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Re: Extreme Slowness

  • From: Elijah Savage
  • Date: Fri Oct 27 07:39:52 2006

Adam,

Because of contractual issues it makes it very hard for me to participate on this list hence the vague original post. I was just asking a general question to see if anyone else was having issues. I have peering points with Broadwing(now level3), Sprint, AT&T and MCI (now Verizon) that I can test for throughput from. This was not just about home cable connectivity though when frontline starts to get calls I often use wget (very low overhead) to test throughput between my sites or to home my home box often times simulating the same sort of connectivity that a customer may have. There were customers that could not even get to level3.net yesterday which is their home page, but it is always nice to get the refresher course on ICMP though :).

As for html posted messages truly my mistake I know better and thank you for mentioning it. The new duo core 2 mac mail client which I am still trying to get use to under preferences says it is set to plain text hmmm something I need to look into.

Thank you

On Oct 27, 2006, at 12:22 AM, Adam Rothschild wrote:

Elijah,

On 2006-10-26-16:34:18, Elijah Savage <[email protected]> wrote:
[HTML mail stripped]

It seems anything traversing level3 has very high latency along with
what seems overloaded capacity as if they are running in a degraded
mode I have connections with Time Warner, AT&T, and MCI [...]

On 2006-10-26-16:48:15, Elijah Savage <[email protected]> wrote:
[HTML mail stripped]
Say like this traceroute. This is from TW to a Broadwing DS3.

5 tenge-3-2.car1.Cincinnati1.Level3.net (4.78.216.13) 153.267 ms
207.125 ms
tenge-3-1.car1.Cincinnati1.Level3.net (4.78.216.9) 218.920 ms
6 ae-5-5.ebr2.Chicago1.Level3.net (4.69.132.206) 36.976 ms 26.923
ms 57.770 ms
7 ge-11-0.core2.Chicago1.Level3.net (4.68.101.37) 254.145 ms
ge-11-1.core2.Chicago1.Level3.net (4.68.101.101) 258.522 ms
ge-11-2.core2.Chicago1.Level3.net (4.68.101.165) 227.223 ms
8 broadwing-level3-oc12.Chicago1.Level3.net (209.0.225.10) 231.451 ms
9 so-1-1-0.c1.gnwd.broadwing.net (216.140.15.1) 53.269 ms 35.568
ms 22.511 ms
Your postings appear to be missing two key pieces of information which
would help with the community diagnosis requested: source and
destination IP addresses. From the information you did provide, one
can deduce that you're behind a TW/RoadRunner cable modem:

13.216.78.4.IN-ADDR.ARPA domain name pointer tenge-3-2.car1.Cincinnati1.Level3.net
14.216.78.4.IN-ADDR.ARPA domain name pointer ROADRUNNER.car1.Cincinnati1.Level3.net
9.216.78.4.IN-ADDR.ARPA domain name pointer tenge-3-1.car1.Cincinnati1.Level3.net
10.216.78.4.IN-ADDR.ARPA domain name pointer ROADRUNNER.car1.Cincinnati1.Level3.net

Now, the jitter and high latency you're seeing could be a result of
one or more factors, including but not limited to RF/plant issues, TWC
running their transport and/or Level(3) transit hot (which seems to be
a common occurrence these days), ECMP across two circuits of uneven
loading, or your neighbor might be jacking wifi and downloading a
bunch of torrents -- we, the readers, just don't know.

Of note when performing armchair troubleshooting across Level(3)'s
network: the 'ebr's (PTR record of ebr*.{pop}.level3.net == Force10
E1200; Experimental Backbone Router?) tend to drop a lot of diagnostic
traffic (such as, say, 'ping' and 'traceroute') as a part of overly
aggressive control-plane policers. This loss is, of course, strictly
cosmetic, and has no bearing on end-to-end performance. Hence, the
old "to it, not through it" rule applies.

smokeping[1] and iperf[2] (to end hosts) are your friends.

As an aside, I've noticed your string of postings today were all
HTML-tagged. While not expressly forbidden (or even discouraged) by
the current Mailing List AUP, this is generally regarded as bad form;
you might wish to reconfigure your mail client accordingly...

Hope this helps,
-a

[1] <http://oss.oetiker.ch/smokeping/>
[2] <http://dast.nlanr.net/Projects/Iperf/>