Nortel Networks NN43001-314 - Manual (Page 56)

56 Bandwidth Management
With the Network Bandwidth Management feature, you can configure
bandwidth zones on a network basis so that codec selection and bandwidth
allocation software can identify whether Internet Telephones or gateways
are physically co-located (in the same bandwidth zone) even though they
are controlled by different Call Servers.
Adaptive Network Bandwidth Management is an enhancement of Bandwidth
Management in which Quality of Service (QoS) metrics are used to
automatically lower available bandwidth.
ATTENTION
IMPORTANT!
After all bandwidth is used, any additional calls are blocked or rerouted. Keep this
in mind when designing and implementing Network Bandwidth Management.
Codec negotiation
Codec refers to the voice coding and compression algorithm used by DSPs.
Each codec has different QoS and compression properties.
IP Peer Networking supports the per-call selection of codec standards,
based on the type of call (interzone or intrazone). IP Peer Networking
supports the following codecs (with supported payload sizes in parentheses,
with the default value in bold):
• G.711 A/mu-law (10 ms, 20 ms, and 30 ms)
• G.729 A (10 ms, 20 ms, 30 ms, 40 ms, and 50 ms)
• G.729 AB (10 ms, 20 ms, 30 ms, 40 ms, and 50 ms)
• G.723.1 (30 ms) (though it can limit the number of DSP channels
available)
• T.38 for fax
The G.XXX series of codecs are standards defined by the International
Telecommunications Union (ITU).
By default, the G.711 codec must be supported at both ends of a call.
Codec configuration is performed for each node and is independent of the
signaling gateway (SIP or H.323) that is used on the node.
If a CS1000E system is used, the same payload sizes for the same codec
type should be configured on all IPMG cabinets in a system. Otherwise,
TDM to TDM calls between IPMG cabinets are not successful.
If more than one codec is configured, then the minimum payload size among
the configured codecs is used for the SIP Trunk Gateway codec negotiation.
Nortel Communication Server 1000
Branch Office Installation and Commissioning
NN43001-314 01.02 Standard
Release 5.0 20 June 2007
Copyright © 2007, Nortel Networks
.