rfc1043.txt

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Network Working Group                                          A. Yasuda
Request for Comments: 1043                                   T. Thompson
                                             Defense Intelligence Agency
Updates: RFC 732                                           February 1988


                   TELNET Data Entry Terminal Option
                         DODIIS Implementation

Status of this Memo

   This RFC suggests a proposed protocol on the TELNET Data Entry
   Terminal (DET) Option - DODIIS Implementation for the Internet
   community.  It is intended that this specification be compatible with
   the specification of DET Option in RFC-732.  Discussion and
   suggestions for improvements are encouraged.  Distribution of this
   memo is unlimited.

Introduction

   In the early 1980s, the Defense Intelligence Agency (DIA) undertook
   the tasks of developing a TELNET capability to access full screen
   applications across a packet switching network.  This effort was
   successful by implementing Data Entry Terminal (DET) options within
   the TELNET protocol based on RFC 732.  These DET options have been
   implemented on IAS, MVS, OS86 and UNIX operating systems.  DET
   options are being developed for VM and VMS operating systems.

   The Department of Defense Intelligence Information System (DODIIS) is
   a confederation of heterogeneous computer systems and remote
   terminals utilizing the Defense Data Network (DDN) as the
   communications backbone (namely the SCINET/DSNET-3).

   Although the reason for implementing a DET option specification was
   based upon data base application interfaces, the use of a full screen
   TELNET provides a method to achieve higher efficiency on the network.
   Most terminal to host applications on the ARPANET are character echo
   TELNETs.  This is both costly in time and network utilization, since
   one character pressed on the keyboard generates a datagram composed
   of TCP/IP headers plus the character sent to the host and the host
   echoes back a similar datagram.  In the DODIIS community, programmers
   are highly encouraged to implement full screen applications; line at
   a time is acceptable; and character remote echo mode is discouraged.

   This RFC in its final form will be implemented on SCINET.  During the
   interim period, the "DODIIS TELNET Network Virtual Data Entry
   Terminal (NVDET) Option Specification", DIA, April 1983, will be
   implemented.



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                             TABLE OF CONTENTS
                                                                Page No.
                                                                --------

   SECTION 1   COMMAND NAME AND OPTION CODE                          4

   SECTION 2   COMMAND MEANINGS                                      4
                 Facilities Subcommands                              4
                 Edit Subcommands                                    8
                 Transmit Subcommands                                8
                 Erase Subcommands                                  10
                 Format Subcommands                                 10
                 Miscellaneous Subcommands                          13

   SECTION 3   DEFAULT AND MINIMAL IMPLEMENTATION                   15

   SECTION 4   MOTIVATION FOR THE OPTION                            17

   SECTION 5   DESCRIPTION AND IMPLEMENTATION RULES                 17
                 The DODIIS DET Model                               17
                 Negotiating the DET Option                         18
                 DET Facilities Negotiation                         18
                 General DET Interaction                            19
                 Form Construction                                  20
                 Form response                                      21
                 Function Keys                                      22
                 Field Selection                                    22
                 Out-Of-Context Data                                23
                 Line Discipline                                    23
                 Standard TELNET Control Functions                  24
                 Other Implementation Notes                         24

   APPENDIX 1  DET OPCODES AND SUBCOMMAND SYNTAX                    25

   APPENDIX 2  DET ERROR CODES                                      26
















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   The convention in the documentation of the TELNET NVDET Protocol is
   to express numbers in decimal.  Data fields are described left to
   right, with the most significant octet on the left and the least
   significant octet on the right.

   The order of transmission of the data described in this document is
   resolved to the octet level.  Whenever a diagram shows a group of
   octets, the order of transmission of those octets is the normal order
   in which they are read in English.  For example, in the following
   diagram the octets are transmitted in the order they are numbered.

       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |       1       |       2       |       3       |       4       |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |       5       |       6       |       7       |       8       |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |       9       |      10       |      11       |      12       |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                        Transmission Order of Bytes

   Whenever an octet represents a numeric quantity, the left most bit in
   the diagram is the high order or most significant bit.  That is, the
   bit labeled 0 is the most significant bit.  For example, the
   following diagram represents the value 170 (decimal).

                              0 1 2 3 4 5 6 7
                             +-+-+-+-+-+-+-+-+
                             |1 0 1 0 1 0 1 0|
                             +-+-+-+-+-+-+-+-+

                           Significance of Bits

   Similarly, whenever a multi-octet field represents a numeric
   quantity, the left most bit of the whole field is the most
   significant bit.  When a multi-octet quantity is transmitted the most
   significant octet is transmitted first.












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   1. Command Name and Option Code

      DET         20

   2. Command Meanings

      IAC WILL DET

         The sender of this command REQUESTS permission to begin, or
         AGREES that it will begin, sending and receiving Data Entry
         Terminal (DET) subcommands to control session interactions.

      IAC WONT DET

         If the connection is already operating in DET mode, the sender
         of this command DEMANDS that the connection stop operating in
         DET mode and begin operating in TELNET NVT mode.  If the
         connection is not operating in DET mode, the sender REFUSES to
         begin operating in DET mode.  A connection is operating in
         TELNET NVT mode when both parties are interpreting data as
         described by the TELNET SPECIFICATION, MIL-STD-1782.

