bearer capability (BC)

When establishing a connection in the D- channel ofISDN, an ISDN terminal first requests a certain transport service from the network.

Such a bearer service may be audio transmission at 3.1 kHz, voice-only transmission, or unrestricted bearer service at 64 kbit/s. Data transmissions over the 64 kbit/s service may not be compressed, but voice transmissions may be compressed to 12 kbit/s, allowing multiple use of a 64 kbit/s line within the network.