Nortel BCM200 Integration Manual page 22

22 BCM 200/400 Release 4.0 configuration
Field
Enable Voice
Activity Detection
Jitter Buffer
G.729 payload size
(ms)
G.723 payload size
(ms)
G.711 payload size
(ms)
Enable T.38 fax
Solution Integration Guide for Multisite Business Communications Manager Systems
Copyright © 2007, Nortel Networks
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Value
G.723
<check box>
Auto
None
Small
Medium
Large
10,20,30,40,50,60
30
10,20,30,40,50,60
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Enterprise: Common
NN49000-303 01.01 Standard
Release 4.0, 3.7 29 June 2007
Description
Performance note: Codecs on all networked
BCMs must be consistent to ensure the proper
functionality of interacting features such as
Transfer and Conference.
Systems running BCM Release 3.5 or later
allow codec negotiation and renegotiation to
accommodate inconsistencies in codec settings
over VoIP trunks.
Voice Activity Detection (VAD), also known
as silence suppression, identifies periods of
silence in a conversation and stops sending
IP speech packets during those periods. In
a typical telephone conversation, most of the
conversation is half-duplex, meaning that one
person is speaking while the other is listening. If
VAD is enabled, no voice packets are sent from
the listener end. This greatly reduces bandwidth
requirements. G.723.1 and G.729 support VAD.
G.711 does not support VAD.
Performance note: VAD on all networked BCMs
and IPT systems must be consistent to ensure
functionality of features such as Transfer and
Conference. The Payload size on the IPT must
be set to 30ms.
Select the size of jitter buffer for your system.
Set the maximum required payload size, per
codec, for the VoIP calls sent over H.323 trunks.
Note: Payload size can also be set for Nortel
IP telephones. See BCM 4.0 Telephony Device
Installation Guide (N0060609).
When enabled, the system supports T.38 fax
over IP.
Caution: Fax tones broadcast through a
telephone speaker may disrupt calls at other
telephones using VoIP trunks in the vicinity of