Network Working Group                                        J. Reynolds
Request for Comments: 901                                      J. Postel
                                                                    ISI
Obsoletes: RFCs  880, 840                                      June 1984


                   OFFICIAL ARPA-INTERNET PROTOCOLS


Status of this Memo

  This memo is an official status report on the protocols used in the
  ARPA-Internet community.

Introduction

  This RFC identifies the documents specifying the official protocols
  used in the Internet.  Annotations identify any revisions or changes
  planned.

  To first order, the official protocols are those in the "Internet
  Protocol Transition Workbook" (IPTW) dated March 1982.  There are
  several protocols in use that are not in the IPTW.  A few of the
  protocols in the IPTW have been revised.  Notably, the mail protocols
  have been revised and issued as a volume titled "Internet Mail
  Protocols" dated November 1982.  Telnet and the most useful option
  protocols were issued by the NIC in a booklet entitled "Internet
  Telnet Protocol and Options" (ITP), dated June 1983.  Some protocols
  have not been revised for many years, these are found in the old
  "ARPANET Protocol Handbook" (APH) dated January 1978.  There is also
  a volume of protocol related information called the "Internet
  Protocol Implementers Guide" (IPIG) dated August 1982.

  This document is organized as a sketchy outline.  The entries are
  protocols (e.g., Transmission Control Protocol).  In each entry there
  are notes on status, specification, comments, other references,
  dependencies, and contact.

     The status is one of: required, recommended, elective, or
     experimental.

     The specification identifies the protocol defining documents.

     The comments describe any differences from the specification or
     problems with the protocol.

     The other references identify documents that comment on or expand
     on the protocol.

     The dependencies indicate what other protocols are called upon by
     this protocol.



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     The contact indicates a person who can answer questions about the
     protocol.

     In particular, the status may be:

        required

           - all hosts must implement the required protocol,

        recommended

           - all hosts are encouraged to implement the recommended
           protocol,

        elective

           - hosts may implement or not the elective protocol,

        experimental

           - hosts should not implement the experimental protocol
           unless they are participating in the experiment and have
           coordinated their use of this protocol with the contact
           person, and

        none

           - this is not a protocol.

        For further information about protocols in general, please
        contact:

           Joyce Reynolds
           USC - Information Sciences Institute
           4676 Admiralty Way
           Marina del Rey, California  90292-6695

           Phone: (213) 822-1511

           ARPA mail: [email protected]











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Overview

  Catenet Model  ------------------------------------------------------

     STATUS:  None

     SPECIFICATION:  IEN 48 (in IPTW)

     COMMENTS:

        Gives an overview of the organization and principles of the
        Internet.

        Could be revised and expanded.

     OTHER REFERENCES:

        RFC 871 - A Perspective on the ARPANET Reference Model

     DEPENDENCIES:

     CONTACT: [email protected]

Network Level

  Internet Protocol (IP)  ---------------------------------------------

     STATUS:  Required

     SPECIFICATION:  RFC 791 (in IPTW)

     COMMENTS:

        This is the universal protocol of the Internet.  This datagram
        protocol provides the universal addressing of hosts in the
        Internet.

        A few minor problems have been noted in this document.

        The most serious is a bit of confusion in the route options.
        The route options have a pointer that indicates which octet of
        the route is the next to be used.  The confusion is between the
        phrases "the pointer is relative to this option" and "the
        smallest legal value for the pointer is 4".  If you are
        confused, forget about the relative part, the pointer begins
        at 4.

        Another important point is the alternate reassembly procedure
        suggested in RFC 815.


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        Note that ICMP is defined to be an integral part of IP.  You
        have not completed an implementation of IP if it does not
        include ICMP.

     OTHER REFERENCES:

        RFC 815 (in IPIG) - IP Datagram Reassembly Algorithms

        RFC 814 (in IPIG) - Names, Addresses, Ports, and Routes

        RFC 816 (in IPIG) - Fault Isolation and Recovery

        RFC 817 (in IPIG) - Modularity and Efficiency in Protocol
        Implementation

        MIL-STD-1777 - Military Standard Internet Protocol

     DEPENDENCIES:

     CONTACT: [email protected]

  Internet Control Message Protocol (ICMP)  ---------------------------

     STATUS:  Required

     SPECIFICATION:  RFC 792 (in IPTW)

     COMMENTS:

        The control messages and error reports that go with the
        Internet Protocol.

