PPP, Point-to-Point Protocol

Description Glossary RFCs Publications Obsolete RFCs


Protocol suite: PPP.
Protocol type:Link layer protocol.
Working groups: pppext, Point-to-Point Protocol Extensions.
Links: PPP Assigned numbers.

A collection of protocols designed for moving datagrams across serial point-to-point links. These protocols are used to establish and configure the communications link, the network layer protocols and also to encapsulate datagrams. PPP has several components:

Packet format:

1 or 2Protocol.
0 or moreData :::

Protocol. 8 or 16 bits.
The structure of this field is consistent with the ISO 3309 extension mechanism for address fields. All valid protocols have the least significant bit of the least significant byte set to 1 and the least significant bit of the most significant byte is cleared to 0. Frames that do not comply are treated as having an unrecognized protocol.

 0x0XXX - 0x3XXX, Network layer protocols. 
0x0001Padding Protocol.RFC 1661
0x0003 ROHC small-CID. RFC 3095, RFC 3241
0x0005 ROHC large-CID. RFC 3095, RFC 3241
Reserved (transparency inefficient).RFC 1661
0x0021 IP, Internet Protocol. 
0x0023OSI Network Layer. 
0x0025Xerox NS IDP. 
0x0027DECnet Phase IV. 
0x002DVan Jacobson Compressed TCP/IP. 
0x002FVan Jacobson Uncompressed TCP/IP. 
0x0031Bridging PDU. 
0x0033ST-II, Stream Protocol. 
0x0035Banyan Vines. 
0x0037Reserved (until 1993). 
0x0039AppleTalk EDDP. 
0x003BAppleTalk SmartBuffered. 
0x003D MP, PPP Multilink Protocol.RFC 1717
0x003F NETBIOS Framing. 
0x0041Cisco Systems. 
0x0043Ascom Timeplex. 
0x0045LBLB, Fujitsu Link Backup and Load Balancing. 
0x0047DCA Remote Lan. 
0x0049 SDTP, PPP Serial Data Transport Protocol. 
0x004BSNA over 802.2. RFC 2043
0x004DSNA. RFC 2043
0x004FIP6 Header Compression. 
0x0051KNX Bridging Data. 
0x0053Encryption.RFC 1968
0x0055Individual Link Encryption.RFC 1968
0x0057 IPv6, Internet Protocol version 6.RFC 5072
0x0059PPP Multiplexing. RFC 3153
0x005B VSNP, Vendor-Specific Network Protocol. RFC 3772
0x005D TNP, TRILL Network Protocol. RFC 6361
0x0061 RTP IPHC Full Header. RFC 3544
0x0063 RTP IPHC Compressed TCP. RFC 3544
0x0065 RTP IPHC Compressed Non TCP. RFC 3544
0x0067 RTP IPHC Compressed UDP 8. RFC 3544
0x0069 RTP IPHC Compressed RTP 8. RFC 3544
0x006F Stampede Bridging.  
0x0073 MP+, PPP Ascend's Multilink Protocol Plus.  
0x007D Reserved (Control Escape). RFC 1661
0x007F Reserved (compression inefficient). RFC 1662
0x0081 Reserved (until 20-Oct-2000).  
0x0083 Reserved (until 20-Oct-2000).  
0x00C1 NTCITS IPI.  
0x00CF Reserved (PPP NLPID).  
0x00FBSingle link compression in multilink. RFC 1962
0x00FDCompressed datagram. RFC 1962
0x00FF Reserved (compression inefficient).  
0x02XX - 0x1EXX, Compression inefficient protocols.  
0x0201802.1d Hello Packets. RFC 1220
0x0203 IBM Source Routing BPDU.  
0x0205 DEC LANBridge100 Spanning Tree.  
0x0207 CDP, Cisco Discovery Protocol. 
0x0209Netcs Twin Routing. 
0x020B STP, Scheduled Transfer Protocol.  
0x020D EDP, Extreme Discovery Protocol.  
OSCP, Optical Supervisory Channel Protocol.  
0x0231 Luxcom.  
0x0233 Sigma Network Systems.  
0x0235 Apple Client Server Protocol.  
0x0281 MPLS, Multi-Protocol Label Switching, unicast.  
0x0283 MPLS, Multi-Protocol Label Switching, multicast.  
0x0285 IEEE p1284.4 standard - data packets.  
0x0287 ETSI TETRA Network Protocol Type 1.  
0x0289 Multichannel Flow Treatment Protocol.  
0x2063 RTP IPHC Compressed TCP No Delta. RFC 3544
0x2065 RTP IPHC Context State. RFC 3544
0x2067 RTP IPHC Compressed UDP 16. RFC 3544
