Network Working Group
Request for Comments: 820
Obsoletes RFCs: 790, 776, 770, 762
758, 755, 750, 739, 604, 503, 433, 349
Obsoletes IENs: 127, 117, 93
J. Postel
J. Vernon
January 1983


This Network Working Group Request for Comments documents the currently assigned values from several series of numbers used in network protocol implementations. This RFC will be updated periodically, and in any case current information can be obtained from Jon Postel. The assignment of numbers is also handled by Jon, subject to the agreement between DARPA/IPTO and DDN/PMO about number allocation, documented in Appendix A of this RFC. If you are developing a protocol or application that will require the use of a link, socket, port, protocol, or network number please contact Jon to receive a number assignment.

   Jon Postel
   USC - Information Sciences Institute
   4676 Admiralty Way
   Marina del Rey, California  90291


          (213) 822-1511

The ARPANET community is making the transition form the ARPANET to the ARPA Internet. This has been characterized as the NCP/TCP transition [63], although many other the protocols are involved, too. The working documents for the new Internet environment have been collected by the Network Information Center (NIC) in a book entitled the "Internet Protocol Transition Workbook" [62].

Most of the protocols mentioned here are documented in the RFC series of notes. The more prominent and more generally used are documented in the "Internet Protocol Transition Workbook" or in the old "Protocol Handbook" [17] prepared by the NIC. Some of the items listed are undocumented.

In all cases the name and mailbox of the responsible individual is indicated. In the lists that follow, a bracketed entry, e.g., [17,iii], at the right hand margin of the page indicates a reference for the listed protocol, where the number cites the document and the "iii" cites the person.

RFC 820                                                     January 1983
                                                        Assigned Numbers
Network Numbers


The network numbers listed here are used as internet addresses by the Internet Protocol (IP) [33,62]. The IP uses a 32-bit address field and divides that address into a network part and a "rest" or local address part. The division takes 3 forms or classes.

The first type of address, or class A, has a 7-bit network number and a 24-bit local address. The highest-order bit is set to 0. This allows 128 class A networks.

                           1                   2                   3   
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 
      |0|   NETWORK   |                Local Address                  |

Class A Address

The second type of address, class B, has a 14-bit network number and a 16-bit local address. The two highest-order bits are set to 1-0. This allows 16,384 class B networks.

                           1                   2                   3   
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 
      |1 0|           NETWORK         |          Local Address        |

Class B Address

The third type of address, class C, has a 21-bit network number and a 8-bit local address. The three highest-order bits are set to 1-0-0. This allows 2,097,152 class C networks.

                           1                   2                   3   
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 
      |1 1 0|                    NETWORK              | Local Address |

Class C Address

One commonly used notation for internet host addresses divides the 32-bit address into four 8-bit fields and specifies the value of each field as a decimal number with the fields separated by periods. This is called the "dotted decimal" notation. For example, the internet address of ISIF in dotted decimal is, or

RFC 820                                                     January 1983
                                                        Assigned Numbers
Network Numbers

The dotted decimal notation will be used in the listing of assigned network numbers. The class A networks will have nnn.rrr.rrr.rrr, the class B networks will have nnn.nnn.rrr.rrr, and the class C networks will have nnn.nnn.nnn.rrr, where nnn represents part or all of a network number and rrr represents part or all of a local address or rest field.

For various reasons, the assigned numbers of networks are sometimes changed. To ease the transition the old number will be listed as well. These "old number" entries will be marked with a "T" following the number and preceeding the name.

To reflect the allocation of network identifiers among various categories (see Appendix A), a one-character code is placed to the left of the network number (in the column marked by an asterisk): R for Research and Development, D for DoD, and C for Commercial.

   Assigned Network Numbers
   Class A Networks
      * Internet Address  Name          Network               References
        ----------------  ----          -------               ----------
        000.rrr.rrr.rrr                 Reserved                   [JBP]
      R 001.rrr.rrr.rrr T BBN-PR        BBN Packet Radio Network  [JAW3]
      R 002.rrr.rrr.rrr T SF-PR-1       SF-1 Packet Radio Network  [JEM]
      R 003.rrr.rrr.rrr   RCC-NET       BBN RCC Network            [JGH]
      R 004.rrr.rrr.rrr   SATNET        Atlantic Satellite Network[DM11]
      D 005.rrr.rrr.rrr T DEMO-PR-1     Demo-1 Packet Radio Network[LCS]
      R 006.rrr.rrr.rrr T SF-PR-2       SF-2 Packet Radio Network  [JEM]
        007.rrr.rrr.rrr                 Unassigned                 [JBP]
      R 008.rrr.rrr.rrr   BBN-NET       BBN Network                [JGH]
      D 009.rrr.rrr.rrr T BRAGG-PR      Ft. Bragg Packet Radio Net [JEM]
      R 010.rrr.rrr.rrr   ARPANET       ARPANET              [17,1,REK2]
      R 011.rrr.rrr.rrr T UCLNET        University College London   [PK]
        012.rrr.rrr.rrr                 Unassigned                 [JBP]
        013.rrr.rrr.rrr                 Unassigned                 [JBP]
      C 014.rrr.rrr.rrr   PDN           Public Data Network       [REK2]
        015.rrr.rrr.rrr                 Unassigned                 [JBP]
        016.rrr.rrr.rrr                 Unassigned                 [JBP]
        017.rrr.rrr.rrr                 Unassigned                 [JBP]
      R 018.rrr.rrr.rrr   MIT           MIT Network          [10,43,NC3]
        019.rrr.rrr.rrr                 Unassigned                 [JBP]
        020.rrr.rrr.rrr                 Unassigned                 [JBP]
      D 021.rrr.rrr.rrr   EDN           DCEC EDN                   [EC5]
        022.rrr.rrr.rrr                 Unassigned                 [JBP]
      R 023.rrr.rrr.rrr   MITRE         MITRE Cablenet          [44,APS]
        024.rrr.rrr.rrr                 Unassigned                 [JBP]

