JTM - a former OSI standard

ISO 8831 - JTM concepts and service

ISO 8832 - JTM protocol

Note that these documents have been withdrawn as ISO/IEC standards and can therefore only be used under the sole responsibility of the user(s): consequently ISO will always decline any responsibility and liability.

Brief history of the standard

• JTM - "Job Transfer and Manipulation" was one of the initial set of OSI application-layer standards
• Work on JTM started in ISO in the early 1980's and the first edition was published in 1989 as two standards:  ISO 8831 - JTM concepts and services and  ISO 8832 - JTM protocol
• The 1989 edition defined both the Basic and Full Class services, but the protocol specification covered only the Basic Class; a second edition including Full Class protocol was published in 1992
• Interest in JTM gradually declined (from not very high in the first place), and (as far as is known) no implementations were ever completed
• When the standards came up for 5-year review, it was recommended that they be withdrawn
• Accordingly, ISO/IEC 8831:1992 and ISO/IEC 8832:1992 were withdrawn as International Standards in 1997 (I'm not sure of exact date of withdrawal)

What was JTM technically

• JTM was originally conceived as providing an open standard for remote job entry (as with card reader and line printer)
• JTM in fact was much more flexible than the original RJE environment - the activity of job processing was generalised into the concept of an "execution agency" which received some set of input documents and produced a set of output documents.
• The sources of the input documents and the onward routing, further processing and final destination of the output documents was controlled by the JTM "work-specification", defined by the initiator of the activity, wheras all the execution agency had to worry about was processing the documents, without being concerned with where they were going.
• This clear separation between the processing and the distribution of the activity as a whole, could have made JTM applicable to scenarios far removed from classic RJE, and indeed, attempts were made to publicise the suitablity of JTM in EDI and similar areas. (See reconstructed example of one of these on JTM and supermarkets)
• Some of the features of JTM that might be worth looking at for comparison or reuse today are:
• it does not assume all systems are under common management - a set of user-identifications, with appropriate credentials, can be carried, each applicable within a different system
• the task could send reports back on its progress as it moved from system to system and started and completed various stages of its activity
• the JTM systems could be interrogated to find out which tasks they had queued or were processing
• the routing and other features of the task could be modified after some processing had been done, while the task was in a queue somewhere somewhere, given appropriate authorisation
• the "documents" that are the basis of the processing model could be defined with a loose or narrow type definition - the document types defined in the standard were simple things like text-file, binary file, but it would have been possible to identify something as "invoice" or "planning application".
• JTM used the OSI two-phase commit protocol CCR (Commitment, Concurrency and Recovery); the transfers (and in some cases the processing) were under two-phase commit control to avoid loss or duplication of the work.
• there were three levels of "commitment" defined - the lowest would allow the task to be queued at each system; an intermediate level which required that the processing of the task had started (not just it's transfer to the server system); and the highest level in which the entire processing, distribution of the output (including, potentially the further processing of that output, and so on, unto the nth generation) was all one atomic action.
• JTM drew considerably from a system-independent protocol used in the UK academic community "Red-Book JTMP" (Job Transfer and Manipulation Protocol - one of a series of system-independent protocols, collectively known as the "Coloured Books"). RedBook used a string encoding for its protocol information, whereas JTM was defined in ASN.1 and there are various aspects in which JTM is more flexible and general.

JTM as web pages and a warning on the status of the documents

While JTM was an International Standard, there were restrictions on the availability of the text. Since it is now withdrawn, it has been possible to make a version of the text freely available on the web. The official ISO position was given by Jacques-Olivier Chabot in an email (dated 27 April 1998):

From our point of view, an ISO standard, whether valid, cancelled or cancelled and replaced by another standard or a revised edtion, remains under the ISO copyright. The ISO copyright also protects DISs, FDISs or CDs, although they are not yet valid documents.

Nevertheless we have no objection if you put the text of these two withdrawn standards on your web page: Our one condition is that you make it clear, in a warning notice appearing immediately when you open the files, that these two standards are withdrawn and can therefore only be used under the sole responsibility of the user(s): consequently ISO will always decline any responsibility and liability.

What now