User's Manual

During survivable mode, when registered to the B5800 Branch Gateway system, the
phone is not able to obtain dial plan information from the Avaya Aura
®
Session Manager
as it would normally expect. This DIALPLAN strings can be used to set what numbers are
dialed immediately when matched without waiting for any dialing timeout. Multiple entries
can be used, separated by | characters. For example, on a typical B5800 Branch Gateway
system, the following might be used. The first entry matches local extension numbers.
The next two entries match numbers for other branches. The final entry matches US
national number dialing:
SET DIALPLAN [2]xx|[8]xxxxx|[6]xxxxxx|9Z1xxxxxxxxxx
• DISCOVER_AVAYA_ENVIRONMENT
This setting is used by the phone to set whether is should request if the controller to which
it has registered supports AST (Advanced SIP Telephony). B5800 Branch Gateway
systems do not support AST. However, since survivable phones connect in normal mode
to Avaya Aura
®
Session Manager, the setting DISCOVER_AVAYA_ENVIRONMENT 1
can be used.
• ENABLE_REMOVE_PSTN_ACCESS_PREFIX
Enables the removal of the PSTN access prefix from collected dial strings when the phone
is registered with a non-AST controller such as B5800 Branch Gateway. Enabling this
parameter (1) when the phone is communicating with an AST-capable controller has no
effect. The default is 0 (do not remove prefix).
• FAILBACK_POLICY
This setting controls how the phone checks for return to its primary server when available.
The following values are used:
• admin (SET FAILBACK_POLICY admin)
The phone waits for administrative interventions. This option should not be used with
B5800 Branch Gateway.
• auto (SET FAILBACK POLICY auto)
The phone periodically checks the availability of the primary controller and
dynamically fails back. This is the default setting.
• FAST_RESPONSE_TIMEOUT
This timer terminates SIP INVITE transactions if no SIP response is received within the
specified number of seconds after sending the request. This is useful when a phone goes
off-hook after connectivity to the centralized SIP Server is lost, but before the phone has
detected the connectivity loss. After the SIP INVITE is terminated, the phone immediately
transitions to Survivable Mode. Default 4 seconds.
• MSGNUM
This sets the number dialed when the Message button is pressed and the phone is in
normal centralized mode. For example, the extension number for the Modular Messaging
system.
Survivable extensions
Implementing the Avaya B5800 Branch Gateway November 2011 199