|"Internet protocol suite|
Open Network Computing (ONC) Remote Procedure Call (RPC) is a "remote procedure call system. ONC was originally developed by "Sun Microsystems in the 1980s as part of their "Network File System project, and is sometimes referred to as Sun RPC.
ONC is based on "calling conventions used in "Unix and the "C programming language. It "serializes data using the "External Data Representation (XDR), which has also found some use to encode and decode data in files that are to be accessed on more than one platform. ONC then delivers the XDR payload using either "UDP or "TCP. Access to RPC services on a machine are provided via a "port mapper that listens for queries on a "well-known port (number 111) over UDP and TCP.
Implementations of ONC RPC exist in most "Unix-like systems. "Microsoft supplies an implementation for "Windows in their "Microsoft Windows Services for UNIX product; in addition, a number of third-party implementation of ONC RPC for Windows exist, including versions for "C/"C++, "Java, and ".NET (see external links).
ONC is considered "lean and mean", but has limited appeal as a generalized RPC system for "WANs or heterogeneous environments["citation needed]. Systems such as "DCE, "CORBA and "SOAP are generally used in this wider role["citation needed].