The file size that I tested was 500MB.  While the backup is running at 11 
MB/sec I used FTP to send another large file down the same pipes and it 
transfered at 49 MB/sec.  So I know that the pipes between server and client 
will handle the load.

I have adjusted the TCPWINDOWSIZE to 64 on the server and 63 on the client 
according to the Tuning Guide.  I also increased the client's TCPBUFFSIZE from 
16 to 32.

When I backed up on the 100MB network we were seeing 7-8MB/sec, so we have 
increased performance a little.

There is no client compression.

Thanks for all of your input.

DW