Codec Freedom -- Specifications -- Finding end-to-end bandwidth

In the interest of both data and codec frames getting through, the bandwidth must be properly utilised.

Codec frames are generated at a fixed pace, and they take precedence over data. Therefore, overuse of the end-to-end bandwidth can easily be detected by a user:

These are signs that the codec settings must be changed. This topic is likely to be addressed anyway; not every codec fits into every band and instructions to users tend to be platform-specific, in which case the connection profile is known and user experiences can easily be shared.

The end-to-end bandwidth is determined by end points, so setting up proper codecs on each should suffice. A landline phone might try to offer G.711 to a remote mobile phone, but it is not going to accept that option on simple grounds that it has not been configured locally as a feasible protocol to pass through a CSD connection.