        A few minor errors in the document have been noted.
        Suggestions have been made for additional types of redirect
        message and additional destination unreachable messages.

        Note that ICMP is defined to be an integral part of IP.  You
        have not completed an implementation of IP if it does not
        include ICMP.

     OTHER REFERENCES:

     DEPENDENCIES: Internet Protocol

     CONTACT: [email protected]






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Host Level

  User Datagram Protocol (UDP)  ---------------------------------------

     STATUS:  Recommended

     SPECIFICATION:  RFC 768 (in IPTW)

     COMMENTS:

        Provides a datagram service to applications.  Adds port
        addressing to the IP services.

        The only change noted for the UDP specification is a minor
        clarification that if in computing the checksum a padding octet
        is used for the computation it is not transmitted or counted in
        the length.

     OTHER REFERENCES:

     DEPENDENCIES: Internet Protocol

     CONTACT: [email protected]

  Transmission Control Protocol (TCP)  --------------------------------

     STATUS:  Recommended

     SPECIFICATION:  RFC 793 (in IPTW)

     COMMENTS:

        Provides reliable end-to-end data stream service.

        Many comments and corrections have been received for the TCP
        specification document.  These are primarily document bugs
        rather than protocol bugs.

        Event Processing Section:  There are many minor corrections and
        clarifications needed in this section.

        Push:  There are still some phrases in the document that give a
        "record mark" flavor to the push.  These should be further
        clarified.  The push is not a record mark.

        Listening Servers:  Several comments have been received on
        difficulties with contacting listening servers.  There should
        be some discussion of implementation issues for servers, and



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        some notes on alternative models of system and process
        organization for servers.

        Maximum Segment Size:  The maximum segment size option should
        be generalized and clarified.  It can be used to either
        increase or decrease the maximum segment size from the default.
        The TCP Maximum Segment Size is the IP Maximum Datagram Size
        minus forty.  The default IP Maximum Datagram Size if 576.  The
        default TCP Maximum Segement Size is 536.  For further
        discussion, see RFC 879.

        Idle Connections:  There have been questions about
        automatically closing idle connections.  Idle connections are
        ok, and should not be closed.  There are several cases where
        idle connections arise, for example, in Telnet when a user is
        thinking for a long time following a message from the server
        computer before his next input.  There is no TCP "probe"
        mechanism, and none is needed.

        Queued Receive Data on Closing:  There are several points where
        it is not clear from the description what to do about data
        received by the TCP but not yet passed to the user,
        particularly when the connection is being closed.  In general,
        the data is to be kept to give to the user if he does a RECV
        call.

        Out of Order Segments:  The description says that segments that
        arrive out of order, that is, are not exactly the next segment
        to be processed, may be kept on hand.  It should also point out
        that there is a very large performance penalty for not doing
        so.

        User Time Out:  This is the time out started on an open or send
        call.  If this user time out occurs the user should be
        notified, but the connection should not be closed or the TCB
        deleted.  The user should explicitly ABORT the connection if he
        wants to give up.

     OTHER REFERENCES:

        RFC 813 (in IPIG) - Window and Acknowledgement Strategy in TCP

        RFC 814 (in IPIG) - Names, Addresses, Ports, and Routes

        RFC 816 (in IPIG) - Fault Isolation and Recovery

        RFC 817 (in IPIG) - Modularity and Efficiency in Protocol
        Implementation



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        RFC 879 - TCP Maximum Segment Size

        RFC 889 - Internet Delay Experiments

        RFC 896 - TCP/IP Congestion Control

        MIL-STD-1778 - Military Standard Transmission Control Protocol

     DEPENDENCIES: Internet Protocol

     CONTACT: [email protected]

  Host Monitoring Protocol (HMP)  -------------------------------------

     STATUS:  Elective

     SPECIFICATION:  RFC 869

     COMMENTS:

        This is a good tool for debugging protocol implementations in
        remotely located computers.

