Official ARPA-Internet protocols
RFC 901

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.

Reynolds & Postel [Page 1]



Official ARPA-Internet Protocols RFC 901

 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: JKREYNOLDS@USC-ISIF.ARPA

Reynolds & Postel [Page 2]



Official ARPA-Internet Protocols RFC 901

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: Postel@USC-ISIF.ARPA

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.

Reynolds & Postel [Page 3]



Official ARPA-Internet Protocols RFC 901

 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: Postel@USC-ISIF.ARPA

 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: Postel@USC-ISIF.ARPA

Reynolds & Postel [Page 4]



Official ARPA-Internet Protocols RFC 901

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: Postel@USC-ISIF.ARPA

 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

Reynolds & Postel [Page 5]



Official ARPA-Internet Protocols RFC 901

 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

Reynolds & Postel [Page 6]



Official ARPA-Internet Protocols RFC 901

 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: Postel@USC-ISIF.ARPA

 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: Hinden@BBN-UNIX.ARPA

 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

Reynolds & Postel [Page 7]



Official ARPA-Internet Protocols RFC 901

 DEPENDENCIES: Internet Protocol

 CONTACT: Postel@USC-ISIF.ARPA

 "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: Mills@USC-ISID.ARPA

 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: Brescia@BBN-UNIX.ARPA

Reynolds & Postel [Page 8]



Official ARPA-Internet Protocols RFC 901

 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: Postel@USC-ISIF.ARPA

 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: jwf@LL-EN.ARPA

Reynolds & Postel [Page 9]



Official ARPA-Internet Protocols RFC 901

 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: Casner@USC-ISIB.ARPA

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: Postel@USC-ISIF.ARPA

Reynolds & Postel [Page 10]



Official ARPA-Internet Protocols RFC 901

 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

Reynolds & Postel [Page 11]



Official ARPA-Internet Protocols RFC 901

 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: Postel@USC-ISIF.ARPA

 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

Reynolds & Postel [Page 12]



Official ARPA-Internet Protocols RFC 901

 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:

Reynolds & Postel [Page 13]



Official ARPA-Internet Protocols RFC 901

 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: Postel@USC-ISIF.ARPA

 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: Postel@USC-ISIF.ARPA

 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.

Reynolds & Postel [Page 14]



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: Postel@USC-ISIF.ARPA

 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: Accetta@CMU-CS-A.ARPA

Reynolds & Postel [Page 15]



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: Postel@USC-ISIF.ARPA

 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: Braden@USC-ISIA.ARPA

Reynolds & Postel [Page 16]



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: Postel@USC-ISIF.ARPA

 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: Postel@USC-ISIF.ARPA

Reynolds & Postel [Page 17]



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: Postel@USC-ISIF.ARPA

 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: Postel@USC-ISIF.ARPA

 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

Reynolds & Postel [Page 18]



Official ARPA-Internet Protocols RFC 901

 CONTACT: Postel@USC-ISIF.ARPA

 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: Postel@USC-ISIF.ARPA

 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: Postel@USC-ISIF.ARPA

 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.

Reynolds & Postel [Page 19]



Official ARPA-Internet Protocols RFC 901

 Some changes are are needed for TCP.

 OTHER REFERENCES:

 DEPENDENCIES: Transmission Control Protocol

 CONTACT: Postel@USC-ISIF.ARPA

 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: Feinler@SRI-NIC.ARPA

 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: Mockapetris@USC-ISIF.ARPA

Reynolds & Postel [Page 20]



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: Feinler@SRI-NIC.ARPA

 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: Postel@USC-ISIF.ARPA

Reynolds & Postel [Page 21]



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: Solomon@UWISC.ARPA

 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: Postel@USC-ISIF.ARPA

 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:

Reynolds & Postel [Page 22]



Official ARPA-Internet Protocols RFC 901

 DEPENDENCIES: Transmission Control Protocol
 or User Datagram Protocol

 CONTACT: Postel@USC-ISIF.ARPA

 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: Mills@USC-ISID.ARPA

 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: Admin.MRC@SU-SCORE.ARPA

Reynolds & Postel [Page 23]



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: Postel@USC-ISIF.ARPA

 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: Postel@USC-ISIF.ARPA

Reynolds & Postel [Page 24]



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: Postel@USC-ISIF.ARPA

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: JKReynolds@USC-ISIF.ARPA

Reynolds & Postel [Page 25]



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: Postel@USC-ISIF.ARPA

 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: Postel@USC-ISIF.ARPA

 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: Postel@USC-ISIF.ARPA

Reynolds & Postel [Page 26]



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: jtk@PURDUE.ARPA

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

 STATUS: Elective

 SPECIFICATION: RFC 891

 COMMENTS:

 OTHER REFERENCES:

 RFC 778 - DCNET Internet Clock Service

 CONTACT: Mills@USC-ISID.ARPA

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

 STATUS: Recommended

 SPECIFICATION: RFC 894

 COMMENTS:

 OTHER REFERENCES:

 RFC 893

 CONTACT: Postel@USC-ISIF.ARPA

Reynolds & Postel [Page 27]



Official ARPA-Internet Protocols RFC 901

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

 STATUS: Recommended

 SPECIFICATION: RFC 895

 COMMENTS:

 OTHER REFERENCES:

 CONTACT: Postel@USC-ISIF.ARPA

 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: Postel@USC-ISIF.ARPA

Reynolds & Postel [Page 28]