[f-nsp] LTE base station on FES2402

[Wilbur Smith]

I’ll see what I can dig up.

The FES is an old switch, but it has a solid design. The 24 port and 48 port versions are not oversubscribed and the GigE uplink should operate at line rate. It is a store-and-forward switch and It does have limited buffers space though, but that was to help it reach predictable latency values. By default, you may be bouncing up against the internal QOS system that tries to reserve some buffer space for other ports.

I’ll see if I can fins one of our old WP on how to configure the advanced buffer settings for a FES.

Wilbur

Wilbur Smith
SE Ninja, Brocade
wilbur.k.smith at gmail.com
wsmith at brocade.com


Disclosure: While I am a Brocade employee, my participation in this community is a personal choice and not directed by my employer. And information or recommendation I provide are my own and not an official recommendation from Brocade. Sorry folks, just need to make sure you know I’m ‘doin this “off the clock”!



From: Rens <rens at autempspourmoi.be<mailto:rens at autempspourmoi.be>>
Date: Tuesday, February 25, 2014 at 11:06 AM
To: "foundry-nsp at puck.nether.net<mailto:foundry-nsp at puck.nether.net>" <foundry-nsp at puck.nether.net<mailto:foundry-nsp at puck.nether.net>>
Subject: [f-nsp] LTE base station on FES2402

Dear all,

We are currently testing LTE equipment and we see serious speed problems when connecting the LTE base station on a FastE port of a FES2402
We see packet-loss and packet out-of-order coming out of the FES2402 (before entering to the LTE base station) as result we see very low TCP throughputs

This leads us to suspect that there may be a buffer overrun or high packet jitter in the FES2402 switch, when going from GigE to FastE or vice versa…

The downlink capacity we can get out of this LTE base station is 80Mbps so that should be doable for a FastE port

With the LTE base station on a FastE port we get 40Mbps downstream and when we move it to a GigE port we get 80Mbps down

When I swap the FES2402 with a Cisco 3560 I get 80Mbps down with the LTE on a FastE port
However the uplink has to be GigE port of the Ciscp else if all ports of the Cisco are FastE I get the same results as with the LTE on FES2402 FastE port

Has anyone ever seen this kind of problem?
Is there any magic command to solve this?

All help appreciated

Regards,

Rens

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