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TELNET OUTPUT FORMFEED DISPOSITION OPTION RFC 655, NIC 31158 (Oct. 25, 1974) D. Crocker (UCLA-NMC) Online file: [ISI]<DCROCKER>NAOFFD.TXT

            TELNET OUTPUT FORMFEED DISPOSITION OPTION

1. Command name and code

 NAOFFD - 13
    (Negotiate About Output Formfeed Disposition)

2. Command meanings

 In the following, we are discussing a simplex connection, as described in 
 the NAOL and NAOP Telnet Options specifications.
    IAC DO NAOFFD
       The data sender requests or agrees to negotiate about output
       formfeed disposition with the data receiver.  In the case
       where agreement has been reached and in the absence of
       further subnegotiations, the data receiver is assumed to be
       handling output formfeeds.
    IAC DON'T NAOFFD
       The data sender refuses to negotiate about output formfeed
       disposition with the data receiver, or demands a return to
       the unnegotiated default mode.
    IAC WILL NAOFFD
       The data receiver requests or agrees to negotiate about
       output formfeed disposition with the sender.  In the case
       where agreement has been reached and in the absence of
       further subnegotiations, the data receiver alone is assumed
       to be handling output formfeeds.
    IAC WON'T NAOFFD
       The data receiver refuses to negotiate about output formfeed
       disposition, or demands a return to the unnegotiated default
       mode.
    IAC SB NAOFFD DS <8-bit value> IAC SE
       The data sender specifies, with the 8-bit value, which party
       should handle formfeeds and what their disposition should be.
       The code for DS is 1.
    IAC SB NAOFFD DR <8-bit value> IAC SE
       The data receiver specifies, with the 8-bit value, which
       party should handle formfeeds and what their disposition
       should be.  The code for DR is 0.

3. Default

 DON'T NAOFFD/WON'T NAOFFD
    In the default absence of negotiations concerning which party, data 
    sender or data receiver, is handling output formfeeds, neither party
    is required to handle formfeeds and neither party is prohibited from 
    handling them; but it is appropriate if at least the data receiver 
    handles formfeed considerations, albeit primitively.

4. Motivation for the Option

 Please refer to section 4 of the NAOL and of the NAOFFD Telnet option 
 descriptions.

 5. Description of the Option

 The data sender and the data receiver use the 8-bit value along with the
 DS and DR SB commands as follows:

    8-bit value                      Meaning                       

    0            Command sender suggests that he alone will handle  
                 formfeeds, for the connection.                     
    1 to 250     Command sender suggests that the other party alone 
                 should handle formfeeds, but suggests that the
                 indicated value be used.  The value is the number  
                 of character-times to wait or number of NULs to    
                 insert in the data stream before sending the next
                 data character.
    251          Command sender suggests that the other party alone 
                 handle formfeeds, but suggests that each           
                 occurrence of the character be replaced by         
                 carriage-return/line-feed.                         
    252          Command sender suggests that the other party alone 
                 handle formfeeds, but suggests that they be        
                 discarded.                                         
    253          Command sender suggests that the other party alone 
                 should handle formfeeds, but suggests that         
                 formfeeds be simulated.                            
    254          Command sender suggests that the other party alone 
                 should handle output formfeeds but suggests        
                 waiting for a character to be transmitted (on the  
                 other simplex connection) before sending more      
                 data. Note that, due to the assynchrony of the two 
                 simplex connections, phase problems can occur with 
                 this option.                                       
    255          Command sender suggests that the other party alone 
                 should handle output formfeeds and suggests        
                 nothing about how it should be done. 

 The guiding rules are that: 

    1) if neither data receiver nor data sender wants to handle output 
    formfeeds, the data receiver must do it, and
    2) if both data receiver and data sender want to handle output
    formfeeds, the data sender gets to do it. 

 The reasoning for the former rule is that if neither wants to do
 it, then the default in the NAOFFD option dominates.  If both want
 to do it, the sender, who is presumed to have special knowledge
 about the data, should be allowed to do it, taking into account any
 suggestions the receiver may make.  Simulation is defined as the
 replacement of the formfeed character by enough line-feeds (only)
 to advance the paper (or line-pointer) to the top of the next page
 (or to the top of the terminal screen).  Note that delays,
 controlled by the data sender, must consist of NUL characters
 inserted immediately after the formfeed character.  This is
 necessary due to the assynchrony of network transmission.  As with
 all option negotiations, neither party should suggest a state
 already in effect except to refuse to negotiate; changes should be
 acknowledged; and once refused, an option should not be resuggested
 until "something changes" (e.g., another process starts).  At any
 time, either party can disable further negotiation by giving the
 appropriate WON'T NAOFFD or DON'T NAOFFD command.