3. Settings file
4. DHCP server (Option 242)
The phone performs the DNS queries to resolve hostnames and the signaling protocol. The order is
set as TLS, TCP, and then UDP when there is no DNS NAPTR or SIP URI. The phone sends the
SIP REGISTER request for each CONTROLLER_SEARCH_INTERVAL. The phone retries the
monitoring attempt using the RECOVERYREGISTERWAIT parameter.
If the value of the SIPREGPROXYPOLICY parameter is alternate and a user is logged in, the phone
maintains a single active SIP registration. SIP registration is done with the highest priority available
controller. Also, the parameter FAILBACK_POLICY controls the SIP registration priority. If the
FAILBACK_POLICY parameter is configured with automatic instead of admin, then the phone’s
active controller has the highest priority.
If the value of the SIPREGPROXYPOLICY parameter is simultaneous and a user is logged in, the
phone maintains all active SIP registrations. The phone simultaneously registers using the value
provided in the SIMULTANEOUS_REGISTRATIONS and SIPDOMAIN parameters.
The phone uses a SIP URI instead of SIPS URI unless SRTP is enabled. When registration is
successful, the phone sets the SIPPROXYSRVR_IN_USE parameter to the IP address of this active
controller.
The phone starts a search for a new active controller whenever it encounters one of the following
triggers :
• Trigger 1: The TCP socket closes or TCP Keep-alive timeout occurs.
• Trigger 2: The phone receives an administrative failback trigger from a Configured Controller.
• Trigger 3: Fast Response Timer.
• Trigger 4: The phones receives n incoming INVITE from a non-active controller.
• Trigger 5: Re-registration with the active controller is timed out.
Advanced SIP Telephony feature determination
The parameter DISCOVER_AVAYA_ENVIRONMENT determines whether the selected controller
supports the Advanced SIP Telephony (AST) feature. When the parameter value is set to 1, the
phone sends a SUBSCRIBE request to the active controller for the Feature Status Event Package
(avaya-cm-feature-status).
The phone determines the AST mode based on the response 202. Then it starts an internal timer of
16 seconds and waits to receive a NOTIFY message as
active
.
If the phone does not receive a NOTIFY message and receives a termination message instead, then
the non-AST mode is enabled. Synchronization with the Personal Profile Manager (PPM) server
starts when the AST mode is enabled.
Synchronization with the Personal Profile Manager server
The phone performs the synchronization with the Personal Profile Manager (PPM) server only when
the
getAllEndpointConfiguration
request is successful. If the
Failover and survivability overview
September 2017
Installing and Administering Avaya J129 IP Phone
75
