Integrated Library Systems: A Primer on Z39.50: Part Seven Available to Purchase

I promised that this month I would demonstrate a Z39.50 connection by emulating the two systems, showing the messages the protocol data units (PDUs) generated by each system. Before doing this, however, I need to digress to discuss syntaxes. In order for two systems to communicate, they not only need to agree on what will be sent but also on how this information will be represented. OSI protocols in general, and Z39.50 in particular, specify information representation by defining a “transfer syntax.” A transfer syntax consists of a humanly representable definition of the information, called the “abstract syntax,” and specification of the rules used to encode the abstract syntax into a format manageable by machines.