Dialing one of two extensions, plus additional single exten

I have the need to do the following, and thought I found something to do this, but did not bookmark it.

I need to do the following.
I have three locations with SIP extensions off an * server which works very well. At location number 1, there are three extensions, and at location #2 there are two extensions, and at location #3 there is one extension.

Lets call then A-1, A-2, A-3, B-1, B-2, and C-1

What I want to have happen is an incoming call rings on the first available extension at each location. For example the first call would ring at A-1, B-1, and C-1. Whoever gets the call owns the call at that point. Say for example someone is talking on A-1, then the call should ring on A-2, B-1, and C-1. If someone is talking on A-1, and B-1, and B-2, then the call should only ring on A-2, and C-1.

I know I could use a simple Dial command with all the extensions listed, but that means that every line will ring which makes no sense. I can write a simple script to try each extension sequentually, but that does not allow it to ring at the same time in multiple places.

How do I “split” the dialing so that I can seperately dial multiple what I would call “hunt groups”?

Thank you for your assistance.

I think you need to make an agi script to check the status of every extension, then with this information make a DIAL string with the extensions who has the status you need.

if you need some help please let me to know.

OrvUx: Masking the Hard… Soft with Debian GNU/Linux.

I have tried the functions to ask the SIP box what it’s status is, etc. and I cannot seem to figure out if the box is off the hook for example.

If you could help me, that would be great.

I seem to remember there was a way to “split” the call into two seperate threads so that you could process it concurrently. Am I forgetting something on that idea?