hi eric On 11/05/15 at 04:48pm, Eric Dugas wrote: ... > Linux test machine in customer's VRF <-> SRX100 <-> Carrier CPE (Cisco > 2960G) <-> Carrier's MPLS network <-> NNI - MX80 <-> Our MPLS network <-> > Terminating edge - MX80 <-> Distribution switch - EX3300 <-> Linux test > machine in customer's VRF > > We can full the link in UDP traffic with iperf but with TCP, we can reach > 80-90% and then the traffic drops to 50% and slowly increase up to 90%. if i was involved with these tests, i'd start looking for "not enough tcp send and tcp receive buffers"
for flooding at 100Mbit/s, you'd need about 12MB buffers ... udp does NOT care too much about dropped data due to the buffers, but tcp cares about "not enough buffers" .. somebody resend packet# 1357902456 :-) at least double or triple the buffers needed to compensate for all kinds of network whackyness: data in transit, misconfigured hardware-in-the-path, misconfigured iperfs, misconfigured kernels, interrupt handing, etc, etc - how many "iperf flows" are you also running ?? - running dozen's or 100's of them does affect thruput too - does the same thing happen with socat ?? - if iperf and socat agree with network thruput, it's the hw somewhere - slowly increasing thruput doesn't make sense to me ... it sounds like something is cacheing some of the data magic pixie dust alvin > Any one have dealt with this kind of problem in the past? We've tested by > forcing ports to 100-FD at both ends, policing the circuit on our side, > called the carrier and escalated to L2/L3 support. They tried to also > police the circuit but as far as I know, they didn't modify anything else. > I've told our support to make them look for underrun errors on their Cisco > switch and they can see some. They're pretty much in the same boat as us > and they're not sure where to look at. >