Date: Wed, 6 May 1998 12:16:04 +0200 (SAT) From: Reinier Bezuidenhout <rbezuide@oskar.nanoteq.co.za> To: freebsd-hackers@FreeBSD.ORG Subject: Weird UDP T/P on fxp0/de0 - 2.2.6-RELEASE Message-ID: <199805061017.MAA01011@oskar.nanoteq.co.za>
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Hi ...
I have the following basic setup:
A B
PII/266 <--- 100Mbit CAT 5 X-over ----> PII/266
I am using ttcp on both sides to test data transfers with
diffirent packet sizes. I ran into some really STRANGE numbers
during these test. I have basically two setups on each side
A is the receiver while B is the transmitter. The one setup
is where B transmits, but nothing on A is listening - this
causes ICMP port unreachable packets to be sent to B (full-duplex
line). In the second test I have ttcp listening on A - thus no
ICMP packets is returned (I veryfied this on B with a tcpdump).
I use ttcp to set the packet size in powers of 2. I repeated
each of the tests a few times, just to make sure I get a good
average. I configured ttcp in such a way that all transfers take
at leas 7 seconds as to reduce strage numbers with too few data.
I also dit these test with a Intel Ether express 10/100B and
an SMC 9332BDT (fxp and de respectively)
The numbers jump up and down in large jumps and the two
network cards differ substantialy e.g. 3.1 MB/sec and 10 MB/sec
for 512 byte packets. The other VERY VERY strange thing is
that in most cases the FXP card transfers faster when there
is ICMP port unreachable packets being sent back ??????
How is this possible ????
The first number is the packet size and the second is the
transfer rate in KB/sec
Intel Ether Express (100 - full duplex)
UDP transfers
TTCP listening (-r -s -u) No daemon listening
-----------------------------------------------------------------
Pkt fxp0 | de0 Pkt fxp0 | de0
-----------------------------------------------------------------
64 - 3320 4952 64 - 1903 1897
128 - 2620 7994 128 - 3522 3412
256 - 1873 9685 256 - 7087 7122
512 - 3102 4730 512 - 3182 10800
1024 - 5960 7550 1024 - 5975 8790
2048 - 5874 7268 2048 - 5882 7673
4096 - 7870 7604 4096 - 7870 7795
8096 - 7734 6951 8196 - 7733 6980
Any ideas ??
Thanx
Reinier
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