I work for a company that uses WebEx.

The service for the meetings is no more available as it was before, it is slow and often unreachable. The company suggest some whitelstings.

I contacted the kindenservice of o2 and they told me they will not do anything delegating to the settings of  the router, which is not what requested.

You have to call your Internet provider and ask them to whitelist webex.com, *.webex.com and open ports 443, 45 and 9000 for TCP and UDP services. here are the references if you need them.
Ports needed.
https://help.webex.com/en-us/WBX264/How-Do-I-Allow-Webex-Meetings-Traffic-on-My-Network#id_135400
Domains that need to be whitelisted
https://help.webex.com/en-us/WBX264/How-Do-I-Allow-Webex-Meetings-Traffic-on-My-Network#id_135010
Just in case, IP addresses needed
https://help.webex.com/en-us/WBX264/How-Do-I-Allow-Webex-Meetings-Traffic-on-My-Network#id_135011
 

Is anyone experiencing the same?

Thanks,

   Nunzio