All things related to multicast

[Hitoshi Asaeda <>]

> I think 10s must be the default for VLC.  I see our system on the
> list and as far as I know we have done nothing to change VLC to send
> at anything but the default rate.
> 
> > We've tried to collect some statistics for sources currently sending to
> > the IPv4 SAP group. See attachment if you like.
> >
> > Right now (when we checked), there was one source (193.10.29.5) sending
> > 10 pps to SAP, which is rather high.
> >
> > Next up there are a handful of sources sending announcement 1pps which
> > also is rather high. Many others at about one packet every 10s which
> > still is rather high.

Either 10pps or 1pps is rather high. 10s SAP interval is also too
short.

According to RFC 2974 (SAP specification), the next SAP message
transmission time for an announcement should be longer than 200 sec.

And in my calculation based on rfc2974, when we assume the average
message size of a single multicast session information is about 300
bytes, an interval time of each session announcement becomes greater
than 300 seconds. And if the total number of active multicast sessions
is more than 500 the average announcement interval increases
proportionally.

BTW, as I promised, I submitted an individual I-D whose title is
"Requirements for IP Multicast Session Announcement in the Internet"
on July 6.
http://www.ietf.org/internet-drafts/draft-asaeda-mboned-session-announcement-req-00.txt
If you are interested in it, please read it.
I'd appreciate your comment.

Regards,
--
Hitoshi Asaeda