cant sign in to skype for business:The server is temporary unavailable for External users

Umair Hafeez 0

Hello,

I am experiencing an issue with external users attempting to sign in to Skype for Business Server 2015. However, the problem is only occurring with external users using laptops, while external users with Android mobiles are able to connect to the Skype for Business 2015 Edge Server. I attempted to troubleshoot the issue by testing the 443 and 5061 ports via telnet, and both ports are open externally.

JimmyYang-MSFT 49,031 Reputation points Microsoft Vendor

2024-01-11T05:52:38.29+00:00
@Umair Hafeez It's possible that the issue is related to the configuration of the laptops or the network they are connecting from. Here are a few things you can try:

Check the firewall settings on the laptops and make sure that the necessary ports are open.

Check the network settings on the laptops and make sure they are configured correctly for the Skype for Business Server.

Check the DNS settings on the laptops and make sure they are resolving correctly to the Skype for Business Server.

Check the certificate configuration on the laptops and make sure they trust the certificate chain for the Skype for Business Server. For more details about its troubleshooting process, you could refer to:

https://blog.matrixpost.net/troubleshooting-skype-for-business-external-sign-in-issues-and-examine-the-whole-client-sign-process/
Umair Hafeez 0 Reputation points

2024-01-12T16:14:40.8033333+00:00

Thanx for your response, I will let you know once i verify the configuration.
Umair Hafeez 0 Reputation points

2024-01-15T09:00:38.93+00:00

Hello Jimmy, after changing Skype client settings from 'Tools -> Options -> Personal -> Advanced' - 'Automatic Configuration' to 'Manual Configuration' with internal IP 192.168.10.x and external IP 94.x.x.x, a sign-in error occurred. It changed to 'Can't sign in to Skype for Business. There was a problem verifying the certificate from the server.' Could you please advise on whether I should import and export certificates from the Skype server to the Skype client to resolve this issue. Which certificates should I export from the server, and how can I import them into the Skype client machine
JimmyYang-MSFT 49,031 Reputation points Microsoft Vendor

2024-01-25T07:40:28.4366667+00:00

@Umair Hafeez In this blog, it shows the guidance for how to import them: http://blog.schertz.name/2016/03/skype-for-business-2015-edge-server-deployment/