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diff --git a/doc/rfc/rfc654.txt b/doc/rfc/rfc654.txt new file mode 100644 index 0000000..9107c9a --- /dev/null +++ b/doc/rfc/rfc654.txt @@ -0,0 +1,112 @@ +TELNET OUTPUT HORIZONTAL TAB DISPOSITION OPTION +RFC 654, NIC 31157 (Oct. 25, 1974) +D. Crocker (UCLA-NMC) +Online file: [ISI]<DCROCKER>NAOHTD.TXT + + TELNET OUTPUT HORIZONTAL TAB DISPOSITION OPTION + +1. Command name and code + NAOHTD 12 + (Negotiate About Output Horizontal Tab Disposition) + +2. Command meanings + In the following, we are discussing a simplex connection, as described in + the NAOL and NAOP Telnet options. + IAC DO NAOHTD + The data sender requests or agrees to negotiate about output + horizontal tab character 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 + horizontal tab character considerations. + IAC DON'T NAOHTD + The data sender refuses to negotiate about output horizontal tab + characters with the data receiver, or demands a return to the + unnegotiated default mode. + IAC WILL NAOHTD + The data receiver requests or agrees to negotiate about output + horizontal tab characters 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 horizontal tab character considerations. + IAC WON'T NAOHTD + The data receiver refuses to negotiate about output horizontal tab + characters, or demands a return to the unnegotiated default mode. + IAC SB NAOHTD DS <8-bit value> IAC SE + The data sender specifies, with the 8-bit value, which party should + handle output horizontal tab characters and what their disposition + should be. The code for DS is 1. + IAC SB NAOHTD DR <8-bit value> IAC SE + The data receiver specifies, with the 8-bit value, which party + should handle output horizontal tab characters and what their + disposition should be. The code for DR is 0. + +3. Default + DON'T NAOHTD/WON'T NAOHTD. + In the default absence of negotiations concerning which party, data + sender or data receiver, is handling output horizontal tab character + considerations, neither party is required to handle horizontal tab + characters and neither party is prohibited from handling them; but it + is appropriate if at least the data receiver handles horizontal tab + character considerations, albeit primitively. + +4. Motivation for the Option + Please refer to section 4 of the NAOL and of the NAOP 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 + horizontal tab characters, for the connection. + 1 to 250 Command sender suggests that the other party alone + should handle horizontal tab characters, but + suggests that a delay of 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 horizontal tabs, but suggests that each + occurrence of the character be replaced by a space. + 252 Command sender suggests that the other party alone + handle horizontal tabs, but suggests that they be + discarded. + 253 Command sender suggests that the other party alone + should handle horizontal tab characters, but + suggests that tabbing be simulated. + 254 Command sender suggests that the other party alone + should handle horizontal tab characters, but + suggests that 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 horizontal tabs 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 + horizontal tab characters, the data receiver must do it, and + 2) if both data receiver and data sender wants to handle output + horizontal tab characters, 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 NAOHTD 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 horizontal tab + character by enough spaces to move the printer head (or line-pointer) to + the next horizontal tab stop. + Note that delays, controlled by the data sender, must consist of NUL + characters inserted immediately after the horizontal tab character. This + is necessary due to the assynchrony of network transmissions. 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 NAOHTD or + DON'T NAOHTD command. |