How much lag between live and streamed is there when using TCS Multicast?

[Wes Smith]

Hello

We are looking for a low lag/delay solution to stream 'town hall' live events to remote users.

One of the top requirements is running a Q&A session.   Our media group want people to be able call in and ask questions.

This means we must keep transcoding delays to the bare minimum. 

Less than 5 seconds is the ask.

We have looked at various web streaming services (SNS, QUMU etc) and they all have to much delay.
RTMP seems to be the best, but even it has an 8 second or longer lag between the live event and the stream.

Our network is multicast enabled.

We're wondering if using multicast with minimal tanscoding would be be a low lag way to solve this issue?

[Wayne DeNardi]

I'm not sure about when multicasting, but here, when viewing a Live Stream of a conference that is recording via the TelePresence Content Server's web interface, it's about 10 seconds behind real time.

Do you have an MCU?  If so, you may be better off routing the call via that (as well as to your TCS) and using the MCU's streaming capability for your remote users.

Wayne
--
Please remember to rate responses and to mark your question as answered if appropriate.

[Wes Smith]

Thanks.

I'm the network guy and don't have deep skills with the various TP components.

I'm trying to help out our video team with some of this Multicast work.

Does streaming multicast from the MCU require a separate Windows Media Server or other server like Wowza? 

What client app is used to view the multicast streams from the MCU?   

We'd prefer windows media player on windows or quicktime on Macs.

The goal is to minimize the transcoding lag between live and the streamed versions.

Is it feasible to replicate the live RTP streams from the live event directly into a multicast stream without transcoding?

If so .. is it also feasible to pull a SD and HD stream from the live event and then multicast both from the MCU?