Point-to-Point Protocol for the transmission of multi-protocol datagrams over Point-to-Point links
RFC 1171

 
Document Type RFC - Draft Standard (July 1990; No errata)
Obsoleted by RFC 1331
Obsoletes RFC 1134
Last updated 2013-03-02
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IESG IESG state RFC 1171 (Draft Standard)
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Network Working Group                                         D. Perkins
Request for Comments: 1171                                           CMU
Obsoletes: RFC 1134                                            July 1990

                      The Point-to-Point Protocol
                                for the
   Transmission of Multi-Protocol Datagrams Over Point-to-Point Links

Status of this Memo

   This RFC specifies an IAB standards track protocol for the Internet
   community.

   Please refer to the current edition of the "IAB Official Protocol
   Standards" for the standardization state and status of this protocol.

   This proposal is the product of the Point-to-Point Protocol Working
   Group of the Internet Engineering Task Force (IETF). Comments on this
   memo should be submitted to the IETF Point-to-Point Protocol Working
   Group chair.

   Distribution of this memo is unlimited.

Abstract

   The Point-to-Point Protocol (PPP) provides a method for transmitting
   datagrams over serial point-to-point links.  PPP is composed of three
   parts:

      1. A method for encapsulating datagrams over serial links.

      2. An extensible Link Control Protocol (LCP).

      3. A family of Network Control Protocols (NCP) for establishing
         and configuring different network-layer protocols.

   This document defines the encapsulation scheme, the basic LCP, and an
   NCP for establishing and configuring the Internet Protocol (IP)
   (called the IP Control Protocol, IPCP).

   The options and facilities used by the LCP and the IPCP are defined
   in separate documents.  Control protocols for configuring and
   utilizing other network-layer protocols besides IP (e.g., DECNET,
   OSI) are expected to be developed as needed.

Perkins                                                         [Page i]


RFC 1171                Point-to-Point Protocol                July 1990

                           Table of Contents

     1.     Introduction ..........................................    1
        1.1       Motivation ......................................    1
        1.2       Overview of PPP .................................    1
        1.3       Organization of the document ....................    2

     2.     Physical Layer Requirements ...........................    3

     3.     The Data Link Layer ...................................    4
        3.1       Frame Format ....................................    5

     4.     The PPP Link Control Protocol (LCP) ...................    9
        4.1       The LCP Automaton ...............................   11
           4.1.1  Overview ........................................   11
           4.1.2  State Diagram ...................................   11
           4.1.3  State Transition Table ..........................   13
           4.1.4  Events ..........................................   13
           4.1.5  Actions .........................................   16
           4.1.6  States ..........................................   17
        4.2       Loop Avoidance ..................................   20
        4.3       Timers and Counters .............................   20
        4.4       Packet Format ...................................   21
           4.4.1  Configure-Request ...............................   23
           4.4.2  Configure-Ack ...................................   24
           4.4.3  Configure-Nak ...................................   25
           4.4.4  Configure-Reject ................................   27
           4.4.5  Terminate-Request and Terminate-Ack .............   29
           4.4.6  Code-Reject .....................................   31
           4.4.7  Protocol-Reject .................................   32
           4.4.8  Echo-Request and Echo-Reply .....................   34
           4.4.9  Discard-Request .................................   36
        4.5       Configuration Options ...........................   38
           4.5.1  Format ..........................................   39

     5.     A PPP Network Control Protocol (NCP) for IP ...........   40
        5.1       Sending IP Datagrams ............................   40

     APPENDICES ...................................................   42

     A.     Asynchronous HDLC .....................................   42

     B.     Fast Frame Check Sequence (FCS) Implementation ........   44
        B.1       FCS Computation Method ..........................   44
        B.2       Fast FCS table generator ........................   46

     REFERENCES ...................................................   47

Perkins                                                        [Page ii]


RFC 1171                Point-to-Point Protocol                July 1990

     SECURITY CONSIDERATIONS ......................................   48

     CHAIRMAN'S ADDRESS ...........................................   48
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