>I would like to know if TSM uses RPC (remote procedure calls) in any way.

From all that I've seen, ADSM and TSM have always used direct socket
communication, not RPC calls.  You can verify this with the 'rpcinfo -p'
command to see what services are portmap-registered, and use something
like 'lsof' to see what processes are listening on those RPC ports.
   Richard Sims, BU