PPP over Ethernet
From Encyclopedia of Cybersecurity
PPP over Ethernet (PPPoE)
PPP over Ethernet (PPPoE) is a network protocol used to establish a point-to-point connection over Ethernet networks. It enables the encapsulation of Point-to-Point Protocol (PPP) frames within Ethernet frames, allowing the transmission of PPP packets over Ethernet-based networks, such as DSL, cable modem, and fiber-optic broadband connections.
Operation
PPPoE operates by establishing a session between a client device and an Internet Service Provider (ISP) through a broadband modem or router. The PPPoE session involves the following steps:
- Discovery: The client sends a PPPoE discovery packet to the ISP's PPPoE access concentrator (often called a "PPPoE server"), requesting to establish a PPPoE session.
- Session Establishment: Upon receiving the discovery packet, the PPPoE server responds with a PPPoE session confirmation, assigning a unique session ID to the client.
- Authentication: The client and server authenticate each other using various authentication methods, such as Password Authentication Protocol (PAP) or Challenge Handshake Authentication Protocol (CHAP).
- Data Transfer: Once the session is established and authenticated, PPP frames encapsulated within Ethernet frames are exchanged between the client and server, allowing for the transmission of PPP packets over the Ethernet network.
Features
PPPoE provides several features that make it suitable for broadband Internet access:
- Broadband Access: PPPoE is commonly used by ISPs to provide broadband Internet access to residential and small business users over DSL, cable modem, and fiber-optic connections.
- Authentication and Encryption: PPPoE supports various authentication methods, allowing ISPs to authenticate subscribers before granting access to the network. It also supports encryption through the use of PPP's built-in encryption protocols.
- Dynamic IP Address Assignment: PPPoE allows ISPs to dynamically assign IP addresses to client devices using PPP's Network Control Protocol (NCP), simplifying IP address management.
Advantages
- Broadband Compatibility: PPPoE is widely supported by ISPs and networking equipment, making it compatible with various broadband technologies.
- Security: PPPoE provides built-in authentication and encryption mechanisms, enhancing the security of broadband connections.
Disadvantages
- Overhead: PPPoE introduces additional overhead due to the encapsulation of PPP frames within Ethernet frames, potentially reducing network throughput.
- Configuration Complexity: Configuring PPPoE connections on client devices may require additional setup compared to other broadband connection methods.
See Also
- Point-to-Point Protocol (PPP)
- Ethernet Protocol
- Digital Subscriber Line (DSL)
- Cable Modem
- Broadband Internet
