Basic Provisioning of the Cisco SC2200

Note The following procedures require reasonable proficiency in UNIX, and must be done in superuser mode. The following commands are entered at the command prompt (represented by a generic ">").

Installing the Solaris Operating System

If the Solaris OS has not yet been installed, refer to "Installing the Sun Solaris 2.6 Operating System," Chapter 1 in Cisco Media Gateway Controller Software Release 7 Installation and Configuration Guide, at the following URL:

http:// www.cisco.com/univercd/cc/td/doc/product/access/sc/rel7/swinst/1inst_os.htm

The above website also covers the following topics:

Booting from a local CD-ROM
Loading the Sun Solaris 2.6 operating system (including disk partitioning
Installing Sun Solaris patches
Installing alarm management software
Configuring a second Ethernet interface
Configuring a second disk drive (including Volume Manager, to support mirroring of the operating system)
Installing log and spool file systems

Uninstalling Preexisting Media Gateway Controller Software

You may need to uninstall existing software. If so, proceed as follows.

Step 1 Make sure the Cisco SC2200 software is not running. To stop the software, enter the following:

 
sc2200% /etc/init.d/CiscoMGC stop

Step 2 Go to the home directory where the Cisco SC2200 installation packages reside, then enter the following:

 
sc2200% uninstall.sh 

Step 3 To ensure that all the old software packages are completely uninstalled, enter the following:

 
sc2200% pkginfo | grep CSC

Look for package files (with the.pkg extension). If packages are listed in the output, uninstall them manually by entering the following:

 
pkgrm package_name_without_.pkg_extension

Installing Signaling Controller Packages

Step 1 Go to the home directory where the Cisco SC2200 installation packages reside (/opt/CiscoMGC), then enter the following:

 
sc2200% sh install.sh

Step 2 As the install script proceeds, choose the following options in response to various questions that will appear:

a. Select the BASE directory for the installation (the default is /opt/CiscoMGC.)

b. Use the admin file for automated installation, which overrides all install-time questions.

c. Select UID and GID for user mgcuser and group mgcgroup, which are created when the Utilities are installed.

Installing Patches (If Available)

The following procedure is necessary when patches are available. For the latest patches from Sun, refer to the following URL:

http://sunsolve.sun.com

Refer also to Installing the Sun Solaris Patches in "Installing the Sun Solaris 2.6 Operating System," Chapter 1 in Cisco Media Gateway Controller Software Release 7 Installation and Configuration Guide, at the following URL:

http:// www.cisco.com/univercd/cc/td/doc/product/access/sc/rel7/swinst/1inst_os.htm

Assigning User mgcuser to User Group mgcgroup

To enable the software to be used by a regular user other than the superuser, you must log in upon completion of the last reboot and assign the Cisco SC2200 users to belong to the mgcuser group. See Assign User mgcuser to User Group mgcgroup.

Editing the File XECfgParm.dat

The file XECfgParm.dat contains a variety of parameters that must be edited for your system to function. See Edit the File XECfgParm.dat.

For a complete list of parameters, including their functions, definitions, and sample values, see the Cisco Media Gateway Controller Software Release 7 Reference Guide at the following URL:

http://www.cisco.com/univercd/cc/td/doc/product/access/sc/rel7/sw_ref/index.htm

Restarting and Provisioning the Cisco SC2200

Enter the following commands at the prompt.

Note The name of the host machine prompt will vary.

Step 1 First stop all processes (through procM, the process manager).

 
sc2200% /etc/init.d/CiscoMGC stop

The following appears:

 
Waiting for procM to exit

 
...shutdown complete

Step 2 Restart the software:

 
sc2200% /etc/init.d/CiscoMGC start

The following appears:

 
sc2200% 

 
Provisioning the SC2200

 
Starting MML

This completes the basics of provisioning the Cisco SC2200 Signaling Controller. For the details of configuration, see Configuring the Cisco Signaling Controllers.

Installing Cisco SLT Hardware and Software

Installing Cisco SLT Hardware

Step 1 Refer to Cisco SS7 Interconnect for Voice Gateways Solution, Release 1.1, at the following URL:

http://www.cisco.com/univercd/cc/td/doc/product/access/sc/rel7/soln/voip11/index.htm

The following steps refer to documents at the above website.

Step 2 Refer to the following online document at the Cisco SS7 Interconnect for Voice Gateways Solution, Release 1.1 site:

Cisco Media Gateway Controller Hardware Installation Guide

Step 3 Refer to the following chapter in the Cisco Media Gateway Controller Hardware Installation Guide:

"Preparing the Installation Site"

Note the instructions that are specific to the hardware you have selected.

Step 4 Refer to the following chapter in the Cisco Media Gateway Controller Hardware Installation Guide:

"Hardware Installation Instructions"

a. Read the section "Installation Preview" in the above chapter, and note the instructions specific to the hardware you have selected.

b. Read the section "Installing the Cisco SLT" in the above chapter, and follow the instructions there.

c. Refer to the section "Installing and Configuring PCI Interface Cards" in the above chapter, and install the interface cards required for your network.

d. For further information on installing Cisco SLT interface cards and connecting to a network, refer to the Cisco WAN Interface Cards Hardware Installation Guide, at the following URL:

http://www.cisco.com/univercd/cc/td/doc/product/access/acs_mod/cis2600/hw_inst/wic_inst/wic_doc/index.htm

Step 5 Refer to the following chapter in the Cisco Media Gateway Controller Hardware Installation Guide:

"Cabling and Connections"

Connect your hardware components to the network as appropriate for your installation.

