EDI
Tymshare EDI, MD Payment Systems Company, MCI EDI Department
Tymshare was one of the pioneers in the EDI field. Under McDonnell Douglas, the Payment Systems Company continued that legacy and maintained its own network monitoring and support group. They used Tandem computers connected to a high speed data link using Tymnet as the connection and translation medium. Tymshare developed a bi-sync modem interface (HSA), a translation module to translate between EBCDIC and ASCII (BBXS), and a highly customized x.25 module (XCOM) to interface with the Tandem computers.
Apparently, there was no TCP/IP equivalent service, so to continue use of this service after the shutdown of Tymnet, an ingenious solution was selected. A special version of Tymnet Engine node code which allows nodes and interfaces to communicate with one another and the rest of the network was created. Instead of relying on the supervisor to validate calls, a table of permitted connections was defined per customer to allow an incoming call to be made from the HSA interface to the BBXS interface to the XCOM interface and on to the Tandem computer. In effect, they created a Tymnet Island consisting of a single Tymnet node that accepted calls for a pre-determined list of clients. No supervisor needed.
These islands of Tymnet have not only outlived the parent company, Tymshare, and the operations company, Tymnet, but also the Tymnet Network itself. As of 2008, these Tymnet Island nodes are still running and doing their jobs.
Tymshare EDI, MD Payment Systems Company, MCI EDI Department
Tymshare was one of the pioneers in the EDI field. Under McDonnell Douglas, the Payment Systems Company continued that legacy and maintained its own network monitoring and support group. They used Tandem computers connected to a high speed data link using Tymnet as the connection and translation medium. Tymshare developed a bi-sync modem interface (HSA), a translation module to translate between EBCDIC and ASCII (BBXS), and a highly customized x.25 module (XCOM) to interface with the Tandem computers.
Apparently, there was no TCP/IP equivalent service, so to continue use of this service after the shutdown of Tymnet, an ingenious solution was selected. A special version of Tymnet Engine node code which allows nodes and interfaces to communicate with one another and the rest of the network was created. Instead of relying on the supervisor to validate calls, a table of permitted connections was defined per customer to allow an incoming call to be made from the HSA interface to the BBXS interface to the XCOM interface and on to the Tandem computer. In effect, they created a Tymnet Island consisting of a single Tymnet node that accepted calls for a pre-determined list of clients. No supervisor needed.
These islands of Tymnet have not only outlived the parent company, Tymshare, and the operations company, Tymnet, but also the Tymnet Network itself. As of 2008, these Tymnet Island nodes are still running and doing their jobs.
No comments:
Post a Comment