MCU bandwidth usage and quality

[Bo Bo Aung]

Dear All,

I have some query with regards to the bandwidth usage and quality of MCU conference call.

If I have 4 parties and each connected to MCU with differenct bandwidth and resolution,

will the overall conference quality be downgraded to the lowest quality?

e.g. An ISDN endpoint connected to MCU with 384kbps

       An IP endpoint connected to MCU with 768kbps

      Another IP endpoint connectd to MCU with 1920kbps

      And one party joined to MCU from jabber client with 768 kbps

What video quality would receive on ISDN, IP endpoints and jabber client?

I hope someone can share some knowlodge with me.

Thanks in advance.

Regards

[Nick Halbert-Lillyman]

No - the conference wouldn't be downgraded, each participant should be able to send and recieve up to their maximum bitrate, although at best you can only see an upscaled version of what the other participants are sending, so for example your 1920kbps endpoint would only ever get at best an upscaled 768kbps image, because in your scenario that's the highest bitrate that any other participant is sending.

That said, I believe if you are using a conference layout that shows multiple participants at the same time, the 1920Kbps endpoint could get close to 1920kbps on its video stream, with participants in different "boxes" on the screen at their own bitrate.

Essentially, an MCU's job is to MUX everything and transcode between different bitrates, but you are still limited by what the remote participants are sending - I hope this helps.