Avaya 555-245-600 manual Auto fallback process

Reliability and Recovery

The auto fallback process

While LSP is the acting call controller, the Media Gateway attempts to register with the primary server every 30 seconds or whenever there are no active calls (this signaling also acts as keep-alive messages to the primary server). The first registration request with the primary server will set up encryption on TCP link for H.248 messages. The MG will keep LSP registration until MG is accepted by primary server. Once registered with primary, Media Gateway will drop LSP link. Once all Media Gateways have migrated form LSP, LSP will un-register all IP end points, which automatically will re-register with primary server.

This automatic migration of H.248 to primary server can be administered to happen immediately (default), or when there are no active calls, or can be scheduled for a time of a day window.

Connection preserving failover/failback for H.248 media gateways

This feature allows existing stable calls to be preserved when the media gateway fails over to another server, or LSP, or returns to its primary server. It is supported on all H.248 media gateways. It applies to failover and fallback of media gateway to or from an LSP and to or from an ESS.

During the failover/fallback process the bearer connection of stable calls are preserved. These include, analog stations and trunks, DCP stations, digital trunks, IP stations using media gateway resources, ISDN-PRI trunks, calls between gateways, IGAR, and previously connection-preserved calls.

G250 and IG550 Media Gateway standard local survivability function (SLS)

SLS is new survivable call processing engine that provides service to the media gateway when the gateway cannot reach Avaya Communication Manager. This engine is resident in the media gateway firmware and provides basic telephony functions at the branch without being registered to Avaya Communication Manager.

The SLS features are:

●Local station and outbound PSTN calling

●Inbound calls over the trunks to be delivered to available stations

●Acts as an H.323 gatekeeper for local IP phones to register (maximum of 10 IP phones can register)

●Call Detail Recording in a syslog format

During transition to survivability mode, only local IP-IP calls are preserved.

274 Avaya Application Solutions IP Telephony Deployment Guide