file transfer between vax (unix 4.2) and ibm 3081 (vm370) ?

[P Wei]

We have vax running UNIX 4.2BSD , ckermit program, modem (/dev/tty18),
vcu ( to use modem ). The ibm3081 also has cmskermit program. 
the question is : is it possible to transfer ascii file between this
two system via that modem ?
I tried to use vcu to connect to ibm3081, but when I type 'kermit'
in CMS , I got 'an ascii terminal must be used' error message.
Even if i didn't get that message, I couldn't get (escape) back to 
vax to invoke ckermit because vcu doesn't allow me to 'escape'.
Then I tried to use 'kermit -l /dev/tty18 -b 1200'. The phone line
was connected. However, when ibm ask my terminal type, whatever I
answer it warned me to check parity etc...
I don't have time to go through further. I would like to ask if
any one knows my intention (file transfer) is possible.
If anyone has experience, would you please mail me some sample
session (as detail as possible)? (e.g. the parameter settings...)
thanks a lot !
HP Wei