      IAC DO DET

         The sender of this command REQUESTS permission to begin, or
         AGREES that it will begin, sending and receiving Data Entry
         Terminal (DET) subcommands to control session interactions.

      IAC DONT DET

         If the connection is already operating in DET mode, the sender
         of this command DEMANDS that the connection stop operating in
         DET mode and begin operating in TELNET NVT mode.  If the
         connection is not operating in DET mode, the sender REFUSES  to
         begin  operating in DET mode.    A connection is operating in
         TELNET NVT mode when both parties are interpreting data as
         described by the TELNET SPECIFICATION, MIL-STD-1782.

      DODIIS implementations of the DET option use the subcommands
      described in the remainder of Section 2.  A description of the
      DODIIS DET model and DET subcommand usage is contained in Section
      5.

   FACILITIES SUBCOMMANDS.  Facilities subcommands are used to negotiate
   DET facilities (subcommands and attributes).  The facility
   subcommands indicate the DET facilities the sender supports.
   Facility negotiation may be viewed as the terminal indicating the
   facilities it provides and the application indicating the facilities



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   it desires.  The bits of the facility maps are numbered from the
   right starting at zero.  Thus, if bit 2 is set, the field will have a
   decimal value of 4.

      IAC SB DET EDIT-FACILITIES <facility map> IAC SE

         subcommand code:  1

         This subcommand indicates the edit facilities the sender
         supports.  The <facility map> parameter is one eight bit byte
         containing the following flags:

             Bits 5-7        Reserved
             Bit  4          Read Cursor
             Bits 0-3        Reserved

         where:

             If the Read-Cursor bit is set, the sender supports the
             READ-CURSOR and CURSOR-POSITION subcommands.

             Reserved bits represent edit facilities that are not
             defined for DODIIS implementations;  therefore, no
             descriptions are provided.  Reserved bits must be zeroed
             to indicate non support of the associated edit facilities.

      IAC SB DET ERASE-FACILITIES <facility map> IAC SE

         subcommand code:  2

         This subcommand indicates the erase facilities the sender
         supports.  The <facility map> parameter is one eight bit
         byte containing flags.  Since no erase facilities are
         defined for DODIIS implementations, no descriptions are
         provided.  The ERASE-FACILITIES subcommand is part of the
         minimal DET implementation and is included for that reason.
         DODISI implementors must declare non support of erase
         facilities by sending this subcommand with a zeroed facility
         map.

      IAC SB DET TRANSMIT-FACILITIES <facility map> IAC SE

         subcommand code:  3

         This subcommand indicates the transmit facilities the sender
         supports.  The <facility map> parameter is one eight bit byte
         containing the following flags:




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             Bits 6-7        Reserved
             Bit  5          Data Transmit
             Bits 0-4        Reserved

         where:

             If the Data-Transmit bit is set, the sender supports the
             DATA-TRANSMIT subcommand.

             Reserved bits represent transmit facilities that are not
             defined for DODIIS implementations; therefore, no
             descriptions are provided.  Reserved bits must be zeroed
             to indicate non support of the associated transmit
             facilities.

      IAC SB DET FORMAT-FACILITIES <facility map> IAC SE

         subcommand code:  4

         This subcommand indicates the format facilities the sender
         supports.  The <facility map> parameter is two eight bit bytes
         containing the following:

             Byte 0
                Bit  7       Function Key
                Bit  6       Modified
                Bit  5       Field Selection
                Bit  4       Repeat
                Bit  3       Blinking
                Bit  2       Reverse Video
                Bit  1       Right Justification
                Bit  0       Reserved

             Byte 1
                Bit  7       Reserved for color
                Bit  6       Reserved
                Bit  5       Protection
                Bit  4       Alphabetic-Only
                Bit  3       Numeric-Only
                Bits 0-2     Intensity

             where:

                If the Function-Key bit is set, the sender supports the
                FUNCTION-KEY and ENABLE-FUNCTION-KEY subcommands.

                If the Modified bit is set, the sender supports the
                FORMAT-DATA subcommand's Modified attribute and the



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                TRANSMIT-MODIFIED subcommand.

                If the Field-Selection bit is set, the sender supports
                the FORMAT-DATA subcommand's Selectable attribute and
                the SELECTED-FIELD subcommand.

                If the Repeat bit is set the sender supports the REPEAT
                subcommand.

                If the Blinking bit is set, the sender requests or
                provides the ability to emphasize a string of characters
                by causing them to blink when displayed.  (See the
                FORMAT-DATA subcommand.)

                If the Reverse-Video bit is set, the sender requests or
                provides the ability to emphasize a string of characters
                by "reversing their video image".  If characters are
                normally displayed as dark characters on a light
                background, they are reversed and displayed as light
                characters on a dark background, or
                vice versa.  (See the FORMAT-DATA subcommand.)

                If the Right-Justification bit is set, the sender
                requests or provides the ability to cause data entered
                in a field to be right justified within the field.  (See
                the FORMAT-DATA subcommand.)

                If the Protection bit is set, the sender requests or