Ip Trans-Coding - LG iPECS Feature Description & Operation

IPECS Release 5
Feature Description & Operation
Conditions
Programming
Related Features
Hardware
2.48 IP T -
RANS CODING
Description
The system employs either IEEE g.711, g.729 or g.723 codec to digitize and compress voice signals
for RTP packets between iPECS devices. iPECS terminals and gateway Modules incorporate DSP
functions to support codec conversion Available VOIMs include DSP circuitry used to support trans-
coding (converting) codecs for incoming VoIP calls to devices, such as the MFIM VoIP channels, the
VSF channels and the Feature Server, which have no built-in codec. The VOIMs will trans-code the
incoming voice codec (g.711, g.723, g.729) to the system codec and reverse the process for the
outgoing packets. When the external VoIP connection can only support g.729 and the system codec
is g.723, the DSP must implement a complex trans-coding operation, which requires 2 DSP channels.
In all other cases, trans-coding only requires a single channel per call.
Operation
System
System flow with trans coding:
Conditions
1. The system codec toward the VOIM can be changed anytime within an IP call.
2. The VOIM DSP can generate and detect in-band DTMF and Call Progress tones in support of
DISA functionality.
3. For complex trans-coding (g.723/g.729), the VOIM DSP will require 2 channels.
2-95
5.0