Lucent Technologies Release 7 Loop Start Operation, Ground Start Operation

DEFINITY Enterprise Communications Server Release 7
Maintenance for R7r
555-230-126 Issue 4 June 1999
Maintenance Object Repair Procedures
9-428CO-TRK (Analog CO Trunk)
9
Loop Start Operation
Idle State: Tip = ground, Ring = CO Battery Outgoing Call:
1. PBX Off-Hook (Seize Message): Closes the Tip-Ring Loop
CO Response: DC loop current + D ial tone
2. PBX On-Hook (Drop Message): Open Tip-Ring loop, no loop current
CO Response: CO goes to idle state (see Note)
Incoming Call:
1. CO Applies Ringing Voltage
PBX Response: Detect ringing current
2. PBX Off-Hook (Answer Message): Close loop
CO Response: Trip ringing, provid e loop current
3. PBX On-Hook (Drop Message): Open Tip-Ring loop, no loop current
CO Response: CO goes to idle state (see Note)
NOTE:
CO does not normally provid e an On-Hook (Disconnect) signal.
Exceptions to this rule includ e Netherlands loop start and UK
loop-calling g uarded-clearing.
Ground Start Operation
Idle state: Tip = open, Ring = CO Battery Outgoing Call:
1. PBX Off-Hook (Seize Message): Places ground on Ring
CO Response: Places ground on Tip
PBX Response: Close the loop
CO Response: Provide loop current
PBX response: Dial out digits
2. PBX On-Hook first (Drop Message): Open the Tip-Ring Loop , no loop
current
CO Response: Open circuit on Tip
3. CO On-Hook first (Disconnect): Op en circuit on Tip, no loop c urrent
PBX Response: Open Tip-Ring loop