| PPP (Point-to-Point Protocol) |
A protocol for establishing direct connections between two network nodes over serial links. |
Used in dial-up connections, VPNs, and some broadband connections. |
| HDLC (High-Level Data Link Control) |
A bit-oriented protocol for point-to-point and multipoint communication with framing and error detection. |
Used in telecommunications and WANs for leased lines and satellite links. |
| MAC (Media Access Control) |
A sub-layer of the Data Link Layer managing access to shared media and defining MAC addresses. |
Essential in Ethernet, Wi-Fi, and other network technologies for addressing and managing medium access. |
| SCTP (Stream Control Transmission Protocol) |
A message-oriented, connection-oriented protocol for reliable, ordered data delivery with multi-homing and multi-streaming. |
Used in telecommunication networks, WebRTC, and for signaling in cellular networks. |
| ATM (Asynchronous Transfer Mode) |
A data link protocol that encapsulates data into fixed-size cells, offering efficient data transmission in LANs and WANs. |
Used in high-speed telecommunications networks and some legacy WANs. |
| Frame Relay |
A data link protocol for transmitting data over WANs using frames, offering lower overhead compared to traditional telephony services. |
Common in legacy WANs to support IP, IPX, and other network protocols over virtual circuits. |
| MPLS (Multiprotocol Label Switching) |
A protocol that routes data based on labels, allowing for efficient traffic engineering across large-scale networks. |
Used by service providers for VPNs, traffic management, and large-scale enterprise networks. |
| Bluetooth |
A short-range wireless protocol for data exchange between devices like phones, headsets, and computers. |
Used in personal area networks (PANs) for connecting devices like headphones, keyboards, and smartphones. |
| ARP (Address Resolution Protocol) |
Resolves IP addresses to MAC addresses for local network communication. |
Used in Ethernet networks for mapping IP addresses to MAC addresses. |
| LACP (Link Aggregation Control Protocol) |
Combines multiple physical links into one logical link for higher bandwidth and redundancy. |
Common in network switches for implementing Link Aggregation (802.1AX). |
| LLDP (Link Layer Discovery Protocol) |
A vendor-neutral protocol used by network devices to advertise their identity and capabilities to neighbors. |
Used for topology discovery and management in networking devices. |
| PAgP (Port Aggregation Protocol) |
Cisco proprietary protocol that automates the creation of link aggregation groups (LAGs). |
Used in Cisco networking devices to implement EtherChannel groups. |
| STP (Spanning Tree Protocol) |
Prevents network loops by dynamically choosing the best path for Ethernet frames. |
Used in bridges and switches to maintain a loop-free network topology. |
| VTP (VLAN Trunking Protocol) |
Cisco protocol for managing and propagating VLAN information across network switches. |
Used to distribute VLAN configurations in large Cisco networks. |
| LLDP-MED (Link Layer Discovery Protocol - Media Endpoint Discovery) |
An extension of LLDP that provides endpoint discovery for IP telephony and media devices, including power requirements. |
Used in VoIP and multimedia networks for managing media endpoints. |
| CDP (Cisco Discovery Protocol) |
Cisco proprietary protocol for discovering information about directly connected Cisco devices. |
Used in Cisco networks for device discovery and topology management. |
| DTP (Dynamic Trunking Protocol) |
Cisco proprietary protocol used for automatic trunking negotiation between switches. |
Used in Cisco networks to establish trunking links on Ethernet interfaces. |
| VLAN (Virtual Local Area Network) |
A protocol that segments networks into virtual subnets for isolation and better management. |
Used in LANs to reduce broadcast domains, increase security, and improve network management. |
| RTP (Real-time Transport Protocol) |
A protocol for delivering real-time data like audio and video over IP networks. |
Common in VoIP, video conferencing, and multimedia streaming applications. |
| UDP (User Datagram Protocol) |
A connectionless protocol for fast, unreliable transmission of data packets without guarantee of delivery. |
Used for real-time communication like video streaming, VoIP, and DNS. |
| TCP (Transmission Control Protocol) |
A reliable, connection-oriented protocol for data transmission, ensuring data is received in order without errors. |
Used in most internet communications, including web browsing (HTTP), email (SMTP), and file transfer (FTP). |
| DCCP (Datagram Congestion Control Protocol) |
A connectionless protocol offering congestion control for applications like multimedia streaming. |
Experimentally used in real-time communication and multimedia streaming. |
| QUIC (Quick UDP Internet Connections) |
A transport protocol built on UDP designed to reduce latency, improve performance, and provide built-in encryption. |
Used by Google services (e.g., Chrome, YouTube) for faster browsing and reduced latency with HTTP/3. |