I agree with your statements;
User is not interested in partial results, as he/she is
not even aware/interested in which NSAs/domains are involved. User
doesn’t care (if everything works fine ;) ).
The protocol should be designed with the user in mind. The user
does not care about guard time values, differences in setup times for
MPLS vs optical lambdas, and concern itself with choices an NSA/NRM
will make in path-finding.
The protocol designers can keep the user in mind, but
the protocol
is between the RA and the PA and and has a specific purpose: to
reserve and instantiate a connection across the globe. We need to keep
in mind that the RA is not always the end user - it is by definition
another NSA and could be an NSA in the tree/chain somewhere. If we
want to differentiate between the user and the network, then we can
create a simplified User to Network API, and a different Network to
Network API...but I don't think thats what we want to do (:-) We need
to IMO *not* think about the user, but to think about the Requesting
Agent - regardless of who it represents.