Avaya 9601 Administering page 136

System Failover and Survivability
Related Links
User experience during failover transition
Moving subscriptions from one SM to another SM/BSM (Branch System
Manager) due to failover
Transition is comprised of the following conditions for moving subscriptions:
• Limbo - The phone has lost its connection to its primary controller, but has not yet detected this
condition, regardless of whether a user is on a call or not.
• Moving Subscriptions Interval (MSI) - The phone has detected a lost connection to the primary
controller and since it has already registered with a non-primary controller, this is the interval
between limbo and successful subscription to the non-primary controller. The subscription can
be moved regardless of whether a user is on a call or not. The Call Preservation Message Box
or the Acquiring Services screen are not displayed during MSI.
• Call Preservation - During an active call, the phone has detected a lost connection to the
primary controller and exhibits media preservation behavior.
• The failover icon displays on the Top Line when failing over to a non-AST controller (for
example, Audiocodes) or in the very short interval after limbo and before a successful
subscription from one SM to another (or BSM) in the same community.
• When transition to the secondary server (or back to the primary server) occurs, all deskphone
functionality is restored to normal.
Moving subscriptions occurs immediately after limbo has ended or when there is a graceful socket
closure. For an active call scenario, media preservation will only keep shuffled calls or calls using
direct media between endpoints up with a direct RTP stream until the call has ended. The user can
only put this call on Hold, resume the call, or end the call. The user can also answer any incoming
call and the media preserved call is put on hold. During MSI the user can't use call related softkeys
(Hold, Conf, Transfer) for call appearances or bridged calls and the softkeys are not removed from
the screen. If the user presses another call appearance or a Favorite Feature an error beep occurs.
The Prompt Line displays "Limited phone service". Click to dial links do not work.
All AST features and BCAs are displayed on the phone and SBM24 during MSI regardless if there is
an active call. If a user tries to use an AST feature, the feature fails and the phone displays "Feature
invocation failed." When the Phone Button is pressed, the Home Screen (if there is one) displays
instead of the Phone Screen. The user can press the Phone button to navigate to the Home Screen
(if there is one) and all Home Screen sub-screens are accessible. The phone does not block new
invites during transition. Changes to applications other than Contacts, for example, Speed Dial, are
cached and are updated by whichever PPM with which the phone successfully registers. Any
changes made under the Avaya menu Options & Settings take place (including the Home Screen)
immediately.
If the deskphone is idle when failover occurs and the user presses a call appearance or Favorite
Feature, the phone plays an error beep. Going off hook produces no dial tone. The Prompt Line
displays "Limited phone service" and no digits are displayed on the screen. All Home Screen sub-
screens are accessible. The user can access all the web links from any of the Home Screen options
except for a "Click to Dial Link," which produces an error beep if selected. The Prompt Line displays
"Limited phone service" in this case.
Administering Avaya 9601/9608/9611G/9621G/9641G/9641GS IP Deskphones SIP
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on page 135
Comments on this document? infodev@avaya.com
August 2015