We have all been there. We see an email from Microsoft 365 Message center – and the first reaction is “another one?” I got caught out for not paying close attention to one of these Major Change Update Notifications.
As it goes, I received an alert from AudioCodes OVOC stating that the Microsoft Proxy Set was offline. I could not divine what the problem was. I had the firewalls checked, and did all preliminary tests – everything panned out. I then proceeded to raise a ticket with both vendors (AudioCodes and Microsoft), neither of them seemed to be aware of what the problem could be except point fingers at the other party. AudioCodes said it Microsoft’s issue – and Microsoft Support , well was Microsoft support.
Then, I noticed that the proxy set that was down: sip3.pstnhub.microsoft.com resolved to sip-du-a-jaea.japaneast.cloudapp.azure.com with IP address of 52.114.32.169. Now where had I seen “Japan” and this IP address in the same context?
Launched Outlook and typed in “Japan”, I hit gold at my first attempt.
Two new Direct Routing endpoints in Japan. MC258632
This article surely describes my situation. Clicking the link supplied above takes me to: Plan Direct Routing – Microsoft Teams | Microsoft Docs and there it was:
! Important
As part of Teams Direct Routing expansion and service improvement, we have deployed new instances of Direct Routing infrastructure in Japan in May 2021. This is reflected in two additional IP addresses (52.114.36.156 and 52.114.32.169) to which the following FQDNs will be resolved for Japan customers – sip.pstnhub.microsoft.com, sip2.pstnhub.microsoft.com, and sip3.pstnhub.microsoft.com. You need to make sure these two IP addresses (52.114.36.156 and 52.114.32.169) are allowed in your IP Access Control Lists (ACLs) and ports are open for all these IP addresses in your firewall to allow incoming and outgoing traffic to and from the addresses for signaling.
I reached out to my firewall team – and we all lived happily ever after.
Lesson learnt.