RFC 820                                                     January 1983
                                                        Assigned Numbers
Network Numbers

      R 025.rrr.rrr.rrr   RSRE-PPSN     RSRE / PPSN                 [NM]
      D 026.rrr.rrr.rrr   MILNET        MILNET                     [HH6]
      R 027.rrr.rrr.rrr   NOSC-LCCN     NOSC / LCCN                [KTP]
      R 028.rrr.rrr.rrr   WIDEBAND      Wide Band Satellite Net   [CJW2]
        029.rrr.rrr.rrr                 Unassigned                 [JBP]
      R 030.rrr.rrr.rrr   DCN-UCL       UCL DCNET                   [PK]
        031.rrr.rrr.rrr                 Unassigned                 [JBP]
      R 032.rrr.rrr.rrr   UCL-TAC       UCL TAC                     [PK]
        033.rrr.rrr.rrr                 Unassigned                 [JBP]
        034.rrr.rrr.rrr                 Unassigned                 [JBP]
      R 035.rrr.rrr.rrr   RSRE-NULL     RSRE Null Network           [NM]
      R 036.rrr.rrr.rrr T SU-NET        Stanford University Network[JCM]
        037.rrr.rrr.rrr                 Unassigned                 [JBP]
        038.rrr.rrr.rrr                 Unassigned                 [JBP]
      R 039.rrr.rrr.rrr   SRINET        SRI Local Network         [GEOF]
        040.rrr.rrr.rrr                 Unassigned                 [JBP]
      R 041.rrr.rrr.rrr   BBN-LN-TEST   BBN Local Network Testbed  [KTP]
        042.rrr.rrr.rrr                 Unassigned                 [JBP]
        043.rrr.rrr.rrr                 Unassigned                 [JBP]
      R 044.rrr.rrr.rrr   AMPRNET       Amateur Radio Experiment Net[HM]
      R 045.rrr.rrr.rrr T C3-PR         Testbed Development PRNET  [BG5]
      R 046.rrr.rrr.rrr   UCB-ETHER     UC Berkeley Ethernet       [SXL]
      R 047.rrr.rrr.rrr T SAC-PR        SAC Packet Radio Network   [BG5]
      R 048.rrr.rrr.rrr   NDRE-TIU      NDRE-TIU                   [PS3]
        049.rrr.rrr.rrr                 Unassigned                 [JBP]
      R 050.rrr.rrr.rrr   NDRE-RING     NDRE-RING                  [PS3]
        051.rrr.rrr.rrr                 Unassigned                 [JBP]
      R 052.rrr.rrr.rrr T ROCKWELL-PR   Rockwell Packet Radio Net  [EHP]
        053.rrr.rrr.rrr-126.rrr.rrr.rrr Unassigned                 [JBP]
        127.rrr.rrr.rrr                 Reserved                   [JBP]

   Class B Networks

      * Internet Address  Name          Network               References
        ----------------  ----          -------               ----------
        128.000.rrr.rrr                 Reserved                   [JBP]
      R 128.001.rrr.rrr   BBN-TEST-B    BBN-GATE-TEST-B            [RH6]
      R 128.002.rrr.rrr   CMU-NET       CMU-Ethernet              [HDW2]
      R 128.003.rrr.rrr   LBL-CSAM      LBL-CSAM-RESEARCH          [MO1]
      R 128.004.rrr.rrr   DCNET         LINKABIT DCNET            [DLM1]
      R 128.005.rrr.rrr   FORDNET       FORD DCNET                [DLM1]
      R 128.006.rrr.rrr   RUTGERS       RUTGERS                   [CLH3]
      R 128.007.rrr.rrr   DFVLR         DFVLR DCNET Network       [HDC1]
      R 128.008.rrr.rrr   UMDNET        Univ of Maryland DCNET    [DLM1]
      R 128.009.rrr.rrr   ISI-NET       ISI Local Network          [CMR]
      R 128.010.rrr.rrr   PURDUE-CS     Purdue Computer Science    [CXK]
      R 128.011.rrr.rrr   BBN-CRONUS    BBN DOS Project         [12,WIM]
      R 128.012.rrr.rrr   SU-NET        Stanford University Net    [JCM]

RFC 820                                                     January 1983
                                                        Assigned Numbers
Network Numbers

      D 128.013.rrr.rrr   MATNET        Mobile Access Terminal Net[DM11]
      R 128.014.rrr.rrr   BBN-SAT-TEST  BBN SATNET Test Net       [DM11]
      R 128.015.rrr.rrr   S1NET         LLL-S1-NET                [EAK1]
      R 128.016.rrr.rrr   UCLNET        University College London   [PK]
        128.017.rrr.rrr                 Unassigned                 [JBP]
        128.018.rrr.rrr                 Unassigned                 [JBP]
        128.019.rrr.rrr                 Unassigned                 [JBP]
        128.020.rrr.rrr                 Unassigned                 [JBP]
      R 128.021.rrr.rrr   SF-PR-1       SF-1 Packet Radio Network  [JEM]
      R 128.022.rrr.rrr   SF-PR-2       SF-2 Packet Radio Network  [JEM]
      R 128.023.rrr.rrr   BBN-PR        BBN Packet Radio Network  [JAW3]
      R 128.024.rrr.rrr   ROCKWELL-PR   Rockwell Packet Radio Net  [EHP]
      D 128.025.rrr.rrr   BRAGG-PR      Ft. Bragg Packet Radio Net [JEM]
      D 128.026.rrr.rrr   SAC-PR        SAC Packet Radio Network   [BG5]
      D 128.027.rrr.rrr   DEMO-PR-1     Demo-1 Packet Radio Network[LCS]
      D 128.028.rrr.rrr   C3-PR         Testbed Development PR NET [BG5]
        128.029.rrr.rrr-191.254.rrr.rrr Unassigned                 [JBP]
        191.255.rrr.rrr                 Reserved                   [JBP]

