Avaya CMC1 Manual Do Utilizador

2. Be aware that there are installations that use repeatered metallic lines between the MUX 

and the “dumb” block. These lines require DC power for the repeaters and this DC power is 
present at the “dumb” block interface to the CPE equipment. A loopback jack is required in 
this configuration to properly isolate and terminate the DC power.

To check for the presence of DC, make the following 4 measurements at the network interface 
jack:

3. From transmit tip (T, Pin 5) to receive tip (T1, Pin 2)

4. From transmit ring (R, Pin 4) to receive ring (R1, Pin 1)

5. From transmit tip (T, Pin 5) to transmit ring (R, Pin 4)

6. From receive tip (T1, Pin 2) to receive ring (R1, Pin 1)

All measurements should read 0 (zero) volts DC. For pin numbers and pin designations, refer to 
Integrated Channel Service Unit (ICSU) Installation and Operation.

.

This section provides information on ISDN converters and adapters that are sometimes 
necessary when connecting to coaxial facilities in either a multicarrier cabinet or a single carrier 
cabinet.

Connections include:

●

Integrated Services Data Network Primary Rate Interface (ISDN-PRI) to Direct Access 
Secondary Storage (DASS)

●

PRI to Digital Private Network Signaling System (DPNSS)

●

PRI to ISDN Basic Rate Interface (ISDN-BRI)

Converter circuit packs known as common channel signaling converter (CCSC), types 1 and 2.