"John Neiberger" wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > I suppose it depends on the unit but ours mainly use unicast to the Cisco > MCU. As far as I know they use standard H.323. The downside if you're > using an MCU is that the PolyComm units have a lot of different codecs > available that might not be known by the MCU. For example, the Cisco MCU > can only do G.711 audio, but if you let two video units speak directly to > each other they use G.726 ( I think. Maybe it's G.722?) and it sounds much > better.
That brings up an interesting question tho.... unless the MCU is converting between codecs for end stations that might want to use different codecs, must the MCU "understand" the codec or would it simply act as a relay startion for that data..... (i.e. if two end-stations are using a codec that they understand but the MCU doesn't, would it be a problem since the MCU would merely forward the "unknown" (to it) audio data to the other end station). The Cisco MCU supports many more codecs than G.711 including the popular G.729 codec (which gives roughly G.711 quality with an 8:1 compression). The G.722 (you were right.. it's G.722, not G.726) that covers from 50-6900Hz instead of 50-3900Hz as most narrowband codecs do. So if you're trying to play more high fidelity sound, you may want to use that. I haven't seen many units that support this codec though (but I have by no means seen tons of units, just a few). However, if the audio you're trasmitting is human speech, the G.722 isn't going to gain you much in terms of sound quality since it would be preserving an additional frequency range that's not used alot by human speech. Does anyone have any input or experience with how and/or when the MCU codec support comes into play? I would think that if the endpoints are at the same datarate and using the same audio/video codecs, the MCU would just be a bounce point and the actual codecs in the MCU wouldn't be utilized.... Just a theory tho.. Mike W. Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=49900&t=49882 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
