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Re: Route cache performance under stress

To: Jamal Hadi <hadi@xxxxxxxxxxxxxxxx>
Subject: Re: Route cache performance under stress
From: chas williams <chas@xxxxxxxxxxxxxxxx>
Date: Tue, 10 Jun 2003 07:41:01 -0400
Cc: ralph+d@xxxxxxxxx, CIT/Paul <xerox@xxxxxxxxxx>, "'Simon Kirby'" <sim@xxxxxxxxxxxxx>, "'David S. Miller'" <davem@xxxxxxxxxx>, "fw@xxxxxxxxxxxxx" <fw@xxxxxxxxxxxxx>, "netdev@xxxxxxxxxxx" <netdev@xxxxxxxxxxx>, "linux-net@xxxxxxxxxxxxxxx" <linux-net@xxxxxxxxxxxxxxx>
In-reply-to: Your message of "Tue, 10 Jun 2003 06:53:04 EDT." <20030610061010.Y36963@xxxxxxxxxxxxxxxx>
Sender: netdev-bounce@xxxxxxxxxxx
In message <20030610061010.Y36963@xxxxxxxxxxxxxxxx>,Jamal Hadi writes:
>is we actually test on real environments or maybe even collect real
>world traffic patterns and run them in the lab.
>Typically, real world is less intense than the lab. Ex: noone sends
>100Mbps at 64 byte packet size. Typical packet is around 500 bytes
>average. If linux can handle that forwarding capacity, it should easily

i was curious at one point and collected a some packet size stats on
our border router.  while the average packet size is close to 500,
the bulk (by count) of the traffic seems to be in the 64-95 byte range.
(the length here is the link level size as given by tcpdump -e)

# 27100000 packets  average length = 747
0-31 5271
32-63 0
64-95 12143442
96-127 934314
128-159 202984
160-191 98772
192-223 49279
224-255 37826
256-287 28276
288-319 41675
320-351 42359
352-383 93709
384-415 24557
416-447 73969
448-479 25100
480-511 23210
512-543 86515
544-575 77779
576-607 146066
608-639 23967
640-671 23005
672-703 87471
704-735 13154
736-767 8818
768-799 20850
800-831 7678
832-863 7379
864-895 7920
896-927 5789
928-959 48122
960-991 35512
992-1023 26081
1024-1055 63541
1056-1087 23673
1088-1119 8397
1120-1151 5780
1152-1183 5133
1184-1215 8820
1216-1247 40251
1248-1279 6295
1280-1311 11420
1312-1343 31610
1344-1375 21802
1376-1407 22442
1408-1439 4932071
1440-1471 594385
1472-1503 439460
1504-1535 6434071

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