Determine Which Monitored Controllers Are Available; Select The Active Controller - Avaya 9601 Administering

System Failover and Survivability
administrative/automatic failback parameters and the monitoring intervals might be obtained via the
46xxsettings file, the PPM, or the deskphone's user interface.
The priority order in which the list is obtained is as follows:
1. Deskphone user interface (set using SIP CRAFT procedure)
2. PPM
3. Settings file
4. DHCP (Option 242)
Each of these sources might provide a list of controllers (servers). The contents of each one of
these lists is assumed to be in priority order.
Related Links
Controller Determination and Survivability Activity

Determine which monitored controllers are available

Using the Monitored Controllers list, the deskphone performs DNS queries to resolve hostnames
and the signaling protocol (TLS, TCP, UDP in that order when no DNS NAPTR or SIP URI
parameter is located). To determine which of the Monitored Controllers is actually available to
provide service, the phone performs a maintenance activity for each Monitored Controller. The
phone starts the controller search timer and sends a SIP REGISTER (adding bindings) message to
each controller, which may necessitate establishing a TLS or TCP connection to the controller.
The controller is considered available once a 200 OK response is received in response to the
REGISTER request. Once a controller has been marked as available, the phone unregisters from
the controller. If all the Monitored Controllers are available before the end of the
CONTROLLER_SEARCH_INTERVAL the phone continues with selecting the Active Controller. If at
least one Monitored Controller is available at the end of the CONTROLLER_SEARCH_INTERVAL,
the phone continues determining which controllers are available.
If a failure response to the REGISTER request is received, the controller is considered unavailable
and depending on the failure code, either retries the query, provides the requested credentials,
abandons the query, or stops monitoring this specific controller entirely.
If no response to the REGISTER request is received within the timeout period, the phone retries the
monitoring attempt using the RECOVERYREGISTERWAIT parameter value as a guideline.
Related Links
Controller Determination and Survivability Activity

Select the active controller

If the value of the SIPREGPROXYPOLICY parameter is "alternate" and a user is logged in, the
phone must attempt and maintain a single active SIP registration with the highest priority Available
Controller; the number of Available Controllers that the phone simultaneously registers with is the
Administering Avaya 9601/9608/9611G/9621G/9641G/9641GS IP Deskphones SIP
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Comments on this document? infodev@avaya.com
August 2015