Here's the quick synopsis: Freeswitch on CentOS 6 freshly installed 2 days ago. Freeswitch was grabbed via git. Phones are Mitel 5220 SIP phones that are in SIP mode. Mitel has a Broadsoft implementation called SIP_SCA in the device registration. There is 1 Cisco 7960 but its not configured at all for the shared extension. I can't get it to work. I *think* I have it narrowed down to the presence ID being different on a per-phone basis. The LEDS show the correct call status (on-hook, ringing, on hold, etc). However, when you press the shared line from another phone, it dials the extension again and goes straight to voicemail/busy instead of seizing the line. All extensions are configured correctly (calling the shared extension from the Cisco results in both phones ringing and able to pick up the call initially) Logfiles are located at: http://iis.powertogrow.com/fs Each one has the same actions: Mitel phone 1 (192.168.1.106/extention 1002) calls Cisco Phone 2 (192.168.1.103/#1000) on Shared Line 1003. Cisco answers. Mitel Phone 1 puts call on hold. Mitel phone 2 (192.168.1.100/#1001) tries to pick up Shared Line 1003 and then hangs up when it hears the voicemail system. It normally does this twice. Then Mitel phone 1 picks up Shared Line 1003 and ends it. No matter what order the steps are done with whatever phone (well, except the Cisco doesn't have a shared line), the results are the same. Picking up the shared line results in a forward to the VM system Thanks, Adam