The MM721 Basic Rate Interface (BRI) media module has eight ports. You can administer these ports either as BRI trunk or BRI endpoint connections, such as a phone and data module.

You cannot administer the MM721 BRI media module to support both BRI trunks and BRI endpoints at the same time. You can use all eight ports on the MM721 media module only for stations or trunks. You cannot use a mixture of ports for both applications.

For BRI trunking, the MM721 BRI media module supports up to eight BRI interfaces to the central office at the ISDN S/T reference point.

For BRI endpoints, each of the eight ports on the MM721 BRI media module supports integrated voice and data endpoints for up to 2 BRI stations or data modules or both. The MM721 BRI media module provides 48-volt phantom power to BRI endpoints.

The MM721 BRI media module supports 4-wire S/T ISDN BRI on each interface.

The MM721 BRI media module transmits data in the following ways:

• Over two 64-kbps channels called B1 and B2. You can circuit-switch these channels simultaneously.

• Over a 16-kbps channel called the D-channel, which is used for signaling.

The circuit-switched connections have an A-law or Mu-law option for voice operation. In Data mode, circuit-switched connections operate as 64-kbps clear channels.

The MM721 BRI media module is compatible with Avaya Aura® Communication Manager Release 6.0.1 and later and Branch Gateway firmware version 31.18.1 and later.