nanog mailing list archives

Re: RFC2544 Testing Equipment


From: Saku Ytti <saku () ytti fi>
Date: Wed, 31 May 2017 13:56:47 +0300

Cool. Seems you're using AF_PACKET, which makes it actually unique.
iperf/netperf etc use UDP or TCP socket, so UDP performance is just
abysmal, you can't saturate 1GE link with any reliability. So
measuring for example packet loss is not possible at all.

I've been meaning to write AF_PACKET based UDP sender/receiver and
have gotten pretty far with friend of mine on rust version, we can
congest 1GE (on minimum size frames) on Linux reliably and actually
tell if you're lossy. It has server/client design, where client
requests via JSON based messages through control-channel server to
receive or send, and what exactly.
Alas, we're only 80% there, and seem to struggle to find time to
polish it for initial release.

We definitely need tool like iperf, which performs at least to 1GE,
and AF_PACKET can do that, UDP socket cannot. Alas 10GE is still pipe
dream for anything as portable as iperf, as you'd need to use DPDK,
netmap or equivalent which will remove the NIC from userland, there
are quite few options for that use-case, but no good option for
use-case when you want at least 1GE but you cannot remove NIC from
userland.


On 31 May 2017 at 13:36, James Bensley <jwbensley () gmail com> wrote:
On 30 May 2017 at 16:22, Nick Olsen <nick () flhsi com> wrote:
 Greetings all,

 Looking for a good test set. Primary use will be testing L2 circuits
(It'll technically be VPLS, But the test set will just see L2). Being able
to test routed L3 would also be useful. Most of the sets I've seen are two
sided, A "reflector" at the remote side, And the test set in hand run by
the technician.

 Looking to test up to 1Gb/s at various packet sizes, Measure Packet loss,
Jitter..etc. Primarily Copper, But if it had some form of optical port, I
wouldn't complain. Outputting a report that we can provide to the customer
would be useful, But isn't mandatory. Doesn't need anything fancy, Like
MPLS awareness, VLAN ID's..etc.


   Nick Olsen
 Sr. Network Engineer
 Florida High Speed Internet
 (321) 205-1100 x106


If you are just testing the forwarding at layer 2 and have no budget
you can use free software and a laptop (for your copper requirement).
I've been writing this (https://github.com/jwbensley/Etherate) and we
use that as well as hardware testers.

Cheers,
James.



-- 
  ++ytti


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