[Asterisk-Users] Automathic call forwarding

[Gianni (priv.)]

Hello. 


I wonder if someone cal help me to find the right way to implement the below
described TO-BE scenario (basically  automatic farwarding from incoming
calls).


*** Background:
- a VoIP/PSTN gateway Mediatrix 1104 registers on Asterisk at Home as UAs from
301 to 304. This Mediatrix is the gateway (4 port FXS) between a SIP/VoIP
domain and a legacy PBX Nortel Meridian 1.

- others UA (SIP/VoIP terminals extension from 100 to 140) also register
into Asterisk at home

*** AS-IS situation
1) UA 100 dial let's say 301 and get a PSTN line from the Mediatrix
(mediatrix is then connected by FSX/FXO to a Nortel Meridian 1)
2) If another UA, let's say 101 wants to have a PSTN line, it should now
that 301 is busy because of 100 in progress call and therefore it shall
call. let's say 302 (likely after having found 301 busy) 
3) And so on... 


*** TO-BE scenario (to be achieved)
1) UA 301 to 304 (Mediatrix VoIP gateway registered UA) are logically
grouped and referred by a virtual extesion, let's say 999

2) any UA from VoIP domain calls 999 and Asterisk automatically route the
incoming call on the first available line or if not, put it on hold.
Something like

IF port 301 is busy THEN reroute call on 302 
IF port 302 is busy THEN reroute call on 303 
IF port 303 is busy THEN reroute call on 303 
IF port 304 is busy THEN put on hold for x minutes


Thanks in advance for your help

Gianni