Nortel Networks SRG 50 NN43001-307 - Manual (Page 113)

Adaptive Network Bandwidth Management 113
When a call is made from a zone with Adaptive Network Bandwidth
Management enabled, to a third party gateway, which has no zone, then the
zone of the Virtual Trunk (VTRK) is used and appears in the zone table.
Figure 35 "Adaptive Network Bandwidth Management graph" (page
113)
shows an example of the bandwidth changes.
Figure 35
Adaptive Network Bandwidth Management graph
When a Call Server receives a QoS alarm, the two zones that originated
the alarm are determined. Using this information, the Call Server reduces
the bandwidth limit between the two zones. This zone-to-zone bandwidth
limit (in effect at any particular time) is known as the Sliding Maximum
Bandwidth Limit and is a percentage of the Configured Interzone bandwidth
limit. The Sliding Maximum value is displayed using the
prt interzone
command. The QoS Factor % is also displayed and is the percentage of
the Sliding Maximum versus the configured allowable bandwidth. The Call
Server checks the Network Bandwidth zone management tables for the
originating and terminating zones of the new call to determine the available
bandwidth for the call.
For more information about alarms, see Software Input Output
Reference—System Messages (NN43001-712).
When feedback indicates a significant QoS change in a zone, the Call
Server reduces the available bandwidth (Sliding Maximum Bandwidth Limit)
in the zone until the QoS reaches a satisfactory level. Once satisfactory
QoS is reached, the bandwidth is slowly raised until either the full bandwidth
is available or until QoS degrades again. Bandwidth changes can be
configured to be gradual (to reduce rapid swings and variations) or rapid.
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
.