Skype connection fall back to HTTP

[Paul Westlake]

If a users Skype client falls back to HTTP to SIP connect is the connection encrypted?

I GPO you can stop the client from falling back to HTTP to make SIP connections, but I have a client whos users are unable to connect if this GPO option is enabled.. They want confirmation that if they disable this tha the users do fall back to HTTP is the connection secure?

Whilst investigating the problem, we found that there is a GPO which sets “Disable HTTP fallback for SIP connection” parameter for Lync / Skype to “Enabled”.

Based on the MS explanation, looks like clients can’t connect via TLS /TCP, and are unable to fallback to http as it is blocked by policy. Could you please advise why clients are unable to connect via secure channels?

[#2]

Have you verified all things with the SSL certificate and DNS are configured correctly. That's likely the reason. If you can't determine why, please open a case and support should be able to help you find the problem.

[#3]

The client connects ok as long as the GPO setting allows them to fallback to HTTP.. the main question is, if the client uses this Fallback for SIP connections are they encrypted.. I think the GPO tag line is misleading the users into thinking that fallback is not encrypted as it fails to state HTTP(S)

[#4]

Have you traced it and verified it's using HTTPS during that, and edge based sign in is always SIP TLS based on the 443 port for edge sign in.

[#5]

Thanks Again Aaroin, whilst we are confident that the connection is secure and encrypted, we are just waiting on MS confirmation on the generic wording on the GPO setting :)

[#6]

You might want to open a support case to get an answer to this and how it's worded.