   Class C Networks

      * Internet Address  Name          Network               References
        ----------------  ----          -------               ----------
        192.000.000.rrr                 Reserved                   [JBP]
      R 192.000.001.rrr   BBN-TEST-C    BBN-GATE-TEST-C            [RH6]
        192.000.002.rrr-192.000.255.rrr Unassigned                 [JBP]
      R BBN local networks         [SGC]
      R 192.005.001.rrr   CISLNET       CISL Multics Network       [CH2]
      R 192.005.002.rrr   WISC          Univ of Wisconsin Madison [RS23]
      C 192.005.003.rrr   HP-DESIGN-AIDS HP Design Aids            [NXK]
      C 192.005.004.rrr   HP-TCG-UNIX   Hewlett Packard TCG Unix   [NXK]
      D 192.005.005.rrr   BRLNET        BRLNET                  [1,MJM2]
      D 192.005.006.rrr   MINET         MINET                    [1,DHH]
      R 192.005.007.rrr   CIT-CS-NET    Caltech-CS-Net          [65,DSW]
      R 192.005.008.rrr   WASHINGTON    University of Washington  [JAR4]
      R 192.005.009.rrr   AERONET       Aerospace Labnet         [9,LCN]
      R 192.005.010.rrr   ECLNET        USC-ECL-CAMPUS-NET         [MXB]
      R 192.005.011.rrr   CSS-RING      SEISMIC-RESEARCH-NET       [RR2]
      R 192.005.012.rrr   UTAH-NET      UTAH-COMPUTER-SCIENCE-NET  [RF1]
        192.005.013.rrr                 Unassigned                 [JBP]
        192.005.014.rrr                 Unassigned                 [JBP]
        192.005.015.rrr                 Unassigned                 [JBP]
        192.005.016.rrr                 Unassigned                 [JBP]
        192.005.017.rrr                 Unassigned                 [JBP]
        192.005.018.rrr                 Unassigned                 [JBP]
        192.005.019.rrr                 Unassigned                 [JBP]
        192.005.020.rrr                 Unassigned                 [JBP]
      D 192.005.021.rrr   BRLNET1       BRLNET1                 [1,MJM2]

RFC 820                                                     January 1983
                                                        Assigned Numbers
Network Numbers

      D 192.005.022.rrr   BRLNET2       BRLNET2                 [1,MJM2]
      D 192.005.022.rrr   BRLNET3       BRLNET3                 [1,MJM2]
      D 192.005.022.rrr   BRLNET4       BRLNET4                 [1,MJM2]
      D 192.005.022.rrr   BRLNET5       BRLNET54                [1,MJM2]
        192.005.026.rrr-223.255.254.rrr Unassigned                 [JBP]
        223.255.255.rrr                 Reserved                   [JBP]

Other Reserved Internet Addresses

        Internet Address  Name          Network               References
        ----------------  ----          -------               ---------- Reserved                   [JBP]
   Network Totals
         Class         A         B         C     Total
         Research     26        19      1033      1078
         Defense       4         5         7        16
         Commercial    1         0         2         3
         Total        31        24      1042      1097
      Maximum Allowed
         Class         A         B         C     Total
         Research      8      1024     65536     66568
         Defense      24      3072    458752    461848
         Commercial   94     12286   1572862   1585242
         Total       126     16382   2097150   2113658

RFC 820                                                     January 1983
                                                        Assigned Numbers
Internet Version Numbers


In the Internet Protocol (IP) [33,62] there is a field to identify the version of the internetwork general protocol. This field is 4 bits in size.

Assigned Internet Version Numbers

      Decimal   Octal      Version                            References
      -------   -----      -------                            ----------
          0      0         Reserved                                [JBP]
        1-3    1-3         Unassigned                              [JBP]
          4      4         Internet Protocol                 [33,62,JBP]
          5      5         ST Datagram Mode                     [20,JWF]
       6-14   6-16         Unassigned                              [JBP]
         15     17         Reserved                                [JBP]


In the Internet Protocol (IP) [33,62] there is a field, called Protocol, to identify the the next level protocol. This is an 8 bit field.

Assigned Internet Protocol Numbers

      Decimal    Octal      Protocol                          References
      -------    -----      ----------------                  ----------
           0       0         Reserved                              [JBP]
           1       1         ICMP                            [53,62,JBP]
           2       2         Unassigned                            [JBP]
           3       3         Gateway-to-Gateway             [48,49,JFH2]
           4       4         CMCC Gateway Monitoring Message  [18,19,MB]
           5       5         Stream (ST)                        [20,JWF]
           6       6         Transmission Control (TCP)      [34,62,JBP]
           7       7         UCL                                    [PK]
           8      10         Exterior Gateway Protocol (EGP)    [66,RH6]
           9      11         Unassigned                            [JBP]
          10      12         BBN RCC Monitoring                    [SGC]
          11      13         NVP                                [12,SC3]
          12      14         PUP                                [4,EAT3]
       13-14   15-16         Unassigned                            [JBP]
          15      17         Cross Net Debugger (XNET)         [25,JFH2]
          16      20         Chaos Stream                          [NC3]
          17      21         User Datagram (UDP)             [42,62,JBP]
          18      22         Multiplexing                       [13,JBP]
          19      23         DCN Measurement Subsystems           [DLM1]
          20      24         Host Monitoring (HMP)              [55,RH6]
          21      25         Packet Radio Measurement              [ZSU]

