Product Overview and Deployment Guidelines
Special Requirements for Voice Deployments
Cisco Small Business WRP400 Administration Guide
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The available connection bandwidth determines the maximum number of
simultaneous calls that the system can support with the appropriate audio quality.
Use this information to determine the maximum number of simultaneous VoIP
connections that the system can support.
For asymmetric connections, such as ADSL, the maximum number of calls is
determined by the upstream bandwidth. In general it is a good practice to use no
more than 75% of the total available bandwidth for calls. This provides space for
data traffic and helps ensure good voice quality.
NOTE
Some ITSP SIP trunk services limit the maximum number of simultaneous calls.
Please check with your Service Provider to understand the maximum number of
simultaneous calls each SIP trunk supports.
The following table provides the approximate bandwidth budget for different
codecs.
For more information about bandwidth calculation, refer to the following web sites:
www.erlang.com/calculator/lipb/
www.bandcalc.com/
Codec
Approximate bandwidth
budget for each side of
conversation
2 calls
4 calls
6 calls
8 calls
G.711
110 kbps
220
kbps
440
kbps
660
kbps
880
kbps
G.726-
40
87 kbps
174
kbps
348
kbps
522
kbps
696
kbps
G.726-
32
79 kbps
158
kbps
316
kbps
474
kbps
632
kbps
G.726-
24
71 kbps
142
kbps
284
kbps
426
kbps
568
kbps
G.726-
16
63 kbps
126
kbps
252
kbps
378
kbps
504
kbps
G.729
55 kbps
110
kbps
220
kbps
330
kbps
440
kbps