I'm trying to learn to use programs designed for modem to modem communications with high error rate. In order to simulate the link, I connected the ttyS0 to the ttyS1 with a null modem cable. I tried to use lrzsz, opening two terminal windows (one for lrz, one for lsz), sending one text file ("osi"). On the first terminal, I wrote:
~/1 $ lrz < /dev/ttyS1
On the second one:
~/0 $ lsz osi > /dev/ttyS0
It always gives me the same error:
Retry 0: Timeout on pathname

Transfer incomplete
I tried using several options (-a, -b, -f, -Z) but nothing changes.
I tried to use g-kermit too, but it looks like it doesn't work. I wrote on the first terminal:
~/1 $ gkermit -r </dev/ttyS1
An on the second one:
~/0 $ gkermit -s osi > /dev/ttyS0
It writes on the first one:
KERMIT READY TO RECEIVE...
# N3
And on the second one:
KERMIT READY TO SEND...
but nothing happens. I tried using the options -i or -T, but nothing changes.
I use Ubuntu Linux 4.10.