Nortel Networks 553-3001-211 manual Outgoing Calls, Call Disconnect from far end

Overview Page 49 of 894

•In order to detect distant end disconnect for calls terminating on the lineside T1 card, the hook flash feature within the SAL software must be enabled.

•In order to detect distant end disconnect for calls originating and terminating on the lineside T1 card, both the battery reversal and hook flash features must be enabled within the SAL software.

Call disconnect from lineside T1 terminal equipment

Alternatively, while a call is in process, the terminal equipment may disconnect by going on-hook. The terminal equipment detects no loop current and sends signaling to the lineside T1 card that causes its receive A bit to change from 1 to 0. The call is now released.

Table 3 outlines the lineside T1’s A and B bit settings in each state of call processing.

Table 3

Loop Start Call Processing A/B Bit Settings (Part 1 of 2)

		Transmit		Receive
State		A	B	A	B
Idle		0	1	0	1
Incoming Calls:
•	Idle	0	1	0	1
• Ringing is applied from lineside T1 card		0	1/0	0	1
• Terminal equipment goes off-hook		0	1/0	1	1
• Lineside T1 card stops ringing		0	1	1	1
Outgoing Calls:
•	Idle	0	1	0	1
• Terminal equipment goes off-hook		0	1	1	1
Call Disconnect from far end:

Circuit Card Description and Installation