Frequently Asked Questions
Bandwidth for calncall / callacould / cloudtokyo
overhead Bandwidth for each calls
- RTP – 4.8 kbps
- UDP – 3.2 kbps
- IP – 8 kbps
- Ethernet (not using QOS) – 15.2 kbps
|Codec||Audio Quality||CPU Resources||Base Size(KBps)||Overheads||Total Size (Base + Overhead)|
|G711 A/U||Good||Very Low||64||31.2||95.2 kbps|
|G722 ||Very Good||Low||64||31.2||95.2 kbps|
The above are stats for one audio stream. A VoIP call will use one audio stream for each leg (or endpoint). Thus a call between two parties will use double the bandwidth shown above.
All our service primary codec would be 711A and secondary are 729 .
Note that the above bandwidth consumption is in kilobits per second. You will need to divide by 8 in order to get the equivalent in kilobytes per second. Using the above data, we can come up with the following stats:
|Codec||Audio Quality||CPU Resources||Base Size||Total Size |
(Base + Overhead) Kilobits per second
|Kilobytes per second||Kilobytes per minute||Megabytes per minute||Megabytes per minute |
(For duplex audio stream)
|Megabytes per minute |
(For a simple 5 min call)
|G711||Good||Very Low||64 kbps||95.2 kbps||11.9||714||0.714||1.428||7.14|
|G722||Very Good||Low||64 kbps||95.2 kbps||11.9||714||0.714||1.428||7.14|
|GSM||Acceptable||Average||13 kbps||44.2 kbps||5.525||331.5||0.3315||0.663||3.315|
|G729||Average||High||8 kbps||39.2 kbps||4.9||294||0.294||0.588||2.94|
Here are some notes and suggestions for the application of specific codecs:
- G729 is the codec which consumes the least bandwidth and has a relatively good audio quality. However that comes with two drawbacks:
- Its efficiency comes at a cost, CPU usage. It is more CPU intensive to encode audio in such a low size while maintaining the quality.
- Although G711 and G722 consume over twice as much bandwidth as the other codecs, most Local Area Networks are able to handle this bandwidth. Using the above table, a 1 hour call using G711 is equivalent to transferring a 41.8 MB file. If that causes an issue, you should consider upgrading your network.
Last Updated 6 years ago