Co-Trk (Analog Co Trunk); Interactions Between Switch And Co; Loop Start Operation - Avaya G250 Maintenance Manual

CO-TRK (Analog CO Trunk)

Table 44: CO-TRK (Analog CO Trunk)
MO Name (in
Alarm Log)
CO-TRK
CO-TRK
CO-TRK
Note: For Avaya G250/G350 systems, you must consult local records for
the location and designation of the equipment rack where the G250/G350
is mounted.
**A MAJOR alarm on a trunk indicates that alarms on these trunks are
not downgraded by the set options command and that at least 75% of
the trunks in this trunk group are alarmed.
Analog CO trunks are 2-wire analog lines to the CO which support both incoming and outgoing
calls. CO trunk media modules have eight ports.

Interactions Between Switch and CO

The following sequences show the interactions between the switch and the CO during call setup
for both loop-start and ground-start trunks.

Loop Start Operation

Idle State:
Tip = ground, Ring = CO Battery
Outgoing Call:
1. PBX Off-Hook (Seize Message): Closes the Tip-Ring Loop.
2. CO Response: DC loop current + Dial tone.
3. PBX On-Hook (Drop Message): Open Tip-Ring loop, no loop current.
4. CO Response: CO goes to idle state (see Note).
Alarm Initial Command to
Level Run*
MAJOR** test port GGGVSpp l
MINOR test port GGGVSpp l
WARNING test port GGGVSpp l
CO-TRK (Analog CO Trunk)
Full Name of
MO
Analog CO Trunk
Analog CO Trunk
Analog CO Trunk
Issue 1.1 June 2005 117