Just as is the case with using a signaling gateway, this form of integration relies on the third-party endpoint and the Lync endpoint sharing a common codec within their media stack. This common codec was also traditionally H.263 CIF quality, so even with native registration the video quality with a Lync 2010 client was not very clear on large screens. Even if the codec supported native registration and Lync presence, the video quality was still limited to 352×288.
Polycom was the only vendor to add native support for RTVideo, which was introduced as an RTVideo license key for their HDX codec series. This change enabled a regular Lync client to conduct a CIF, VGA, or 720p-quality peer-to-peer video call using RTVideo.