RE: multicast problems
> >From: "Sinada, Yasir" <Yasir.Sinada --at-- Marconi.com>
> >To: "'dast --at-- nlanr.net'" <dast --at-- nlanr.net>
> >Subject: multicast problems
> >Date: Wed, 22 Oct 2003 19:57:17 -0400
> >
> >Hi,
> >I am using iperf version 1.7 on WIN32 platform. I had these issues with the
> >multicast:
> >1. What is the proper order in starting? Is it client first then servers or
> >vice versa?
With Iperf, servers should always be started before clients. Servers need
the time to set up and start listening before a client attempts a
connection.
> >2. Does the -P (--parallel) work with the -B option for multicast servers?
The -P on the server side limits the number of incoming connections
handled. Unfortunately WIN32 has a HORRIBLE UDP implementation which
forces WIN32 UDP servers to only be able to handle one connection at a
time. So if you have only one stream flowing at any given time then the -P
works fine and will close the server after the given number of
connections.
> >3. Does the -o option work without the -D option? I want to use it instead
> >of redirecting the output ( .. > outputfile)
At this time no. The -o was added for use with the -D, and implemented in
that narrow outlook. I was not here when WinService was added to Iperf but
I may change that behavior in a future version. It would also be nice to
have a portable version of the -o instead of the WIN32 only version we
have now.
> >3. Can I bind (-B) to 2 or more different multicast addresses on the same
> >port, on the same interface (NIC) while sending to a third multicast on the
> >same port, in other words can I do the follwing from 1.1.56.18 with only one
> >NIC (of course these addresses are not the actual ones :o)
> >>iperf -s -u -p 5009 -i 1 -B 239.200.56.51
> >>iperf -s -u -p 5009 -i 1 -B 239.200.56.55
> >>iperf -u -b 1K -p 5009 --ttl 5 -t 10 -c 239.200.56.60
There should be no reason why this wouldn't work. Be sure however that
there is only ONE client per Multicast address when using WIN32 servers
because of the previously mentioned junkie WIN32 UDP support. I see you
have realized the need for the --ttl option, make sure that the value is
high enough to reach your servers (but I am guessing you have that under
control =-).
Kevin
PS: Thanks for the extremely well written and informative questions. It is
nice not to have to guess what people are trying to do or how they are
trying to do it.