Step 6 Refer to the following chapter in the Cisco Media Gateway Controller Hardware Installation Guide:

"Power and Grounding"

Refer to the section "Connecting the Cisco SLT," and ensure that you observe the appropriate power and grounding requirements.

Step 7 Refer to Cisco SS7 Interconnect for Voice Gateways Solution, Release 1.1, at the following URL:

http://www.cisco.com/univercd/cc/td/doc/product/access/sc/rel7/soln/voip11/index.htm

Step 8 Refer to the following online document at the Cisco SS7 Interconnect for Voice Gateways Solution, Release 1.1 website:

Cisco Media Gateway Controller Software Release 7 Installation and Configuration Guide

Step 9 Refer to the following chapter in the Cisco Media Gateway Controller Software Release 7 Installation and Configuration Guide:

"Configuring the Cisco Signaling Link Terminal"

Read the section "Before Configuration" in the above chapter, with emphasis on the subsections "Prerequisites" and "Installing the Hardware."

Installing Cisco SLT Software

To function as a Cisco SLT and terminate SS7 signaling links, the Cisco 2611 router must be running a special version of the Cisco IOS software. The Cisco SLT is shipped with this Cisco IOS software, but if you have an existing Cisco 2611, you must install the correct version. For the latest information, refer to the online release notes for the most recent version of the Cisco Media Gateway Controller (Signaling Controller) software.

Cisco SLT WAN Interface Cards and Cables

To support your network and traffic requirements, you can select from a variety of WAN interface cards (WICs) and voice/WAN interface cards (VWICs) to connect to the SS7 network.

About the T1/E1 Multiflex Trunk Interfaces

The T1/E1 multiflex trunk interface cards are dual-mode T1 or E1 interfaces in a VWIC (Voice/WAN Interface Card) form for voice, data, and integrated voice/data applications. They support the SS7 Cisco SLT function, as do serial WICs.

The T1/E1 VWIC supports the following T1/E1 functionality:

Single or dual port, structured or unstructured T1/E1 functionality
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 allowing the interchange of time-division multiplexing (TDM) slots between the ports on a two-port card
Physical layer alarm forwarding feature between the two T1/E1 ports on dual-port cards

For additional information about the T1/E1 multiflex trunk interface cards, see Cisco WAN Interface Cards Hardware Installation Guide at the following URL:

http://www.cisco.com/univercd/cc/td/doc/product/access/acs_mod/cis2600/hw_inst/wic_inst/wic_doc/index.htm

Note For serial WICs, no particular configuration is required, except to ensure that the interfaces are not shut down.

For information about configuring other types of WICs, see Cisco WAN Interface Cards Hardware Installation Guide.

Table 5-2 lists the WAN interface cards, their part numbers, and the cable types required.

Table 5-3 Cisco SLT WAN Interface Cards and Cables

Card Type	Description	Product Number	Cable Type Required
VWIC	1-port T1 multiflex trunk interface	VWIC-1MFT-T1	T1/E1 cable with RJ-45 connector
	1-port E1 multiflex trunk interface	VWIC-1MFT-E1
	2-port T1 multiflex trunk interface	VWIC-2MFT-T1
	2-port E1 multiflex trunk interface	VWIC-2MFT-E1
Drop and Insert¹ VWIC	2-port T1 multiflex trunk interface with drop and insert	VWIC-2MFT-T1-D1
Drop and Insert¹ VWIC	2-port E1 multiflex trunk interface with drop and insert	VWIC-2MFT-E1-D1
Serial WIC	1-port high-speed serial interface	WIC-1T	RS-449, RS-530, V.35
Serial WIC	2-port high-speed serial interface	WIC-2T	the above or blue "smart" cable

1Drop and Insert is another term for the TDM cross-connect function.

About Logical Channels

Each SS7 link defined on the SC is considered a logical channel, and each logical channel corresponds to a physical interface on the Cisco 2611. You can define two SS7 links (logical channels) from the SC to a Cisco 2600 series router. The logical channels map to the physical serial interfaces on the router from right to left, as follows:

Numbering for an interface in the first slot always starts with channel 0.
Numbering for an interface in the second slot always starts with channel 2.
If a slot is empty, these rules still apply.

Table 5-4 shows some examples of how different signaling termination channels might map to physical interface positions on the Cisco 2611.

For more information about configuring the Signaling Controller software, see the documentation that came with it.

