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


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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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.


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 protocol and above, protocols that apply to the whole Internet; and (2) network-specific protocols, generally specifications of how to do IP on particular types of networks.

5.1.2. Draft Standard Protocol

The IAB is actively considering this protocol as a possible Standard Protocol. Substantial and widespread testing and comment is desired. Comments and test results should be submitted to the IAB. There is a possibility that changes will be made in a Draft Standard Protocol before it becomes a Standard Protocol.

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5.1.3. Proposed Protocol

These are protocol proposals that may be considered by the IAB for standardization in the future. Implementation and testing by several groups is desirable. Revisions of the protocol specification are likely.

5.1.4. Experimental Protocol

A system should not implement an experimental protocol unless it is participating in the experiment and has coordinated its use of the protocol with the developer of the protocol.

Typically, experimental protocols are those that are developed as part of a specific ongoing research project not related to an operational service offering. While they may be proposed as a service protocol at a later stage, and thus become proposed, draft, and then standard protocols, the designation of a protocol as experimental is meant to suggest that the protocol, although perhaps mature, is not intended for operational use.

5.1.5. Historic Protocol

These are protocols that are unlikely to ever become standards in the Internet either because they have been superseded by later developments or due to lack of interest. These are protocols that are at an evolutionary dead end.

5.2. Definitions of Protocol Status

5.2.1. Required Protocol

All systems must implement the required protocols.

5.2.2. Recommended Protocol

All systems should implement the recommended protocols.

5.2.3. Elective Protocol

A system may or may not implement an elective protocol. The general notion is that if you are going to do something like this, you must do exactly this.

5.2.4. Not Recommended Protocol

These protocols are not recommended for general use. This may be because of their limited functionality, specialized nature, or

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experimental or historic state.

6. The Protocols

This section list the standards in groups by protocol state.

6.1. Recent Changes:

The Host Requirements [RFC-1122, RFC-1123] is now a Required Standard.

The Network Time Protocol [RFC-1119] is now a Recommended Standard.

The Internet Group Multicast Protocol [RFC-1112] is now a Recommended Standard.

The mail Content Type Header Field [RFC-1049] is now a Recommended Standard.

The "Internet Numbers" list was recently issued as RFC-1117.

The Telnet Linemode Option [RFC-1116] is now a Elective Proposed standard.

The mail Privacy procedures [RFC-1113, RFC-1114, and RFC-1115] are now Elective Draft Standards.

The Border Gateway Protocol [RFC-1105] is a Not-Recommended Experimental protocol.

A procedure for sending IP over FDDI networks [RFC-1103] is now a Specific Standard.

The Trivial File Transfer Protocol [RFC-783] is now a Elective Draft Standard.

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6.2. Standard Protocols

Protocol Name Status RFC
-------- ---- ------ ---
           Assigned Numbers                          Required       1010
           Gateway Requirements                      Required       1009
           Host Requirements - Communications        Required       1122
           Host Requirements - Applications          Required       1123
IP         Internet Protocol                         Required        791
            as amended by:
             IP Subnet Extension                     Required        950
             IP Broadcast Datagrams                  Required        919
             IP Broadcast Datagrams with Subnets     Required        922
ICMP       Internet Control Message Protocol         Required        792
IGMP       Internet Group Multicast Protocol         Recommended    1054
UDP        User Datagram Protocol                    Recommended     768
TCP        Transmission Control Protocol             Recommended     793
DOMAIN     Domain Name System                     Recommended  1034,1035
TELNET     Telnet Protocol                           Recommended     854
FTP        File Transfer Protocol                    Recommended     959
SMTP       Simple Mail Transfer Protocol             Recommended     821
MAIL       Format of Electronic Mail Messages        Recommended     822
CONTENT    Content Type Header Field                 Recommended    1049
EGP        Exterior Gateway Protocol                 Recommended     904
ECHO       Echo Protocol                             Recommended     862
NTP        Network Time Protocol                     Recommended    1119
NETBIOS    NetBIOS Service Protocols                 Elective  1001,1002
DISCARD    Discard Protocol                          Elective        863
CHARGEN    Character Generator Protocol              Elective        864
QUOTE      Quote of the Day Protocol                 Elective        865
USERS      Active Users Protocol                     Elective        866
DAYTIME    Daytime Protocol                          Elective        867
TIME       Time Server Protocol                      Elective        868

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6.3. Specific Standard Protocols

