Media Bypass has been around since Lync 2010, however the implementation in Teams is different in many regards. In Teams in comes in two flavours, Media Bypass and Local Media Optimization. In the next couple of posts, I’ll cover what these are, and why you might want or need to use them, and why you might not.

In Lync and SfB, the basic voice path is from the device to the Mediation server and then off to the gateway/SBC. Media Bypass allowed media to flow directly between the device and the gateway/SBC. There were two main reasons to do this:

• To reduce load on the Mediation server.
• To reduce WAN bandwidth usage by preventing tromboning of traffic to the Mediation server and back, in scenarios where the user and gateway are not located in the same site at the Mediation server.
• Tromboning or hairpinning, is where traffic leaves a devices and proceeds to another, usually in a different site, and then returns to the original site

10+ years ago, these were serious considerations for organizations.

With Teams, we have a very different architecture. There aren’t any servers, and traffic to/from the PSTN doesn’t (usually) traverse the WAN. If it does, something is probably wrong if your media is tromboning through your WAN.

In Media Bypass for Teams, media traffic from a devices connects to the outside interface of a Session Border Controller (SBC). Local Media Optimization (LMO) allows traffic from the device to connect to the inside interface of the SBC. A more advanced configuration of LMO creates a 2-level hierarchy of SBCs that can help in scenarios where remote sites have no (or terrible) Internet, and when two remote sites have no direct WAN connectivity.

In the next post, I’ll dive into Teams Media Bypass.