SUMMARY: Network file transfers are VERY slow

Many thanks to all of you that responded to my questions.

Almost everyone that responded pointed to the automatic speed
arbitration on the network interfaces between the Sun machine
and our Cisco router.  It was suggested that I use "ndd" to 
set the parameters on the interface to disable auto configuration.

This worked for the built-in "hme" interface but the other 
two "znb" interfaces apparently are not software programmable.
Reading their attributes with "nbb -get /dev/znb \?" results
in all of the registers being "read only".

The problem appeared to be complicated by the fact that 2 of
the network connection were also plugged into hubs between the
computer and the router.

We finally eliminated the problem by eliminating the hubs between
the computer and router and plugged the computer directly into
the router.

Thanks again to all those that helped with this problem!