Protocol Name Status RFC
-------- ---- ------ ---
ARP Address Resolution Protocol Elective 826
RARP A Reverse Address Resolution Protocol Elective 903
IP-ARPA Internet Protocol on ARPANET Elective BBN 1822
IP-WB Internet Protocol on Wideband Network Elective 907
IP-X25 Internet Protocol on X.25 Networks Elective 877
IP-E Internet Protocol on Ethernet Networks Elective 894
IP-EE Internet Protocol on Exp. Ethernet Nets Elective 895
IP-IEEE Internet Protocol on IEEE 802 Elective 1042
IP-DC Internet Protocol on DC Networks Elective 891
IP-HC Internet Protocol on Hyperchannnel Elective 1044
IP-ARC Internet Protocol on ARCNET Elective 1051
IP-SLIP Transmission of IP over Serial Lines Elective 1055
IP-NETBIOS Transmission of IP over NETBIOS Elective 1088
IP-FDDI Transmission of IP over FDDI Elective 1103

Note: It is expected that a system will support one or more physical
networks and for each physical network supported the appropriate
protocols from the above list must be supported. That is, it is
elective to support any particular type of physical network, and for the
physical networks actually supported it is required that they be
supported exactly according to the protocols in the above list.

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6.4. Draft Standard Protocols

Protocol Name Status RFC
-------- ---- ------ ---
           Mail Privacy: Procedures                 Elective        1113
           Mail Privacy: Key Management             Elective        1114
           Mail Privacy: Algorithms                 Elective        1115
SNMP       Simple Network Management Protocol       Recommended     1098
CMOT       Common Management Information Services   Recommended     1095
           and Protocol over TCP/IP
MIB        Management Information Base              Recommended     1066
SMI        Structure of Management Information      Recommended     1065
BOOTP      Bootstrap Protocol                  Recommended 951,1048,1084
TFTP       Trivial File Transfer Protocol           Elective         783

The Internet Activities Board has designated two different network
management protocols with the same status of "Draft Standard" and
"Recommended". The two protocols are the Common Management Information
Services and Protocol over TCP/IP (CMOT) [RFC-1095] and the Simple
Network Management Protocol (SNMP) [RFC-1098]. The IAB intends each of
these two protocols to receive the attention of implementers and
experimenters. The IAB seeks reports of experience with these two
protocols from system builders and users. By this action, the IAB
recommends that all IP and TCP implementations be network manageable
(e.g., implement the Internet MIB [RFC-1066], and that implementations
that are network manageable are expected to adopt and implement at least
one of these two Internet Draft Standards. The motivation for this
position is discussed in RFCs 1052 and 1109.

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6.5. Proposed Protocols

Protocol Name Status RFC
-------- ---- ------ ---
SUN-NFS Network File System Protocol Elective 1094
POP3 Post Office Protocol, Version 3 Elective 1081,1082
RIP Routing Information Protocol Elective 1058
SUN-RPC Remote Procedure Call Protocol Elective 1057
PCMAIL Pcmail Transport Protocol Elective 1056
VMTP Versatile Message Transaction Protocol Elective 1045
NFILE A File Access Protocol Elective 1037
           Mapping between X.400 and RFC-822        Elective    987,1026
STATSRV    Statistics Server                        Elective         996
NNTP       Network News Transfer Protocol           Elective         977
NICNAME    WhoIs Protocol                           Elective         954
HOSTNAME   HOSTNAME Protocol                        Elective         953
POP2       Post Office Protocol, Version 2          Elective         937
SFTP       Simple File Transfer Protocol            Elective         913
RLP        Resource Location Protocol               Elective         887
RTELNET    Remote Telnet Service                    Elective         818
FINGER     Finger Protocol                          Elective         742
SUPDUP     SUPDUP Protocol                          Elective         734
NETED      Network Standard Text Editor             Elective         569
RJE        Remote Job Entry                         Elective         407

6.6. Experimental Protocols

Protocol Name Status RFC
-------- ---- ------ ---
BGP Border Gateway Protocol Not Recommended 1105
IP-DVMRP IP Distance Vector Multicast Routing Not Recommended 1075
TCP-LDP TCP Extensions for Long Delay Paths Not Recommended 1072
IP-MTU IP MTU Discovery Options Not Recommended 1063
NETBLT Bulk Data Transfer Protocol Not Recommended 998
IMAP2 Interactive Mail Access Protocol Not Recommended 1064
COOKIE-JAR Authentication Scheme Not Recommended 1004
IRTP Internet Reliable Transaction Protocol Not Recommended 938
AUTH Authentication Service Not Recommended 931
RATP Reliable Asynchronous Transfer Protocol Not Recommended 916
THINWIRE Thinwire Protocol Not Recommended 914
LDP Loader Debugger Protocol Not Recommended 909
RDP Reliable Data Protocol Not Recommended 908
ST Stream Protocol Not Recommended IEN 119
NVP-II Network Voice Protocol Not Recommended ISI memo

