Registering Mitel 6900 Series with Generic SIP to Non-Mitel PBX/SBC

[CornHead764]

Starting in at least version 5.1 per a comment I found on a blogspot post linked below, Mitel restricts SIP registration on 6900 series phones (6920, 6930, 6940, etc) to only Mitel software/hardware, for instance, a 3300 PBX. So if you try to register a 6900 series phone to a non-mitel SBC (like Anynode in my case), it will instantly unregister itself and provide no information as to why. Fortunately, if you have a means of spoofing the user-agent header in the SIP messages sent by the SBC, you can make them work. Anynode has the ability to do this, so I set it to spoof the user agent to "Mitel-3300-ICP" and my 6940 and 6920 instantly came up and no longer had the instant unregistration problem. The 6940 is running a 6.0 software revision, and the 6920 is running a 5.1 software revision.

Just another case of unnecessary vendor locking. Hope this helps someone!


http://randomcontributions.blogspot.com/2019/02/mitel-6940-handsets-on-asterisk.html

[dilkie]

try this in your config file instead.

sip register blocking: 0  # necessary to connect to 3rd party

[sarond]

try this in your config file instead.

sip register blocking: 0  # necessary to connect to 3rd party

Wow, that's a trade secret.

I can confirm that this works. I've always wanted to know this.

Thanks!!

[bobfindlay]

try this in your config file instead.

sip register blocking: 0  # necessary to connect to 3rd party

you Sir are a forking genius.  I've spent 2 days trying to figure out why these phones wouldn't register!

[bobfindlay]

try this in your config file instead.

sip register blocking: 0  # necessary to connect to 3rd party

do you have any more secret settings you can share?  Is there one that stops a phone from DHCPing to anything but a Mitel DHCP server?  I have a 6920 that refuses to DHCP, not matter what options I use.  I've replicated exactly what our Mitel provides using isc-dhcpd, but it still doesn't work

[dilkie]

sounds like a bug. I don't have any issues with dhcp with my 69xx sets.