This is possible using CallManager 4.0(1) via two methods. One is a Line Group with Broadcast ring pattern. Or you can a shared line with the busy threshold set to at least 2, and this will still allow the other phone to ring on that shared line when one is busy.
If you have CallManager 3.3 or below, neither of these methods are available. Shared lines are available, but as you've probably seen, the shared line is locked out when one phone is using it. If you have 7960s or other phones with two available line buttons, you could configure two shared lines, and configure the first one to forward on busy to the second.
If you don't have phones like that available, as a workaround, you can configure each phone with a different directory number, and set up a TCD (Telephony Call Dispatcher) hunt group to hunt from one phone to the other in a longest idle, first available or circular pattern (depending on version). TCD is the server-side component of Attendant Console, so you configure this as a hunt group with a pilot as you would for Attendant Console. Unfortunately this won't ring both phones simultaneously, but there's not much to be done about it under older versions of CallManager.
SIP traces provide key information in troubleshooting SIP Trunks, SIP
endpoints and other SIP related issues. Even though these traces are in
clear text, these texts can be gibberish unless you understand fully
what they mean. This document attempts to br...
Please find the attached HTML document, download and open it on your PC.
This provides an easy to use form where you simply answer a few
questions and it will render the proper jabber-config.xml file for you
to copy/paste. There is built in logic to verif...
CUCM Database Replication is an area in which Cisco customers and
partners have asked for more in-depth training in being able to properly
assess a replication problem and potentially resolve an issue without
involving TAC. This document discusses the bas...