RFC 820                                                     January 1983
                                                        Assigned Numbers
Internet Protocol Numbers

          22      26         XEROX NS IP                        [59,JBP]
          23      27         Trunk-1                               [BML]
          24      30         Trunk-2                               [BML]
       25-60   31-74         Unassigned                            [JBP]
          61      75         any host internal protocol            [JBP]
          62      76         CFTP                              [60,HCF2]
          63      77         any local network                     [JBP]
          64     100         SATNET and Backroom EXPAK            [DM11]
          65     101         MIT Subnet Support                    [NC3]
          66     102         MIT VAX Remote Disk Protocol          [MBG]
          67     103         Internet Pluribus Packet Core        [DM11]
          68     104         Unassigned                            [JBP]
          69     105         SATNET Monitoring                    [DM11]
          70     106         Unassigned                            [JBP]
          71     107         Internet Packet Core Utility         [DM11]
       72-75 110-113         Unassigned                            [JBP]
          76     114         Backroom SATNET Monitoring           [DM11]
          77     115         Unassigned                            [JBP]
          78     116         WIDEBAND Monitoring                  [DM11]
          79     117         WIDEBAND EXPAK                       [DM11]
      80-254 120-376         Unassigned                            [JBP]
         255     377         Reserved                              [JBP]

RFC 820                                                     January 1983
                                                        Assigned Numbers
Port Numbers


Ports are used in the TCP [34,62] to name the ends of logical connections which carry long term conversations. For the purpose of providing services to unknown callers a service contact port is defined. This list specifies the port used by the server process as its contact port. The contact port is sometimes called the "well-known port".

To the extent possible these same port assignments are used with UDP [42,62].

The assigned ports use a small portion of the possible port numbers. The assigned ports have all except the low order eight bits cleared to zero. The low order eight bits are specified here.

Port Assignments:

      Decimal   Octal     Description                         References
      -------   -----     -----------                         ----------
      1         1         Old Telnet                            [40,JBP]
      3         3         Old File Transfer               [27,11,24,JBP]
      5         5         Remote Job Entry                    [6,17,JBP]
      7         7         Echo                                  [35,JBP]
      9         11        Discard                               [32,JBP]
      11        13        Who is on or SYSTAT                      [JBP]
      13        15        Date and Time                            [JBP]
      15        17        Who is up or NETSTAT                     [JBP]
      17        21        Short Text Message                       [JBP]
      19        23        Character generator or TTYTST         [31,JBP]
      20        24        File Transfer (Default Data)       [36,62,JBP]
      21        25        File Transfer (Control)            [36,62,JBP]
      23        27        Telnet                             [41,62,JBP]
      25        31        SMTP                               [54,62,JBP]
      27        33        NSW User System FE                    [14,RHT]
      29        35        MSG ICP                               [29,RHT]
      31        37        MSG Authentication                    [29,RHT]
      33        41        Unassigned                               [JBP]
      35        43        IO Station Spooler                       [JBP]
      37        45        Time Server                           [22,JBP]
      39        47        Unassigned                               [JBP]
      41        51        Graphics                           [46,17,JBP]
      42        52        Name Server                        [38,62,JBP]
      43        53        WhoIs                             [57,62,JAKE]
      45        55        Message Processing Module (receive)   [37,JBP]
      46        56        MPM (default send)                    [37,JBP]
      47        57        NI FTP                                 [50,SK]
      49-53     61-65     Unassigned                               [JBP]
RFC 820                                                     January 1983
                                                        Assigned Numbers
Port Numbers

      55        67        ISI Graphics Language                  [3,RB6]
      57        71        Unassigned                               [JBP]
      59        73        Augment File Mover                       [WWB]
      61        75        NIMAIL                                 [56,SK]
      63        77        Unassigned                               [JBP]
      65        101       Unassigned                               [JBP]
      67        103       Datacomputer at CCA                    [8,JZS]
      69        105       Trivial File Transfer              [47,62,KRS]
      71        107       NETRJS                              [5,17,RTB]
      72        110       NETRJS                              [5,17,RTB]
      73        111       NETRJS                              [5,17,RTB]
      74        112       NETRJS                              [5,17,RTB]
      75        113       Unassigned                               [JBP]
      77        115       any private RJE server                   [JBP]
      79        117       Name or Finger                     [23,17,KLH]
      81        121       HOSTS2 Name Server                      [EAK1]
      83        123       MIT ML Device                            [DPR]
      85        125       MIT ML Device                            [DPR]
      87        127       any terminal link                        [JBP]
      89        131       SU/MIT Telnet Gateway                    [MRC]
      91        133       MIT Dover Spooler                        [EBM]
      93        135       Device Control Protocol                  [DCT]
      95        137       SUPDUP                                [15,MRC]
      97        141       Datacomputer Status                    [8,JZS]
      99        143       Metagram Relay                          [GEOF]
      101       145       NIC Host Name Server              [64,62,JAKE]
      103       147       CSNET Mailbox Name Server (Telnet)   [58,MHS1]
      105       151       CSNET Mailbox Name Server (Program)  [58,MHS1]
      107       153       Remote Telnet Service                 [61,JBP]
      109-129   155-201   Unassigned                               [JBP]
      131       203       Datacomputer                           [8,JZS]
      132-223   204-337   Reserved                                 [JBP]
      224-241   340-361   Unassigned                               [JBP]
      243       363       Survey Measurement                      [2,AV]
      245       365       LINK                                  [7,RDB2]
      247-255   367-377   Unassigned                               [JBP]

RFC 820                                                     January 1983
                                                        Assigned Numbers
Autonomous System Numbers


The Exterior Gateway Protocol (EGP) [66] specifies that groups of gateways may for autonomous systems. The EGP provides a 16-bit field for identifying such systems. The values of this field are registered here.