        This protocol is used to monitor Internet gateways and the
        TACs.

     OTHER REFERENCES:

     DEPENDENCIES: Internet Protocol

     CONTACT: [email protected]

  Cross Net Debugger (XNET)  ------------------------------------------

     STATUS:  Elective

     SPECIFICATION:  IEN 158

     COMMENTS:

        A debugging protocol, allows debugger like access to remote
        systems.

        This specification should be updated and reissued as an RFC.

     OTHER REFERENCES:

        RFC 643



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     DEPENDENCIES: Internet Protocol

     CONTACT: [email protected]

  "Stub" Exterior Gateway Protocol  -----------------------------------

     STATUS:  Recommended for Gateways

     SPECIFICATION:  RFC 888

     COMMENTS:

        The gateway protocol now under development.

        Please discuss any plans for implementation or use of this
        protocol with the contact.

     OTHER REFERENCES:  RFC 827, RFC 890

     DEPENDENCIES: Internet Protocol

     CONTACT: [email protected]

  Gateway Gateway Protocol (GGP)  -------------------------------------

     STATUS:  Experimental

     SPECIFICATION:  RFC 823

     COMMENTS:

        The gateway protocol now used in the core gateways.

        Please discuss any plans for implementation or use of this
        protocol with the contact.

     OTHER REFERENCES:

     DEPENDENCIES: Internet Protocol

     CONTACT: [email protected]










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  Multiplexing Protocol (MUX)  ----------------------------------------

     STATUS:  Experimental

     SPECIFICATION:  IEN 90

     COMMENTS:

        Defines a capability to combine several segments from different
        higher level protocols in one IP datagram.

        No current experiment in progress.  There is some question as
        to the extent to which the sharing this protocol envisions can
        actually take place.  Also, there are some issues about the
        information captured in the multiplexing header being (a)
        insufficient, or (b) over specific.

        Please discuss any plans for implementation or use of this
        protocol with the contact.

     OTHER REFERENCES:

     DEPENDENCIES: Internet Protocol

     CONTACT: [email protected]

  Stream Protocol (ST)  -----------------------------------------------

     STATUS:  Experimental

     SPECIFICATION:  IEN 119

     COMMENTS:

        A gateway resource allocation protocol designed for use in
        multihost real time applications.

        The implementation of this protocol has evolved and may no
        longer be consistent with this specification.  The document
        should be updated and issued as an RFC.

        Please discuss any plans for implementation or use of this
        protocol with the contact.

     OTHER REFERENCES:

     DEPENDENCIES: Internet Protocol

     CONTACT: [email protected]


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  Network Voice Protocol (NVP-II)  ------------------------------------

     STATUS:  Experimental

     SPECIFICATION:  RFC xxx

     COMMENTS:

        Defines the procedures for real time voice conferencing.

        The specification is an ISI Internal Memo which should be
        updated and issued as an RFC.

        Please discuss any plans for implementation or use of this
        protocol with the contact.

     OTHER REFERENCES:

     DEPENDENCIES: Internet Protocol, Stream Protocol

     CONTACT: [email protected]

Application Level

  Telnet Protocol (TELNET)  -------------------------------------------

     STATUS:  Recommended

     SPECIFICATION:  RFC 854 (in "Internet Telnet Protocol and
     Options")

     COMMENTS:

        The protocol for remote terminal access.

        This has been revised since the IPTW.  RFC 764 in IPTW is now
        obsolete.