0x2069 RTP IPHC Compressed RTP 16. RFC 3544
0x4XXX - 0x7XXX, Low volume traffic without an associated NCP.  
0x4001 Cray Communications Control Protocol.  
0x4003 CDPD Mobile Network Registration Protocol.  
0x4005 Expand accelerator protocol.  
0x4007 ODSICP NCP.  
0x4021 LZS, PPP Stac LZS Compression Protocol. 
0x4023 RefTek Protocol.  
0x4025 Fibre Channel.  
0x4027 EMIT Protocols.  
0x405B VSP, Vendor-Specific Protocol. 
0x405DTLSP, TRILL Link State Protocol.RFC 6361
0x8XXX - 0xBXXX, Network Control Protocols. 
Reserved. RFC 1661
0x8021 IPCP, PPP Internet Protocol Control Protocol.  
0x8023 OSINLCP, PPP OSI Network Layer Control Protocol.  
0x8025 XNSCP, PPP XNS IDP Control Protocol.  
0x8027 DNCP, DECnet Phase IV Control Protocol.  
0x8029 ATCP, PPP AppleTalk Control Protocol.  
0x802B IPXCP, PPP IPX Control Protocol.  
0x802D Reserved.  
0x802F Reserved.  
0x8031 BCP, PPP Bridging Control Protocol.  
0x8033 Stream Protocol Control Protocol.  
0x8035 BVCP, Banyan Vines Control Protocol.  
0x8037 Reserved (until 1993).  
0x8039 Reserved.  
0x803B Reserved.  
0x803D Multi-Link Control Protocol.  
0x803F NBFCP, PPP NetBIOS Frames Control Protocol.  
0x8041 PPP-LEX, PPP LAN extension protocol.  
0x8043 Ascom Timeplex.  
0x8045 Fujitsu LBLB Control Protocol.  
0x8047 RLNCP, DCA Remote Lan Network Control Protocol.  
0x8049 SDCP, PPP Serial Data Control Protocol.  
0x804B SNACP, SNA over 802.2 Control Protocol.  
0x804D SNACP, SNA Control Protocol.  
0x804F IP6 Header Compression Control Protocol.  
0x8051 KNX Bridging Control Protocol.  
0x8053 ECP, PPP Encryption Control Protocol.  
0x8055 Individual Link Encryption Control Protocol.  
0x8057 IPV6CP, PPP IPv6 Control Protocol.  
0x8059 PPP Multiplexing Control Protocol. RFC 3153
0x805B VSNCP, Vendor-Specific Network Control Protocol. RFC 3772
0x805DTNCP, TRILL Network Control Protocol.RFC 6361
0x806FStampede Bridging Control Protocol. 
0x8071 Reserved.  
0x8073 MP+ Control Protocol.  
0x807DReserved. RFC 1661
0x8081 Reserved (until 20-Oct-2000).  
0x8083 Reserved (until 20-Oct-2000).  
0x80C1 NTCITS IPI Control Protocol.  
0x80CFReserved. RFC 1661
0x80FB Compression on single link in multilink group control. RFC 1962
0x80FD CCP, PPP Compression Control Protocol.  
0x80FFReserved (not used). RFC 1661
0x8207 Cisco Discovery Protocol Control.  
0x8209 Netcs Twin Routing.  
0x820B STP, Control Protocol.  
0x820DEDPCP, Extreme Discovery Protocol Control Protocol. 
0x8235Apple Client Server Protocol Control. 
0x8281 MPLSCP, MPLS Control Protocol.RFC 3032
0x8283Tag Switching - Multicast. 
0x8285IEEE p1284.4 standard - Protocol Control. 
0x8287ETSI TETRA NSP1 Control Protocol. 
0x8289Multichannel Flow Treatment Protocol. 
0xCXXX - 0xFXXX, Link Control Protocols. 
0xC021 LCP, Link Control Protocol. 
0xC023 PAP, Password Authentication Protocol. 
0xC025 Link Quality Report. 
0xC027SPAP, Shiva Password Authentication Protocol. 
0xC029CBCP, CallBack Control Protocol. 
0xC02B BACP, PPP Bandwidth Allocation Control Protocol.RFC 2125
0xC02D BAP, PPP Bandwidth Allocation Protocol.RFC 2125
0xC05B VSAP, Vendor-Specific Authentication Protocol.RFC 3772
0xC081Container Control Protocol. 
0xC223 CHAP, Challenge Handshake Authentication Protocol. 
0xC225RSA Authentication Protocol. 
0xC227 EAP, Extensible Authentication Protocol. RFC 2284
0xC229SIEP, Mitsubishi Security Info Exch Protocol. 
0xC26FStampede Bridging Authorization Protocol. 
0xC281Proprietary Authentication Protocol. 
0xC283Proprietary Authentication Protocol. 
0xC481Proprietary Node ID Authentication Protocol. 

