defense of the Telnet Go-Ahead(3)

　　The problem of links containing system output intermixed with user　input is more difficult. In any implementation it seems the LAAT user　will have to be aware of what is happening and manually control his　terminal to some extent, but that is reasonable when dealing with an　"alien" system. More definition work is called for in this area, to　solve the efficiency problem for LAAT hosts.

　　"A PROPOSAL"

　　The proposal appears on the surface to be that "suppress GA" should　be the NVT default, which would be perfectly acceptable to me (and I　would suppose to other LAAT users): two additional messages upon　opening a connection is a small enough price.

　　But in fact that is not the proposal at all -- the proposal is really　to remove the requirement that all server systems implement the GA.

　　This I object to very strenuously since, as I feel I have shown, the　benefit to the LAAT system and user of GA far outweigh its cost to　other types of server systems. And of course the expense of going　into "suppress GA" mode when appropriate is truly negligible.

　　The proposal for having those user TELNET's which do not support　reverse break retain permanent control over terminals is also weak,　even without GA. In our current implementation the assumption is that　for each line entered by the user, the server system will respeed　with something. Control of the terminal is thus retained after input　until some output is received and printed, when the terminal is again　made available for input. The "attention" key is defined as a toggle　switch to control the terminal keyboard: if pressed while the　keyboard is unlocked (open for input) it will lock it until the next　available output message and if pressed while keyboard is locked　it will be unlocked for input. The user may also enter a true unlocked　mode, in which the terminal is always returned to him for additional　input (after printing all queued output). This is used, for　example, for input to a text editor which does not issue prompts for　each line, the mode may be changed at any time by the user, and the　"attention" key may of course be used to retrieve expected but　infrequent output. This combination mode has proven much more effective　than the proposed "user must press attention for all input" mode.

　　Of course the addition of GA will allow the user process to wait for　a "complete" reply before printing anything, which will eliminate　much of the use of "attention", as well as improve system efficiency.

　　A GRIPE OF MY OWN

　　I would like to add one complaint of my own at this point. The　implementation schedule for the new TELNET called for a date of July 1　when systems should accept new TELNET without causing errors.

　　This date was presumably agreed to by responsible representatives of　effectively all active network sites. My system has been using the　new TELNET since early September (significantly after the allowable　date) but I have been forced to disable all server-generated GA's　because (among other problems) TENEX "SNDMSG" does not work when GA's　are received over the FTPTELNET control connection. Disabling the　GA's was of course required in order for me to receive any deliveries　from the Network Information Center. This brings up three points.

　　First, I sincerely hope that service functions like the NIC intend to　accept the new TELNET protocol by the January 1 implementation date.　Second, in response to RFC#593 by Alex McKenzie and Jon Postel, I do　not feel that attempting to use a second TCP socket for "new TELNET"　will work, because of the use of TELNET by FTP. In fact, it does not　seem too difficult to make a "compatible" TELNET which will accept　either mode (which sites have had since July 1 to do) and I feel that　this is the most reasonable implementation method, even if it makes　the January 1 date impractical. And third, perhaps sites should be　more cautious about commitments to implementation schedules in the　future.

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