G.6 AMR TFO: Mismatch Case

28.0623GPPInband Tandem Free Operation (TFO) of speech codecsService descriptionStage 3TS

The following protocol flow shows the example where the Codec Types or Codec Configurations do not match and where an immediate TFO is not possible. Potentially a mismatch resolution is following, in which case a second TFO establishment is attempted (indicated in dashed lines for local side).
In this example the TRAU reports the Optimal Configuration to the BTS and to the BSC.

Figure G.6-1: AMR TFO Mismatch Case