Let's take a peek inside one of those clouds and see how the magic works. The first thing you'll note is that MPLS networks are private networks. The big public network, the Internet, has a completely different structure. The Internet is designed to get massive numbers of packets from hundreds of millions of users from source to destination on a best effort basis. "Best effort" means no guarantees. You launch your packets and hope for the best. Most of the time they get where they are going in a reasonable amount of time. If not, that what the TCP part of TCP/IP is for. Send a packet enough times and it will reach its destination if at all possible.
So what's wrong with that? After all, the Internet is about the cheapest transport medium you can find for digital data. For non-critical applications it works just fine. Especially if you use a dedicated connection, such as a T1 line or Ethernet connection. Security on the Internet isn't so hot, but can be improved with encryption to create a VPN or Virtual Private Network.
MPLS networks are designed to address these limitations of Internet transport. Instead of being virtually private, they are private by design. An MPLS carrier manages the network and only for its paying customers. The public gets no entree. That improves security from the get-go. As a managed network, the carrier can ensure the performance of its network with enough bandwidth available to accommodate all customers all the time.
The technology of MPLS does the rest. The LS of MPLS stands for label switching. A packet enters the network though a label router or tag switch which adds a label field to the packet. That label defines source, destination and quality of service. Throughout the network, other label routers get the packet efficiently to its destination and make sure that it gets the priority specified. That's a huge advantage for real-time services such as VoIP telephone or live video. The Internet doesn't differentiate between packets, so if there is congestion or re-routing, you get jitter, latency and perhaps dropped packets.
Note that MPLS networks don't care about the IP data fields on the packets. They rely strictly on their own labels. That's where the MP comes in. MP stands for multi-protocol. An MPLS network doesn't care what protocol generated the packet. It could be IP, TDM or something else. They all get labels established on entry and removed on exit. So an MPLS networks can transport just about anything digital you can generate.
That's the magic, but who uses MPLS networks? The answer is anyone who needs to connect multiple locations and needs a combination of high quality and low cost. MPLS network solutions are considerably lower in cost compared to private point to point data lines and are an excellent replacement for older Frame Relay networks. Access to the network cloud is typically by a T1 line or Ethernet connection at each location. The network may span a metropolitan area or be nationwide.
If you have two or more business locations that need to be connected with a secure high performance network, see how affordable MPLS networking can be. The more locations you have, the more you'll save.
