WAN Computer Network Connections

Computer networks are often categorized as LAN, MAN and WAN. The LAN is your local network. You design and maintain it to meet your specifications. Or, you hire a contractor to do this. When you need to connect your LAN to another LAN across town or around the world, you enter the realm of the MAN and WAN. Here’s a quick look at what’s available in the way of metro and long haul connections.

The difference between the MAN and the WAN is largely a matter of degree. The MAN is a Metropolitan Area Network. As the name suggests, MAN services are limited to a particular city or city and suburbs. It’s the right connectivity for companies that have multiple offices in the same city, a main facility and a remote data center across town, a factory or warehouse in an industrial park plus some satellite offices. Hospitals and their associated medical centers are good candidates for MAN service, especially higher bandwidths for medical image transmission.

A difference between the LAN and MAN is that you own your LAN and buy services from the MAN. A Metropolitan Area Network is typically privately owned and offers services to numerous clients. The network operator manages bandwidth and security to ensure that every customer feels like they have the network all to themselves.

Most MANs are organized as SONET rings that encircle the metropolitan area. A SONET ring is actually two fibers with the same traffic running in opposite directions. One is the primary service and the other is the backup. This is done to ensure reliability. If one fiber or its associated equipment experiences a failure, service is automatically switched to the other fiber in the ring within 50 milliseconds. SONET has designated service levels at OC-3 (155 Mbps), OC-12 (622 Mbps), OC-24 (1.24 Gbps), OC-48 (2.49 Gbps), OC-192 (9.95 Gbps) or OC-768 (39.8 Gbps). You may also be able to get DS3 service multiplexed onto an OC-3 service for transport across town.

Newer metro networks may offer Carrier Ethernet instead of SONET. Ethernet is highly scalable from as low as 1 Mbps on up through 10 Gigabit Ethernet. Popular MAN service levels are 10 Mbps, 100 Mbps, and 1,000 Mbps or GigE. An advantage of Ethernet is that changes in service level can be accomplished faster than with traditional SONET. You can also get layer 2 Ethernet connectivity, such as E-Line and E-LAN, to connect your LANs at other locations into one large bridged network. The MAN itself may have an IP core or be running as Ethernet over SONET to use existing facilities.

Think of the WAN as a very large MAN and you probably won’t be far off. WAN networks may also have SONET rings or IP core networks. They are certainly fiber optic based and often with so many strands that you can lease wavelengths or even dark fibers. Many WAN networks are structured as MPLS or Multi-Protocol Label Switching networks for flexibility. A MPLS network has inherent security due to a propriety routing technology that is not IP. MPLS networks can transport any protocol by encapsulating the packets within the switching labels.

WAN networks may have a regional, national or international footprint. Some are designed with low latency paths that are especially important for financial trading. WAN networks may also peer with other networks of similar size to share traffic. The newest wrinkle is the Ethernet Exchange that exchanges Ethernet traffic without having to first convert it to SONET.

How do you connect to a WAN network? Often you can pick the connection that is both readily available and lowest in cost for your particular application. These range from T1 lines to Ethernet over Copper, Ethernet over Fiber, and SONET last mile connections. In some cases, fixed wireless access is also available. The mix of copper, fiber and wireless access should accommodate just about any need.

Do you have a need to connect your LAN to another facility across town, or to locations in other states or countries? Compare prices and availability of various MAN and WAN connectivity options to meet your requirements.

Managed Hosting in Clouds and Colos

When it comes to hosting, you have all sorts of options. Most individuals and smaller companies opt for shared hosting. It provides decent performance at a rock bottom price. Once you get too big for shared Web hosting, you’ve got a decision to make. Do you do it yourself or opt for a managed solution?

There was a time when you needed the savvy to run your own web server to even get a site up and running. Now that Linux and Windows hosting has become so common and standardized, there are lots of places to get hosted. Even larger companies that insisted on maintaining control by buying their own servers and rack mounting them in their own temperature controlled data centers are taking a second look at colocation and clouds. Why? It’s mostly about cost but also about resources.

One of the big resource bottlenecks today is bandwidth. Certainly, carriers have kept up with offerings at GigE, 10 GigE, OC-768, wavelengths and dark fiber. What they haven’t done is provide universal access. While competitive fiber optic networks are expanding their service footprints every day, the majority of business locations still aren’t lit and aren’t likely to be in the near future. Ethernet over Copper bridges the gap for some. Speeds are up to 200 Mbps now. EoC is distance limited, however, so that your best chance for service is in a downtown business district.

Move to a colocation facility or cloud service, however, and your bandwidth issues may be over. They may not be if you need a high bandwidth pipe between your facility and the cloud. But if most of your bandwidth demand is coming from Internet users rather than in-house users, colos and clouds look pretty attractive. Cloud providers locate with the same facility at major carriers to ensure themselves of almost unlimited bandwidth. You can do the same thing by packing up your high bandwidth demand servers and shipping them to a colo facility. The best deals are where multiple carriers have established points of presence and are willing to bid for your business.