Autonomous System Numbers:

      Decimal   Description                                   References
      -------   -----------                                   ----------
            0   Reserved                                           [JBP]
            1   The BBN Gateways                                   [JBP]
      2-65534   Unassigned                                         [JBP]
        65535   Reserved                                           [JBP]


The word "link" here refers to a field in the original ARPANET Host/IMP interface leader. The link was originally defined as an 8 bit field. Some time after the ARPANET Host-to-Host (AHHP) protocol was defined and, by now some years ago, the definition of this field was changed to "Message-ID" and the length to 12 bits. The name link now refers to the high order 8 bits of this 12 bit message-id field. The low order 4 bits of the message-id field are to be zero unless specifically specified otherwise for the particular protocol used on that link. The Host/IMP interface is defined in BBN report 1822 [1].

Link Assignments:

      Decimal   Octal     Description                         References
      -------   -----     -----------                         ----------
      0         0         AHHP Control Messages              [28,17,JBP]
      1         1         Reserved                                 [JBP]
      2-71      2-107     AHHP Regular Messages              [28,17,JBP]
      72-149    110-225   Reserved                                 [JBP]
      150       226       Xerox NS IP                           [59,LLG]
      151       227       Unassigned                               [JBP]
      152       230       PARC Universal Protocol               [4,EAT3]
      153       231       TIP Status Reporting                     [JGH]
      154       232       TIP Accounting                           [JGH]
      155       233       Internet Protocol (regular)        [33,62,JBP]
      156-158   234-236   Internet Protocol (experimental)   [33,62,JBP]
      159-195   237-303   Unassigned                               [JBP]
      196-255   304-377   Experimental Protocols                   [JBP]
      248-255   370-377   Network Maintenance                      [JGH]
RFC 820                                                     January 1983
                                                        Assigned Numbers
Ethernet Numbers of Interest


Many of the networks of all classes are Ethernets (10Mb) or Experimental Ethernets (3Mb). These systems use a message "type" field in much the same way the ARPANET uses the "link" field.


      Ethernet          Exp. Ethernet    Description          References
      --------------    --------------   -----------          ----------
      decimal    Hex    decimal  octal
         512   02,00        512   1000   XEROX PUP              [4,EAT3]
        1536   06,00       1536   3000   XEROX NS IDP           [59,LLG]
        2048   08,00        513   1001   DOD IP              [33,62,JBP]
        2054   08,06        -      -     Address Res           [67,DCP1]


One of the Internet Class A Networks is the international system of Public Data Networks. This section lists the mapping between the Internet Addresses and the Public Data Network Addresses.


      Internet          Public Data Net     Description       References
      ---------------   ---------------     -----------       ----------                       Reserved               [JBP]   311031700035 00     PURDUE-TN              [CXK]   311060800027 00     UWISC-TN               [CXK]   311030200024 00     UDEL-TN                [CXK]   234219200149 23     UCL-VTEST               [PK]   234219200300 23     UCL-TG                  [PK]   234219200300 25     UK-SATNET               [PK]       Unassigned             [JBP]                       Reserved               [JBP]

RFC 820                                                     January 1983
                                                        Assigned Numbers



   [1]    BBN, "Specifications for the Interconnection of a Host and an
          IMP", Report 1822, Bolt Beranek and Newman, Cambridge,
          Massachusetts, May 1978.
   [2]    Bhushan, A., "A Report on the Survey Project", RFC 530,
          NIC 17375, 22 June 1973.
   [3]    Bisbey, R., D. Hollingworth, and B. Britt, "Graphics Language
          (version 2.1)", ISI/TM-80-18, USC/Information Sciences
          Institute, July 1980.
   [4]    Boggs, D., J. Shoch, E. Taft, and R. Metcalfe, "PUP: An
          Internetwork Architecture", XEROX Palo Alto Research Center,
          CSL-79-10, July 1979; also in IEEE Transactions on
          Communication, Volume COM-28, Number 4, April 1980.
   [5]    Braden, R., "NETRJS Protocol", RFC 740, NIC 42423,
          22 November 1977.  Also in [17].
   [6]    Bressler, B., "Remote Job Entry Protocol",  RFC 407, NIC
          12112, 16 October 72.  Also in [17].
   [7]    Bressler, R., "Inter-Entity Communication -- An Experiment",
          RFC 441, NIC 13773, 19 January 1973.
   [8]    CCA, "Datacomputer Version 5/4 User Manual", Computer
          Corporation of America, August 1979.
   [9]    Aerospace, Internal Report, ATM-83(3920-01)-3, 1982.
   [10]   Clark, D., "Revision of DSP Specification", Local Network Note
          9, Laboratory for Computer Science, MIT, 17 June 1977.
   [11]   Clements, R., "FTPSRV -- Extensions for Tenex Paged Files",
          RFC 683, NIC 32251, 3 April 1975.  Also in [17].
   [12]   Macgregor, W., and D. Tappan, "The CRONUS Virtual Local
          Network", RFC 824, Bolt Beranek and Newman, Inc.,
          22 August 1982.
   [13]   Cohen, D. and J. Postel, "Multiplexing Protocol", IEN 90,
          USC/Information Sciences Institute, May 1979.

