All things related to multicast

["Richard Mavrogeanes" <>]

Just one more comment to go along with Marshall:

There is no need to employ multicast to sort out codec / player
compatibility issues.  In fact, multicast (or the lack thereof) tends to
confuse the codec issues, at least in the minds of the target viewers.
Why doesn't this work? Packet loss? Flooding? Routing? Or an oddball
codec?

You may be better off doing http:// and rtsp:// server first,
discovering the codec compatibility.  Then, after you think all is well,
releasing the multicast to the world community.  Generally, there is a
small number of folks willing to look at your stream for testing, so the
problem multicast solves (global distribution) is not needed anyway.

I think it does "multicast" a disservice when there is "stuff" that does
not work being advertised.

My two cents, anyway!

/rich


-----Original Message-----
From: Frank Fulchiero 
[mailto:]
 
Sent: Friday, September 28, 2007 11:51 AM
To: wg-multicast
Subject: Re: multicast testing etiquette


On Sep 28, 2007, at 11:25 AM, Marshall Eubanks wrote:

> If you want a little advice then...
>
> Multicast is just udp and routing. If you have got one UDP stream  
> to work, there is no
> reason to push lots of stream variations, assuming that they work  
> in unicast, unless you plan to use them.

Marshall, thanks for the advice.
One of the other issues is codec and client  
compatibility....specifically H264 (Wirecast and QT Brodacaster  
flavors)  in VLC on PC, Mac and linux, and QT on PC and Mac. I  
mention this as in my first test stream, some folks were getting  
video and not others, even here on our own multicast subnet.
I did not figure out the cause of this, but then went from QT  
Broadcaster to Wirecast. So I will have to revisit this.


> Conversely, don't mix up debugging the stream and the routing. Make  
> sure that the stream works well in UDP unicast before you launch  
> forth into multicast, where problems tend to be more obscure.
>

Thanks, will work on that also. Appreciate the feedback.

Frank