External Data Representation

eXternal Data Representation (XDR) is an implementation of the presentation layer in the OSI model. XDR allows data to be wrapped in an architecture independent matter so data can be transferred between heterogenous computer systems. Converting from the local representation to XDR is called encoding. Converting from XDR to the local representation is called decoding. XDR is implemented as a software library of functions that is portable between different operating systems and is also independent of the transport layer. Sun RPC uses XDR.

XDR data types

XDR defines the following data types:

• boolean
• char
• short
• int
• long
• float
• double
• enumeration
• structure
• string
• fixed length array
• variable length array
• union
• opaque data

External links

RFC1832

The XDR data format is in use by backup software like Legato's NetWorker in its newer releases.

See also: External Data Representation, Computer, OSI model, Operating system, Presentation layer, Remote procedure call, Transport layer