Multiprotocol Label Switching (Mpls)
Introduction
In computer networking and telecommunications, Multi Protocol Label Switching (MPLS) is a data-carrying mechanism that belongs to the family of packet-switched networks.
When it comes to getting network traffic from point A to point B, no single way suits every application. Voice and video applications require minimum delay variation, while mission-critical applications require hard guarantees-of-service and rerouting.
So far, only circuit-switched networks have provided the differentiated services and guarantees required by many of these applications. But a new technology called Multiprotocol Label Switching (MPLS) is changing all that. With MPLS, you can support all the above applications on an IP network without having to run large subsets of the network with completely different transport mechanisms, routing protocols, and addressing plans.
Although the standard is a work in progress, many vendors and service providers are announcing MPLS products and services. As such, now seems like a good time to learn how the technology works, how it can be deployed, and what issues still need to be addressed.
MPLS operates at an OSI Model layer that is generally considered to lie between traditional definitions of Layer 2 (data link layer) and Layer 3 (network layer), and thus is often referred to as a "Layer 2.5" protocol. It was designed to provide a unified data-carrying service for both circuit-based clients and packet-switching clients which provide a datagram service model. It can be used to carry many different kinds of traffic, including IP packets, as well as native ATM, SONET, and Ethernet frames.
MPLS was originally proposed by a group of engineers from Ipsilon Networks, but their "IP Switching" technology, which was defined only to work over ATM, did not achieve market dominance. Cisco Systems, Inc. introduced a related proposal, not restricted to ATM transmission, called "Tag Switching" when it was a Cisco proprietary
In computer networking and telecommunications, Multi Protocol Label Switching (MPLS) is a data-carrying mechanism that belongs to the family of packet-switched networks.
When it comes to getting network traffic from point A to point B, no single way suits every application. Voice and video applications require minimum delay variation, while mission-critical applications require hard guarantees-of-service and rerouting.
So far, only circuit-switched networks have provided the differentiated services and guarantees required by many of these applications. But a new technology called Multiprotocol Label Switching (MPLS) is changing all that. With MPLS, you can support all the above applications on an IP network without having to run large subsets of the network with completely different transport mechanisms, routing protocols, and addressing plans.
Although the standard is a work in progress, many vendors and service providers are announcing MPLS products and services. As such, now seems like a good time to learn how the technology works, how it can be deployed, and what issues still need to be addressed.
MPLS operates at an OSI Model layer that is generally considered to lie between traditional definitions of Layer 2 (data link layer) and Layer 3 (network layer), and thus is often referred to as a "Layer 2.5" protocol. It was designed to provide a unified data-carrying service for both circuit-based clients and packet-switching clients which provide a datagram service model. It can be used to carry many different kinds of traffic, including IP packets, as well as native ATM, SONET, and Ethernet frames.
MPLS was originally proposed by a group of engineers from Ipsilon Networks, but their "IP Switching" technology, which was defined only to work over ATM, did not achieve market dominance. Cisco Systems, Inc. introduced a related proposal, not restricted to ATM transmission, called "Tag Switching" when it was a Cisco proprietary
References: www.technopedia.com.pk www.networkcomputing.com www.miercom.com www.cisco.com www.bitpipe.com www.wikipedia.org