Nortel Succession 1000 Installation And Configuration Manual page 29

load-sharing basis for the Internet Telephone Proxy Server (TPS) and an
alternate route for the H.323 Gateway software.
When planning survivability strategies for the Succession Signaling Server, a
second Succession Signaling Server should be included in the plan. Two
Succession Signaling Servers can load-share when the system contains
multiple VGMCs. Also, one Succession Signaling Server is a Leader
Succession Signaling Server that acts as the primary, or master, TPS. The
other Succession Signaling Server is a Follower Succession Signaling Server
that acts as a secondary, redundant TPS, Virtual Trunk, and Gatekeeper. The
Gatekeeper (Primary, Alternate, or Failsafe) must reside on the Leader
Succession Signaling Server.
If the Leader Succession Signaling Server fails, an election process takes
place and the Follower Succession Signaling Server becomes the master TPS.
The Internet Telephones reregister to the Follower Succession Signaling
Server and system operation resumes. If the Follower fails, the Internet
Telephones registered to the Follower reregister to the Leader Succession
Signaling Server.
This process is explained in the following steps:
1 The Internet Telephones are distributed between the two Succession
Signaling Servers (load-sharing). The H.323 Gateway runs on the Leader
Succession Signaling Server.
2 The Leader Succession Signaling Server fails.
3 The Follower Succession Signaling Server takes on the role of the Leader
Succession Signaling Server and acquires the Leader Succession
Signaling Server's IP address if necessary.
4 The Time-to-Live (TTL) of Internet Telephones registered with the
failed Succession Signaling Server expires. This causes those Internet
Telephones to reset and register with the new Leader Succession
Signaling Server.
Note: Only the Internet Telephones registered with the failed
Succession Signaling Server are reset.
Planning and engineering
Signaling Server Installation and Configuration
Page 29 of 116