Ess No Service Timer; Link Recovery; Server-To-Gateway Link Recovery - Avaya ESS User Manual

ESS Design and Planning

ESS no service timer

During ESS administration, a value is entered for the no service timer. The value of the no
service timer determines the amount of time the IPSI waits, after losing communication with the
Main server or controlling ESS server, before requesting service from the highest ranked ESS
server on its priority list. All stable calls remain in a stable condition when the no service timer
activates. The time from when the no service timer actives, to the time the IPSI requests service
of an ESS server, is called the no service time out interval. If the communication to the Main
server is restored before the no service time out interval expires, normal system recovery
occurs.
The value for the no service timer is administrable from three to 15 minutes, with a default of
five minutes. For more information on the no service timer see,
page seven on page 126.

Link Recovery

!
Important:
This section provides a high-level overview of Link Recovery. For more detailed
Important:
information see, Maintenance Procedures for Avaya Communication Manager
3.0, Media Gateways and Servers (03-300192).
Communication Manager offers two levels of Link Recovery:
H.248 server-to-gateway Link Recovery
●
H.323 gateway-to-endpoint Link Recovery
●
H.248 server-to-gateway Link Recovery
The H.248 link between an Avaya server running Avaya Communication Manager Software and
the Avaya Media Gateway provides the signaling protocol for:
Call setup
●
Call control (user actions such as Hold, Conference, or Transfer) while the call is in
●
progress
Call tear-down
●
If the link goes down, Link Recovery preserves any existing calls and attempts to re-establish
the original link. If the gateway cannot reconnect to the original server, then Link Recovery
automatically attempts to connect with another server or Local Survivable Processor (LSP).
84 Avaya Enterprise Survivable Servers (ESS) Users Guide
System-parameters ess form -
on page 84
on page 87