Avaya 700393762

Avaya 700393762 MM721 BRI HV3 Media Module

The Avaya MM720 Media Module contains eight ports that interface to the central office at the ISDN T reference point. Information is communicated in two ways:

Over two 64-kbps channels called B1 and B2
Can be circuit-switched simultaneously
Over a 16-kbps channel called the D channel
Used for signaling
Occupies one time slot for all eight D channels