Microsoft are removing support for the sip-all.pstnhub.microsoft.com and sip-all.pstnhub.gov.teams.microsoft.us FQDN’s used in Direct Routing.
This is a major change if you have used these domains in any of your configurations.
For my customers I have typically used it in Access Control Lists on Session Border Controlers (SBC) to simplify configuration. Going forward this will not be possible, and instead you will need to use the full subnets e.g. 220.127.116.11/14 and 18.104.22.168/14 – see here for the latest configuration information.
The deadline for this change is currently 31 May 2022, after which time, calling could start failing.
Some other important Message Centre Direct Routing changes:
- MC299923: Trusted certificate authorities for Direct Routing SIP interface are changing – Starting on February 1, 2022, the Direct Routing SIP interface will only trust certificates that are signed by Certificate Authorities (CAs) that are part of the Microsoft Trusted Root Certificate Program. See here for the list.
MC297438: TLS1.2 enforcement for Direct Routing SIP interface – On February 1st, 2022, to provide the best-in-class encryption to our customers, we will begin retiring Transport Layer Security (TLS) versions 1.0 and 1.1 and begin obligating TLS1.2 usage for the Direct Routing SIP interface.