Bridged appearances, Shared Line appearances, these are not easily done in Asterisk. I would suggest you look at using ring groups. If you had 5 people working in a lab, Tech1, Tech2, Tech3, Tech4, and Tech5, set up 5 ring groups naming them Tech1, etc. with a prefix of Tech1:, etc. Each ring group would have all of the lab phones. If someone called in for Tech1, it will ring each of the phones, displaying Tech1: and the callerid. Looking at the phone, each tech can then decide whether to answer the phone or not. If no answer, the ring group can be directed to the Tech1 mailbox.
If the technician has an office phone and also wants to be able to get calls in the lab, look at followme. Send the calls to the ring group if no answer at the office extension.
Use call park to allow technicians to get "held" calls from any phone.
I have read that there are projects using sla.conf. But I have also read a lot of people are not real happy with the journey or result.