     OTHER REFERENCES:

        MIL-STD-1782 - Telnet Protocol and Options (TELNET)

     DEPENDENCIES: Transmission Control Protocol

     CONTACT: [email protected]






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  Telnet Options (TELNET-OPTIONS)  ------------------------------------

     STATUS:  Elective

     SPECIFICATION:  General description of options:  RFC 855
     (in "Internet Telnet Protocol and Options")

     Number   Name                                RFC  NIC  ITP APH USE
     ------   ---------------------------------   --- ----- --- --- ---
        0     Binary Transmission                 856 ----- yes obs yes
        1     Echo                                857 ----- yes obs yes
        2     Reconnection                        ... 15391  no yes  no
        3     Suppress Go Ahead                   858 ----- yes obs yes
        4     Approx Message Size Negotiation     ... 15393  no yes  no
        5     Status                              859 ----- yes obs yes
        6     Timing Mark                         860 ----- yes obs yes
        7     Remote Controlled Trans and Echo    726 39237  no yes  no
        8     Output Line Width                   ... 20196  no yes  no
        9     Output Page Size                    ... 20197  no yes  no
       10     Output Carriage-Return Disposition  652 31155  no yes  no
       11     Output Horizontal Tabstops          653 31156  no yes  no
       12     Output Horizontal Tab Disposition   654 31157  no yes  no
       13     Output Formfeed Disposition         655 31158  no yes  no
       14     Output Vertical Tabstops            656 31159  no yes  no
       15     Output Vertical Tab Disposition     657 31160  no yes  no
       16     Output Linefeed Disposition         658 31161  no yes  no
       17     Extended ASCII                      698 32964  no yes  no
       18     Logout                              727 40025  no yes  no
       19     Byte Macro                          735 42083  no yes  no
       20     Data Entry Terminal                 732 41762  no yes  no
       21     SUPDUP                          734 736 42213  no yes  no
       22     SUPDUP Output                       749 45449  no  no  no
       23     Send Location                       779 -----  no  no  no
       24     Terminal Type                       884 -----  no  no yes
       25     End of Record                       885 -----  no  no yes
      255     Extended-Options-List               861 ----- yes obs yes

                                                       (obs = obsolete)

     The ITP column indicates if the specification is included in the
     Internet Telnet Protocol and Options.  The APH column indicates if
     the specification is included in the ARPANET Protocol Handbook.
     The USE column of the table above indicates which options are in
     general use.

     COMMENTS:

        The Binary Transmission, Echo, Suppress Go Ahead, Status,
        Timing Mark, and Extended Options List options have been


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        recently updated and reissued.  These are the most frequently
        implemented options.

        The remaining options should be reviewed and the useful ones
        should be revised and reissued.  The others should be
        eliminated.

        The following are recommended:  Binary Transmission, Echo,
        Suppress Go Ahead, Status, Timing Mark, and Extended Options
        List.

     OTHER REFERENCES:

     DEPENDENCIES: Telnet

     CONTACT: [email protected]

  File Transfer Protocol (FTP)  ---------------------------------------

     STATUS:  Recommended

     SPECIFICATION:  RFC 765 (in IPTW)

     COMMENTS:

        The protocol for moving files between Internet hosts.  Provides
        for access control and negotiation of file parameters.

        There are a number of minor corrections to be made.  A major
        change is the deletion of the mail commands, and a major
        clarification is needed in the discussion of the management of
        the data connection.  Also, a suggestion has been made to
        include some directory manipulation commands (RFC 775).

        Even though the MAIL features are defined in this document,
        they are not to be used.  The SMTP protocol is to be used for
        all mail service in the Internet.

        Data Connection Management:

           a.  Default Data Connection Ports:  All FTP implementations
           must support use of the default data connection ports, and
           only the User-PI may initiate the use of non-default ports.

           b.  Negotiating Non-Default Data Ports:   The User-PI may
           specify a non-default user side data port with the PORT
           command.  The User-PI may request the server side to
           identify a non-default server side data port with the PASV
           command.  Since a connection is defined by the pair of


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           addresses, either of these actions is enough to get a
           different data connection, still it is permitted to do both
           commands to use new ports on both ends of the data
           connection.

           c.  Reuse of the Data Connection:  When using the stream
           mode of data transfer the end of the file must be indicated
           by closing the connection.  This causes a problem if
           multiple files are to be transfered in the session, due to
           need for TCP to hold the connection record for a time out
           period to guarantee the reliable communication.  Thus the
           connection can not be reopened at once.

              There are two solutions to this problem.  The first is to
              negotiate a non-default port (as in (b) above).  The
              second is to use another transfer mode.