Data. Variable length.
0 or more bytes up to the MTU of the connection.


Link Control Protocol.
A protocol used to configure the link with the remote system.

Network Control Protocol.
A protocol used to establish and configure one or more network layer protocols that will be used by the link. Protocol field values in the range of 0x8XXX to 0xBXXX identify packets belonging to the associated Network Control Protocol.

The remote end of a point-to-point link.

A type of network in which each computer has equivalent responsibilities.


[RFC 1332] The PPP Internet Protocol Control Protocol (IPCP).

[RFC 1377] The PPP OSI Network Layer Control Protocol (OSINLCP).

[RFC 1378] The PPP AppleTalk Control Protocol (ATCP).

[RFC 1471] The Definitions of Managed Objects for the Link Control Protocol of the Point-to-Point Protocol.

[RFC 1472] The Definitions of Managed Objects for the Security Protocols of the Point-to-Point Protocol.

[RFC 1473] The Definitions of Managed Objects for the IP Network Control Protocol of the Point-to-Point Protocol.

[RFC 1474] The Definitions of Managed Objects for the Bridge Network Control Protocol of the Point-to-Point Protocol.

[RFC 1547] Requirements for an Internet Standard Point-to-Point Protocol.

[RFC 1552] The PPP Internetwork Packet Exchange Control Protocol (IPXCP).

[RFC 1570] PPP LCP Extensions.

[RFC 1598] PPP in X.25.

[RFC 1618] PPP over ISDN.

[RFC 1661] The Point-to-Point Protocol (PPP).

[RFC 1662] PPP in HDLC-like Framing.

[RFC 1663] PPP Reliable Transmission.

[RFC 1762] The PPP DECnet Phase IV Control Protocol (DNCP).

[RFC 1763] The PPP Banyan Vines Control Protocol (BVCP).

[RFC 1764] The PPP XNS IDP Control Protocol (XNSCP).

[RFC 1812] Requirements for IP Version 4 Routers.

[RFC 1841] PPP Network Control Protocol for LAN Extension.

[RFC 1877] PPP Internet Protocol Control Protocol Extensions for Name Server Addresses.

[RFC 1915] Variance for The PPP Connection Control Protocol and The PPP Encryption Control Protocol.

[RFC 1934] Ascend's Multilink Protocol Plus (MP+).

[RFC 1962] The PPP Compression Control Protocol (CCP).

[RFC 1963] PPP Serial Data Transport Protocol (SDTP).

[RFC 1967] PPP LZS-DCP Compression Protocol (LZS-DCP).

[RFC 1968] The PPP Encryption Control Protocol (ECP).

[RFC 1973] PPP in Frame Relay.

[RFC 1974] PPP Stac LZS Compression Protocol.

[RFC 1975] PPP Magnalink Variable Resource Compression.

[RFC 1976] PPP for Data Compression in Data Circuit-Terminating Equipment (DCE).

[RFC 1977] PPP BSD Compression Protocol.

[RFC 1978] PPP Predictor Compression Protocol.

[RFC 1979] PPP Deflate Protocol.

[RFC 1989] PPP Link Quality Monitoring.

[RFC 1990] The PPP Multilink Protocol (MP).

[RFC 1993] PPP Gandalf FZA Compression Protocol.

[RFC 1994] PPP Challenge Handshake Authentication Protocol (CHAP).

