AT&T 3.0 Telephone User Manual


 
Testing Trunks
CAUTION:
Be careful not to connect tie trunks to GS, LS
J
or DID ports. Since all the
jacks on the termination block are 8-wire jacks, it is possible to
interchange tie trunk wires with GS, LS, or DID wires accidentally.
RJ48C/X Interface
The RJ48C/X interface terminates a DS1 trunk at the customer’s premises.
Both RJ48C and RJ48X interfaces have 8-wire modular jacks. However, the
RJ48X interface includes shorting bars that loop the DS1 trunk’s receive pair
to the transmit pair. This helps in testing the DS1 trunk from the central office.
Testing Trunks
Before you connect the central office trunks to the control unit, verify that there
is dial tone and that you can dial out on every trunk. DID trunks can be tested
only through the control unit. Do not test DID trunks at this time.
CAUTION:
Do not use analog multiline telephones or MLX telephones for testing.
They do not work for these tests and can be damaged if you use them
for this purpose.
Testing Loop-Start Trunks
To perform this test, you need a single-line telephone or an installer’s test
telephone (craft set). If you are installing rotary-dial trunks, use a rotary
telephone to perform this test.
To test loop-start trunks, follow the steps below:
1 Plug the single-line telephone or the craft set into each central office
line/trunk jack (either at the network interface or at the cross-connect
field) and listen for dial tone.
4-12 Connecting the Control Unit to the Network Interface