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Cisco AS5800 Series Universal Gateways

Trunk Group Dial Out Feature Module

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DS0 Trunk Group Dial Out Feature Module

Table Of Contents

DS0 Trunk Group Dial Out Feature Module

Overview

Platform and Signalling Support

Trunk Group Resource Manager

Trunk Group CLI Command

DS0 Trunk Group Configuration Example

PRI Trunk Configuration

Show Trunk Group Command

Glossary


DS0 Trunk Group Dial Out Feature Module


Overview

The DS0 Trunk Group Dial Out feature adds functionality that enhances outbound call routing by giving the user control over individual DS0s for outbound calls. Previous to this feature, outbound DS0s could not be configured separately from DS1s. The dial out capabilities of a DS1 applied to all DS0s under that DS1.

Currently, the aggregation of DS1s into trunk groups is done via the Trunk Group Resource Manager (TGRM). The DS0 Trunk Group Dial Out feature enables the TGRM subsystem to aggregate DS0s into trunk groups also. The dial out capabilities of these DS0 trunk groups can then be configured directly at the DS0 level, via the TGRM CLI and by setting the Authentication Authorization and Accounting (AAA) attributes.

The configuration of DS0s for outbound calls enables the Dial on Demand feature to initiate outbound calls over a set of B channels.

DS0 Dial Out Trunk Groups are configured on a Network Access Server (NAS). They support both digital and asynchronous calls and can be configured for the following types of circuits.

Integrated Services Digital Network (ISDN)

Primary Rate Interface (PRI)

Non-Facility Associated Signaling (NFAS)

A trunk group is a logical grouping of multiple T1/E1 interfaces with the same signaling characteristics. A single trunk group can contain up to 64 trunks. Each trunk group can consist of DS0s from different circuits, but each individual DS0 can belong to only one trunk group. Trunk groups configured for ISDN can consist of both PRI and NFAS interfaces.

Platform and Signalling Support

DS0 Dial Out Trunk Groups are supported on Cisco AS5350, AS5400, and AS5850 Universal Gateways.


Note DS0 Dial Out Trunk Groups can be provisioned for dial out only at present and should not be provisioned as targets of dial-peers.



Note DS0 Dial Out Trunk Groups do not support voice interfaces.


Trunk Group Resource Manager

The Trunk Group Resource Manager (TGRM) supports the logical grouping, configuration, and joint management of one or more interfaces. The TGRM is used to store configuration information and to accept or select an interface from a trunk group when requested.

A trunk group is provisioned as the target of a dial peer or a dial out profile on an AAA server, and the TGRM transparently selects the specific interface and channels to use for incoming or outgoing calls. Trunks are selected based on the trunk that is least used (default configuration) or the hunt-scheme configured.

Using trunk groups simplifies the task of configuring dial peers and interfaces, and also enables the dynamic selection of interfaces as needed in the access server.

A trunk group can include any number of interfaces, but all the interfaces in a trunk group must use the same type of signaling.

The TGRM subsystem has been enhanced to add fractional trunks to a trunk group. A fractional trunk is a single DS0 or a group of DS0s from a trunk.

Trunk Group CLI Command

The trunk-group command assigns a trunk to a trunk group by specifying the trunk group label parameter and optionally setting the preference parameter.

The DS0 Dial Out Trunk Group feature adds two new optional keywords:

timeslots <list of timeslots>

preference <preference>

The timeslots keyword allows you to selectively add DS0s from a signaling circuit. Fractional trunk-groups are configured from the controller configuration mode only (as a PRI serial interface may represent multiple member interfaces, including NFAS). If the timeslots option is not specified, all the DS0s in the signaling circuit are assigned to the trunk-group.

The preference keyword is configured after the timeslots option and is visible only when the timeslots option is used. This helps to differentiate between the list of timeslots number and the preference number.

