Most of the network communication protocols used today have a structure based on the OSI model. Though it does not exactly match the layers used in the TCP/IP stack used by all Internet Protocols, it is directly used by many other existing and new networking protocols, and it still a good teaching model, as evidanced by its appearance in the majority of networking courses. On a transmitting stack/machine each layer of the model appears to the higher layers to make direct communication with the corresponding layer on the receiving PC/Network card.
| Layer 7 | Application LayerECHO, ENRP, FTP, Gopher, HTTP, NFS, RTSP, SIP, SMTP, SNMP, SSH, Telnet, Whois, XMPP |
|---|---|
| Layer 6 | Presentation LayerXDR, ASN.1, SMB, AFP, NCP |
| Layer 5 | Session LayerASAP, TLS, SSL, ISO 8327 / CCITT X.225, RPC, NetBIOS, ASP |
| Layer 4 | Transport LayerTCP, UDP, RTP, SCTP, SPX, ATP, IL |
| Layer 3 | Network LayerIP, ICMP, IGMP, IPX, OSPF, RIP, IGRP, EIGRP, ARP, RARP, X.25 |
| Layer 2 | Data Link LayerEthernet, Token ring, HDLC, Frame relay, ISDN, ATM, 802.11 WiFi, FDDI, PPP |
| Layer 1 | Physical Layer10BASE-T, 100BASE-T, 1000BASE-T, SONET/SDH, G.709, T-carrier/E-carrier, various 802.11 physical layers |