I'm wondering if any one has an idea on how I might achieve this. We're using OpenSIPs to convert termination/origination into multi-call-path sip trunks that our customers can access via authentication with an ATA. We are looking for a way to implement rollover just like you would get with AT&T. I did have it working with Asterisk using a hunt group, but we ran into intermittent connectivity issues. Currently we're using a Grandstream GXW4004 which has a hunt group, but it's a round robin hunt group; meaning that when a call comes in the first time it rings on line 1, when a call comes in the second tim irregardless of whether line 1 is tied up or not it rings line two, and when a call comes in a third time it goes to line 3 even if line 1 and 2 are available, and so on and so forth until it gets back to line 1. I'm looking for something that will only ring line 2 when line 1 is tied up and only ring line 3 when lines 1 and 2 are tied up. Anyone have any ideas?
Thanks in advance for any advice,