If you want to use your Snom as a legacy IP phone with your OBi device like I do then you will encounter an issue where although the phone registers ok and you can make outbound calls, (providing you have setup call routes as per the previous guide) your Snom will not receive any inbound calls! Below are the changes you need to make to your Snom phones configuration settings, these are not mentioned in any of the guides I found.
- Identity > SIP> Support broken Registrar: on
- Advanced > Behaviour > Challenge Response on Phone: off
- Advanced > Behaviour > Prioritise PBX number lookup: off (maybe try on?)
- Advanced > SIP/RTP > Network identity (port): 5063 (whatever port you used in the previous guide)
- Advanced > SIP/RTP > Listen on SIP TCP port: on
- Advanced > QoS/Security > Filter Packets from Registrar: off
Note: I could not get my phone to stay registered using the latest stable firmware 220.127.116.11.5! No matter what I tried I got a 401 Unauthorised in the sip trace!!!
I reverted back to 8.4.35, which is the most reliable firmware version I have used to date. Registration is no longer an issue for me so let me know if you can get the latest firmware to hold a registration.