rfc1130.txt

<VC++网络游戏建摸与实现>源代码

Network Working Group                          Internet Activities Board
Request for Comments: 1130                             J. Postel, Editor
Obsoletes: RFCs 1100, 1083                                  October 1989



                    IAB OFFICIAL PROTOCOL STANDARDS


Status of this Memo

   This memo describes the state of standardization of protocols used in
   the Internet as determined by the Internet Activities Board (IAB).
   Distribution of this memo is unlimited.

Introduction

   An overview of the standards procedures is presented first, followed
   by discussions of the standardization process and the RFC document
   series, then the explanation of the terms is presented, the lists of
   protocols in each stage of standardization follows, and finally
   pointers to references and contacts for further information.

   This memo is issued quarterly, please be sure the copy you are
   reading is dated within the last three months.  Current copies may be
   obtained from the Network Information Center or from the Internet
   Assigned Numbers Authority (see the contact information at the end of
   this memo).  Do not use this memo after 31-Jan-90.

   See Section 6.1 for a description of recent changes.

1.  Overview of Standards Procedures

   The Internet Activities Board maintains a list of documents that
   define standards for the Internet protocol suite (see RFC-1120 for an
   explanation of the role and organization of the IAB).  The IAB
   provides these standards with the goal of co-ordinating the evolution
   of the Internet protocols; this co-ordination has become quite
   important as the Internet protocols are increasingly in general
   commercial use.

   Protocol standards may be suggested by anyone in the Internet
   community, by writing and submitting an RFC.  In general, any
   suggested protocol will be reviewed or developed in the context of
   some Task Force of the IAB, or some research group or working group
   within that Task Force.  The IAB will assign a suggested protocol to
   a working group or research group if official delegation is
   necessary.



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   Given the important role of the Internet Engineering Task Force in
   the evolution of the Internet Architecture, all proposed protocols
   will be reviewed by the Internet Engineering Steering Group (IESG)
   which is composed of the Technical Area Directors.

   The recommendation of the IESG and working group or research group is
   given major consideration in the decision by the IAB to assign a
   state and status to the protocol.  The general policy is to gain
   implementation experience with a protocol before considering a
   possible designation as an official standard.

   In cases where there is uncertainty as to the proper decision
   concerning a protocol, the IAB may convene a special review committee
   consisting of interested parties from the working group and members
   of the IAB itself, with the purpose of recommending some explicit
   action to the IAB.

   A few protocols have achieved widespread implementation without the
   approval of the IAB.  For example, some vendor protocols have become
   very important to the Internet community even though they have not
   been proposed or reviewed by the IAB.  However, the IAB strongly
   recommends that the IAB standards process be used in the evolution of
   the protocol suite to maximize interoperability (and to prevent
   incompatible protocol requirements from arising).  The IAB reserves
   the use of the term "standard" in any RFC to only those protocols
   which the IAB has approved.

2.  The Standardization Process

   Anyone can invent a protocol, document it, implement it, test it, and
   so on.  The IAB believes that it is very useful to document a
   protocol at an early stage to promote suggestions from others
   interested in the functionality the of protocol and from those
   interested in protocol design.  Once a protocol is implemented and
   tested it is useful to report the results.  The RFC document series
   is the preferred place for publishing these protocol documents and
   testing results.

   The IAB encourages the documenting of every protocol developed in the
   Internet (that is, the publication of the protocol specification as
   an RFC), even if it is never intended that the protocol become an
   Internet standard.  A protocol that is not intended to become a
   standard is called "experimental".

   Protocols that are intended to become standards are first designated
   as "proposed" protocols.  It is expected that while in this state the
   protocol will be implemented and tested by several groups.  It is
   likely that an improved version of the protocol will result from this



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   activity.

   Once a proposed protocol has become stable and has a sponsor (an
   individual willing to speak for the protocol to the IAB) it may
   advance to the "draft standard" state.  In this state, it should be
   reviewed by the entire Internet community.  This draft standard state
   is essentially a warning to the community that unless an objection is
   raised or a flaw is found this protocol will become a "standard".

   Once a protocol has been a draft standard for a sufficient time
   (usually 6 months) without serious objections the IAB may act to
   declare the protocol an official Internet standard.

   Some protocols have been superseded by better protocols or are
   otherwise unused.  Such protocols are designated "historic".

   In addition to a state (like proposed or standard) a protocol is also
   assigned a status.  A protocol can be required, meaning that all
   systems in the Internet must implement it.  For example, the Internet
   Protocol (IP) is required.  A protocol may be recommended, meaning
   that systems should implement this protocol.  A protocol may be
   elective, meaning that systems may implement this protocol; that is,
   if (and only if) the functionality of this protocol is needed or
   useful for a system it must use this protocol to provide the
   functionality.  A protocol may be termed not recommended if it is not
   intended to be generally implemented; for example, experimental or
   historic protocols.

   Few protocols are required to be implemented in all systems.  This is
   because there is such a variety of possible systems; for example,
   gateways, terminal servers, workstations, multi-user hosts.  It is
   not necessary for a gateway to implement TCP and the protocols that
   use TCP (though it may be useful).  It is expected that general
   purpose hosts will implement at least IP (including ICMP), TCP and
   UDP, Telnet, FTP, SMTP, Mail, and the Domain Name System (DNS).

