Teams Meetings - Blocking Issues

Marcel Meth

We have approximately 4,000 enterprise users enabled for Teams and generally speaking, the issues you outline are not present in our environment. A few thoughts and suggestions:

1. If you are an Office 365 admin for your tenant, I strongly suggest opening a support ticket through the support portal. OR if you have an Enterprise Agreement, open a Premiere case. Either way, issues like this need to be identified, tracked and triaged to understand whether it is a Service Issue (Microsoft's responsibility) or an environment issue (customer responsibility).
2. "Connecting" and "drop out" issues are most commonly related to network traffic flows from your clients to the Office365 service. This could manifest itself as a result of several network preparation tasks that may not have been completed for your enterprise network:
   1. Outbound firewall ports have not been enabled
   2. HTTP Proxy exemptions for O365 URLs have not been enabled
   3. TLS/SSL interception and decryption exemption for O365 URLs have not been enabled
   4. IDP/IPS exemptions for O365 URLs and O365 IP ranges have not been enabled
   5. Internet egress bandwidth planning and/or reservations for real-time media have not been enabled
   6. VPN split-tunneling have not been enabled

Start with the support ticket first and then work in validating your network configuration:

https://docs.microsoft.com/en-us/office365/enterprise/network-planning-and-performance

https://docs.microsoft.com/en-us/office365/enterprise/assessing-network-connectivity

https://aka.ms/o365networkingprinciples

There have been some service issues Microsoft has identified as of the past week. Downdetector is not a reliable source for those issues unless you start seeing thousands of reports in a given day. Always try to look at first-party sources such as the Office 365 portal and Office 365 twitter accounts first:

https://twitter.com/MSFT365Status