Media Transcoding Gateways

Another approach to integrating with Lync is to use a media transcoding gateway. This gateway typically works in conjunction with a signaling gateway to provide additional capabilities, such as the capability to transcode different codecs between two endpoints. For example, a third-party endpoint can send 720p H.264 video to the media transcoding gateway while a Lync endpoint can send 720p RTVideo to the same gateway. The media transcoding device then transcodes, or converts, the streams to the appropriate formats for each endpoint. The endpoints do not communicate directly in this scenario, so the third-party endpoints maintain an H.264 peer-to-peer conversation with the gateway, and the Lync client maintains an RTVideo peer-to-peer conversation with the gateway.

Figure 20.4 shows an example of the traffic flow in this scenario.

Figure 20.4. Media transcoding gateway.

This approach works around the limitation of Lync and the third-party endpoint only supporting H.263 CIF as a common codec, and allows for higher-resolution video to take place between the two systems. The disadvantage here is that just as with a signaling gateway, the media transcoding gateway becomes a single point of failure.