Bearer Capability
Bearer Capability is one of the Information Elements of the Q.931 SETUP message. It is used by the calling party to specify the kind of B channel that is being requested.
For example, if a Bearer Capability of Speech is specified, then the network is free to select a set of facilities that are able to provide this service.
If, on the other hand, a Bearer Capability of Unrestricted Digital Information is specified, then the network is required to set up the call using only end-to-end digital facilities, or reject the call if no end-to-end digital circuit is available.
The Bearer Capability is augmented by the Higher Layer Compatibility Information Element, which informs the network of the use that the caller intends to make of the channel.
