DEFINITY ECS Release 8.2 Maintenance for R8.2csi
555-233-119 Issue 1
April 2000
Maintenance Objects
3-473DID-TRK (DID Trunk)
3
For each call, the CO switch sig nals the system by opening and closing
individual DID loops (one of the eig ht ports) and ca using the starting or stopp ing
of loop current.
A DID trunk operation involves three signi ficant aspects:
1. Transmission—deals with the interface requirements reg arding all AC
signals. Transmission includes gain, analog to digital encod ing, and
digital to analog decoding.
2. Signaling—involves interpretation of DC sig nals appearing on Tip and
Ring to and from the CO. These signals includ e off-hook, on-hook, and
dial pulse detection.
3. Switch Connection—involves the connec tion between the trunk circui try
and the TDM Bus of the system. It operates the switc hhook connection to
the TDM Bus.
Four tests are implemented to diag nose the health of a DID trunk. All of them test
on-board circuitry only. They are:
1. Looparound and Conferenc e Circuit Test—verifies the transmission
operation of the circuit pa ck (loop around within the por t), and checks the
conference capabilities of all ports.
This test may fail due to noise induced by adjacent elec tric power lines.
Customers having this proble m should resolve it with their local p ower
company. To temporarily alleviate the alarm caused b y the failure of this
test, the test may be disabled from trunk administration Test field. (This
also disables the por t diagnostic test).
2. NPE Crosstalk Test—verifies the switch connection operation of the circ uit
pack. The test also verifies that the trunk ci rcuitry only talks on the
selected time slot on the TDM Bus and never crosses over to time slots
reserved for other connections.
3. Port Diagnostic Test—the battery feed circ uitry is tested for hook
detection.
4. Port Audit Update Test—updates the DID translation inform ation on
individual ports of th e DID trunk. The port translation data consists of
signaling parameters whos e values depend on the CO s witch connected
to the trunk. These parameters include:
■wink (signal indicating PBX is ready to receive digits) or immed iate
start
■dial tone or rotary dialing trunk
■rotary dialing inter-dig it timing
■network balance R/RC
■disconnect timing