

Multi-Protocol label switching is a different way of routing data packets. It is unique from standard routing-in that it will allow a diverse list of connectivity means using various protocols, and its basic nature is that it is a mesh network, but not a broadcast domain, which means that it provides “any-to-any” connectivity.
Suitable for companies that require high bandwidth between a small number of sites.
Layer 2 point to point is a cost effective and flexible alternative to high bandwidth leased lines. Many wholesale network operators have based their core network infrastructure on Ethernet and use Layer 2. This type of transport is protocol agnostic and allows anything running over the LAN to be sent over the WAN without having to use routers to convert packets up to Layer 3, the network layer.
Particularly suitable for large multi-site enterprise, i.e. retail chains, which deploy a large number of low bandwidth sites or large corporates with global offices, this type of service is a natural progression away from legacy Frame Relay and ATM services.
Virtual Private LAN services are growing in popularity for delivering Ethernet services. They combine MPLS and Ethernet allowing both customers and carriers to benefit. For over two decades, Ethernet switching has dominated the local area network while IP routing has dominated the carrier network. IP backbones have been used to provide Internet access and more recently to provide IP VPN access. Corporate VPN services have been typically provided with existing TDM, ATM and Frame Relay Networks.(Resource: vpls.org executive overview).
Frame Relay, until recently, was a networking technology that was the primary service for Wide Area Networks. Relies on the underlying assumption by carriers that not all customers will be using the full bandwidth of their circuits at the same time.
AT&T was by far the largest Frame Relay provider, with an installed base estimated at $6 billion per annum. This number has decreased as customers have adopted newer and more cost effective MPLS networks.
Multi-protocol label switching (MPLS) was initiated in order to bridge protocols like Frame Relay, Ethernet, and ATM. MPLS has increasingly become the most widely used internet technology with more providers choosing this service each year.
Carriers have opted to deploy MPLS/IP core routers to better support legacy networks in a more cost effective way. MPLS utilizes an encapsulation method that provides Internet across different devices and technologies.