This command test memory to memory copies over rsh (a low overhead protocol). This should be about all the throughput you are going to get from your network adapters:
export RSH_TEST_HOST=hostname
time dd if=/dev/zero count=1000 bs=1M | rsh $RSH_TEST_HOST dd of=/dev/null
If you want to test TCP, here’s the same thing using FTP:
ftp> put "|dd if=/dev/zero bs=1M count=1000" /dev/null
and NCFTP with time:
time dd if=/dev/zero bs=1M count=1000 | /usr/local/bin/ncftpput -u USER -p PASSWORD -c HOST /dev/null