cvs remote: rsh vs. ssh protocols

[kevinm]

We had been using rsh and CVS to remotely update our Web site between 
two Solaris boxes (staging server to live server) with no problem. 
Now that we are using shh as opposed to telnet for remote login, rsh 
does not work in the same way. That is, even though we can use rsh 
without a specified command to login, and then are able to run 
commands, we cannot do the two in one step. We keep 
getting 'permission denied' returned. 
We have tried every conceivable modifications of permissions but have 
come to the conclusion that instituting 'ssh' is preventing us from 
utilizing rsh completely as is needed for CVS to work between 
machines.
Do we now need to use 'ssh' as the protocol for CVS updates? If so, 
what would be the best way to implement this? I saw an earlier thread 
that described this somewhat but haven't had luck in getting the two 
machines to communicate yet.

TIA.