PRIMARY RATE INTERFACE UNIT The Primary Rate Interface Unit provides for the termination of an ISDN PRI line for voice service only. This unit supports 4ESS(AT&T Custom), AT&T 5ESS(Lucent Custom), DMS-100(Custom and National ISDN) and NI-2 protocols. A CLKG-U10 unit must be connected to the CPUI( )-U10 ETU. |