Hey Mark,
The only QoS policies we have in place are for VoIP phones so I don’t think that should have any effect.
I’m actually doing my testing on the core. I noticed the issue offsite in another building and then came back to the office to test at the source. Yep - the server and clients are both on the core switch. This switch does the routing between vlans. As soon as the clients move out of the server vlan, multicast suffers.
I might have to look into the Iperf tests - it sounds like a neat tool. All other traffic seems okay though - I can copy files from PCs around the network and still get gigabit speeds.
Thanks for the thoughts! At this point the issue is only slowing me down a little bit - we’re just unicasting everything at the moment so it’s not a major problem, just something I’d like to try to fix.
Edit: forgot the IOS version, it is 12.2(17r)S4