Automatically Route Outbound Calls To Alternative Line If PrimaryLine Is In Use

[xray]

As the subject indicates.  If ObiTalk from a remote caller is using Primary Line ie sp1 ,  Obi110 is able to automatically route other outbound call to sp2 or land line.  Is it possible? 
Thanks. 

[QBZappy]

Yes, I think so.

Go here:
1) Voice Services->Gateways and Trunk Groups->Trunk Group1->TrunkList
change it to any one of these setups you choose to use. I'm not certain if the Trunk can have 3 strunks. I think it should. Two trunks should work.
li,sp1,sp2
li,sp1
li,sp2

2) Then goto
System Management->Outbound Settings->Phone PrimaryLine (and the Attendant PrimaryLine, if you like)
Select the Phone PrimaryLine as Trunk Group 1

This will allow you to make a call on any available line. You may have to tweak your digimaps not to allow any long distance calls going out you POTS line.

[xray]

Thanks.  I will play around with the digimaps and settings.