Forwarding of Call Request to external telephone

This article describes how a Call Request can be forwarded to an external telephone via a SIP Gateway. Two types of call forwarding are described:

• Manual Call Forwarding: The Call Forwarding is switched on and off by the operator by dialling a code or pressing a DAK key.
• Automatic Call Forwarding: If the Call Request is not answered within a programmable time, the calling station is connected to the telephone

You can choose to use both types of forwarding, or only one of them.

The call to the telephone will be activated only if there is a free telephone line. If all available lines are busy, the system will retry every 5 seconds until a line is free. The macro %tin (Trunk In Use) is used to check if there are any free lines.

There will be no redial if the telephone subscriber is busy. Also there is no option for dialling of alternative telephone numbers.

Software requirement: AMC 11.2.3.3 or newer.

Manual Call Forwarding

The Call Forwarding is turned on and off from the Queuing Station by forwarding the Call Request to a dummy station. The dummy number can be any station directory number in the exchange that is not in use. In this article 5152 on physical 552 is used as an example.

• Call Forwarding On: Dial 7870 + Dummy Number (e.g. dial 7870 + 5152, or press a DAK key with the programming: I 7870 I 5152).
• Call Forwarding Off: Dial 70

In AlphaPro, Exchange & System -> Events, press Insert to add a new event.

Event 1: This event will start a 1 second timer when the dummy station receives a call request.

Event Owner:	The Dummy Station
Event type:	10 - Received Mail
Subevent:	0
When change to:	ON
When related to:	All
Action:	$ST L%1.dir W10 %2.ref

Event 2: When the timer expires, and if there is a free phone line, the calling station will be connected to the SIP gateway (i.e. dial "0") and the phone number 12345678 will be dialled.

If there are no free lines the timer is restarted, and a new attempt will be made 5 seconds later.

Event Owner:	The Dummy Station
Event type:	21 - Event Timeout
Subevent:	0
When change to:	ON
When related to:	All
Action:	IF %op(%tin(100),=,1) (If 1 line is in use on SIP Trunk node 100...)
	$ST L%1.dir W50 %2.ref
	STOP
	ENDIF
	$PD %2.ref "0W12345678" (Dial 0, then 1 sec pause, then dial 12345678)
	$CANM %2.ref L%1.dir (Delete the call request from the dummy station)

Automatic Call Forwarding

The programming below will forward the call request to the external telephone if the call request is not answered within 30 seconds. The time can of course be adjusted to suit your requirements.

In AlphaPro, Exchange & System -> Events, press Insert to add a new event.

Event 1: When a Call Request is received at the queuing station, a 30 sec timer is started:

Event Owner:	The Queing Station
Event type:	10 - Received Mail
Subevent:	0
When change to:	ON (When the call request is received)
When related to:	All
Action:	$ST L%1.dir W300 %2.ref

Event 2: When the timer exipres, and there is a free line on the SIP Gateway, the calling station is connected to the SIP gateway. Else the timer is restarted and a new attempt is made 5 seconds later:

Event Owner:	The Queing Station
Event type:	21 - Event Timeout
Subevent:	0
When change to:	ON
When related to:	All
Action:	IF %op(%tin(102),=,1) (If 1 line is in use on SIP Trunk node 100...)
	$ST L%1.dir W50 %2.ref
	STOP
	ENDIF
	$PD %2.ref "0W12345678" (Dial 0, then 1 sec pause, then dial 12345678)
	$CANM %2.ref L%1.dir (Optional: Delete the call request from the queing station)