              A comment on transfer modes.  The stream transfer mode is
              inherently unreliable, since one can not determine if the
              connection closed prematurely or not.  The other transfer
              modes (Block, Compressed) do not close the connection to
              indicate the end of file.  They have enough FTP encoding
              that the data connection can be parsed to determine the
              end of the file.  Thus using these modes one can leave
              the data connection open for multiple file transfers.

              Why this was not a problem with the old NCP FTP:

                 The NCP was designed with only the ARPANET in mind.
                 The ARPANET provides very reliable service, and the
                 NCP counted on it.  If any packet of data from an NCP
                 connection were lost or damaged by the network the NCP
                 could not recover.  It is a tribute to the ARPANET
                 designers that the NCP FTP worked so well.

                 The TCP is designed to provide reliable connections
                 over many different types of networks and
                 interconnections of networks.  TCP must cope with a
                 set of networks that can not promise to work as well
                 as the ARPANET.  TCP must make its own provisions for
                 end-to-end recovery from lost or damaged packets.
                 This leads to the need for the connection phase-down
                 time-out.  The NCP never had to deal with
                 acknowledgements or retransmissions or many other
                 things the TCP must do to make connection reliable in
                 a more complex world.

        LIST and NLST:



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           There is some confusion about the LIST an NLST commands, and
           what is appropriate to return.  Some clarification and
           motivation for these commands should be added to the
           specification.

     OTHER REFERENCES:

        RFC 678 - Document File Format Standards

        MIL-STD-1780 - File Transfer Protocol (FTP)

     DEPENDENCIES: Transmission Control Protocol

     CONTACT: [email protected]

  Trivial File Transfer Protocol (TFTP)  ------------------------------

     STATUS:  Elective

     SPECIFICATION:  RFC 783 (in IPTW)

     COMMENTS:

        A very simple file moving protocol, no access control is
        provided.

        No known problems with this specification.  This is in use in
        several local networks.

     OTHER REFERENCES:

     DEPENDENCIES: User Datagram Protocol

     CONTACT: [email protected]

  Simple Mail Transfer Protocol (SMTP)  -------------------------------

     STATUS:  Recommended

     SPECIFICATION:  RFC 821 (in "Internet Mail Protocols")

     COMMENTS:

        The procedure for transmitting computer mail between hosts.

        This has been revised since the IPTW, it is in the "Internet
        Mail Protocols" volume of November 1982.  RFC 788 (in IPTW) is
        obsolete.



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Official ARPA-Internet Protocols                                 RFC 901


        There have been many misunderstandings and errors in the early
        implementations.  Some documentation of these problems can be
        found in the file [ISIF]<SMTP>MAIL.ERRORS.

        Some minor differences between RFC 821 and RFC 822 should be
        resolved.

     OTHER REFERENCES:

        RFC 822 - Mail Header Format Standards

           This has been revised since the IPTW, it is in the "Internet
           Mail Protocols" volume of November 1982.  RFC 733 (in IPTW)
           is obsolete.  Further revision of RFC 822 is needed to
           correct some minor errors in the details of the
           specification.

        MIL-STD-1781 - Simple Mail Transfer Protocol (SMTP)

     DEPENDENCIES: Transmission Control Protocol

     CONTACT: [email protected]

  Resource Location Protocol (RLP)  -----------------------------------

     STATUS:   Elective

     SPECIFICATION:   RFC 887

     COMMENTS:

        A resource location protocol for use in the ARPA-Internet.
        This protocol utilizes the User Datagram Protocol (UDP) which
        in turn calls on the Internet Protocol to deliver its
        datagrams.

     OTHER REFERENCES:

     DEPENDENCIES: User Datagram Protocol

     CONTACT:   [email protected]










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Official ARPA-Internet Protocols                                 RFC 901


  Remote Job Entry (RJE)  ---------------------------------------------

     STATUS:  Elective

     SPECIFICATION:  RFC 407 (in APH)

     COMMENTS:

        The general protocol for submitting batch jobs and retrieving
        the results.

        Some changes needed for use with TCP.

