On 5 Nov 2015 21:50, "Eric Dugas" <edu...@unknowndevice.ca> wrote: > > Hello NANOG, > > We've been dealing with an interesting throughput issue with one of our > carrier. Specs and topology: > > 100Mbps EPL, fiber from a national carrier. We do MPLS to the CPE providing > a VRF circuit to our customer back to our data center through our MPLS > network. Circuit has 75 ms of latency since it's around 5000km. > > 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%. > > 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. > > Thanks > Eric
Hi Eric, Sounds like a TCP problem off the top of my head, however just throwing it out there, we use a mix of wholesale access circuit providers and carriers for locations we haven't PoP'ed and we are an LLU provider (CLEC in US terms). For such issues I have been developing an app to test below TCP/UDP and for pseudowires testing etc: https://github.com/jwbensley/Etherate It may or may not shed some light when you have an underlying problem (although yours sounds TCP related). Cheers, James.