Re: network speed

[Patrick Welche <prlw1%cam.ac.uk@localhost>]

On Mon, Jul 20, 2009 at 09:53:12PM +0100, Matthias Scheler wrote:
> 
> Try "ttcp -r -s -b 131072" and "ttcp -t -s -b 131072 <target>", please:
> 
> NetBSD 5.0_STABLE amd64

5.99.15/amd64

> ttcp-t: buflen=32768, nbuf=8192, align=16384/0, port=5001,
> sockbufsize=131072  tcp  -> excalibur
> ttcp-t: 268435456 bytes in 2.52 real seconds = 104183.62 KB/sec +++

ttcp-r: buflen=8192, nbuf=2048, align=16384/0, port=5001, sockbufsize=131072  
tcp
ttcp-r: 268435456 bytes in 2.36 real seconds = 111096.37 KB/sec +++

So tcp seems fine!

> I can get more then that out of my system:
> 
> tron@colwyn:~>ttcp -r -s -b 131072 -u
> ttcp-r: buflen=8192, nbuf=2048, align=16384/0, port=5001,
> sockbufsize=131072  udp
> ttcp-r: socket
> ttcp-r: rcvbuf
> ttcp-r: 44457344 bytes in 0.38 real seconds = 115586.01 KB/sec +++
> ttcp-r: 30204 I/O calls, msec/call = 0.01, calls/sec = 80412.98
> ttcp-r: -1.9user 0.0sys 0:00real 10% 0i+0d 0maxrss 0+0pf 472+4csw

re udp:

quantz% ttcp -r -s -b 131072 -u
ttcp-r: buflen=8192, nbuf=2048, align=16384/0, port=5001, sockbufsize=131072  
udp
ttcp-r: socket
ttcp-r: rcvbuf
ttcp-r: 67018752 bytes in 14.89 real seconds = 4394.53 KB/sec +++
ttcp-r: 8183 I/O calls, msec/call = 1.86, calls/sec = 549.45
ttcp-r: 0.0user 0.0sys 0:14real 0% 0i+0d 0maxrss 0+1pf 8172+0csw

% ttcp -t -s -b 131072 -l 32768 -n 8192 -u quantz
ttcp-t: buflen=32768, nbuf=8192, align=16384/0, port=5001, 
sockbufsize=131072ttcp-t: socket
ttcp-t: sndbuf
ttcp-t: 268435456 bytes in 14.89 real seconds = 17604.65 KB/sec +++
ttcp-t: 8694 I/O calls, msec/call = 1.75, calls/sec = 583.86
ttcp-t: -1.9user 0.7sys 0:14real 4% 0i+0d 0maxrss 0+8pf 496+0csw
  udp  -> quantz

simple question: why is the number of bytes different in that transfer
according to the receiver and the transmitter?
(nearly exactly factor 4 difference)

Cheers,

Patrick