Point-to-Point Protocol over Ethernet TIPC Transparent Inter-process Communication Layer 3 (Network Layer) CLNP Connectionless Networking Protocol IPX Internetwork Packet Exchange NAT Network Address Translation Routed-SMLT SCCP Signalling Connection Control Part AppleTalk DDP HSRP Hot Standby Router protocol VRRP Virtual Router Redundancy Protocol IP Internet Protocol ICMP Internet Control Message Protocol ARP Address Resolution Protocol RIP Routing Information Protocol (v1 and v2) OSPF Open Shortest Path First (v1 and v2) IPSEC IPsec Layer 3+4 (Protocol Suites) AppleTalk DECnet IPX/SPX Internet Protocol Suite Xerox Network Systems Layer 4 (Transport Layer) AEP AppleTalk Echo Protocol AH Authentication Header over IP or IPSec DCCP Datagram Congestion Control Protocol ESP Encapsulating Security Payload over IP or IPSec FCP Fibre Channel Protocol NetBIOS NetBIOS, File Sharing and Name Resolution IL Originally developed as transport layer for 9P iSCSI Internet Small Computer System Interface NBF NetBIOS Frames protocol SCTP Stream Control Transmission Protocol Sinec H1 for telecontrol TUP, Telephone User Part SPX Sequenced Packet Exchange NBP Name Binding Protocol {for AppleTalk} TCP Transmission Control Protocol UDP User Datagram Protocol QUIC Layer 5 (Session Layer) This layer, presentation Layer and application layer are combined in TCP/IP model. 9P Distributed file system protocol developed originally as part of Plan 9 ADSP AppleTalk Data Stream Protocol ASP AppleTalk Session Protocol H.245 Call Control Protocol for Multimedia Communications iSNS Internet Storage Name Service NetBIOS, File Sharing and Name Resolution protocol - the basis of file sharing with Windows. NetBEUI, NetBIOS Enhanced User Interface NCP NetWare Core Protocol PAP Printer Access Protocol RPC Remote Procedure Call RTCP RTP Control Protocol SDP Sockets Direct Protocol SMB Server Message Block SMPP Short Message Peer-to-Peer SOCKS "SOCKetS" ZIP Zone Information Protocol {For AppleTalk} This layer provides session management capabilities between hosts. For example, if some host needs a password verification for access and if credentials are provided then for that session password verification does not happen again. This layer can assist in synchronization, dialog control and critical operation management (e.g., an online bank transaction). Layer 6 (Presentation Layer) TLS Transport Layer Security SSL Secure Socket Tunneling AFP Apple Filing Protocol Independent Computing Architecture (ICA), the Citrix system core protocol Lightweight Presentation Protocol (LPP) NetWare Core Protocol (NCP) Network Data Representation (NDR) Tox, The Tox protocol is sometimes regarded as part of both the presentation and application layer eXternal Data Representation (XDR) X.25 Packet Assembler/Disassembler Protocol (PAD) Layer 7 (Application Layer) SOAP, Simple Object Access Protocol