The HTTP fallback for SIP connection in Lync must be disabled.
An XCCDF Rule
Description
Prevents from HTTP being used for SIP connection in case TLS or TCP fail.
- ID
- SV-223345r1043178_rule
- Version
- O365-LY-000002
- Severity
- Medium
- References
- Updated
Remediation Templates
A Manual Procedure
Set the policy value for Computer Configuration >> Administrative Templates >> Skype for Business 2016 >> Microsoft Lync Feature Policies "Disable HTTP fallback for SIP connection" to "Enabled".