We will be upgrading our Azure SBC network to the latest software versions.

Each SBC will take up to 30 seconds to update. If you are using DNS entries as advised in our Interop documents, you will not notice any disruption as any incoming calls will be automatically routed to an alternative SBC. However if you have hard-coded a fixed SBC, you may be unable to receive any calls during the 30 second window your particular hard coded SBC is being updated.