Proxy servers for Skype for Business Online
Skype for Business Online was retired on July 31, 2021. If you haven't upgraded your Skype for Business Online users yet, they will be automatically scheduled for an assisted upgrade. If you want to upgrade your organization to Teams yourself, we strongly recommend that you begin planning your upgrade path today. Remember that a successful upgrade aligns technical and user readiness, so be sure to leverage our upgrade guidance as you navigate your journey to Teams.
This article provides guidance about using a proxy server with Skype for Business.
Not using a proxy server is recommended
When it comes to Skype for Business traffic over proxies, Microsoft recommends bypassing proxies. Proxies don't make Skype for Business more secure because the traffic is already encrypted.
And having a proxy can cause issues. Performance-related problems can be introduced to the environment through latency and packet loss. Issues such as these will result in a negative experience in such Teams or Skype for Business scenarios as audio and video, where real-time streams are essential.
If you need to use a proxy server
Some organizations have no option to bypass a proxy for Skype for Business traffic. If that's the case for you, the problems mentioned above need to be kept in mind.
Microsoft also strongly recommends:
Using external DNS resolution
Using direct UDP based routing
Allowing UDP traffic
Following the other recommendations in our networking guidelines:
Following this guidance should minimize potential problems.