Media Flow

It is important to understand that all media must pass through this gateway to be converted when using a media transcoding gateway. This is not an issue for SIP signaling traffic, but it can have a significant impact on the user experience when the media transcoding gateway is located across a WAN connection.

Consider a scenario in which a Lync endpoint and third-party endpoint are in the same office, but the media transcoding device is in a datacenter geographically far from the office. Instead of relaying the traffic between the two endpoints in a peer-to-peer sense, both endpoints must submit their media stream across the WAN connection to the media transcoding gateway, as shown in Figure 20.5. The voice and video quality might suffer depending on the latency between the office and the datacenter.

Figure 20.5. Media transcoding gateway WAN.