Network Working Group                                          J. Postel
Request for Comments: 861                                    J. Reynolds
                                                                    ISI
Obsoletes: NIC 16239                                            May 1983

                TELNET EXTENDED OPTIONS - LIST 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

  EXTENDED-OPTIONS-LIST (EXOPL)     255

2.  Command Meanings

  IAC DO EXOPL

     The sender of this command REQUESTS that the receiver of this
     command begin negotiating, or confirms that the receiver of this
     command is expected to begin negotiating, TELNET options which are
     on the "Extended Options List".

  IAC WILL EXOPL

     The sender of this command requests permission to begin
     negotiating, or confirms that it will begin negotiating, TELNET
     options which are on the "Extended Options List".

  IAC WON'T EXOPL

     The sender of this command REFUSES to negotiate, or to continue
     negotiating, options on the "Extended Options List".

  IAC DON'T EXOPL

     The sender of this command DEMANDS that the receiver conduct no
     further negotiation of options on the "Extended Options List".

  IAC SB EXOPL <subcommand>

     The subcommand contains information required for the negotiation
     of an option of the "Extended Options List".  The format of the
     subcommand is discussed in section 5 below.

3.  Default

  WON'T EXOPL, DON'T EXOPL




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RFC 861                                                         May 1983


     Negotiation of options on the "Extended Options List" is not
     permitted.


4.  Motivation for the Option

  Eventually, a 257th TELNET option will be needed.  This option will
  extend the option list for another 256 options in a manner which is
  easy to implement.  The option is proposed now, rather than later
  (probably much later), in order to reserve the option number (255).

5.  An Abstract Description of the Option

  The EXOPL option has five subcommand codes:  WILL, WON'T, DO, DON'T,
  and SB.  They have exactly the same meanings as the TELNET commands
  with the same names, and are used in exactly the same way.  For
  consistency, these subcommand codes will have the same values as the
  TELNET command codes (250-254).  Thus, the format for negotiating a
  specific option on the "Extended Options List" (once both parties
  have agreed to use it) is:

     IAC SB EXOPL DO/DON'T/WILL/WON'T/<option code> IAC SE

  Once both sides have agreed to use the specific option specified by
  <option code>, subnegotiation may be required.  In this case the
  format to be used is:

     IAC SB EXOPL SB <option code> <parameters> SE IAC SE





















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