What is Multi-Protocol Label Switching, MPLS?

In order to understand MPLS (Multiprotocol Label Switching), you must first know that is not a service, but a technique. This technique is used for sending services such as IP VPNs, metro Ethernet and optical services. While carriers design MPLS backbone network, the current purchasing service companies are not called MPLS, rather than going by the name IP VPN, Metro Ethernet, or whatever the industry decides to label it at that time.

Package labeling is the main concept behind MPLS. Standard IP routed networks consist of routers each independently decide where to send the packet whenever the packet arrives at the router. The decision is entirely based on network-layer packet header.

When a packet on the network, it is combined with a specific forwarding equivalence class (FEC), which gives a short bit sequence (label) to the package. Tables for each router in the network are then used to identify how FEC packets of a specific type must be managed. Header analysis is no longer necessary once the packet enters the network. In contrast, an FEC is performed again every time you use the label from the router to index into a table.

The tables allow an MPLS network to order in a consistent way the packages based on their individual characteristics (eg, packets from certain ports or packets carrying data for some applications). While a challenging task, packets carrying real-time traffic (ie, voice and video) can be given priority over others by assigning low latency routes within the network. The important thing to remember is that the labels are used to "stick" more infomation on each packet of the router that originally had ....