I'm working on an i386 serial device driver.  While it functions under low
stress, high stress such as outgoing ftp, causes the ftpdata to never be
transfered.  The odd thing is that all other connections continue to work
correctly.  I can ping the ftp target host, and basically everything works
fine.  The ftp data buffers up on the sender:

tcp        0  14848  gabriella.1284         darkstar.UCSC.ED.ftp-d ESTABLISHED

and nothing is buffered on the receiver.

Until I get a copy of Comers new books, can anyone shed light on this?  I
suspect we're not getting acks back from the receiver or some such.  Perhaps
I'll dropping data in my intr routine.  But the flawless success of light load
makes me wonder.  Any ideas?

-john