3.  The Request for Comments Documents

   The documents called Request for Comments (or RFCs) are the working
   notes of the Internet research and development community.  A document
   in this series may be on essentially any topic related to computer
   communication, and may be anything from a meeting report to the
   specification of a standard.

   Notice:

      All standards are published as RFCs, but not all RFCs specify
      standards.



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   Anyone can submit a document for publication as an RFC.  Submissions
   must be made via electronic mail to the RFC Editor (see the contact
   information at the end of this memo).

   While RFCs are not refereed publications, they do receive technical
   review from the task forces, individual technical experts, or the RFC
   Editor, as appropriate.

   Once a document is assigned an RFC number and published, that RFC is
   never revised or re-issued with the same number.  There is never a
   question of having the most recent version of a particular RFC.
   However, a protocol (such as File Transfer Protocol (FTP)) may be
   improved and re-documented many times in several different RFCs.  It
   is important to verify that you have the most recent RFC on a
   particular protocol.  This "IAB Official Protocol Standards" memo is
   the reference for determining the correct RFC to refer to for the
   current specification of each protocol.

   The RFCs are available from the Network Information Center at SRI
   International.  For more information about obtaining RFCs see the
   contact information at the end of this memo.

4.  Other Reference Documents

   There are four other reference documents of interest in checking the
   current status of protocol specifications and standardization.  These
   are the Assigned Numbers, the Official Protocols, the Gateway
   Requirements, and the Host Requirements.  Note that these documents
   are revised and updated at different times; in case of differences
   between these documents, the most recent must prevail.

   Also one should be aware of the MIL-STD publications on IP, TCP,
   Telnet, FTP, and SMTP.  These are described in section 4.5.

4.1.  Assigned Numbers

   This document lists the assigned values of the parameters used in the
   various protocols.  For example, IP protocol codes, TCP port numbers,
   Telnet Option Codes, ARP hardware types, and Terminal Type names.
   Assigned Numbers was most recently issued as RFC-1010.

   Another document, Internet Numbers, lists the assigned IP network
   numbers, and the autonomous system numbers.  Internet Numbers was
   most recently issued as RFC-1117.

4.2.  Official Protocols

   This document list the protocols and describes any known problems and



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   ongoing experiments.  Official Protocols was most recently issued as
   RFC-1011.

4.3.  Gateway Requirements

   This document reviews the specifications that apply to gateways and
   supplies guidance and clarification for any ambiguities.  Gateway
   Requirements is RFC-1009.

4.4.  Host Requirements

   This pair of document reviews the specifications that apply to hosts
   and supplies guidance and clarification for any ambiguities.  Host
   Requirements was recently issued as RFC-1122 and RFC-1123.


4.5.  The MIL-STD Documents

   The Internet community specifications for IP (RFC-791) and TCP (RFC-
   793) and the DoD MIL-STD specifications are intended to describe
   exactly the same protocols.  Any difference in the protocols
   specified by these sets of documents should be reported to DCA and to
   the IAB.  The RFCs and the MIL-STDs for IP and TCP differ in style
   and level of detail.  It is strongly advised that the two sets of
   documents be used together.

   The IAB and the DoD MIL-STD specifications for the FTP, SMTP, and
   Telnet protocols are essentially the same documents (RFCs 765, 821,
   854).  The MIL-STD versions have been edited slightly.  Note that the
   current Internet specification for FTP is RFC-959.

          Internet Protocol (IP)                      MIL-STD-1777
          Transmission Control Protocol (TCP)         MIL-STD-1778
          File Transfer Protocol (FTP)                MIL-STD-1780
          Simple Mail Transfer Protocol (SMTP)        MIL-STD-1781
          Telnet Protocol and Options (TELNET)        MIL-STD-1782

5.  Explanation of Terms

   There are two independent categorizations of protocols.  The first is
   the state of standardization which is one of "standard", "draft
   standard", "proposed", "experimental", or "historic".  The second is
   the status of this protocol which is one of "required",
   "recommended", "elective", or "not recommended".  One could expect a
   particular protocol to move along the scale of status from elective
   to required at the same time as it moves along the scale of
   standardization from proposed to standard.




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   At any given time a protocol is a cell of the following matrix.
   Protocols are likely to be in cells in about the following
   proportions (indicated by the number of Xs).  Most will be on the
   main diagonal.  A new protocol is most likely to start in the
   (proposed, elective) cell, or the (experimental, not recommended)
   cell.

                     Req   Rec   Ele   Not
                   +-----+-----+-----+-----+
           Std     | XXX |  XX |  X  |     |
                   +-----+-----+-----+-----+
           Draft   |     |  X  |  XX |     |
                   +-----+-----+-----+-----+
           Prop    |     |     | XXX |  X  |
                   +-----+-----+-----+-----+
           Expr    |     |     |  X  | XXX |
                   +-----+-----+-----+-----+
           Hist    |     |     |     | XXX |
                   +-----+-----+-----+-----+


   Some protocol are particular to hosts and some to gateways; a few
   protocols are used in both.  The definitions of the terms below will
   refer to a "system" which is either a host or a gateway (or both).
   It should be clear from the context of the particular protocol which
   types of systems are intended.

5.1.  Definitions of Protocol State

   5.1.1.  Standard Protocol

      The IAB has established this as an official standard protocol for
      the Internet.  These are separated into two groups: (1) IP