Avaya 555-245-600 Manual Do Utilizador

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Reliability and Recovery
272 Avaya Application Solutions IP Telephony Deployment Guide
 
IGAR relies on Call Admission Control.   When all VoIP RTP resources have been used the next 
attempt to get a VoIP RTP resource results in denial of the VoIP connection. Communication 
Manager 3.0 will attempt to use existing applications and features to redirect the call 
accordingly. Each IP audio stream will require a VoIP RTP resource from either a TN2302AP IP 
Media Processor or a G700 media gateway. Exactly how many audio streams can be supported 
by these resources depends on the codec selection. Upon hitting the VoIP RTP resource limit, 
IGAR immediately attempts to use an alternate path for a bearer connection to the network 
region of the called party using PSTN facilities allocated for use by the IGAR feature.
Survivability for branch office media gateways
This section describes the survivability features for branch-office media gateways.
H.248 Media Gateway recovery via LSP
If the link between the remote media gateway and the media gateway controller is broken, or 
the controller is down, the local survivable processor (LSP) activates and assume call 
processing for the media gateway. The media gateway controller can be the S8700, S8500, or 
S8300. The strategy by which the media gateways change control from the primary to the LSP 
controller is driven by the gateway using the media gateway controller list.
When the media gateway controller 
is an S8700-series or S8500 server
Note:
Note:
The following description applies to the S8500 as well as the S8700-series 
server.
In this configuration, the connectivity path between the remote Media Gateway and the S8700 
Call Controller is as follows:
Media Gateway <=> IP network <=> C-LAN <=> PN back plane <=> IPSI <=> IP network <=> S8700
Link connectivity between the S8700 call controller and the G700 or G350 media gateway is 
monitored through the exchange of keepalive messages between the two components. If the 
link between the active call controller and the media gateway is severed, the gateway tries to 
reestablish the link using its alternate gatekeeper list. The alternate gatekeeper list is divided 
into primary and secondary addresses. All primary addresses receive priority weighting over the 
secondary addresses. Normal practice is to designate all C-LANs for the primary controller as 
primary gatekeeper addresses, and all the Local Survivable Processors (LSP) as secondary 
addresses. This practice gives a media gateway the best possible chance of registering with its 
primary call controller before registering with the LSP and entering into survivable mode.