It is a network option to support the procedures in this Annex.
When a preferred bearer requires a larger bandwidth than an allowed alternate fallback, e.g. 6 × 64 kbit/s to 64 kbit/s, multiple channel identifications may be present in the SETUP message. In this case, one Channel identification information element will be included for each Bearer capability information element in the SETUP message. If the bandwidth required for two of the bearers is the same, then the same channel shall be indicated for the two bearers. Channel selection procedures for each bearer will follow 5.1.2 and 5.2.3 independently, except that the selection of the same channel for more than one of the bearer alternatives will be allowed and will not constitute a conflict. The bearer capability selected for the call will determine the final selection of the channel for the call.
Procedures for early cut through, the use of the Repeat indicator information element for the channel identifications and the confirmed release of unused channels are for further study.