I was researching this problem (usually with status 41's or networking
status codes) and came upon these 2 links dealing with the keepalive
settings in NT's registry.
        http://support.microsoft.com/default.aspx?scid=kb;en-us;140325
        http://support.microsoft.com/default.aspx?scid=kb;EN-US;120642
The problem with a few of my NT backups (as noted by a Network person) is
that a backup will start, the connect will be made from client over to
Netbackup server, then for some reason no traffic will be sent over Network.
This lack of data being sent triggers the connection to be killed off.
Increasing the timeouts may only prolong getting the error return status and
mask the real problem.  Of course I don't want something to delay the backup
from sitting there hanging and never exiting; just something to help get the
backup off the ground in the beginning.
  Has anyone played around with the keepalive settings in NT registry before
and with any luck?

Thank You
David