What is VPLS? It’s basically an Ethernet transport service that runs on MPLS networks. It doesn’t replace the MPLS network. It enhances it.What does VPLS do that MPLS alone can’t do? The big advantage to VPLS technology is that it bridges all of your individual LANs into a single companywide LAN. That LAN isn’t limited to a single building, campus, metro area or even country. You can have international VPLS connections if your business spans the globe.
VPLS works its magic by keeping everything in the Ethernet protocol. That’s the natural state of affairs on your local networks. Traditionally, there has been a need to do a protocol conversion to transfer data over telecom networks. That’s because telecom protocols were developed by the telephone companies for their own needs. The lowest common denominator isn’t the packet, it’s the telephone channel. Today’s circuitry can make the transfer to and from telecom protocols like T1, DS3 or SONET OCx. What gets lost in translation is that seamless connection between locations.
The other thing to realize is that telecom lines are inherently point to point connections. If you are interested in connecting dozens or hundreds of locations you are going to need a lot of point to point connections. That’s a lot of traffic to manage and a lot of monthly expense. Essentially, you are running your own telecom company to create a WAN or Wide Area Network service.
Fortunately, someone else is willing to do all the hard work for you. That someone is the MPLS network operator. MPLS means Multi Protocol Label Switching. What MPLS providers do is construct their own regional, national or international fiber optic networks. They connect all those fiber runs using label switching routers. These aren’t IP routers like you would implement on your own network. What they do is take whatever packet is received at the edge of the network and wrap it with a proprietary label. That label is used to forward the packets at each router. When the packet reaches its destination, the label is removed and the packet goes on its way intact.
The label system has a couple of big of advantages. First, the network doesn’t care what is in the packet. The label contains source & destination addresses and class of service. That means the packet can be anything. It can be data, voice, video or something proprietary. Also, using the label system makes MPLS networks hard to crack for intruders. Normal IP tools won’t work. Access is limited to customers of the network, not the general public, which increases security further.
Your connections over an MPLS network are virtual as opposed to the dedicated hardwired connections of a point to point telecom line. You are sharing the network with other clients, although you have absolutely no access to any packets that are not your own. This reduces the cost for everyone sharing the network. As a privately run operation, the provider ensures that there are adequate resources so that nothing one client is doing will affect the traffic of another.
Running virtual connections on a very large network offers more than cost savings. You can specify which nodes can talk to other nodes to create everything from a point to point connection right on up to a fully meshed network interconnecting all your locations.
VPLS adds capability to the fully meshed MPLS network setup. It gives you a layer 2 switched Ethernet meshed network. This is how you get that large bridged network covering all your locations. Well, almost. You need one more thing. That’s Ethernet protocol last mile connections. If you switch to a T1 line or OC3 fiber to get you to the MPLS network, you’ll lose the Ethernet advantages. Instead, make each last mile connection using Ethernet over Copper (EoC), Ethernet over Fiber (EoF) or something like EoDS1 or EoDS3 that transport Ethernet over traditional telecom lines.
Would you learn more about the advantages of VPLS for interconnecting your company LANs? Get the latest cost savings and features for VPLS over MPLS network services.
