Cisco TelePresence IP VCR Series

Long pause before playback starts when streaming/pausing a recording

When I start streaming or pause a recording on a IP VCR, why is there a significant pause before playback starts/resumes?

Streaming media is designed to be several seconds later than media shown in video calls. This is because video calls are two way: people can listen and speak, and therefore it is important to keep the delay as low as possible to provide a realistic conversation. However, when streaming users just watch the conference, therefore low delay is not necessary. Delaying the video improves the chance that all the media packets will be correctly received by the player, consequently the media quality will be higher.

Therefore there may be a delay before playback starts when you start to stream a recording, and after pausing playback or changing the position of the playhead. This is because your media player is buffering data. This is normal behavior and no cause for concern.

The amount of buffering that takes place is decided by the media player, not the browser. Your media player may allow you to set the size of the buffer: if this is the case, see the media player's documentation for instructions. In addition, packet loss and jitter will cause a media player to buffer for longer. All these factors together mean that you may experience different delays on different PCs when streaming.

This article applies to the following products:

  • Cisco TelePresence IP VCR 2200 / MSE VCR blade

June 22nd, 2011TAA_KB_100