Re: OT: ip sla packet loss w/o responder ?

Thanks for the additional info.

For inbound, I think I misunderstood how you have your sites set up. I had
thought you were indicating you have multiple remote sites coming into a
single site, and in this case the remote sites were over running the remote
site. Too much over subscription.

Yes, for OER the remote site has to be configured to respond and if I
understand your setup, this is not possible.

IP SLA can work without the remote router knowing it for ICMP and simple
echo configs. For TCP connect and all, the remote router has to be
configured to respond.

So does this help you? Not sure ... and of course, over email I am not
going to be able to offer as much insight. A few thoughts though:

1) If multiple paths exist, how is the load sharing configuring? Is each
link being maxed?
2) Can you perform some marking on non-priority traffic on class-default and
use wred? Might help if tcp synchronization if occurring.
 - 2a) side note ... ask a company which traffic is priority and be ready
for either politics to show its ugly head, or the answer "all of our traffic
is priority"
3) Can you increase the bandwidth? The question that needs to be answered
"how much do I need?"
- 3a) the answer to this question is "depends on the performance, queuing,
and amount of drops that are acceptable" All of these are related.
4) Can the provider provide a measurement point? Some providers have a
router or web site that you can use for monitoring and measurements. In
this way, you can gain some measurements, perhaps some understanding of the
drops and jitter, etc ...

I think someone else mentioned ping plotter and this type ... this might be
helpful to help you understand the patterns and baseline.

Carlos, not sure I helped you much ... I could probably ramble on some more,
but this would likely be noisy .. ;-)

Have a great day Carlos and team. For me ... I raked huge loads of leaves
yesterday and you cannot tell. Yuck ... too much to do, and it is raining
today to boot!

Andrew Lee Lissitz

On Sat, Oct 31, 2009 at 6:25 AM, Carlos G Mendioroz <tron_at_huapi.ba.ar>wrote:

> Andrew,
> yes, this is public (Internet) BE traffic. So yes, no visibility at ISP
> side.
> Small note, OER does not have its own probes AFAIK. If active, it uses
> ip sla, but the passive monitoring is the interesting one for me.
> It deduces packet loss from watching tcp sequence numbers!
> (Good luck with WAAS traffic though :)
> My desire is to tap into this info somehow, is possible.
>
> And as I said, the problem is with inbound, so shapping makes no sense
> to me. No way to get to the far side (the cloud).
>
> Thanks,
> -Carlos
>
> ALL From_NJ @ 30/10/2009 23:02 -0300 dixit:
> > Hey Carlos,
> >
> > Do I understand that you are loosing packets in the cloud? Can we assume
> > you do not have any visibility?
> >
> > If your traffic traverses a private network, then the provider should
> have
> > some reporting to help you see where the packet loss is. If you are
> going
> > over a best-effort public network then good luck ...
> >
> > So your idea of adding probes via IP SLA might give you some insight as
> to
> > where traffic problems are occurring. Will this help you to know?
> >
> > OER is supposed to address this by having it's own probes as you mention.
> >
> > For outbound traffic between sites, does it make sense to configure some
> > shaping and slow that traffic down some? If the far side is getting over
> > run, then this is not good either.
> >
> > Sorry if this response is not all that helpful, however, do please
> respond
> > back with some additional info and thoughts. Kindest regards,
> >
> > Andrew
> >
> >
> >
> >
> >
> > On Fri, Oct 30, 2009 at 9:40 AM, Carlos G Mendioroz <tron_at_huapi.ba.ar
> >wrote:
> >
> >> JR,
> >> I'm trying to monitor packet loss in a real network.
> >> The whole picture is a medium site with asimetrical connectivity
> >> to a couple of providers via 4 links, one of them 8:1 bigger
> >> than the next (26M/4M).
> >>
> >> It is congested INBOUND and we are experiencing outbound issues in
> >> services, I suspect related to inbound packet loss. So I want to track
> >> loss to be able to put some facts in my theory.
> >>
> >> I've been pointed to OER, which in fact does track packet loss w/o
> >> peer cooperation (as needed AFAIK by ip sla). The problem is that
> >> I have not been able to find a way to extract that knowledge from it :(
> >> Border routers talk to controllers using a propietary protocol (DRIP),
> >> and no MIB is published to expose the data AFAIK.
> >>
> >> -Carlos
> >>
> >> JR Garcia @ 28/10/2009 14:32 -0300 dixit:
> >>> you could run a program like ping plotter or something similar on your
> >>> network.
> >>> put a pc on your router and do a ping plot to the other side. it will
> >> graph
> >>> out latency, drops, ect.
> >>> not as robust as ip sla, but it works if all your looking for is packet
> >> loss
> >>> measurement.
> >>>
> >> --
> >> Carlos G Mendioroz <tron_at_huapi.ba.ar> LW7 EQI Argentina
> >>
> >>
> >> Blogs and organic groups at http://www.ccie.net
> >>
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> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >
> >
>
> --
> Carlos G Mendioroz <tron_at_huapi.ba.ar> LW7 EQI Argentina
>

-- 
Andrew Lee Lissitz
all.from.nj_at_gmail.com
Blogs and organic groups at http://www.ccie.net