Server User Manual

84 System description

— release

— establish

•

Retrieval of DSP information, such as:

— DSP ﬁrmware

— DSP self-test status

— card reset

•

SNMP conﬁguration (that is, community names and trap subscription)

— alarm generation through SNMP traps

• File transfer, including conﬁguration ﬁles, software upgrade, dialing plan

ﬁles, bootp ﬁles, activity log, and call trace ﬁles

Codec proﬁles

Codec refers to the voice coding and compression algor ithm used by the

DSPs on the IP trunk card. The G.XXX series of codecs are standards

deﬁned by the International Telecommunications Union (ITU). Different

codecs have different QoS and compression properties. The speciﬁc

codecs and the order in which they are to be used for codec negotiation is

conﬁgured in TM 3.1.

When conﬁguring the IP Trunk 3.01 (and later) node in TM 3.1, select the

image containing the needed codecs, and the preferred codec negotiation

order. The ﬁnal codec used is determined by the codec negotiation process

with the far end during call setup. Parameters can be conﬁgured for each

codec in an image.

IP Trunk 3.01 (and later) supports the following codecs:

•

G.711

•

G.729AB

•

G.729B

•

G.723.1

G.711

The G.711 codec delivers "toll quality" audio at 64 kbit/s. This codec is

optimal for speech quality, as it has the smallest delay and is resilient

to channel errors. However, it uses the largest bandwidth. The G.711

codec is the default codec if the preferred codec of the originating node

is not available on the destination IP Trunk 3.01 (and later) node. Voice

Activity Detection/Silence Suppression is conﬁgurable through TM 3.1. An

ITG-Pentium 24-port trunk card supports 24 channels per card with G.711.

A Media Card 32-port trunk card supports 32 channels per card with G.711.

Nortel Communication Server 1000

IP Trunk Fundamentals

NN43001-563 02.01 Standard

Release 5.5 21 December 2007