Nortel Networks 553-3001-211 manual 52 of 894 Overview

Page 52 of 894 Overview

Note: By default, the SAL feature opens the tip side for 750 m/s in loop start operation. This is configurable in 10 m/s increments.

•In order to detect distant end disconnect for calls originating on the lineside T1 card, the “battery reversal” feature within the SAL software must be enabled. Enabling the “battery reversal” feature will not provide battery reversal indication when a call is answered; it will only provide battery reversal indication when a call is disconnected.

•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 within the SAL software must be enabled.

Call disconnect from lineside T1 terminal equipment

Alternatively, while a call is in process, the terminal equipment may disconnect by going on-hook, causing the lineside T1’s receive A bit to change to 0. The lineside T1 card responds to this message by simulating the removal of ground from the tip by changing its transmit A bit to 1. The call is now terminated and the interface is once again in the idle condition.

Table 4 outlines the lineside T1’s A and B bit settings in each state of call processing.

Table 4

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

	Transmit		Receive
State	A	B	A	B
Idle	1	1	0	1
Incoming Calls (to terminal equipment):
• Idle	1	1	0	1
• Ringing is applied from lineside T1 card by simulating ground	0	0/1	0	1
on tip lead and ringing on ring lead.

553-3001-211 Standard 2.00 September 2004