Design Requirements

 

1.        Make these as small as possible: memory footprint, execution path. Possibly there should be 2 versions: one for development, terminals with more memory. One for older, low memory terminals. The larger version can have debug logging and tracing capabilities and larger default history buffers.

2.        Terminal agent should do as little work as possible. When there is a choice between the terminal agent doing something or the controller agent do it, let the controller agent do it.

3.        When a terminal is not being monitored, the amount of tcc traffic generated by the terminal agent should be very near zero. Also, the amount of processing done by the tagent process should be very near zero.

4.        Label data structures so device history data can be abstracted from a terminal dump.

5.        Running terminal agent must be able to be completely disabled on demand. This means removing the filtering hooks and stopping the terminal agent process. It does not necessarily mean removing the driver from memory.

6.        Terminal device i/o history records (which are the same as monitor records) should not be saved for display devices if nothing on the display changes. Applications are notorious for writing the same thing to the display over and over.

7.        Terminal device i/o monitor records should be compressed and gathered name="_Toc108835043"> prior to transmission to the controller agent.

8.        Since most 4690 terminals do not have tcp/ip, prs pipes should be used for communications. Use a non-application pipe by default and allow the pipe id to be configured. Tcp/ip could be an alternative interface choice in future versions.

9.        As much common code as possible should be shared across the following platforms: 4690 OS terminals, TS terminals, TC terminals, future 4960 terminal session server terminals.