ASN.1 tools for Python Whenever data structures are described in some machine and programming language independent and unambiguous way, such specification is called abstract syntax, by contrast with machine/language specific methods, which are called 'concrete' or 'transfer' syntaxes. Abstract syntaxes appear useful in networking as a tool for engineering protocols in a clear and portable way. Moreover, once a protocol is described in some abstract language, protocol parsers and builders could be automatically generated for various computing architectures/programming languages, thus saving engineers from implementing low-level transport details by hand. Abstract Syntax Notation One (ASN.1) is a set of ITU standards defining particular implementation of abstract data description language accompanied by a collection of transfer encoding methods. Perhaps the most widely used among these data serialization methods is Basic Encoding Rules (BER) together with its derivatives (DER and CER), while Packed Encoding Rules (PER) aims at most compact data representation whilst in the wire.