Remote Administration & Local serial line snooping

[<a_ninaber () hotmail com>]

Hi,

I am looking for a product that allows us to remote administrate a number 
of computers while the customer can locally snoop the incoming serial line 
connection to see whether we are breaching any of the pre-agreed rules. 

For this the customer will have to be able to check every incomming 
command. It should be impossible to hack the line without the customer 
noticing this. I think one possible solution is to have on the incomming 
side a modem to which we can dial in from remote and that the serial cable 
from the modem to the incomming computer is snooped by means of a very 
simple printer that prints each incomming character directly to paper. The 
security is sufficient if the customer can see the start of an 
irregularity.

So the questions are: has this been done before, is there a company that 
sells certified solutions and are there better solutions to this problem?

Thanks very much,

Alex