Nortel Networks NN43001-563

20 Overview of IP Trunk3.01

In addition to routing IP Telephonycalls with locally conﬁgured call-routing

options, IP Trunk3.01 takes advantage of the centralized IP Telephony call

routing of an H.323 Gatekeeper residing on a Signaling Server elsewhere

on the network.

The H.323 Gatekeeper allows or denies access to IP network gateways. It

also provides address analysis to ﬁnd the destination gateway or device.

A gateway is a devicethat translates circuit-switched signaling into H.323

signaling and translates circuit-switched bit stream user data into packetized

user data to enable the data to be delivered across an IP network. IP Trunk

3.01 (and later) provides IP access between the Meridian 1/CS 1000M

system and the IP network carrying voice trafﬁc.

IP Trunk3.01 (and later) interworks with ITG Trunk 2.x, but not with ITG

Trunk1.0. For ITG Trunk1.0 to interwork with IP Trunk 3.01 (and later),

upgrade ITG Trunk1.0 to ITG Trunk 2.0. See Appendix "Upgrade an ITG

Trunk1.0 node to suppor t ISDN signaling trunks" (page 473).

IP Trunk3.01 (and later) interworks with a CS1000M system, which fulﬁls

the role of a Gatekeeper. The Gatekeeper uses directly-routed calls. See

"Directly-routed calls" (page 22). Using H.323 Registration and Admission

Signaling (RAS), IP Trunk3.01 (and later)registers with the Gatekeeper,

if provisioned to do so. IP Trunk 3.01 (and later) then processes calls by

scanning its directory number information and routes unresolved calls to

the Gatekeeper.

For a Meridian 1 system to interwork with a CS 1000M system, the following

requirements must be met:

•The ITG-Pentium 24-port trunk card and the Media Card 32-port trunk

card must be upgraded to IP Trunk 3.01 (and later) software. This

upgrade supports MCDN features and Gatekeeper registration. As well

as this document, see TelephonyManager 3.1 System Administration

(NN43050-601) for more information on installing, upgrading, and

upgrading IP Trunk3.01 (and later) parameters.

•The IP Trunk3.01 (and later) node must be conﬁgured to register with

the CS 1000M Gatekeeper. Refer to "Gatekeeper-resolved endpoints"

(page 334) and to TelephonyManager 3.1 System Administration

(NN43050-601) for more information on how to conﬁgure the IP Trunk

3.01 (and later) options.

IP Trunk3.01 (and later) is subordinate to the Gatekeeper for all calls that

require Gatekeeper intervention. This means that the IP Trunk 3.01 (and

later) node performs the following actions:

•registers with the Gatekeeper

•requests admission

•accepts the reply

Nortel Communication Server 1000

IP TrunkFundamentals

NN43001-563 02.01 Standard

Release 5.5 21 December 2007