An external customer is having problems attending our Skype for Business meeting. It is hosted online through Office 365.
They do not have S4B and are using the web client. They can join and use IM but not desktop sharing or audio. We suspect they have a very strict firewall in place.
I had assumed the web client would simply use standard web ports.
What other ports might the client need?
Best Answer
I have only seen that the client is using http and https (more infos here). But to be on the save side you could run fiddler and check which ports will be used here (including hostnames if you need).
However we had customers who reported the same, so here is the summary for the issues and solutions we collected so far (as we run a very big environment, there are a lot to share):
By the way, the best would be if you run a test on your side as well to ensure that there is no configuration issue on your side somehow. While you do that you could run fiddler and validate the needed ports and hostnames/ips.