MPLS is a highly scalable, protocol agnostic, data-carrying mechanism in high-performance telecommunications networks which directs and carries data from one network node to the next. It belongs to the family of packet-switched networks and here data is transferred in the form of ‘Packets’ and the data packets are assigned a label and the content of the label alone influences packet forwarding decisions and there is no need to examine the packets.
For transmission of data a wide variety of physical hardware is used including fibre, copper circuits, wireless connectivity and many more. The MPLS core service provider network also use high capacity MPLS routers in addition to the MPLS edge routers which send and receive data from the routers located in the individual locations.
A virtual private network (VPN) links two or more computers through an underlying local or wide-area network, while encapsulating the data and keeping it private.
MPLS VPN is a family of methods for harnessing the power of MPLS to create VPNs. MPLS VPN can act as common platform from which a wide range of services such as multimedia, VoIP, videoconferencing, multicast, ERP and access VPN can be offered.
It is said that the MPLS mechanism was designed to allow users to create end-to-end circuits across any type of transport medium using any technology. This technique is supposed to reduce the dependence on Data-Link Layer technology in particular such as ATM, frame relay, SONET or Ethernet. Companies normally have relied on Frame Relay or E1 dedicated links to deploy a wide area network (WAN). Also most VPNs have been provisioned using Layer 2 technologies, such as Frame Relay and asynchronous transfer mode (ATM).
But Frame Relay, ATM and E1 dedicated links are very expensive and are very complex to manage. With MPLS VPN, companies that want to connect its geographically different sites need not have to buy a Frame Relay circuit, or purchase an ATM circuit, or lease a dedicated line. MPLS VPN is a low-cost, highly secure and highly reliable enterprise networking alternative to layer 2 technologies and it allows companies to enhance their operational efficiency and business activity.
As it is installed on an optical fibre backbone, the MPLS VPN network is safe and offers more bandwidth which only makes it more scalable. It allows dynamic bandwidth allocation using which bandwidth can be divided among demanding users and mission critical applications. In Ethernet networks if more users hog the line for resources it will slow down the network or even bring it down.
VPNs that run Internet Protocol (IP) on it are termed as IP VPNs and MPLS IP VPN is a high quality high performance IP VPN. MPLS also offers a cost-effective way for businesses to interconnect multiple sites – new sites can be added and old ones can be removed instantaneously.
Data travels as IP packets in MPLS IP VPN networks and each packet is assigned a unique label and this assignment is done at the incoming port of customer, by physical port identity. There is no chance that one port’s packet to traverse into another port and even if it does it cannot be accessed from there. Security is achieved using data plane and control plane approach. The data plane prevents packets from crisscrossing into boundaries and the control plane security ensures that non-trusted peers cannot inject routes into the MPLS VPN for diverting the packets.
In an MPLS network there are provisions for pro-active monitoring and maintenance which guarantees a minimum downtime. It is also possible to analyse circuit performance continuously and provide immediate fault rectification and support.
Since MPLS provides protocol independent forwarding, MPLS VPN’s can be implemented utilising varying customer edge equipment allowing the customers to leverage their existing investments while benefiting from the advantages of MPLS. This significantly removes the need for any additional investments in infrastructure.
While traversing on a network there is a greater possibility that data is lost so finding an optimal path for data traversal is a vital concern for businesses. MPLS has the ability to store a secondary path through the network. If the main path is inaccessible, MPLS can reroute traffic to a backup path. Even if the backup path goes down another alternative path can be drawn manually. If the MPLS VPN is built with IPSec protocol there is no need for manual defining as the protocol automatically detects path failures and reroutes data around them.
In order to run apps like VoIP networks need to ensure Quality of Service (QoS) because apps like VoIP are intolerant to latency and other irregularities. A major advantage of MPLS is its QoS capabilities – it guarantees bandwidth between the user’s site and the service provider network.
MPLS helps users implement a network on a public infrastructure such as the internet and this is one of the main causes of security concern among users. Also, MPLS VPN’s do not enable encryption of data on their own but by integrating IPSec technology into the MPLS VPN its security and encryption capability can be greatly enhanced allaying users’ concerns. MPLS may be impractical for a very large extranet but with IPSec it is possible to extend the reach of MPLS and establish the connectivity that a modern organization requires.
MPLS is a rapidly expanding technology that provides a number of advantages to its users such as scalability, security, redundancy and QoS. Though there are certain limitations they can easily be overcome with strong industry support and the ability to use MPLS over any transport technology from frame relay to fibre and service providers can employ integrated networks to offer organisations of all sizes cost-effective, secure VPN solutions.