Encapsulation Protocols

These protocols play key roles in network communication by encapsulating data for transmission across various network mediums and infrastructures.

Protocol

Description

Use Case

PPPoE (Point-to-Point Protocol over Ethernet)

Encapsulates PPP frames within Ethernet frames, enabling ISPs to manage individual subscriber sessions over a shared Ethernet infrastructure. PPPoE supports authentication protocols (PAP, CHAP), IP address assignment, and session management. Widely used for broadband Internet access via DSL lines.

DSL broadband subscriber management

PPP (Point-to-Point Protocol)

A data link protocol that encapsulates network layer packets for transmission over serial links. Supports authentication, compression, and encryption. Common for dial-up and VPN links.

Dial-up and VPN connections

GRE (Generic Routing Encapsulation)

Encapsulates a variety of network layer protocols over IP, enabling the creation of VPN tunnels between networks. Useful for connecting remote sites securely.

VPN tunneling and site-to-site links

MPLS (Multiprotocol Label Switching)

Uses labels to encapsulate and route packets efficiently through complex networks. Supports quality of service (QoS) and traffic engineering.

WANs and service provider networks

RFC: RFC 2516

Main Features:

  • Encapsulates PPP frames within Ethernet frames

  • Supports authentication protocols like PAP and CHAP

  • Enables per-user session identification and accounting

  • Operates on standard Ethernet (Layer 2)

  • Provides dynamic IP address assignment

  • Used by ISPs for subscriber session management

Use Cases:

  • DSL broadband subscriber authentication and management

  • Session-based IP address leasing by ISPs

  • Accounting and usage-based billing for residential internet

  • Point-to-point virtual connections over Ethernet infrastructure

Alternative Protocols:

  • IPoE (IP over Ethernet) – A simpler alternative without PPP overhead

  • L2TP – For tunneling PPP over IP networks in broadband aggregation

  • 802.1X + RADIUS – Secure enterprise authentication at Layer 2

  • DHCP + VLANs – For IP provisioning with logical segmentation

Let us learn more about PPPoE:

Jump to “PPPoE”

RFC: RFC 1661

Main Features:

  • Encapsulates Layer 3 protocols over point-to-point links

  • Supports authentication (PAP, CHAP)

  • Includes error detection and framing

  • Optional compression and encryption

  • Multi-protocol support (e.g., IP, IPX, AppleTalk)

  • Link negotiation and teardown mechanisms

Use Cases:

  • Dial-up modem internet access

  • Point-to-point leased lines (ISDN, serial links)

  • Tunneling PPP over IP networks (e.g., PPP over L2TP)

  • Remote user VPN and secure access

Alternative Protocols:

  • HDLC – Simpler point-to-point encapsulation

  • SLIP – Outdated protocol replaced by PPP

  • L2TP – Encapsulates PPP for tunneling

  • Ethernet – For LAN and broadband access

Let us learn more about PPP:

Jump to “PPP”

RFC: RFC 2784, RFC 2890

Main Features:

  • Encapsulates any Layer 3 protocol over IP

  • Adds GRE and IP headers to original packet

  • Stateless and simple configuration

  • Optional support for keys and sequence numbers

  • Transports multicast, IPv6, or non-IP traffic over IPv4

  • Creates virtual point-to-point tunnels

Use Cases:

  • Site-to-site VPN tunneling

  • Connecting remote networks across the Internet

  • Carrying multicast across incompatible networks

  • Overlay networking in hybrid cloud setups

Alternative Protocols:

  • IPsec Tunnel Mode – Adds encryption and authentication

  • L2TP – Provides Layer 2 tunneling with PPP support

  • VXLAN – For encapsulating Layer 2 over Layer 3 in data centers

  • WireGuard / OpenVPN – Secure alternatives for tunneling

Let us learn more about GRE:

Jump to “GRE”

RFC: RFC 3031

Main Features:

  • Forwards packets based on short labels, not IP headers

  • Sits between Layer 2 and Layer 3 (Layer 2.5)

  • Supports QoS, traffic engineering, and VPN services

  • Efficient for large-scale networks with fast failover

  • Works with IP, Ethernet, ATM, Frame Relay backbones

  • Label-Switched Paths (LSPs) simplify routing logic

Use Cases:

  • ISP and enterprise core networks

  • Layer 3 VPNs for enterprise interconnection

  • QoS-sensitive services like VoIP and video

  • Highly available, low-latency paths with redundancy

Alternative Protocols:

  • SD-WAN – Internet-based alternative to MPLS

  • Segment Routing (SR-MPLS/SRv6) – Simpler MPLS evolution

  • IP Routing + DiffServ – For policy-driven routing

  • VXLAN + EVPN – For modern data center overlay networks

Let us learn more about MPLS:

Jump to “MPLS”