Media bypass leverages protocols called Interactive Connectivity Establishment (ICE) on the Teams client and ICE lite on the SBC.

Without media bypass, when a client makes or receives a call, both signaling and media flow between the SBC, the Microsoft Phone System, and the Teams client, as shown in the following diagram: The diagrams below illustrate the difference in call flow with and without media bypass. This article describes the call flow in different scenarios.

If you enable media bypass, this does not mean that all media traffic will stay within the corporate network. You can control media bypass for each SBC by using the Set-CSOnlinePSTNGateway command with the -MediaBypass parameter set to true or false. To configure media bypass, the SBC and the client must be in the same location or network. With media bypass, media is kept between the Session Border Controller (SBC) and the client instead of sending it via the Microsoft Phone System. Media bypass enables you to shorten the path of media traffic and reduce the number of hops in transit for better performance. In this article About media bypass with Direct Routing

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