1) Determine the number, length, and type of E1/T1 cables to be replaced. Obtain a new cable with proper length and type. Note that extra length should be reserved.
2) Add a connector to the new E1/T1 cable for the connection with the DDF.
3) Attach temporary labels to both ends of the new E1/T1 cable. The contents of the temporary labels should be consistent with the contents of the old labels.
4) Lay the new E1/T1 cable based on the original route. If the conditions on site change, lay the new E1/T1 cable according to the new cabling requirements.
5) On the BSC side, remove the fastening screws from the E1/T1 connector by using a flat-head screwdriver. Then, remove the E1/T1 cable to be replaced. On the DDF side, loosen the connector of the E1/T1 cable and then remove the connector from the DDF.
6) Connect the new E1/T1 cable to the original ports on the BSC and on the DDF.
7) On the new E1/T1 cable, replace the temporary labels with the engineering labels.
8) Bind the new E1/T1 cable.