Bandwidth Requirements; Layer 2 Mulaw (G.711) Audio (Normal Setting); Layer 3 Mulaw (G.711) Audio; Layer 2 Adpcm Audio (Reduced Bandwidth Setting) - 3Com 3C10111C - NBX 100 - Modular Exp Base Installation Manual

Bandwidth
Requirements
Layer 2 Mulaw
(G.711) Audio
(Normal Setting)
Layer 3 Mulaw
(G.711) Audio
Layer 2 ADPCM Audio
(Reduced Bandwidth
Setting)
Layer 3 ADPCM Audio
(Reduced Bandwidth
Setting)
Notes on Bandwidth
Requirements
The interconnect bandwidth requirements depend on the selected audio
compression and system configuration [Layer 2 or Layer 3 (IP)] topology.
NBX default audio settings deliver optimum audio quality. Any change to
default audio settings affects audio quality.
The interconnection bandwidth requirements for a device configured as a
Layer 2 device running G.711 audio for each party in a conversation
requires a maximum of 73 Kbps. Thus, a point-to-point call requires this
peak bandwidth in each direction, while a 3-party conference requires a
peak of 219 Kbps in one direction. For more information, see

Bandwidth Requirements"

The overhead for running a device as a Layer 3 device results in a
maximum bandwidth requirement of 86 Kbps per party in the
conversation. Thus, a point-to-point call requires this peak bandwidth in
each direction, while a 3-party conference requires a peak of 258 Kbps in
one direction. For more information, see
Requirements" later in this chapter.
The interconnection bandwidth requirements for a device configured as a
Layer 2 device running ADPCM audio for each party in a conversation
requires a maximum of 42 Kbps. Thus, a point-to-point call requires this
peak bandwidth in each direction, while a 3-party conference requires a
peak of 126 Kbps in one direction. For more information, see
Bandwidth Requirements"later in this chapter.
The overhead for running a device as a Layer 3 device results in a
maximum bandwidth requirement of 54.7 Kbps per party in the
conversation. Thus, a point-to-point call requires this peak bandwidth in
each direction, while a 3-party conference requires a peak of 164 Kbps in
one direction. See

"Notes on Bandwidth Requirements"

Silence suppression reduces bandwidth requirements on average by 30 to
40 percent. However, do not assume this much bandwidth reduction
when determining peak requirements. These bandwidth reduction values
do not include link overhead (packet encapsulation, additional bytes for
error detection/correction, etc.) which may be added by the specific
interconnection device. This overhead is not under the control of the NBX
system, but must be added based upon the device specification.
Bandwidth Requirements
later in this appendix.
"Notes on Bandwidth
193
"Notes on
"Notes on
next.