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6.7. Historic Protocols

Protocol Name Status RFC
-------- ---- ------ ---
SGMP Simple Gateway Monitoring Protocol Not Recommended 1028
HEMS High Level Entity Management Protocol Not Recommended 1021
HMP Host Monitoring Protocol Not Recommended 869
GGP Gateway Gateway Protocol Not Recommended 823
CLOCK DCNET Time Server Protocol Not Recommended 778
MPM Internet Message Protocol Not Recommended 759
NETRJS Remote Job Service Not Recommended 740
XNET Cross Net Debugger Not Recommended IEN 158
NAMESERVER Host Name Server Protocol Not Recommended IEN 116
MUX Multiplexing Protocol Not Recommended IEN 90
GRAPHICS Graphics Protocol Not Recommended NIC 24308

7. Contacts

7.1. Internet Activities Board Contact


Jon Postel
USC Information Sciences Institute
4676 Admiralty Way
Marina del Rey, CA 90292-6695



Please send your comments about this list of protocols and especially about the Draft Standard Protocols to the Internet Activities Board.

7.2. Internet Assigned Numbers Authority Contact


Joyce K. Reynolds
Internet Assigned Numbers Authority
USC Information Sciences Institute
4676 Admiralty Way
Marina del Rey, CA 90292-6695



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The protocol standards are managed for the IAB by the Internet Assigned Numbers Authority.

Please refer to the documents "Assigned Numbers" (RFC-1010) and "Official Internet Protocols" (RFC-1011) for further information about the status of protocol documents. There are two documents that summarize the requirements for host and gateways in the Internet, "Host Requirements" (RFC-1122 and RFC-1123) and "Gateway
Requirements" (RFC-1009).

How to obtain the most recent edition of this "IAB Official Protocol Standards" memo:

The file "in-notes/iab-standards.txt" may be copied via FTP from the VENERA.ISI.EDU computer using the FTP username "anonymous" and FTP password "guest".

7.3. Request for Comments Editor Contact


Jon Postel
RFC Editor
USC Information Sciences Institute
4676 Admiralty Way
Marina del Rey, CA 90292-6695



Documents may be submitted via electronic mail to the RFC Editor for consideration for publication as RFC. If you are not familiar with the format or style requirements please request the "Instructions for RFC Authors". In general, the style of any recent RFC may be used as a guide.

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7.4. The Network Information Center and
Requests for Comments Distribution Contact


DDN Network Information Center
SRI International
Room EJ291
333 Ravenswood Avenue
Menlo Park, CA 94025



The Network Information Center (NIC) provides many information services for the Internet community. Among them is maintaining the Requests for Comments (RFC) library.

RFCs can be obtained via FTP from NIC.DDN.MIL with the pathname RFC:RFCnnnn.TXT where "nnnn" refers to the number of the RFC. A list of all RFCs may be obtained by copying the file RFC:RFC-INDEX.TXT. Log in with FTP username ANONYMOUS and password GUEST.

The NIC also provides an automatic mail service for those sites which cannot use FTP. Address the request to SERVICE@NIC.DDN.MIL and in the subject field of the message indicate the RFC number, as in "Subject: RFC nnnn".

How to obtain the most recent edition of this "IAB Official Protocol Standards" memo:

The file RFC:IAB-STANDARDS.TXT may be copied via FTP from the NIC.DDN.MIL computer following the same procedures used to obtain RFCs.

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7.5. Other Sources for Requests for Comments

NSF Network Service Center (NNSC)

NSF Network Service Center (NNSC)
BBN Systems and Technology Corporation
10 Moulton St.
Cambridge, MA 02238



NSF Network Information Service (NIS)

NSF Network Information Service
Merit Inc.
University of Michigan
1075 Beal Avenue
Ann Arbor, MI 48109



CSNET Coordination and Information Center (CIC)

CSNET Coordination and Information Center
Bolt Beranek and Newman Inc.
10 Moulton Street
Cambridge, MA 02238



8. Security Considerations:

Security issues are not addressed in this memo.

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9. Author's Address:

Jon Postel
USC/Information Sciences Institute
4676 Admiralty Way
Marina del Rey, CA 90292

Phone: (213) 822-1511

Email: Postel@ISI.EDU