        No known active implementations.

     OTHER REFERENCES:

     DEPENDENCIES: File Transfer Protocol
                   Transmission Control Protocol

     CONTACT: [email protected]

  Remote Job Service (NETRJS)  ----------------------------------------

     STATUS:  Elective

     SPECIFICATION:  RFC 740 (in APH)

     COMMENTS:

        A special protocol for submitting batch jobs and retrieving the
        results used with the UCLA IBM OS system.

        Please discuss any plans for implementation or use of this
        protocol with the contact.

        Revision in progress.

     OTHER REFERENCES:

     DEPENDENCIES: Transmission Control Protocol

     CONTACT: [email protected]








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Official ARPA-Internet Protocols                                 RFC 901


  Remote Telnet Service (RTELNET)  ------------------------------------

     STATUS:  Elective

     SPECIFICATION:  RFC 818

     COMMENTS:

        Provides special access to user Telnet on a remote system.

     OTHER REFERENCES:

     DEPENDENCIES: Telnet, Transmission Control Protocol

     CONTACT: [email protected]

  Graphics Protocol (GRAPHICS)  ---------------------------------------

     STATUS:  Elective

     SPECIFICATION:  NIC 24308 (in APH)

     COMMENTS:

        The protocol for vector graphics.

        Very minor changes needed for use with TCP.

        No known active implementations.

     OTHER REFERENCES:

     DEPENDENCIES: Telnet, Transmission Control Protocol

     CONTACT: [email protected]
















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Official ARPA-Internet Protocols                                 RFC 901


  Echo Protocol (ECHO)  -----------------------------------------------

     STATUS:  Recommended

     SPECIFICATION:  RFC 862

     COMMENTS:

        Debugging protocol, sends back whatever you send it.

     OTHER REFERENCES:

     DEPENDENCIES: Transmission Control Protocol
                   or User Datagram Protocol

     CONTACT: [email protected]

  Discard Protocol (DISCARD)  -----------------------------------------

     STATUS:  Elective

     SPECIFICATION:  RFC 863

     COMMENTS:

        Debugging protocol, throws away whatever you send it.

     OTHER REFERENCES:

     DEPENDENCIES: Transmission Control Protocol
                   or User Datagram Protocol

     CONTACT: [email protected]

  Character Generator Protocol (CHARGEN)  -----------------------------

     STATUS:  Elective

     SPECIFICATION:  RFC 864

     COMMENTS:

        Debugging protocol, sends you ASCII data.

     OTHER REFERENCES:

     DEPENDENCIES: Transmission Control Protocol
                   or User Datagram Protocol



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Official ARPA-Internet Protocols                                 RFC 901


     CONTACT: [email protected]

  Quote of the Day Protocol (QUOTE)  ----------------------------------

     STATUS:  Elective

     SPECIFICATION:  RFC 865

     COMMENTS:

        Debugging protocol, sends you a short ASCII message.

     OTHER REFERENCES:

     DEPENDENCIES: Transmission Control Protocol
                   or User Datagram Protocol

     CONTACT: [email protected]

  Active Users Protocol (USERS)  --------------------------------------

     STATUS:  Elective

     SPECIFICATION:  RFC 866

     COMMENTS:

        Lists the currently active users.

     OTHER REFERENCES:

     DEPENDENCIES: Transmission Control Protocol
                   or User Datagram Protocol

     CONTACT: [email protected]

  Finger Protocol (FINGER)  -------------------------------------------

     STATUS:  Elective

     SPECIFICATION:  RFC 742 (in APH)

     COMMENTS:

        Provides information on the current or most recent activity of
        a user.

        Some extensions have been suggested.



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Official ARPA-Internet Protocols                                 RFC 901


        Some changes are are needed for TCP.

     OTHER REFERENCES:

     DEPENDENCIES: Transmission Control Protocol

     CONTACT: [email protected]

  WhoIs Protocol (NICNAME)  -------------------------------------------

     STATUS:  Elective

     SPECIFICATION:  RFC 812 (in IPTW)

     COMMENTS:

        Accesses the ARPANET Directory database.  Provides a way to
        find out about people, their addresses, phone numbers,
        organizations, and mailboxes.

