This article lists protocols, categorized by the nearest layer in the Open Systems Interconnection model. This list is not exclusive to only the OSI protocol family. Many of these protocols are originally based on the Internet Protocol Suite (TCP/IP) and other models and they often do not fit neatly into OSI layers.

OSI model by layer
7. Application layer NNTP SIP SSI DNS FTP Gopher HTTP (HTTP/3) NFS NTP SMPP SSH SMTP SNMP Telnet DHCP NETCONF more....
6. Presentation layer MIME XDR ASN.1 ASCII TLS PGP
5. Session layer Named pipe NetBIOS SAP PPTP RTP SOCKS X.225^[1]
4. Transport layer TCP UDP SCTP DCCP QUIC SPX
3. Network layer IP IPv4 IPv6 ICMP (ICMPv6) IPsec IGMP IPX IS-IS AppleTalk X.25 PLP
2. Data link layer ATM ARP SDLC HDLC CSLIP SLIP GFP PLIP IEEE 802.2 LLC MAC L2TP IEEE 802.3 Frame Relay ITU-T G.hn DLL PPP X.25 LAPB Q.922 LAPF IEEE 802.11
1. Physical layer RS-232 RS-449 ITU-T V-Series I.430 I.431 PDH SONET/SDH PON OTN DSL IEEE 802.3 IEEE 802.11 IEEE 802.15 IEEE 802.16 IEEE 1394 ITU-T G.hn PHY USB Bluetooth
v t e

Layer 1 (physical layer)

Telephone network modems
IrDA physical layer
USB physical layer
EIA RS-232, EIA-422, EIA-423, RS-449, RS-485
Ethernet physical layer 10BASE-T, 10BASE2, 10BASE5, 100BASE-TX, 100BASE-FX, 1000BASE-T, 1000BASE-SX and other varieties
Varieties of 802.11 Wi-Fi physical layers
DSL
ISDN
T1 and other T-carrier links, and E1 and other E-carrier links
ITU Recommendations: see ITU-T
IEEE 1394 interfaces
TransferJet
Etherloop
ARINC 818 Avionics Digital Video Bus
G.hn/G.9960 physical layer
CAN bus (controller area network) physical layer
Mobile Industry Processor Interface physical layer
Infrared
Frame Relay
FO Fiber optics
X.25

Layer 2 (data link layer)

ARCnet Attached Resource Computer NETwork
ARP Address Resolution Protocol
ATM Asynchronous Transfer Mode
CHAP Challenge Handshake Authentication Protocol
CDP Cisco Discovery Protocol
DCAP Data Link Switching Client Access Protocol
Distributed Multi-Link Trunking
Distributed Split Multi-Link Trunking
DTP Dynamic Trunking Protocol
Econet
Ethernet
FDDI Fiber Distributed Data Interface
Frame Relay
ITU-T G.hn
HDLC High-Level Data Link Control
IEEE 802.11 WiFi
IEEE 802.16 WiMAX
LACP Link Aggregation Control Protocol
LattisNet
LocalTalk
L2F Layer 2 Forwarding Protocol
L2TP Layer 2 Tunneling Protocol
LLDP Link Layer Discovery Protocol
LLDP-MED Link Layer Discovery Protocol - Media Endpoint Discovery
MAC Media Access Control
Q.710 Simplified Message Transfer Part
Multi-link trunking Protocol
NDP Neighbor Discovery Protocol
PAgP - Cisco Systems proprietary link aggregation protocol
PPP Point-to-Point Protocol
PPTP Point-to-Point Tunneling Protocol
PAP Password Authentication Protocol
RPR IEEE 802.17 Resilient Packet Ring
SLIP Serial Line Internet Protocol (obsolete)
StarLAN
Space Data Link Protocol, one of the norms for Space Data Link from the Consultative Committee for Space Data Systems
STP Spanning Tree Protocol
Split multi-link trunking Protocol
Token Ring a protocol developed by IBM; the name can also be used to describe the token passing ring logical topology that it popularized.
Virtual Extended Network (VEN) a protocol developed by iQuila.
VTP VLAN Trunking Protocol
VLAN Virtual Local Area Network

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).

TLS Transport Layer Security^[2]
SSL Secure Socket Tunneling^[2]
AFP Apple Filing Protocol^[2]
Independent Computing Architecture (ICA), the Citrix system core protocol
Lightweight Presentation Protocol (LPP)^[2]
NetWare Core Protocol (NCP)
Network Data Representation (NDR)^[2]
Tox, The Tox protocol is sometimes regarded as part of both the presentation and application layer
eXternal Data Representation (XDR)^[2]
X.25 Packet Assembler/Disassembler Protocol (PAD)