Nortel Networks SRG 50 NN43001-307 - Manual (Page 26)

26 Description
CAUTION
Service Interruption
If the network is planned so that IP Phones use a different route
to the main office than that used by the SRG, a fault condition
can occur. When the SRG can reach the main office but the IP
Phone cannot ping the main office due to a network outage, an
IP Phone registration can force the telephone into a cycle of
registering locally, being redirected to the main office, rebooting,
and then registering locally again. When this cycle occurs, further
diagnose the network outage.
Capacity
Each CS 1000 main office can support up to 255 branch offices, which can
be made up of any combination SRG and MGC based MG 1000B. SRG 50
Release 2.0 and later supports up to 80 survivable IP users. However,
since all IP Phones register with the main office, the governing factor is the
maximum number of IP Phones that can be supported at the main office.
This means the total number of IP Phones in all offices can be no greater
than the capacity of the main office. See one of the following documents to
determine the total number of phones your system can support:
• Communication Server 1000E Planning and Engineering (NN43041-220)
• Communication Server 1000M and Meridian 1 Large System Planning
and Engineering (NN43021-220)
Virtual Trunks capacity
The SRG capacity to support a number of simultaneous calls depends on
the specific codec type used and the available bandwidth.
If both the intrazone and interzone codes are configured as Best Quality
(G.711), the SRG supports up to 24 Virtual Trunks (H.323 or SIP),
otherwise, only 15 Virtual Trunks (H.323 or SIP) are supported.
In Normal Mode, the codec selection used is controlled by specific
programming of the CS 1000.
In Local Mode, if the WAN has failed, Virtual Trunks between the SRG
and CS 1000 cannot be established. However, the SRG will continue to
convert calls from IP terminals for communication through the PSTN. Nortel
recommends you use G.711 codec.
Nortel Communication Server 1000
Main Office Configuration Guide for SRG 50
NN43001-307 02.02 Standard
Release 5.0 3 December 2007
Copyright © 2005-2007, Nortel Networks
.