file transfer performance over wireless.
 

my linux box is connected to the internet through an ethernet connection to a wireless router. I also have a powerbook that connects to the internet and my linux box wirelessely through the router

the problem I have is that network performance are abismal :

no problem to get to the internet from either the linux box or the wireless connection but connecting to my nfs or samba shares on the linux pc is very slow.

actually, the speed of the connection is just enough for ssh type of interaction. But transfering a file is hopeless.....

Is there any configuration I need to check anywhere to improve things ?

Thanks all

Hope this is helpful:

http://nfs.sourceforge.net/nfs-howto/performance.html

http://www.higs.net/85256C89006A03D2...NFSPerformance


http://www.samba.org/samba/docs/man/speed.html


Be sure to test FTP speeds which also uses TCP/IP

Check to see if there are any Hubs, etc and any possible issues with auto-negotiation and the network cards.

I would first concentrate on the basic communications, check all physical connections and make sure everything is connected fine. Also check /var/log/messages to see if there are any messages from the driver.

some more details : I have done a transfer test using sftp and at first, it's quite satisfactory. But after say 10 seconds, is slows downs and stalls. does that sound familiar ?

Definitely NOT a fine tuning issue :)

I would check DNS setup and performance on all linux/unix systems involved in the ftp. DNS hang is one thing you want to either rule or rule out first. Can try pinging by name and also dig command. CHeck out /etc/resolv.conf and /etc/nsswitch.conf. resolv.conf should just have a couple of lines specifying the IP address of primary and secondary name servers to use. look at nsswitch.conf and make sure hosts: line
is something like hosts: files dns

If still having stalls after rechecking everything DNS, then you can try running strace -f -o /tmp/strace1.out ftp <wherever>

strace will print out the system calls made to /tmp/strace1.out (you can call the file whatever you want, it will just be a plain ASCII file)

syntax:
strace -f -o <output file> <command>

If looking look near the end of the output file and look for system commands that tend to take more time ( bigger increments in time between system commands) or perhaps be called more frequently.

If still can't find anything then would try to check if there is any possibility of connection problems in any way.

Also be sure to look over /var/log/messages with a fine tooth comb.

I seem to have found what the problem was : the MTU size was 1458 on the router instead of 1500 on both hosts. I've changed it and transfered a movie at 300 kb/s with no stalls and streamed mp3.

Thanks guys.