RPC: Remote Procedure Call Protocol specification (RFC1050)
Original Publication Date: 1988-Apr-01
Included in the Prior Art Database: 2019-Feb-15
Internet Society Requests For Comment (RFCs)
This memo specifies a message protocol used in implementing Sun's Remote Procedure Call (RPC) package. This RFC describes a standard that Sun Microsystems and others are using and is one they wish to propose for the Internet's consideration. It is not an Internet standard at this time.
Network Working Group Sun Microsystems, Inc. Request for Comments: 1050 April 1988
RPC: Remote Procedure Call Protocol Specification
STATUS OF THIS MEMO
This RFC describes a standard that Sun Microsystems and others are using and is one we wish to propose for the Internet’s consideration. This memo is not an Internet standard at this time. Distribution of this memo is unlimited.
This document specifies a message protocol used in implementing Sun’s Remote Procedure Call (RPC) package. The message protocol is specified with the eXternal Data Representation (XDR) language . This document assumes that the reader is familiar with XDR. It does not attempt to justify RPC or its uses. The paper by Birrell and Nelson  is recommended as an excellent background to and justification of RPC.
This document discusses servers, services, programs, procedures, clients, and versions. A server is a piece of software where network services are implemented. A network service is a collection of one or more remote programs. A remote program implements one or more remote procedures; the procedures, their parameters, and results are documented in the specific program’s protocol specification (see Appendix A for an example). Network clients are pieces of software that initiate remote procedure calls to services. A server may support more than one version of a remote program in order to be forward compatible with changing protocols.
For example, a network file service may be composed of two programs. One program may deal with high-level applications such as file system access control and locking. The other may deal with low-level file IO and have procedures like "read" and "write". A client machine of the network file service would call the procedures associated with the two programs of the service on behalf of some user on the client machine.
Sun Microsystems, Inc. [Page 1]
RFC 1050 Remote Procedure Call April 1988
3. THE RPC MODEL
The remote procedure call model is similar to the local procedure call model. In the local case, the caller places arguments to a procedure in some well-specified location (such as a result register). It then transfers control to the procedure, and eventually gains back control. At that point, the results of the procedure are extracted from the well-specified location, and the caller continues execution.
The remote procedure call is similar, in that one thread of control logically winds through two processes -- one is the caller’s process, the other is a server’s process. That is, the caller process sends a call message to the server process and waits (blocks) for a reply message. The call message contains the procedure’s parameters, among other things. The reply message contains the procedure’s results, among other things. Once the reply message is received, the results of the procedure are extracted, and caller’s execution is resumed.
On the server side, a process is dormant awaiting the arrival of a ca...