Table 5-4 Mapping of Logical Signaling Termination Channels to Cisco 2611 Interfaces

Logical Channel	Cisco 2611 Physical Interface
	Two 2-Port WICs	1-Port WIC on Right, 2-Port on Left	Two 2-Port WICs	2-Port WIC on Right, 1-Port on Left
0	Not used: Serial 0/0	Assigned to port in first (right) slot: Serial 0/0	Not used: Serial 0/0	Not used: Serial 0/0
1	Assigned to second port in first (right) slot: Serial 0/1	—	Not used: Serial 0/1	Assigned to second port in first (right) slot: Serial 0/1
2	Not used: Serial 0/2	Assigned to first port in second (left) slot: Serial 0/1	Assigned to first port in second (left) slot: Serial 0/2	Assigned to first port in second (left) slot: Serial 0/2
3	Assigned to second port in second (left) slot: Serial 0/3	Not used: Serial 0/2	Assigned to second port in second (left) slot: Serial 0/3	—

Restrictions

Note the following restrictions on the interface cards:

Only SS7 serial interfaces and protocols are supported. There is no support for HDLC, PPP, Frame Relay, ATM, X.25, or other non-SS7 serial WAN protocols.
Each Cisco SLT supports only two SS7 signaling links.
Each T1 or E1 port supports only one SS7 signaling link.

Although only two MTP 2 links can be terminated using the Cisco SLT, the two MTP 2 links can be terminated by using both ports of a 2-port VWIC/WIC, or two links can be terminated across two VWIC/WICs, one on each.

In addition to the WAN or dual-mode interface cards, the following minimum hardware is required:

For 2T WICs, an individual cable from the following list is needed for each interface being used for link termination:

EIA/TIA-449: CAB-SS-449FC EIA/TIA-449 Cable, DCE Female to Smart Serial, 10 ft; CAB-SS-449MT EIA/TIA-449 Cable, DTE Male to Smart Serial, 10 ft
EIA/TIA-530: CAB-SS-530AMT EIA/TIA-530 Cable, DTE Male to Smart Serial, 10 ft (no female EIA/TIA-530 available)
V.35: CAB-SS-V35FC V.35 Cable, DCE Female to Smart Serial, 10 ft; CAB-SS-V35MT V.35 Cable, DTE Male to Smart Serial, 10 ft

For 1T WICs, an individual cable from the following list is needed for each interface being used for link termination:

EIA/TIA-449: CAB-449MT EIA/TIA-449 Cable, DTE, Male, 10 ft; CAB-449FC EIA/TIA-449 Cable, DCE, Female, 10 ft
EIA/TIA-530: CAB-530MT EIA/TIA-530 Cable, DTE, Male, 10 ft (no female EIA/TIA-530 available)
V.35: CAB-V35MT V.35 Cable, DTE, Male, 10 ft; CAB-V35FC V.35 Cable, DCE, Female, 10 ft

For a T1/E1 VWIC, a T1/E1 cable with RJ-45 connector is required.
Cable connectors—EIA/TIA-449, EIA/TIA-530, V.35, and gender—depend upon your preference and requirements.
The power source—48V DC or AC—depends on your preference and requirements.

Note After the Cisco SLT is configured, you must configure the point codes, linksets, SS7 signaling links, and the associated MTP 2 parameters on the signaling controller. See Create the File config.mml 5-10.

Table of Contents

Provisioning SS7-Based POPs

Overview

Architecture

Cisco SC2200 Node Components

Cisco SC2200 Signaling Controller

Cisco SLT

Configuring the Cisco SC2200 Node Components

Configuring the Cisco Signaling Controllers

Configuring the Designated Active Cisco SC2200

Assign User mgcuser to User Group mgcgroup

Edit the File XECfgParm.dat

Prepare the Designated Standby Cisco SC2200 for Autoprovisioning

Create the File config.mml

Define Cards, Interfaces, and Point Codes

Define SS7 Paths and Their Properties

Defining External Nodes

Define APCs, Linksets, SS7 Routes, and NAS Paths

Define C7 IP Links and IP Links

Importing a Trunk File

Configuring the Designated Standby Cisco SC2200

Configuring the Cisco Signaling Link Terminals

Overview

Configuring Basic Parameters on Both Cisco SLTs

Configuring the Session Manager and RUDP

Configuring the MTP2 Variant

Configuring SLT1

Configure I/O Memory Size

Configure the Session Manager Session

Verify the Configuration

An Overall Configuration: SLT1

Configuring SLT2

Configure the Session Manager Session

An Overall Configuration: SLT2

Installing Cisco SC2200 Node Hardware and Software

Installing Cisco SC2200 Hardware and Software

Introduction

Installing Cisco SC2200 Hardware

Installing Cisco SC2200 Software

Basic Provisioning of the Cisco SC2200

Installing the Solaris Operating System

Uninstalling Preexisting Media Gateway Controller Software

Installing Signaling Controller Packages

Installing Patches (If Available)

Assigning User mgcuser to User Group mgcgroup

Editing the File XECfgParm.dat

Restarting and Provisioning the Cisco SC2200

Installing Cisco SLT Hardware and Software

Installing Cisco SLT Hardware

Installing Cisco SLT Software

Cisco SLT WAN Interface Cards and Cables

About the T1/E1 Multiflex Trunk Interfaces

About Logical Channels

Restrictions