Chapter 1: Introduction to MPLS-IP
Welcome to the world of Multiprotocol Label Switching with IP (MPLS-IP). This chapter introduces the fundamental concepts, history, and advantages of MPLS technology.
What is MPLS?
Multiprotocol Label Switching (MPLS) is a routing technique in telecommunications networks that directs data from one node to the next based on short path labels rather than long network addresses, thus avoiding complex lookups in a routing table and speeding traffic flows.
Key Concept
MPLS operates between the traditional Layer 2 (Data Link Layer) and Layer 3 (Network Layer) of the OSI model, making it a "Layer 2.5" protocol.
The main advantages of MPLS include:
- Traffic Engineering: Better control over traffic paths
- Quality of Service (QoS): Guaranteed service levels
- Virtual Private Networks (VPNs): Secure connectivity
- Performance: Faster forwarding decisions
History & Evolution
MPLS was developed to address the limitations of traditional IP routing and to provide better performance and services. Here's a timeline of its evolution:
| Year | Milestone | Description |
|---|---|---|
| 1996 | Tag Switching | Cisco introduced Tag Switching, the predecessor to MPLS |
| 1997 | MPLS Working Group | IETF formed the MPLS Working Group |
| 2001 | RFC 3031 | MPLS Architecture standardized |
| 2001 | RFC 3036 | Label Distribution Protocol (LDP) standardized |
| 2006 | RFC 4364 | BGP/MPLS IP Virtual Private Networks |
MPLS vs Traditional IP
Understanding the differences between MPLS and traditional IP routing is crucial for network professionals:
Traditional IP Routing
- Simple and well-understood
- Widely deployed
- Best-effort delivery
- Limited traffic engineering
- Complex QoS implementation
MPLS
- Guaranteed service levels
- Advanced traffic engineering
- Built-in VPN support
- Better performance
- More complex to implement
Key Terminology
Before diving deeper into MPLS, it's important to understand the key terms and concepts:
Label
A short, fixed-length identifier that is used to forward packets through the MPLS network.
LSR (Label Switch Router)
A router that supports MPLS forwarding and can forward packets based on labels.
LSP (Label Switched Path)
A predetermined path through the network that packets with a specific label will follow.
FEC (Forwarding Equivalence Class)
A group of IP packets that are forwarded in the same manner over the same path.
Next Steps
Now that you understand the basics of MPLS, continue to Chapter 2: MPLS Fundamentals to learn about label structure and forwarding mechanisms.