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