Another attraction of colocation is jettisoning the capital investment and operating costs associated with running your own data center. The colo has high security, backup power, environmental control and a tech support staff available 24/7. You need to provide the same things. Economy of scale favors the colocation company with its much larger facility and lots of customers to amortize the cost.

Smaller companies may find that they can’t afford an around the clock tech staff nor the investment required to build or expand an in-house data center. A move to a nearby colo center can get them the facilities they need for a monthly fee. But why stop there? Perhaps it makes even more economic sense to forget about having your own hardware at all. Why not pay as you go on everything?

This is the appeal of everything-as-a-service. Hedge your bets by renting rather than buying. You can do that at many colocation centers now. They’ll put a server in the rack for you and keep it maintained. It’s just like having your own hardware except that when you don’t need it anymore, you just walk away. Need a bigger server? Don’t buy one. Simply upgrade your colo service.

The cloud does the colo one better. The cloud philosophy is “why commit to any particular hardware at all?” Why, indeed? In the cloud all services are virtualized. You don’t need to know or care what they’ve mounted in the racks. What you are concerned about is how many instances of virtualized servers you need at the moment. If you find that your demands fluctuate, you can increase or decrease the number of servers or amount of storage almost instantly. The well of resources to tap is nearly unlimited.

The problem now is how to sort out the options. Shared hosting is nearly a commodity these days. Get competitive quotes for colocation and cloud hosting services for your IT operations and then compare with what it costs you to provide the same value in-house.

Choosing Dark Fiber vs Lit Fiber Service

When your applications are demanding enough to require fiber optic transmission, you’re faced with a choice. Do you order one of the lit fiber services available for your business location or do you buy or rent dark fiber and create your own transport services?

The tradeoffs can be tricky, so you’ll probably want to set up a spreadsheet to compare the performance, cost and installation time for all the services you are interested in.

Installation time? By focusing strictly on cost, you can get caught in a situation where you’ll have the best deal possible... whenever they can get it installed. That can be weeks or even months if you have a particularly difficult situation. Will that meet your needs? If you do your planning well in advance, it just might. If circumstances conspire to demand an order of magnitude bandwidth increase immediately, availability may trump lease cost.

The dark vs lit fiber tradeoff is the classic own vs rent situation. Most companies choose to survey the marketplace for bandwidth services and pick the least cost solution that meets their needs. That process is made easy by using a telecom broker, like Telarus, Inc., that represents dozens of service providers. If you have enough competition for your business, you can get much better pricing than if you are eye to eye with the only telecom sales person for a hundred miles.

One characteristic of both dark and lit fiber services is that they are extremely location sensitive. There may well be accessible fiber running on your side of the turnpike and nothing on the other side, or vice versa. Some buildings have already been “lit” by a particular carrier while others remain dark. Those dark buildings may or may not justify the construction costs of bringing in new fiber connections depending on location and how much service is needed by the tenants.

Lit fiber falls into several major categories. The traditional telecom service is SONET/SDH with OC-3 as the lowest bandwidth of 156 Mbps. An OC-3 can also carry 3 multiplexed DS3 circuits at 45 Mbps each. It’s common for companies to order DS3 and have it delivered by fiber optic cables of much higher capacity. Other SONET levels are OC-12 at 622 Mbps, OC-24 at 1.2 Gbps, OC-48 at 2.5 Gbps and OC-192 at 10 Gbps.

The hot competition for fiber optic bandwidth is Carrier Ethernet. Ethernet tends to be both more scalable and lower cost than SONET where it is available. That availability is becoming more and more common, thanks to aggressive build-outs by competitive carriers and business demand for higher bandwidths at lower costs.

Typical fiber optic Ethernet service levels are 100 Mbps Fast Ethernet, 250 Mbps, 500 Mbps, 1 Gbps Gigabit Ethernet and 10 Gbps 10GigE. Lower bandwidth such as 50 Mbps Ethernet that competes directly with DS3 may be provisioned on either copper or fiber, depending on the carrier’s available equipment.

Coming on strong for higher bandwidth fiber optic connections is wavelength services. When you order a wavelength, you are getting a virtual fiber all to yourself. Of course, there are many wavelengths on the same physical glass fiber strand, but they differ in color and do not interact. Wavelength services may sense for 10 Gbps requirements, with the added advantages of low latency and high security. With an entire wavelength dedicated to your use, you can use a different protocol than other customers on the fiber. You may be running Ethernet while others are running SONET.

The ultimate in flexibility is dark fiber. By leasing a dark fiber run, you have all the wavelengths at your disposal. You’ll have to buy the termination equipment for each end, but then you’ll have the option to light up as few or many wavelengths as you want. You can run a different protocol on each wavelength and even operate with something non-standard or experimental. Usually it is the largest companies with the most complex IT requirements that go the dark fiber route.

What type of fiber optic service makes the most sense for your operation? Don’t jump to any conclusions until you get a complete set of prices and install times for fiber optic options available for your business location or locations.



Note: Light bulb photo courtesy of Ulfbastel on Wikimedia Commons.