[e2e] disintermediation?

[Bob Hinden]

Lynne,

>NAT as publishing? Amusing idea. Fortunately, NAT modifies the IP header, 
>not the "contents of the data". (But since NAT changes the address on the 
>piece of mail, it seems to more be analogous to the post office rerouting 
>mail).

NAT modifies more than the the IP header.  In many cases the port numbers 
and checksums in the transport protocol is changed.  In other cases (e.g., 
FTP) the contents of transport payload is also changed.  This change may 
result in changing the amount of data in the payload requiring the TCP 
sequence numbers to also be modified.

These modifications are to change the IP addresses carried in the transport 
payload, but they are changes to the payload.

Bob