From LAN to MAN to WAN

We’re in something of a network revolution right now. Computer networking has deployed many different protocols for communication. Some of these have been borrowed from the telephone industry. But there’s a consolidation underway that is moving toward a single IP networking standard. From LAN to MAN to WAN, it’s all headed toward IP.

The standardization really started in the LAN or Local Area Network. Nearly all LANs are now constructed using Ethernet network interfaces? It’s not that other network architectures don’t have merit. It’s simply economy of scale. Perhaps the PC, more than anything else, helped to settle the issue with 10/100 Mbps NICs (Network Interface Cards) being included as standard equipment. Today’s faster machines offer 10/100/1000 interfaces with RJ-45 as the standard connector. If you want anything else, you have to pay extra.

This economy of scale encompasses not only desktop computers, but laptops, network switches, routers, servers, cabling and various appliances. The higher the volume produced, the cheaper each interface circuit becomes. Until something very much better comes along, Ethernet is the low cost solution.

The situation has been quite different beyond the company premises. The telephone industry has about a 100 year lead on the computer industry. If you’ve wanted to connect two business locations together or join the Internet, you had to convert your Ethernet protocol to something the telephone system could understand. Remember dial-up modems? Today’s equivalent is the T1 line. It’s all digital and offers rock solid 1.5 Mbps connectivity, but it’s a telco standard service.

The LAN to MAN or WAN connection is most often made with an interface called a CSU/DSU. This can be a stand alone box or a card that plugs in an edge router. It provides the protocol and signal level conversion between Ethernet on the LAN and T1 line connecting through the central office.

More recently, the T1 connection and faster speed DS3 and OCx services have been challenged by the rise of Metro Ethernet services. With MetroE, you connect directly from your Ethernet LAN to an Ethernet MAN and back again at other locations around town. Since this is a Level 2 switched service, it’s like having a way to expand your LAN over a much larger area to include other offices, a factory, warehouses, and an offsite data center.

Metro Ethernet melds LAN and MAN with one common service protocol. But what about the WAN or wide area needs? WANs often encompass regional areas of the country or even the entire US. Very large WANs include locations around the world. These, too, can now be joined by Ethernet through MPLS networks. While MPLS has an IP core, it uses its own tag switching system instead of IP routing while on the network. But being a multi-protocol system, it can easily transport Ethernet. Some larger providers have national and international service footprints, making it easier than ever to connect from LAN to MAN to WAN.

Are you interested in maximizing the efficiency of your metropolitan and wide area network services while minimizing your costs? You should get a quick quote on MAN & WAN Network Bandwidth to see how much you could be saving.