The following example shows the syntax for configuring selected DS0s using the timeslots keyword and the preference keyword.

trunk-group <label> timeslot <list of timeslots> preference <preference>

The following example shows the syntax for configuring all the DS0s in the signaling circuit:

trunk-group <label> <preference>

Syntax Parameter Descriptions

label

Trunk group label. Maximum length of the trunk group label is 127 alphanumeric characters.

list of timeslots

List of the interfaces from the signalling circuit to be added to the trunk group.
Range is 1 to 64.

preference

Priority of the trunk group member in a trunk group. Range is from 1 (highest priority) to 64 (lowest priority). Preference can be used to sort a list of trunks in order. A trunk with no preference is given the highest preference.


DS0 Trunk Group Configuration Example

The following example shows the configuration steps for PRI signalling. Controller T1 3 is a trunk configured for PRI.

PRI Trunk Configuration


Step 1 Configure framing, clock source, DS0 group, etc.

AS5400(config)#controller T1 3
AS5400(config-controller)#framing esf
AS5400(config-controller)#clock source line secondary 3
AS5400(config-controller)#linecode b8zs
AS5400(config-controller)#pri-group timeslots 1-24
AS5400(config-controller)#!

Note The timeslots option is NOT available in the serial interface configuration mode since a serial interface may represent an NFAS serial interface.


Step 2 Configure timeslots and preference.

AS5400(config)#controller T1 3
AS5400(config-controller)#framing esf
AS5400(config-controller)#clock source line secondary 3
AS5400(config-controller)#linecode b8zs
AS5400(config-controller)#pri-group timeslots 1-24
AS5400(config-controller)#trunk-group PRI-TRUNK-GROUP-1  timeslots 1-10 
AS5400(config-controller)#trunk-group PRI-TRUNK-GROUP-2  timeslots 11-15 
AS5400(config-controller)#trunk-group PRI-TRUNK-GROUP-3  timeslots 20-22 preference 10 

Note When a PRI/NFAS trunk is fractionally added to a trunk-group, the timeslots keyword is compulsory.



Note DS0 trunk group configuration and conventional trunk group configuration are mutually exclusive. Conventional trunk group configuration is done in the serial interface mode and places all DS0s in the PRI into the trunk group.



Show Trunk Group Command

The show trunk group command displays the DS0s that belong to a particular trunk group.
A trunk-group can be a group of DS0s from various signaling channels.

Show Trunk Group Example - Trunk Group with PRI Trunks

AS5400#show trunk group pri-tg
Trunk group: pri-tg
         Description:
         trunk group label: pri-tg

         Translation profile (Incoming):
         Translation profile (Outgoing):

         Hunt Scheme is least-used
         Max Calls (Incoming):   NOT-SET (Any)   NOT-SET (Voice) NOT-SET (Data)
         Max Calls (Outgoing):   NOT-SET (Any)   NOT-SET (Voice) NOT-SET (Data)
         Retries: 0

         Trunk 2/1:23     Preference 10
                 Channels :  1-23
                 Total channels available : 23
                 Data = 0, Voice = 0, Modem = 0, Pending = 0, Free = 23
         Total calls for trunk group: Data = 0, Voice = 0, Modem = 0
                                      Pend = 0, Free = 23

         advertise_flag 0x00000040, capacity timer 25 sec tripl_config_mask 0x00000000
         AC_curr 24, FD_curr 0, SD_curr 0

         succ_curr 0 tot_curr 0
         succ_report 0 tot_report 0
         changed 0 replacement position 0

Glossary

AAA

Authentication Authorization and Accounting

CLI

Command Line Interface

DS0

Digital Signaling Interface 0. A 64 Kbps link.

DS1

Digital Signaling Interface 1. Multiple DS0 links.

Hunt-scheme

Mechanism configured under trunk group CLI by which TGRM selects a suitable timeslot for an outgoing call.

ISDN

Integrated Services Digital Network

NAS

Network Access Server

NFAS

Non-Facility Associated Signaling

PRI

Primary Rate Interface

TGRM

Trunk Group Resource Management

Trunk group

A configurable logical grouping of DS0-group/pri-group that share the same call parameters

Signaling Circuit

PRI/NFAS/external signaling group configured on a T1/E1 trunk

VoIP

Voice over IP