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Diffstat (limited to 'doc/rfc/rfc859.txt')
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diff --git a/doc/rfc/rfc859.txt b/doc/rfc/rfc859.txt new file mode 100644 index 0000000..068572e --- /dev/null +++ b/doc/rfc/rfc859.txt @@ -0,0 +1,170 @@ + +Network Working Group J. Postel +Request for Comments: 859 J. Reynolds + ISI +Obsoletes: RFC 651 (NIC 31154) May 1983 + + TELNET STATUS OPTION + + +This RFC specifies a standard for the ARPA Internet community. Hosts on +the ARPA Internet are expected to adopt and implement this standard. + +1. Command Name and Code + + STATUS 5 + +2. Command Meanings + + This option applies separately to each direction of data flow. + + IAC DON'T STATUS + + Sender refuses to carry on any further discussion of the current + status of options. + + IAC WON'T STATUS + + Sender refuses to carry on any further discussion of the current + status of options. + + IAC SB STATUS SEND IAC SE + + Sender requests receiver to transmit his (the receiver's) + perception of the current status of Telnet options. The code for + SEND is 1. (See below.) + + IAC SB STATUS IS ... IAC SE + + Sender is stating his perception of the current status of Telnet + options. The code for IS is 0. (See below.) + +3. Default + + DON'T STATUS, WON'T STATUS + + The current status of options will not be discussed. + +4. Motivation for the Option + + This option allows a user/process to verify the current status of + TELNET options (e.g., echoing) as viewed by the person/process on the + other end of the TELNET connection. Simply renegotiating options + + +Postel & Reynolds [Page 1] + + + +RFC 859 May 1983 + + + could lead to the nonterminating request loop problem discussed in + the General Consideration section of the TELNET Specification. This + option fits into the normal structure of TELNET options by deferring + the actual transfer of status information to the SB command. + +5. Description of the Option + + WILL and DO are used only to obtain and grant permission for future + discussion. The actual exchange of status information occurs within + option subcommands (IAC SB STATUS...). + + Once the two hosts have exchanged a WILL and a DO, the sender of the + WILL STATUS is free to transmit status information, spontaneously or + in response to a request from the sender of the DO. At worst, this + may lead to transmitting the information twice. Only the sender of + the DO may send requests (IAC SB STATUS SEND IAC SE) and only the + sender of the WILL may transmit actual status information (within an + IAC SB STATUS IS ... IAC SE command). + + IS has the subcommands WILL, DO and SB. They are used EXACTLY as used + during the actual negotiation of TELNET options, except that SB is + terminated with SE, rather than IAC SE. Transmission of SE, as a + regular data byte, is accomplished by doubling the byte (SE SE). + Options that are not explicitly described are assumed to be in their + default states. A single IAC SB STATUS IS ... IAC SE describes the + condition of ALL options. + + + + + + + + + + + + + + + + + + + + + + + + +Postel & Reynolds [Page 2] + + + +RFC 859 May 1983 + + + The following is an example of use of the option: + + Host1: IAC DO STATUS + + Host2: IAC WILL STATUS + + (Host2 is now free to send status information at any time. + Solicitations from Host1 are NOT necessary. This should not + produce any dangerous race conditions. At worst, two IS's will + be sent.) + + Host1 (perhaps): IAC SB STATUS SEND IAC SE + + Host2 (the following stream is broken into multiple lines only for + readability. No carriage returns are implied.): + + IAC SB STATUS IS + + WILL ECHO + + DO SUPPRESS-GO-AHEAD + + WILL STATUS + + DO STATUS + + IAC SE + + Explanation of Host2's perceptions: It is responsible for echoing + back the data characters it receives over the TELNET connection; + it will not send Go-Ahead signals; it will both issue and request + Status information. + + + + + + + + + + + + + + + + + + +Postel & Reynolds [Page 3] + |