SIP Filter Software Requirements

Owned by Agat Support
Last updated: Mar 23, 2022 by Avi J. Levin (Unlicensed)
1 min read

The following software should be installed on the Skype for Business Front End or Edge before the SIP Filter installation:

  • .NET Framework 4.7.2 or higher
  • C++ Redistributables 2010 and 2015


Generally, we recommend that the SIP Filter will be installed on the Edge server and not on the Front End.

However, there is one specific scenario in which it’s unavoidable – when internal (within the organization) DLP/Ethical Wall filtering is required, installing the SIP Filter on the Front End is mandatory.

This is because of the traffic flow of Skype for Business when it transfers data between clients. When a PC client that is within the LAN tries to send a message to someone else within the company who is also using a PC client that is connected to the LAN, the message will go from the 1st participant’s client to the Front End over SIP protocol and then be sent directly to the client of the 2nd participant. This means that in this scenario if a SIP Filter is not installed on the Front End, the traffic will be able to go through unfiltered.

In order to allow SkypeShield to filter and control the traffic in a scenario as described above, a SIP Filter will need to be installed on the Front End. However, if the above scenario isn’t required then the SIP Filter should be installed on the Edge server.