Need help with sz/rz problem

[Matthias Butt]

I have an account on a Unix machine that I regularly use via
dialin from my Macintosh at home (Terminal software is Micro-
Phone II. Occasionally I need to transfer Files from the
SUN to my Mac or vice versa. I successfully installed Kermit
for that purpose but it is very slow.

Recently I obtained the Sources for sz/rz via ftp. I was able
to unpack and compile the package withot apparent problems
(no error messages) and all the commands included in the
package seem to work as advertised except for the fact that
nothing is transferred:
If I start sz [...] <filename> my terminal software (which
autodetects z-modem transfers) switches to receive mode and
waits for the transfer to start but nothing happens. If I cancel
the transfer sz returns with a message that tells me the transfer
was cancelled by user request. Similarly after starting rz on the
Unix machine I get prompted to start sending a file but after I do
that the actual transfer will newer start.

I certainly tried x-modem as well - with the same results. I don't
believe that the problem is on the side of my Macintosh because I
have been using z-modem and x-modem with other hosts for years.
Somebody suggested that the problem might be related to the fact
that I am logged into the Unix machine via telnet and some other
machine which is in turn connected to the dialin PAD. However,
there's no other way for me to reach my machine by phone and
the exact reason of the trouble remains unclear.

The Unix machine is a SUN SPARC Station the uname -a command
returns "SunOS w203zrz 4.1 1 sun4c". I had the sources compiled
with make sysvr3 and make sysv with no apparent differences in
the result.

I would be very grateful if anybody could suggest any solution to
the problem or hint into the direction of its cause.

Matthias