RFC 820                                                     January 1983
                                                        Assigned Numbers

   [14]   COMPASS, "Semi-Annual Technical Report", CADD-7603-0411,
          Massachusetts Computer Associates, 4 March 1976. Also as,
          "National Software Works, Status Report No. 1,"
          RADC-TR-76-276, Volume 1, September 1976. And COMPASS. "Second
          Semi-Annual Report," CADD-7608-1611, Massachusetts Computer
          Associates, 16 August 1976.

   [15]   Crispin, M., "SUPDUP Protocol", RFC 734, NIC 41953,
          7 October 1977.  Also in [17].

   [17]   Feinler, E. and J. Postel, eds., "ARPANET Protocol Handbook",
          NIC 7104, for the Defense Communications Agency by SRI
          International, Menlo Park, California, Revised January 1978.

   [18]   Flood Page, D., "Gateway Monitoring Protocol", IEN 131,
          February 1980.

   [19]   Flood Page, D., "CMCC Performance Measurement Message
          Formats", IEN 157, September 1980.

   [20]   Forgie, J., "ST - A Proposed Internet Stream Protocol",
          IEN 119, M.I.T. Lincoln Laboratory, September 1979.

   [21]   Forsdick, H., and A. McKenzie, "FTP Functional Specification",
          Bolt Beranek and Newman, Report 4051, August 1979.

   [22]   Harrenstien, K., J. Postel, "Time Server", IEN 142,
          April 1980.  Also in [17].

   [23]   Harrenstien, K., "Name/Finger", RFC 742, NIC 42758,
          30 December 1977.  Also in [17].

   [24]   Harvey, B., "One More Try on the FTP", RFC 691, NIC 32700,
          6 June 1975.

   [25]   Haverty, J., "XNET Formats for Internet Protocol Version 4",
          IEN 158, October 1980.

   [27]   McKenzie, A., "File Transfer Protocol", RFC 454, NIC 14333,
          16 February 1973.

   [28]   McKenzie,A., "Host/Host Protocol for the ARPA Network",
          NIC 8246, January 1972.  Also in [17].

   [29]   NSW Protocol Committee, "MSG: The Interprocess Communication
          Facility for the National Software Works", CADD-7612-2411,
          Massachusetts Computer Associates, BBN 3237, Bolt Beranek and
          Newman, Revised 24 December 1976.

RFC 820                                                     January 1983
                                                        Assigned Numbers

   [31]   Postel, J., "Character Generator Process", RFC 429, NIC 13281,
          12 December 1972.

   [32]   Postel, J., "Discard Process",  RFC 348, NIC 10427,
          30 May 1972.

   [33]   Postel, J., ed., "Internet Protocol - DARPA Internet Program
          Protocol Specification", RFC 791, USC/Information Sciences
          Institute, September 1981.

   [34]   Postel, J., ed., "Transmission Control Protocol - DARPA
          Internet Program Protocol Specification", RFC 793,
          USC/Information Sciences Institute, September 1981.

   [35]   Postel, J., "Echo Process",  RFC 347, NIC 10426, 30 May 1972.

   [36]   Postel, J., "File Transfer Protocol", RFC 765, IEN 149,
          June 1980.

   [37]   Postel, J., "Internet Message Protocol", RFC 759, IEN 113,
          USC/Information Sciences Institute, August 1980.

   [38]   Postel, J., "Name Server", IEN 116, USC/Information Sciences
          Institute, August 1979.

   [39]   Postel, J., "Official Initial Connection Protocol", NIC 7101,
          11 June 1971.  Also in [17].

   [40]   Postel, J., "Telnet Protocol", RFC 318, NIC 9348,
          3 April 1972.

   [41]   Postel, J., "Telnet Protocol Specification", RFC 764, IEN 148,
          June 1980.

   [42]   Postel, J., "User Datagram Protocol", RFC 768 USC/Information
          Sciences Institute, August 1980.

   [43]   Reed, D., "Protocols for the LCS Network", Local Network Note
          3, Laboratory for Computer Science, MIT, 29 November 1976.

   [44]   Skelton, A., S. Holmgren, and D. Wood, "The MITRE Cablenet
          Project", IEN 96, April 1979.

   [45]   Crocker, D., "Standard for the Format of ARPA Internet Text
          Messages", RFC 822, Department of Electrical Engineering,
          University of Delawaugust 1982.

RFC 820                                                     January 1983
                                                        Assigned Numbers

   [46]   Sproull, R., and E. Thomas. "A Networks Graphics Protocol",
          NIC 24308, 16 August 1974.  Also in [17].

   [47]   Sollins, K., "The TFTP Protocol (revision 2)", RFC 783,
          MIT/LCS, June 1981.

   [48]   Strazisar, V., "Gateway Routing:  An Implementation
          Specification", IEN 30, Bolt Berenak and Newman, April 1979.

   [49]   Strazisar, V., "How to Build a Gateway", IEN 109, Bolt Berenak
          and Newman, August 1979.

   [50]   The High Level Protocol Group, "A Network Independent File
          Transfer Protocol",  INWG Protocol Note 86, December 1977.

   [51]   Thomas, R., "A Resource Sharing Executive for the ARPANET",
          AFIPS Conference Proceedings, 42:155-163, NCC, 1973.

   [52]   Flood Page, D., "A Simple Message Generator", IEN 172, Bolt
          Berenak and Newman, March 1981.

   [53]   Postel, J., "Internet Control Message Protocol - DARPA
          Internet Program Protocol Specification", RFC 792,
          USC/Information Sciences Institute, September 1981.

   [54]   Postel, J., "Simple Mail Transfer Protocol", RFC 821,
          USC/Information Sciences Institute, August 1982.

   [55]   Littauer, B., "A Host Monitoring Protocol", IEN 197, Bolt
          Berenak and Newman, September 1981.

   [56]   Bennett, C., "A Simple NIFTP-Based Mail System", IEN 169,
          University College, London, January 1981.