     OTHER REFERENCES:

     DEPENDENCIES: Transmission Control Protocol

     CONTACT: [email protected]

  Domain Name Protocol (DOMAIN)

     STATUS:  Experimental

     SPECIFICATION:  RFC 881, 882, 883

     COMMENTS:

     OTHER REFERENCES:

        RFC 897 - Domain Name Implementation Schedule

     DEPENDENCIES: Transmission Control Protocol

     CONTACT: [email protected]










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Official ARPA-Internet Protocols                                 RFC 901


  HOSTNAME Protocol (HOSTNAME)  ---------------------------------------

     STATUS:  Elective

     SPECIFICATION:  RFC 811 (in IPTW)

     COMMENTS:

        Accesses the Registered Internet Hosts database (HOSTS.TXT).
        Provides a way to find out about a host in the Internet, its
        Internet Address, and the protocols it implements.

     OTHER REFERENCES:

        RFC 810 - Host Table Specification

     DEPENDENCIES: Transmission Control Protocol

     CONTACT: [email protected]

  Host Name Server Protocol (NAMESERVER)  -----------------------------

     STATUS:  Experimental

     SPECIFICATION:  IEN 116 (in IPTW)

     COMMENTS:

        Provides machine oriented procedure for translating a host name
        to an Internet Address.

        This specification has significant problems:  1) The name
        syntax is out of date.  2) The protocol details are ambiguous,
        in particular, the length octet either does or doesn't include
        itself and the op code.  3) The extensions are not supported by
        any known implementation.

        Work is in progress on a significant revision.  Further
        implementations of this protocol are not advised.

        Please discuss any plans for implementation or use of this
        protocol with the contact.

     OTHER REFERENCES:

     DEPENDENCIES: User Datagram Protocol

     CONTACT: [email protected]



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Official ARPA-Internet Protocols                                 RFC 901


  CSNET Mailbox Name Server Protocol (CSNET-NS)  ----------------------

     STATUS:  Experimental

     SPECIFICATION:  CS-DN-2

     COMMENTS:

        Provides access to the CSNET data base of users to give
        information about users names, affiliations, and mailboxes.

        Please discuss any plans for implementation or use of this
        protocol with the contact.

     OTHER REFERENCES:

     DEPENDENCIES: Transmission Control Protocol

     CONTACT: [email protected]

  Daytime Protocol (DAYTIME)  -----------------------------------------

     STATUS:  Elective

     SPECIFICATION:  RFC 867

     COMMENTS:

        Provides the day and time in ASCII character string.

     OTHER REFERENCES:

     DEPENDENCIES: Transmission Control Protocol
                   or User Datagram Protocol

     CONTACT: [email protected]

  Time Server Protocol (TIME)  ----------------------------------------

     STATUS:  Recommended

     SPECIFICATION:  RFC 868

     COMMENTS:

        Provides the time as the number of seconds from a specified
        reference time.

     OTHER REFERENCES:


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Official ARPA-Internet Protocols                                 RFC 901


     DEPENDENCIES: Transmission Control Protocol
                   or User Datagram Protocol

     CONTACT: [email protected]

  DCNET Time Server Protocol (CLOCK)  ---------------------------------

     STATUS:  Elective

     SPECIFICATION:  RFC 778

     COMMENTS:

        Provides a mechanism for keeping synchronized clocks.

     OTHER REFERENCES:

     DEPENDENCIES: Internet Control Message Protocol

     CONTACT: [email protected]

  SUPDUP Protocol (SUPDUP)  -------------------------------------------

     STATUS:  Elective

     SPECIFICATION:  RFC 734 (in APH)

     COMMENTS:

        A special Telnet like protocol for display terminals.

     OTHER REFERENCES:

     DEPENDENCIES: Transmission Control Protocol

     CONTACT: [email protected]















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Official ARPA-Internet Protocols                                 RFC 901


  Internet Message Protocol (MPM)  ------------------------------------

     STATUS:  Experimental

     SPECIFICATION:  RFC 759

     COMMENTS:

        This is an experimental multimedia mail transfer protocol.  The
        implementation is called a Message Processing Module or MPM.

