[c-nsp] asymmetrical performance inside core

[Randy]

--- On Mon, 10/1/12, Tim Densmore <tdensmore at tarpit.cybermesa.com> wrote:

> From: Tim Densmore <tdensmore at tarpit.cybermesa.com>
> Subject: Re: [c-nsp] asymmetrical performance inside core
> To: "Cisco NSP" <cisco-nsp at puck.nether.net>
> Date: Monday, October 1, 2012, 4:30 PM
> Stab in the dark, but have you
> verified you don't have a duplex mismatch 
> anywhere?  IME, they can look exactly like that.
> 
> 
> On 10/1/2012 5:03 PM, Eric A Louie wrote:
> > I'm inheriting a problem that I could use some ideas to
> troubleshoot.
> >
> > Speedtesting from within my core to other locations
> within the core give me
> > "asymmetrical" performance. I've traced the routes and
> the path is the same
> > download and upload, but I'll get very good download
> speeds (30Mbps) and
> > terrible upload speeds (3Mbps, 6Mbps)
> >
> > I've looked at MTU and it doesn't appear that there's a
> lot of packet
> > fragmentation/reassembly
> >
> > I've looked at total bandwidth utilization during the
> test times across the
> > backhaul and I'm not saturating the bandwidth in either
> direction
> >
> > I've looked at the interfaces through which the packets
> are traveling, and there
> > are no CRC errors, no drops, no retransmissions
> >
> > The physical layer radio transmissions seem to be good
> both directions with the
> > performance testing at that level.
> >
> > What do I look at next?  It's a problem because
> customers are speedtesting and
> > seeing this DSL-like performance and making noises.
> >
> >   Much appreciated,
> > Eric Louie


..as was mentioned before: a wireshark packet capture of said sucky-upload would be the place to start.
another stab in the dark:
Besides everyting that has already been mentioned(L2) any possibility of Funky-ECMP with IGP?
..and radio links as well....hard to troulbeshoot!
./Randy