[RFC 2043] The PPP SNA Control Protocol (SNACP).

[RFC 2097] The PPP NetBIOS Frames Control Protocol (NBFCP).

[RFC 2118] Microsoft Point-To-Point Compression (MPPC) Protocol.

[RFC 2125] The PPP Bandwidth Allocation Protocol (BAP) The PPP Bandwidth Allocation Control Protocol (BACP).

[RFC 2153] PPP Vendor Extensions.

[RFC 2290] Mobile-IPv4 Configuration Option for PPP IPCP.

[RFC 2363] PPP Over FUNI.

[RFC 2364] PPP Over AAL5.

[RFC 2419] The PPP DES Encryption Protocol, Version 2 (DESE-bis).

[RFC 2420] The PPP Triple-DES Encryption Protocol (3DESE).

[RFC 2433] Microsoft PPP CHAP Extensions.

[RFC 2472] IP Version 6 over PPP.

[RFC 2484] PPP LCP Internationalization Configuration Option.

[RFC 2516] A Method for Transmitting PPP Over Ethernet (PPPoE).

[RFC 2615] PPP over SONET/SDH.

[RFC 2637] Point-to-Point Tunneling Protocol (PPTP).

[RFC 2686] The Multi-Class Extension to Multi-Link PPP.

[RFC 2687] PPP in a Real-time Oriented HDLC-like Framing.

[RFC 2688] Integrated Services Mappings for Low Speed Networks.

[RFC 2759] Microsoft PPP CHAP Extensions, Version 2.

[RFC 2794] Mobile IP Network Access Identifier Extension for IPv4.

[RFC 2823] PPP over Simple Data Link (SDL) using SONET/SDH with ATM-like framing.

[RFC 3032] MPLS Label Stack Encoding.

[RFC 3078] Microsoft Point-To-Point Encryption (MPPE) Protocol.

[RFC 3153] PPP Multiplexing.

[RFC 3241] Robust Header Compression (ROHC) over PPP.

[RFC 3255] Extending Point-to-Point Protocol (PPP) over Synchronous Optical NETwork/Synchronous Digital Hierarchy (SONET/SDH) with virtual concatenation, high order and low order payloads.

[RFC 3336] PPP Over Asynchronous Transfer Mode Adaptation Layer 2 (AAL2).

[RFC 3337] Class Extensions for PPP over Asynchronous Transfer Mode Adaptation Layer 2 (AAL2).

[RFC 3544] IP Header Compression over PPP.

[RFC 3748] Extensible Authentication Protocol (EAP).

[RFC 3772] Point-to-Point Protocol (PPP) Vendor Protocol.

[RFC 3818] IANA Considerations for the Point-to-Point Protocol (PPP).


Obsolete RFCs:

[RFC 1134] The Point-to-Point Protocol: A Proposal for Multi-Protocol Transmission of Datagrams Over Point-to-Point Links.

[RFC 1171] The Point-to-Point Protocol for the Transmission of Multi-Protocol Datagrams Over Point-to-Point Links.

[RFC 1172] The Point-to-Point Protocol (PPP) Initial Configuration Options.

[RFC 1220] Point-to-Point Protocol Extensions for Bridging.

[RFC 1331] The Point-to-Point Protocol (PPP) for the Transmission of Multi-protocol Datagrams over Point-to-Point Links.

[RFC 1333] PPP Link Quality Monitoring.

[RFC 1334] PPP Authentication Protocols.

[RFC 1376] The PPP DECnet Phase IV Control Protocol (DNCP).

[RFC 1548] The Point-to-Point Protocol (PPP).

[RFC 1549] PPP in HDLC Framing.

[RFC 1619] PPP over SONET/SDH.

[RFC 1638] PPP Bridging Control Protocol (BCP).

[RFC 1716] Towards Requirements for IP Routers.

[RFC 1717] The PPP Multilink Protocol (MP).

[RFC 1969] The PPP DES Encryption Protocol (DESE).

[RFC 2023] IP Version 6 over PPP.

[RFC 2284] PPP Extensible Authentication Protocol (EAP).

[RFC 2509] IP Header Compression over PPP.

[RFC 2878] PPP Bridging Control Protocol (BCP).

Description Glossary RFCs Publications Obsolete RFCs