Linux in a Nutshell, 6th Edition

RPC and XDR

RPC (remote procedure call) is the session protocol used by both NFS and NIS. It allows a host to make a procedure call that appears to be local but is really executed remotely on another machine on the network. RPC is implemented as a library of procedures, plus a network standard for ordering bytes and data structures called XDR (eXternal Data Representation).