Avaya ESS User Manual

Timing considerations
Issue 1.1 June 2005 87
● If the calling party hangs up during Link Recovery, expect inaccuracies in the CDR records
for the recovery time period.
● Phone buttons (including feature access buttons) do not work.
H.323 gateway-to-endpoint Link Recovery
The H.323 link between an Avaya Media Gateway and an H.323-compliant IP endpoint
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 endpoint cannot reconnect to the original Gateway, then H.323 Link
Recovery automatically attempts to connect with alternate TN799DP (CLAN) circuit pack within
the original server’s configuration, or to a LSP.
H.323 Link Recovery does not diagnose or repair the network failure that caused the link
outage, however it:
● Attempts to overcome any network or hardware failure by re-registering the IP Endpoint
with its original Gateway.
● Maintains calls in progress during the re-registration attempt.
● Continues trying to reconnect if the call ends and the IP Endpoint has not yet reconnected
to its original Gateway.
● Attempts connecting to and registering with an alternate Gateway if so configured.
See Table 9
for a synopsis of the recovery outcomes.
Table 9: Synopsis of recovery outcomes
If Then
No Gateway is found The endpoint is out-of-service until it can find a
Gateway.
The IP endpoint registers with a new
Gateway
The call ends and the endpoint is available (full
features and buttons) through the new Gateway.
Original Gateway accepts re-registration The endpoint is available (full features and
buttons) through the new Gateway.
Call in progress but endpoint cannot
re-register
A call in progress remains so.
No new calls are accepted.
Features and buttons are inoperable.

Avaya ESS Specifications

General

Brand	Avaya
Model	ESS
Category	Server
Language	English