   [57]   Harrenstien, K., and V. White, "Nicname/Whois", RFC 812, SRI
          International, March 1982.

   [58]   Solomon, M., L. Landweber, and D, Neuhengen, "The Design of
          the CSNET Name Server", CS-DN-2, University of Wisconsin,
          Madison, Revised November 1981.

   [59]   XEROX, "Internet Transport Protocols",  XSIS 028112, Xerox
          Corporation, Stamford, Connecticut, December 1981.

   [60]   Forsdick, H., "CFTP", Network Message, Bolt Berenak and
          Newman, January 1982.

RFC 820                                                     January 1983
                                                        Assigned Numbers

   [61]   Postel, J., "Remote Telnet Service", RFC 818, USC/Information
          Sciences Institute, November 1982.

   [62]   Feinler, E., "Internet Protocol Transition Workbook", Network
          Information Center, SRI International, March 1982.

   [63]   Postel, J., "The NCP/TCP Transition Plan", RFC 801,
          USC/Information Sciences Institute, November 1981.

   [64]   Harrenstien, K., V. White, and E. Feinler, "Hostnames Server",
          RFC 811, SRI International, March 1982.

   [65]   Whelan, D., "The Caltech Computer Science Department Network",
          5052:DF:82, Caltech Computer Science Department, 1982.

   [66]   Rosen, E., "Exterior Gateway Protocol", RFC 827, Bolt Berenak
          and Newman, October 1982.

   [67]   Plummer, D., "An Ethernet Address Resolution Protocol or
          Converting Network Protocol Addresses to 48-bit Ethernet
          Addresses for Transmission on Ethernet Hardware", RFC 826, MIT
          LCS, November 1982.

RFC 820                                                     January 1983
                                                        Assigned Numbers

   [RB6]     Richard Bisbey      ISI       Bisbey@ISIB
   [RTB]     Bob Braden          UCLA      Braden@ISIA
   [WWB]     Bill Barns          Tymshare  Barns@OFFICE
   [MB]      Michael Brescia     BBN       Brescia@BBN-Unix
   [RDB2]    Robert Bressler     BBN       Bressler@BBN-Unix
   [MXB]     Mark Brown          USC       Mark@USC-ECLB
   [EC5]     Ed Cain             DCEC      cain@EDN-Unix
   [SC3]     Steve Casner        ISI       Casner@ISIB
   [NC3]     J. Noel Chiappa     MIT       JNC@MIT-XX
   [SGC]     Steve Chipman       BBN       Chipman@BBNA
   [HDC1]    Horst Clausen       DFVLR     Clausen@ISID
   [DC]      Danny Cohen         ISI       Cohen@ISIB
   [MRC]     Mark Crispin        Stanford  Admin.MRC@SU-SCORE
   [RF1]     Randy Frank         UTAH      Frank@UTAH-20
   [JAKE]    Jake Feinler        SRI       Feinler@SRI-KL
   [JWF]     Jim Forgie          LL        Forgie@BBNC
   [HCF2]    Harry Forsdick      BBN       Forsdick@BBNG
   [SWG]     Stu Galley          MIT       SWG@MIT-DMS
   [LLG]     Larry Garlick       XEROX     Garlick@PARC-MAXC
   [BG5]     Bob Gilligan        SRI       Gilligan@ISID
   [GEOF]    Geoff Goodfellow    SRI       Geoff@DARCOM-KA
   [MBG]     Michael Greenwald   MIT-LCS   Greenwald@MIT-Multics
   [KLH]     Ken Harrenstien     SRI       KLH@NIC
   [JFH2]    Jack Haverty        BBN       Haverty@BBN-Unix
   [CLH3]    Charles Hedrick     RUTGERS   Hedrick@RUTGERS
   [JGH]     Jim Herman          BBN       Herman@BBN-Unix
   [HH6]     Heidi Heiden        DCA       Heiden@BBNC
   [PLH]     Peter Higginson     UCL       UKSAT@ISID
   [RH6]     Robert Hinden       BBN       Hinden@BBN-Unix
   [CH2]     Charles Hornig      Honeywell Hornig@MIT-Multics
   [DHH]     Doug Hunt           BBN       DHunt@BBN-Unix
   [REK2]    Robert Kahn         ARPA      Kahn@ISIA
   [NXK]     Neil Katin          HP        hpda.neil@BERKELEY
   [CXK]     Chris Kent          PURDUE    cak@PURDUE
   [SK]      Steve Kille         UCL       UKSAT@ISID
   [EAK1]    Earl Killian        LLL       EAK@MIT-MC
   [PK]      Peter Kirstein      UCL       Kirstein@ISIA
   [SXL]     Sam Leffler         Berkeley  sam@BERKELEY
   [BML]     Barry Leiner        ARPA      Leiner@ISIA
   [WIM]     William Macgregor   BBN       macg@BBN
   [NM]      Neil MacKenzie      RSRE      T45@ISID
   [HM]      Hank Magnuski       ---       JOSE@PARC-MAXC
   [JEM]     Jim Mathis          SRI       Mathis@SRI-KL
   [DM11]    Dale McNeill        BBN       mcneill@BBN-Unix
   [DLM1]    David Mills         LINKABIT  Mills@ISID
   [JCM]     Jeff Mogul          STANFORD  Mogul@SU-SCORE

RFC 820                                                     January 1983
                                                        Assigned Numbers

