All things related to multicast

[Marshall Eubanks <>]

Tim;

show ip mroute active

should show the multicast groups with their bit rate
MRTG should also show the groups
rtpdump will show the existance of packets.

Here is what we do

This command dumps two packets using rtpdump - this shows that the group 
is "up"

rtpdump -F ascii 233.64.133.12/7004 | head -2
1018995500.480846 RTP len=120 from=63.105.122.8:32773 v=2 p=0 x=0 cc=0 
m=0 pt=14 (MPA ,0,90000) seq=63834 ts=2426335622 ssrc=0x2712
1018995500.487719 RTP len=120 from=63.105.122.8:32773 v=2 p=0 x=0 cc=0 
m=0 pt=14 (MPA ,0,90000) seq=63835 ts=2426337973 ssrc=0x2712
Broken pipe
[tme@hendrix
 scripts]$


This shows that the router has state for the group (i.e., that it is 
going out the door) :

show ip mroute active 15
Active IP Multicast Sources - sending >= 15 kbps

Group: 233.64.133.32, On-The-I.com Drum Logic 32kbs MP3 Audio
   Source: 206.61.163.86 (morrison.multicasttech.com)
     Rate: 38 pps/44 kbps(1sec), 45 kbps(last 37 secs), 9 kbps(life avg)


And, MRTG will show you the amount of traffic - multicast traffic is 
easy to spot coming and going as it is a step function.

It would be easy to write a cron job to rtpdump every N seconds, wait 1 
second, and put up a flag if traffic was not found.

BTW, can we get this content here on the outside ?

Regards
Marshall Eubanks



-

Kevin C. Almeroth wrote:

> > > Date: Tue, 16 Apr 2002 15:39:34 -0500
> > > From: Tim Ward 
> > > <>
> > > To: 
> > >
> > > Subject: Monitoring multicast groups
> > >
> > > We're into our second day of distribution of 4 off air TV channels to the 
> > > students in four dorms over our campus multicast-enabled network.  We've
> > > seen far more client problems than network problems.  About the biggest
> > > complaint we get is the quality of the picture, which we're working on 
> > > cleaning up before it gets to the encoder.
> > >
> > > One of the issues we're struggling with now is how to monitor that the
> > > system is really working.  One thing I could do is put a beefy machine 
> > > in the NOC to view all four channels at once (software decoding!), but
> > > I'm not sure I want the NOC to be watching TV all of the time!  And if
> > > we go with a 20 channel line up in the fall, I'll need a lot more machines!
> > >
> > > Anyone have any suggestions?  I was thinking a small applet running
> > > on a host that could join the group and successfully tell that there
> > > was traffic on it, but that doesn't actually tell me the content.  Ideally
> > > it would SNMP trap if the traffic went to zero.  How do real CATV operators do 
> > > this?  A bank of monitors?  Or do they rely on the distributed diagnostic 
> > > tool known as "the user"?
> > >
> > > Tim
> > > --
> > > Tim Ward                                  
> > >
> > >       V 847-467-1449
> > > Associate Director                     G172 Leverone Hall  F 847-467-5690
> > > Telecommunications and Network Services            Information Technology
> > > 2001 Sheridan Rd  Evanston IL 60208-2030          Northwestern University


-

T.M. Eubanks
Multicast Technologies, Inc
10301 Democracy Lane, Suite 410
Fairfax, Virginia 22030
Phone : 703-293-9624       Fax     : 703-293-9609
e-mail : 

http://www.multicasttech.com

Test your network for multicast :
http://www.multicasttech.com/mt/
 Status of Multicast on the Web  :
 http://www.multicasttech.com/status/index.html