Issue 1 May 2011 141
Chapter 10: System Failover and Survivability
Supporting survivability
SIP software provides support for simultaneous calls from multiple servers to accommodate
situations that can occur due to network or server failures. This support ensures that contact
data is preserved and actionable during failover transition, active calls continue, and that much
of the deskphone functionality is available. The following secondary gateways are supported:
●
Avaya Secure Router 2330 and 4134
●
Audiocodes MP-series analog and BRI gateways; Audiocodes MP-series using SIP over
TCP or TLS for signaling (UDP is not recommended for signaling) and RTP or SRTP for
media
●
Cisco 2811 ISR; Cisco ISR using at least one combination of TCP or TLS for signaling
(UDP is not recommended for signaling) and RTP or SRTP for media
●
Juniper SRX 210 and 240
●
I55
●
Teldat Vyda gateway
●
Expanded survivability to Avaya Aura
®
Session Manager
Deskphones fail over to a secondary controller for alternate registration (SES Failover to
Session Manager (SM) to a non-AST controller). Simultaneous registration occurs between
SMs/BSM (Branch Session Manager) as opposed to alternate registration from SES to SES or
SES/SM to a non-AST controller. This arrangement facilitates faster failover/failback transitions
than that of the failover solutions offered in previous SIP software releases and provides
minimal (if any) disruption from an end user viewpoint.
Contact caching and caching limits in a Session Manager environment are supported. Multiple
operations on a cached contact are not allowed. Preserved media connections/calls are
supported. During failover, changes to applications other than Contacts are cached and are
updated by the PPM with which the phone successfully registers.
If the SIP connection recovery is in progress due to a brief network outage, the phone will also
attempt to recover its XMPP connection to Presence Server automatically by re-logging in to
PS. If the PS server is unreachable, Presence will not be available. If the connection recovery
fails, the phone will display an appropriate error message.
With SES and non-AST controllers, contact data is cached until the maximum cache size of 25
contacts is reached; configuration data is cached without limitations. With SM, the PPMs are in
sync and the data is sent to the PPM; data is cached only in case of failure.
Moving subscriptions to a secondary SM/BSM for simultaneous registration has the following
effects on call states and transitions:
To Next Page
Loading...
