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ASN.1 and OSI Data Representation
Key concept: abstract syntax, hence
Abstract Syntax Notation One.
ASN.1 is an international standard[1] which was originally developed as part of
the OSI research, and has been adopted for use in various areas of
the Internet architecture, particularly network management.
- Defines structure of data objects in a way which is
implementation independent. This can be contrasted with data
definitions in (eg) programming languages.
- An excellent example is the data type integer, which has quite
a different meaning in maths to that which it has in most
programming languages. It's also stored
differently in memory in different types of computers.
- In general, ASN.1 is used to define data objects in an abstract
(or "real world") way, compared to the concrete definitions used in
programming.
- A companion OSI standard specifies Basic Encoding Rules (BER)[2], which define the way in which ASN.1
objects are encoded into streams of octets for transmission over a
network.
[1] ISO/IEC 8824:1987
- ASN.1 is an example of a Data Description Language in database
terminology
[2] ISO/IEC 8825:1987
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