NEC Univerge SV8500 Operation And Maintenance Manual page 657

When performing loop-back connection tests on the trunks at the user's office, provide cross connection
Note:
as follows:
(1) For a COT
• Set up a loop-back connection between the C.O. Trunk (COT) to be tested and station line.
• The trunk route must be assigned for Loop Start.
(2) For a MC-MG (COT)
• Set up a loop-back connection between the C.O. Trunk (COT) to be tested and station line.
• The trunk route must be assigned for Loop Start.
(3) For a TLT (for DID)
• Set up a loop-back connection between the TIE Line Trunk (TLT) to be tested and another TLT.
• If the TLT is a Direct Inward Dialing (DID) Trunk, connect the related leads as shown below:
CHAPTER 5
LC
A
C LC
LC
B
IP Station
MC-MG (COT)
LC
B
LC
A
LC
A
LC
B
– 610 –
Operation Procedure for System with PIR
COT
TLT
TLT