tcp/ip socket slowdown

Hi list,

        I have a vb.net client that communicates with the iSeries using sockets.
My problem is that the transmission of data is taking too long.  The client
builds a variable length string which contains many self described data
items, including base-64 encoded images, that will typically be in the 1 -
1.5 meg range total.  The transmission takes around 3 minutes on a 100mb
Ethernet and about the same on a 11mb wireless.  The windows client notes
the time before it 'sends' and after it returns yielding an elapsed several
minutes.  The iSeries only becomes aware of the data several minutes after
the windows client turns it loose, and decomposes and saves the data in just
a few seconds.  The same network will behave normally for ftp up/downloads.
One of the clients can download a 20meg file in a few seconds - less time
than it takes to save this 1-1.5 meg data.

        Anybody have any suggestions as to where to start?  My iSeries has :

TCP receive buffer size  . . . .   8192
TCP send buffer size . . . . . .   8192

and the windows is more like 1k but this doesn't seem like enough for this
kind of slowdown...???  I am way not a networking guru. Thanks for any
ideas.

Regards,

Rick DuVall
Systems Manager
Dealer's Auto Auction of Okc
1028 S. Portland
Oklahoma City, OK 73108
(405) 947-2886
rick@xxxxxxxxxx