   [EBM]     Eliot Moss          MIT       EBM@MIT-XX
   [MJM2]    Mike Muuss          BRL       Mike@BRL
   [LCN]     Lou Nelson          AEROSPACE Lou@AEROSPACE
   [MO2]     Michael O'Brien     RAND      OBrien@RAND-Unix
   [MO1]     Mike O'Dell         LBL       mo@LBL-Unix
   [EHP]     Ed Perry            SRI       Perry@SRI-KL
   [DCP1]    David Plummer       MIT       DCP@MIT-MC
   [KTP]     Ken Pogran          BBN       Pogran@BBN-Unix
   [JBP]     Jon Postel          ISI       Postel@ISIF
   [DPR]     David Reed          MIT-LCS   DPR@MIT-XX
   [JAR4]    Jim Rees            WASHINGTON JIM@WASHINGTON
   [CMR]     Craig Rogers        ISI       Rogers@ISIB
   [RR2]     Raleigh Romine      Teledyne  romine@SEISMO
   [RS23]    Russel Sandberg     WISC      root@UWISC
   [JZS]     Joanne Sattely      CCA       JZS@CCA
   [LCS]     Lou Schreier        SRI       Schreier@ISID
   [APS]     Anita Skelton       MITRE     skelton@MITRE
   [KRS]     Karen Sollins       MIT       Sollins@MIT-XX
   [MHS1]    Marvin Solomon      WISC      Solomon@UWISC
   [PS3]     Paal Spilling       NDRE      Paal@DARCOM-KA
   [ZSU]     Zaw-Sing Su         SRI       ZSu@SRI-TSC
   [EAT3]    Ed Taft             XEROX     Taft.PA@PARC-MAXC
   [DCT]     Dan Tappan          BBN       Tappan@BBNG
   [RHT]     Robert Thomas       BBN       BThomas@BBNG
   [AV]      Al Vezza            MIT       AV@MIT-XX
   [HDW2]    Howard Wactlar      CMU       Wactlar@CMU-10B
   [CJW2]    Cliff Weinstein     LL        cjw@LL-11
   [JAW3]    Jil Westcott        BBN       Westcott@BBNF
   [DSW]     Dan Whelan          Caltech   Dan@CIT-20

RFC 820                                                     January 1983
                                                        Assigned Numbers



This appendix summarizes the agreements reached by the DDN/PMO and DARPA at a September 1982 meeting concerning the allocation and assignment of the various numbers associated with DoD Protocol Standards and the DARPA Experimental Standards.

Recommended policy is summarized for each type of number assignment of concern:

Network Identifiers used by the Internet Protocol

It is recommended that the available number spaces for class A, B, and C network addresses be allocated among R&D, DoD and commercial uses, and that assignments of these addresses be the responsibility respectively of DARPA, DCA PCCO/DDN and the National Bureau of Standards. The recommended allocations are given below.

         Class A
            R&D allocation:          8 nets    assigned by:  ARPA
            DoD allocation:         24 nets    assigned by:  TBD
            Commercial allocation:  94 nets    assigned by:  TBD
            Reserved Addresses:  0,127
         Class B
            R&D allocation:          1024 nets    assigned by:  ARPA
            DoD allocation:          3072 nets    assigned by:  TBD
            Commercial allocation:  12286 nets    assigned by:  TBD
            Reserved Addresses:  0,16383
         Class C
            R&D allocation:           65536 nets    assigned by:  ARPA
            DoD allocation:          458725 nets    assigned by:  TBD
            Commercial allocation:  1572862 nets    assigned by:  TBD
            Reserved Addresses:  0,2097151
         Class D

All addresses in this class are reserved for future use, possibly in support of multicast services. They should be allocated to R&D use for the present.

RFC 820                                                     January 1983
                                                        Assigned Numbers

Within the R&D community, it will be the policy that network identifiers will only be granted to applicants who show evidence that they are acquiring standard Bolt Beranek and Newman gateway software or have implemented or are acquiring a gateway meeting the External Gateway Protocol requirements. Acquisition of the Berkeley BSD 4.2 UNIX software might be considered evidence of the latter.

Experimental networks which later become operational need not be renumbered if that would cause hardships. Rather, the identifiers could be moved from R&D to DoD or Commercial status. Thus, network identifiers may change state among R&D, DoD and commercial, but the number of identifiers allocated to each use should remain constant. To make possible this fluid assignment, it is recommended that the network identifier spaces not be allocated by simple partition but rather by specific assignment. It is recommended that DDN/PMO or its designee keep track of the assignments made by DARPA, DDN and NBS to ensure that allocation remains as suggested.

      Protocol Identifiers

In general, all assignments will be made by the R&D community, but any numbers which become R&D, DoD, national or international standards will be marked as such in this RFC.

Protocol identifiers 0 and 255 are reserved.

95 protocol identifiers are allocated for assignment to DoD standards, 32 for R&D use, and 127 for Commercial, national or international standards.

      Port Numbers

A recommendation for allocation and assignment of port numbers is to be developed jointly by representatives of the ICCB and PSTP.

      ARPANET Link Numbers

All unnecessary link number usage will be eliminated by joint effort of the ICCB, PSTP and BBN. BBN will give consideration to the use of link numbers to promote interoperability among various ARPANET interfaces and report to the ICCB, PSTP and DDN/PMO. Examples of possible interoperability issues are:

RFC 820                                                     January 1983
                                                        Assigned Numbers

(i) interoperability of 1822 and X.25 interfaces

(ii) interoperability of SIP and other interfaces

(iii) logical addressing or other special services

      IP Version Numbers

These numbers will be assigned only by the R&D community for the purpose of exploring alternatives in internet protocol service expansion, such as inclusion of stream protocol (ST) services.

TCP, IP and Telnet Option Identifiers

These numbers will be assigned by the R&D community. Any permanent or experimental assignments will be identified in the documents specifying those protcols.


This policy recommendation has not been fully implemented as yet. Currently Jon Postel is acting coordinator for all number assignments.