List of network protocols - Definition and Overview

This is a list of individual network protocols, categorised by their nearest OSI model layers.

Layer 1 protocols (physical layer)

• ISDN Integrated Services Digital Network
• PDH Plesiochronous Digital Hierarchy
  • T-carrier (T1, T3 etc)
• RS-232, a serial line interface originally developed to connect modems and computer terminals
• SDH Synchronous Digital Hierarchy
• SONET Synchronous Optical NETworking

Layer 2 protocols

• ARP Address Resolution Protocol
• Ethernet
• FDDI Fiber Distributed Data Interface
• HDLC High Level Data Link Control
• PPP Point-to-point protocol
• Token ring

Layer 2+3 protocols

• X.25
• Frame relay, a simplified version of X.25
• ATM Asynchronous Transfer Mode
• MPLS Multi-protocol label switching
• Signalling System 7, also called SS7, C7 and CCIS7; a common PSTN control protocol.

Layer 3 protocols

• ICMP Internet Control Message Protocol
• IP the Internet Protocol itself
  • IPv4 Internet Protocol version 4, the current standard
  • IPv6 Internet Protocol version 6, in the process of deployment
• IPX
• Routing protocols:
  • Routing between autonomous systems
    • Exterior Gateway Protocol (EGP) (obsolete)
    • Border Gateway Protocol (BGP)
  • Routing within a single autonomous system
    • Enhanced Interior Gateway Routing Protocol (EIGRP)
    • Interior Gateway Routing Protocol (IGRP)
    • Routing Information Protocol (RIP)
    • Open Shortest Path First (OSPF)

Layer 3+4 protocols

• Xerox network services (XNS)

Layer 4 protocols

• SPX Sequenced Packet Exchange
• TCP Transmission Control Protocol
• UDP User Datagram Protocol
• SCTP Stream Control Transmission Protocol
• RTP Real-time Transport Protocol

Layer 5+ protocols

• NFS Network File System
• SMB Server Message Block (aka CIFS Common Internet FileSystem)
• 9P Distributed file system protocol developed originally as part of Plan 9

Layer 7 protocols

• FTP File Transfer Protocol
• HTTP HyperText Transport Protocol, used in the World Wide Web
• POP3 Post Office Protocol Version 3
• SNMP Simple Network Management Protocol
• SMTP Simple Mail Transfer Protocol
• Telnet, a remote terminal access protocol
• Gnutella, a peer-to-peer file-swapping protocol
• DNS Domain Name Service
• SSH Secure SHell
• IMAP Internet Message Access Protocol
• NTP Network Time Protocol
• Gopher, a precursor of web search engines
• Finger, which gives user profile information
• NNTP News Network Transfer Protocol
• LDAP Lightweight Directory Access Protocol
• DHCP Dynamic Host Configuration Protocol
• IRC Internet Relay Chat
• Jabber, an instant-messenging protocol
• WebDAV Web Distributed Authoring and Versioning
• DICT Dictionary protocol
• BACnet Building Automation and Control Network protocol

and secure versions of the above (as HTTPS, etc.)

Protocol description languages

• Abstract syntax notation one (ASN.1)

Other protocols

• modbus
• CAN
• DCC