MPLS Networking – Ask a Communications Expert

What is MPLS?

MPLS (Multi-protocol Label Switching) is a sophisticated Internet protocol (IP) networking technology that quickly and easily routes traffic to its intended destination. By creating a Virtual Private Network (VPN) over a private network (not the public Internet), the technology allows for a level of control and traffic prioritization beyond that of traditional wide area network (WAN) technologies, and helps businesses handle increasing bandwidth demands like interoffice voice and video traffic and advanced applications like SAP and Citrix.

How can MPLS benefit your business?

Simply put, MPLS allows you to put all sorts of data on your network and prioritize how and where it is delivered. For instance, Voice traffic gets routed faster and to all locations while Internet traffic goes slower and only to some locations. MPLS lets you converge all of your organization’s voice, video, and data applications over a single network, typically yielding lower overall communication costs.

MPLS also allows you to save money when bandwidth is limited. You’ll be able to prioritize network traffic and control quality of service, rather than buying more bandwidth for supporting existing and emerging applications.

Finally, MPLS can be easier to deploy and manage than previous generation network solutions like frame relay. MPLS is a fully meshed architecture allowing any location to communicate to any location on the MPLS network.

How does MPLS work?

The key to the advanced functionality of MPLS is that the IP packets are encapsulated with labels by the first MPLS device they encounter as they enter the network. The MPLS edge router analyzes the contents of the data and selects an appropriate label with which to encapsulate the packet. This analysis can be based on more than just the destination address carried in the IP header and allows “Class of Service” (CoS) and “Quality of Service” (QoS) bits to be set in the label. Subsequent routing decisions are made based on the label and not the original IP address, allowing core network routers to operate at higher speeds without having to examine each packet in detail. "Quality of Service" (QoS) enables enhanced prioritization of different traffic types, like voice, video, internal data applications, and Internet. Finally, as MPLS-labeled packets leave the network, another edge router removes the labels.

If you liken MPLS to a shipping company like UPS or FedEx, you have a comparative example:

Imagine you have three packages to ship out to one of your offices: One package, we will call it “Voice”, has to be delivered as soon as possible. Your second box, called “E-mail”, needs next-day delivery. The last delivery, named “Files”, that can be delivered sometime over the next few days.

You take your packages to your shipper. They put unique labels on each box – “Voice” gets Priority, “E-mail” gets Next-day Delivery, and “Files” gets Ground Shipping. The shipping company puts each package on a different truck based on their label. The priority “Voice” package gets the fastest truck heading directly to the target office. The next-day “E-mail” box gets sent on a truck that needs to make a stop along the way, and lastly the ground “Files” package is on a truck that will be going to several towns first, but will get to the target office over the next few days.

Once each of these packages arrive at the target office, the delivery person pulls off the shipping label to confirm delivery, and your office gets the packages in the priority you requested.

Overall, MPLS could let your business:

- Eliminate redundant costs required to support separate networks and connections

- Take advantage of centralized, simplified network administration and management

- Improve collaboration and security between multiple sites

- Create a network architecture that is inherently disaster-recovery ready

As an economical and flexible alternative to legacy WAN technologies, organizations that adopt an MPLS solution today will not only be ahead of the curve financially, but also be strategically positioned to embrace growth and implement business applications of the future.