What Is MPLS?

MPLS VPN Questions and Answers

MPLS - is it the Future of Communications for Businesses?

MPLS and Its Role With VoIP

What Is MPLS?


MPLS (Multiprotocol Label Switching) is packet-delivery based technology that meets industry standards and is used to speed up and make easier to manage network traffic flow for superior QoS (quality of service) that, for instance, provides real-time video and sound and meets bandwidth requirements of service level agreements (SLAs).

The reason that MPLS is "multiprotocol" is due to the fact that it is compatible with the Asynchronous Transport Mode (ATM), Internet Protocol (IP), and frame relay network protocols.

With regards to the Open Systems Interconnection (OSI), MPLS allows most packets to be forwarded at the layer 2 (switching) level instead of at the layer 3 (routing) level, although MPLS rests outside the seven-layer box of OSI as forwarding mechanisms are separated from their underlying data-link services.

The MPLS network versatility is such that the technology can deliver anything from IP VPNs to Metro Ethernet services in addition to provisioning optical services.

Instead of making the router need to "decide" where to send every bit or byte of information that comes through it, MPLS overcomes possible delay and fragmentation of information flow by assigning every new packet of information in the network an FEC (forwarding equivalence class) by appending a brief "label", or bit of identifying information, to the packet.

Different FEC labels are handled differently according to a table programmed into each router in a network.

This additional information removes the need for the analysis and decision making that routers normally have to make and thus speeds up and makes more organized rapid flows of information (which increase in volume on the Internet on a daily basis). Most of the major Internet Service Providers (ISPs) have already implemented the MPLS.

MPLS makes use of two kinds of routers within a network: label edge routers (LERs) which rest on the edge of the network and do the complex packet analyses and classification calculations before the packet enters the core of the network, and the label switch routers" (LSRs) which rapidly analyze the FEC label and forward the packet in accordance with the information's instructions.

Then the edge routers on the receiving end remove the label from the packet so that only the original information gets translated as signals to a computer user.

MPLS is probably based on Cisco Systems' tag switching layer 3 technology designed for use in Wide Area Networks(WANs) required by many businesses.

About the Author

Van Theodorou will help you slash your telecom expenses over 43% and assist or even become your telecom department at no cost to you. For a free analysis or phone consultation go his site for Voice T1 Service and MPLS VPN.


A Subsidiary of Littel, Inc.