Reliability and Recovery
252 Avaya Application Solutions IP Telephony Deployment Guide
TCP keepalive
This procedure is implemented for the H.225.0/Q.931 call signaling channel. In this procedure,
the endpoint periodically sends TCP keepalive messages to determine if the TCP peer is
reachable or not. The TCP peer can be a C-LAN board (in the case of an S8700 Server), or the
Media Server (in the case of the S8300 Server). The TCP keepalive message is only sent when
the TCP connection is idle.
IP Telephones and Softphones rely on RAS and TCP keepalive procedures to monitor the
signaling connectivity status with ACM Server. For the S8300 Media Server, there is no TCP
keepalive from S8300 to the endpoints.
G700/G350 Media Gateway recovery
If the link between the remote media gateway and the gatekeeper is broken, or the gatekeeper
is down, the LSP activates and assume call processing for the media gateway. The main
gatekeeper can be the
●
S8700, see
S8700/G700/G350 configuration
●
S8500, see
S8700/G700/G350 configuration
●
S8300, see
S8300/G700/G350 configuration
The strategy by which the media gateways change control from the primary to the LSP
gatekeeper is driven by the gateway using the alternate gatekeeper list.
S8700/G700/G350 configuration
Note:
Note:
The following description applies to the S8500 as well as the S8700.
In this configuration, the connectivity path between the remote Media Gateway and the S8700
Call Controller is as follows:
G700/G350
⇔
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.
Summary of Contents for Application Solutions
Page 1: ...Avaya Application Solutions IP Telephony Deployment Guide 555 245 600 Issue 3 4 1 June 2005 ...
Page 20: ...About This Book 20 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 21: ...Issue 3 4 1 June 2005 21 Section 1 Avaya Application Solutions product guide ...
Page 22: ...22 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 106: ...Call processing 106 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 124: ...Avaya LAN switching products 124 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 139: ...Issue 3 4 1 June 2005 139 Section 2 Deploying IP Telephony ...
Page 140: ...140 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 186: ...Traffic engineering 186 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 204: ...Security 204 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 228: ...Avaya Integrated Management 228 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 274: ...Reliability and Recovery 274 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 275: ...Issue 3 4 1 June 2005 275 Section 3 Getting the IP network ready for telephony ...
Page 276: ...276 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 356: ...Network recovery 356 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 366: ...Network assessment offer 366 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 367: ...Issue 3 4 1 June 2005 367 Appendixes ...
Page 368: ...Appendixes 368 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 394: ...Access list 394 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 414: ...DHCP TFTP 414 Avaya Application Solutions IP Telephony Deployment Guide ...