What is P2P (Point to Point Protocol)

The Point-to-Point Protocol (PPP) is a data link protocol used to establish a direct connection between two nodes or devices over a serial interface. Originally designed for dial-up connections over telephone lines, PPP has been widely used in various networking scenarios, including broadband connections, Virtual Private Networks (VPNs), and connections between network devices.

Key features and components of PPP include:

• Authentication: PPP supports multiple methods for authenticating and verifying the identity of the connecting devices or users. Common authentication protocols used with PPP include Password Authentication Protocol (PAP), Challenge Handshake Authentication Protocol (CHAP), and Extensible Authentication Protocol (EAP).
• Encapsulation: PPP encapsulates higher-layer network protocols (such as IP) for transmission over the serial link. It uses a framing mechanism to encapsulate and transport data packets.
• Link Control Protocol (LCP): LCP is part of PPP and is responsible for establishing, configuring, maintaining, and terminating the PPP connection between devices. It negotiates various parameters, such as authentication methods, error detection, and compression.
• Network Control Protocol (NCP): NCP operates on top of LCP and is used to negotiate and manage multiple network-layer protocols, allowing different protocols (such as IP, IPv6, IPX) to be carried over the PPP connection.
• Error Detection and Handling: PPP includes mechanisms for detecting errors in data transmission, ensuring reliable communication between connected devices.

PPP has evolved over time and has several variations, such as:

• Point-to-Point Protocol over Ethernet (PPPoE): A variation of PPP designed to encapsulate PPP frames within Ethernet frames. PPPoE is commonly used by Internet Service Providers (ISPs) to establish connections for DSL and cable modem services.
• Multilink PPP (MLPPP): MLPPP allows multiple physical links to be combined into a single logical link, increasing bandwidth and providing redundancy.

PPP remains a versatile protocol used in various networking environments due to its reliability, support for multiple authentication methods, and ability to work across different types of physical media. While its usage has declined in favor of newer technologies like Ethernet and broadband connections, it still plays a role in specific networking scenarios, especially in legacy systems and some types of internet connections.