        Please discuss any plans for implementation or use of this
        protocol with the contact.

     OTHER REFERENCES:

        RFC 767 - Structured Document Formats

     DEPENDENCIES: Transmission Control Protocol

     CONTACT: [email protected]

  Post Office Protocol (POP)  -----------------------------------------

     STATUS:  Experimental

     SPECIFICATION:  RFC xxx

     COMMENTS:

        This is an experimental procedure for accessing mailbox
        services from personal workstations.

        Please discuss any plans for implementation or use of this
        protocol with the contact.

     OTHER REFERENCES:

     DEPENDENCIES: Transmission Control Protocol

     CONTACT: [email protected]










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Official ARPA-Internet Protocols                                 RFC 901


  Network Standard Text Editor (NETED)  -------------------------------

     STATUS:  Elective

     SPECIFICATION:  RFC 569

     COMMENTS:

        Describes a simple line editor which could be provided by every
        Internet host.

     OTHER REFERENCES:

     DEPENDENCIES:

     CONTACT:  [email protected]

Appendices

  Assigned Numbers  ---------------------------------------------------

     STATUS:  None

     SPECIFICATION:  RFC 900

     COMMENTS:

        Describes the fields of various protocols that are assigned
        specific values for actual use, and lists the currently
        assigned values.

        Issued June 1984, replaces RFC 870, RFC 790 in IPTW, and
        RFC 820 of January 1983.

     OTHER REFERENCES:

     CONTACT: [email protected]














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Official ARPA-Internet Protocols                                 RFC 901


  Pre-emption  --------------------------------------------------------

     STATUS:  Elective

     SPECIFICATION:  RFC 794 (in IPTW)

     COMMENTS:

        Describes how to do pre-emption of TCP connections.

     OTHER REFERENCES:

     CONTACT: [email protected]

  Service Mappings  ---------------------------------------------------

     STATUS:  None

     SPECIFICATION:  RFC 795 (in IPTW)

     COMMENTS:

        Describes the mapping of the IP type of service field onto the
        parameters of some specific networks.

        Out of date, needs revision.

     OTHER REFERENCES:

     CONTACT: [email protected]

  Address Mappings  ---------------------------------------------------

     STATUS:  None

     SPECIFICATION:  RFC 796 (in IPTW)

     COMMENTS:

        Describes the mapping between Internet Addresses and the
        addresses of some specific networks.

        Out of date, needs revision.

     OTHER REFERENCES:

     CONTACT:  [email protected]




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Official ARPA-Internet Protocols                                 RFC 901


  Internet Protocol on X.25 Networks  ---------------------------------

     STATUS:  Recommended

     SPECIFICATION:  RFC 877

     COMMENTS:

        Describes a standard for the transmission of IP Datagrams over
        Public Data Networks.

     OTHER REFERENCES:

     CONTACT:  [email protected]

  Internet Protocol on DC Networks  -----------------------------------

     STATUS:  Elective

     SPECIFICATION: RFC 891

     COMMENTS:

     OTHER REFERENCES:

        RFC 778 - DCNET Internet Clock Service

     CONTACT:  [email protected]

  Internet Protocol on Ethernet Networks  -----------------------------

     STATUS:  Recommended

     SPECIFICATION: RFC 894

     COMMENTS:

     OTHER REFERENCES:

        RFC 893

     CONTACT:  [email protected]









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Official ARPA-Internet Protocols                                 RFC 901


  Internet Protocol on Experimental Ethernet Networks  ----------------

     STATUS:  Recommended

     SPECIFICATION: RFC 895

     COMMENTS:

     OTHER REFERENCES:

     CONTACT:  [email protected]

  Address Resolution Protocol (ARP)  ----------------------------------

     STATUS:  Recommended

     SPECIFICATION: RFC 826

     COMMENTS:

        This is a procedure for finding the network hardware address
        corresponding to an Internet Address.

     OTHER REFERENCES:

     CONTACT:  [email protected]

























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