Method to Provide Queuing of Chained Commands in a Distributed Function Terminal Protocol Attachment
Original Publication Date: 1988-Jan-01
Included in the Prior Art Database: 2005-Feb-14
A method is described to permit distributed function terminal (DFT) non-SNA control units to allow Deferred Response to chained requests sent by the host. The IBM PC 3270 Emulation Program supports DFT attachment to 3270 control units and utilizes the multi-session capability to support up to five concurrent sessions on a PC Local Area Network (LAN). To provide optimum performance, the DFT slow device support is used, which allows a request from the host to be cleared from the DFT buffer and the response deferred until processing is complete. This frees the DFT buffer for the processing of requests for other terminals on the port. The problem is that a host may send a chained sequence of requests and only the response to the last request in the chain may be deferred.