Configuring the LifeSize Gateway
73
Configuring Gateway Settings
G.722 is supported in calls at 224, 256, 336, 384, 448, 512 Kbps (all
LifeSize Gateways) and 768, 1472 and 1920 Kbps.
G.722.1 is supported in calls at 64, 2B, and 128 Kbps.
Both endpoints in a call must support G.722 and G.722.1 audio codecs.
A
BOUT
A
UDIO
T
RANSCODING
The Gateway-PRI supports audio transcoding through the Audio Transcoder
Module (TCM). The Gateway-Serial supports audio transcoding through
on-board Digital Signal Processing (DSP).
The TCM is a PCI mezzanine card (PMC) that implements Digital Signal
Processing (DSP). The TCM has a processing capacity of up to 20 channels for
audio transcoding in video calls.
The LifeSize Gateway TCM can perform audio transcoding between the
following types of audio protocols:
G.711 (ISDN) to G.723.1 (IP)
G.723.1 (IP) to G.711 (ISDN)
G.728 (ISDN) to G.711 (IP)
G.711 (IP) to G.728 (ISDN)
Note
When your unit includes both a LifeSize Gateway and LifeSize Multipoint,
G.728 transcoding is supported on the Multipoint only.
Each audio codec differs in the audio quality, compression, and bit rates that it
provides. The G.711 codec provides toll quality audio at 64 Kbps, the G.728
codec provides near toll quality audio at 16 Kbps, and the G.723.1 codec
provides voice quality audio at 5.3 or 6.4 Kbps.
Endpoints on the ISDN network usually support the G.711 and G.728 codecs.
Endpoints on IP networks support G.711 and G.723.1 codecs. By performing
transcoding between these audio protocols, the LifeSize Gateway can support
communication between endpoints with codecs that are incompatible with each
other.
Audio transcoding can also optimize the audio bandwidth usage either on the IP
network (G.723.1
< >
G.711) or on the ISDN network (G.728
< >
G.711).
Transcoding is particularly useful for ISDN codecs, where bandwidth can be
limited to 128 Kbps for a video call. For example, when transcoding between
Summary of Contents for Gateway-PRI
Page 1: ...LifeSize Gateway User Guide...
Page 8: ...viii LifeSize Gateway User Guide...
Page 26: ...18 LifeSize Gateway User Guide About LifeSize Gateway Functionality...
Page 146: ...138 LifeSize Gateway User Guide Importing Configuration Files...
Page 168: ...160 LifeSize Gateway User Guide Using the Hyperterminal Configuration Commands...
Page 178: ...170 LifeSize Gateway User Guide Using Express Setup...
Page 182: ...174 LifeSize Gateway User Guide Upgrading Software...
Page 190: ...182 LifeSize Gateway User Guide Technical Specifications Table...