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Protocols

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JSON. IANA — Internet Assigned Numbers Authority. Service Name and Transport Protocol Port Number Registry. Introduction to ASN.1. ​ASN.1 was first standardized in 1984 by the CCITT (International Telegraph and Telephone Consultative Committee, now called ITU-T,International Telecommunication Union - Telecommunication Standardization Sector) under the name "X.409 Recommendation".

A little later, ISO (International Organization for Standardization) chose to adopt this notation and split this recommendation into two separate documents: the abstract syntax (ASN.1) and the encoding rules (BER). In 1985, the CCITT decided to collaborate with ISO on these two documents. In 1987, ISO published these documents as 8824 and 8825 (only three new types of character strings are added). In 1988, ISO merged with the IEC (International Electrotechnical Commission) forming a joint technical committee called ISO/IEC JTC 1, which is now in charge of the ASN.1 standard.

For the last version (available since end of 2008), the ISO 8824 standard was split into four parts: ECN (Encoding control notation) ​Encoding rules are used to define how messages travelling between the various parts of a telecoms system are represented along the cable or air interface that connects them. If the representation (or encoding) can be made smaller then clearly more messages can be sent in the same space. In mobile systems especially, this efficiency of encoding for the messages between the mobile station and the base station transmitter is vitally important since the available bandwidth is fixed, you can't just connect a thicker cable!

The techniques and notations are already available for specifying the required data structures in a machine (encoding) independent way, most notable Abstract Syntax Notation 1 (ASN.1). Such ASN.1 protocol descriptions can be used in combination with standardized encoding rules such as the Basic Encoding Rules (BER) and the Packed Encoding Rules (PER).