Nortel Networks NN43001-563

26 Overview of IP Trunk3.01

H.323 RAS, IP Trunk3.01 (and later) uses RAS Messaging to register

with the Gatekeeper if provisioned to do so. IP Trunk 3.01 (and later) then

processes calls by scanning its Directory Number (DN) information. If the

call is not resolved using the local Address TranslationProtocol Module

(ATPM)and IP Trunk 3.01 (and later) is registered with a Gatekeeper, then

IP Trunk3.01 (and later) routes the call to the Gatekeeper.

The IP Trunk3.01 (and later) node is subordinate to the Gatekeeper for all

calls requiring the Gatekeeper. The IP Trunk 3.01 (and later) node registers

with the Gatekeeper according to H.323 protocol, requests admission,

accepts the reply according to H.323 protocol, and handles the call based

on the returned message from the Gatekeeper.

A CS 1000M node consists of two components:

•Call Server – used for call control of CS 1000M gateways

•Signaling Server – used for protocol analysis

The CS 1000M Gatekeeper accepts the registration of multiple IP trunk

cards implicitly in a single RRQ. This means that all Follower cards are

registered at the same time as the Leader card, because the CS 1000M

node returns an endpointIdentiﬁer assigned by the Gatekeeper to that

node. Later, a request to establish a call to a Gatekeeper-controlled

endpoint receives in the response the enpointIdentiﬁer of the endpoints

that was provided at registration.

The CS 1000M gateways interwork with the IP Trunk3.01 (and later)

gateway resident function which generates the FACILITYredirect. The

FACILITYredirect is used when calls terminate at an IP Trunk 3.01 (and

later) node. The CS 1000M gateways do not use this redirection themselves.

Other Gatekeepers accept the FACILITYredirect and registration of multiple

IP trunk cards in a single RRQ; that is, the Followers are registered with,

and at the same time as, the Leader.

IP Trunk3.01 (and later) interworks with the CS 1000M systems and IP

Peer Networking. As CS 1000M and IP Peer Networking use MCDN only,

the only applicable protocol is MCDN. IP Trunk3.01 (and later) uses the

"interoperability format" of the non-standard data with IP Peer Networking

and all other gateways accessiblethrough CS 1000M.

When IP Trunk3.01 (and later) inter-operates with itself, with ITG Trunk

2.x.25, or with BCM 2.5 FP1, the IP PeerNetworking CS 1000M Gatekeeper

is not required. The existing ITG Trunk 2.1 node-based dialing plan is

converted automatically to IP Trunk3.01 (and later) by .

Nortel Communication Server 1000

IP TrunkFundamentals

NN43001-563 02.01 Standard

Release 5.5 21 December 2007