Small Office PBX setup help

We have a system that consists of several polycom soundpoint 650 phones (each with 6 lines) and 4 landlines. I would like the system to behave like our old meridian system, such that if you press Line 1 on the phone, you would connect with the first landline (for both dialing out and picking up). If a landline is in use by any phone, I want the rest to reflect that. I can’t wrap my head around how to get Asterisk to behave like that.

For now, I have a 4 different extensions assigned to each phone, one for each of the 4 trunks and dialing groups that correspond to our 4 landlines. The big drawback to this setup is that I can’t see which lines are currently in use, and it makes internal transfers very confusing.

Can anyone offer some insight as to how to set up the system as I would like?

Call groups and trunks are FreePBX concepts, not Asterisk ones.

The key and lamp type facilities you describe are normally only available on the very smallest of PABXes - in fact they tend really to be PMXes.

I haven’t done any of this myself, but you will need to set call limits on each device, or at least all the SIP devices. The way of doing this changed relatively recently, and I am even less familiar with the new way. You will then need to define dialplan hints for everything and configure the phones to subscribe to those hints.

Outbound routing shoudn’t be difficult. Inbound routing may be more fun. You might be able to have a queue for each incoming line. If you want phones to ring, then you can’t set a use count of one, so the phones will appear in use but never busy, which might cause problems.

There is also a shared lamp appearance application, but I’ve never investigated that.