What is MPLS?

Before going in a discussion that what is MPLS? The question is why we need MPLS?



  • We are in need of a single infrastructure that supports multitude of applications in a secure manner.
  • Provide a highly scalable mechanism that was topology driven rather than flow driven.
  • Load balance traffic to utilize network bandwidth efficiently.
  • Allow core routers / networking devices to switch packets based on some simplified header.
  • Leverage hardware so that simple forwarding paradigm can be used.

Economical solutions to support multitude of applications

  • Eliminating redundant / dedicated access links
  • Save on per distance WAN link costs
  • Collapsing separate networks into a single converged infrastructure
  • Consolidate service resources, host some services and off-load other to the providers

Scalable Segmentation Solution that supports secured Network Infrastructure 

  • VPNs by organizations, sub-organizations, departments, critical application, legacy protocols, data center replications, guest Internet access, secure partner/vendor access or to meet government mandated guidelines (HIPPA, SOX), IT Services

Bandwidth Management

  • Unequal cost load balancing, Network Protection and faster Restoration, virtual Leased Lines for special applications

Simplified Networking

  • Simplify WAN provisioning, management, troubleshooting by means of simplify edge meshing/routing, IP addressing etc.
  • Need to manage a single access at the headend site, rather than, say, 100 circuits for 100 remote sites.

Moving Beyond Connectivity

  • Supports traditional and emerging IP services over a single infrastructure

What is MPLS?

First of all we must be clear in our concepts about MPLS is that MPLS is a technique. It’s not a service.MPLS services can be used to deliver anything whether it’s IPv4 VPNs, Metro Ethernet Services, or to provision optical services.

Basically it is based on the concept of Label Switching as its name states that. MPLS: MP stands for “Multi-Protocol” and LS stands for “Label Switching”

We’ll discuss on Label Switching later in this section.

For now below are some Characteristics of MPLS:

  • Multi-Protocol Label Switching is a technology for delivery of IP services
  • MPLS technology switches packets (IP packets, AAL5 frames) instead of routing packets to transport the data.
  • MPLS packets can run on other layer 2 technologies such as ATM, Frame Relay (FR), PPP, POS, and Ethernet.

    What is MPLS

  • Other layer 2 technologies can be run over an MPLS network.

MPLS Components

Few components play role in creating MPLS network:

  • IGP: Core Routing Protocol
  • MPLS Label
  • Encapsulation of MPLS Label
  • Forwarding Equivalence Class
  • Label Distribution Protocol
  • MPLS Application related protocols: MP-BGP, RSVP… etc.