MCU streaming max RTT

[carlos.bustios]

Hi all,

Does anyone know the maximum RTT (round trip time) recommended for streaming video over WAN links using an MCU 4501 and Windows Media Player as the receiving app. at the destination?

I'm currently using the following parameters for streaming video at the MCU:

Steams: 192k, Polycom (R) Siren14 (TM) audio, H.264 video

Player format: Windows Media Player

Telepresence MCU 4501 sw ver.: 4.4(3.42)

WMP protocol: HTTP

In the streams section the option says 192k, but I'm seeing over 450kbps of traffic over the WAN links for just one streaming session, is this bandwidth consumption correct?

Thanks for your help,

[Martin Koch]

You will get some ip overhead, especially using http, but 192 vs 450 sounds a bit to much.

Did you check with tcpdump/wireshark/... to see whats really send over the network?

Please remember to rate helpful responses and identify helpful or correct answers.

[carlos.bustios]

Hi Martin,

I already revised a Wireshark capture and I only see HTTP traffic coming from the MCU to the streaming client, after a software upgrade of the 4501 MCU to the latest release 4.4(3.54) the maximum bandwidth consumption is now 310kbps which sounds very acceptable taking into consideration that on the conference besides the 192k H.264/Siren14 video streaming there is also the content channel available to share presentations or to write messages.

What I haven't found out yet is how network delay could affect video streaming performance from the MCU over WAN links, because sometimes we´re still seeing video degradation over WAN links with a maximum ICMP RTT of 102ms.

BR,

CB