The MPLS technology was developed to implement the association of privacy and QoS with the flexibility and scalability of the IP.
In contrast to the protocols aimed at point-to-point connection or linkages, this protocol is characterised by being a connectionless protocol - allowing full mesh connectivity (all sites with all VPN sites).
The traffic is not transported through the network using the traditional IP forwarding mechanisms, but is entirely supported through the identification of the path (interface) to the destination from an existing label in the level 2 transmission frame delivered to the router.
The isolation of traffic is similar to that obtained in solutions based on the establishment of logical circuits (ATM or Frame Relay). When IP traffic with a particular destination and associated to a particular VPN is identified by labels, it becomes unequivocal for each VPN.
The commutation capacity is also faster in network nodes, since the use of labels attached to the headers of the IP packages allows the traffic to be forwarded to its destination at each network node (Router or MPLS Commutator) without the processing of level 3 information being necessary. |
