Wavelength Services vs Dark Fiber

Fiber optic services are popular for high bandwidth metro and long haul connections. They typically start about 100 Mbps and go on up to 10 Gbps, 40 Gbps and occasionally 100 Gbps bandwidths. But what if you find that fiber optic bandwidth services are too restrictive for your needs? There are a couple of alternatives. One is leasing dark fiber routes and the other is wavelength services. Let’s see how they compare and why you might find one more attractive than the other.

Fiber optic bandwidth services are standardized, packaged services that offer either SONET or Ethernet connectivity from point to point. You may think of them as private line services, but chances are that you are not the only customer riding on the fiber strand. At lower bandwidths, such as OC3, you are probably being electrically multiplexed with other users to create a much larger bandwidth signal that is more cost effective to transport. If you are using a 10 Gbps or 40 Gbps service, you are still sharing the strand with other users but optically multiplexed using wavelengths.

One problem with these pre-packaged fiber optic services is that they generally limit you to a particular protocol and speed. If you change your mind, it can be time consuming and costly to change or upgrade your service. For this reason, some companies have decided to become their own bandwidth providers by leasing dark fiber and lighting it up with equipment they own. This gives you the ability to have multiple protocols running on the same fiber at whatever bandwidth makes sense. When you want something different, your own engineering staff reconfigures or changes out the equipment one each end. There’s no waiting around for carrier personnel because you are the carrier. The dark fiber is just an empty pipe, as the name implies.

The trick to having multiple protocols on one fiber is called WDM or Wavelength Division Multiplexing. It’s somewhat akin to the idea of electrical multiplexing in that many different signals can share the same transport mechanism. However, technically it is quite different. WDM uses multiple wavelengths or colors of laser light that are separate enough in frequency to be distinct. All of these colors, also called lambdas, exist in the infrared portion of the light spectrum that is seen as nearly transparent through glass fiber.

Think of WDM as shining a whole rainbow of laser beams down a fiber optic cable where they are detected separately at the other end. Each beam is independent of the others. One color doesn’t care that it is running Ethernet and the next color up is carrying SONET or ESCON. They don’t see each other and don’t interfere.

Since WDM is an established technology running on just about all carrier fiber optic networks, there is no reason why you can’t just lease an entire wavelength instead of a service running on that wavelength. That’s fairly easy to do these days because many networks have excess wavelength capacity available. You can have your own wavelength running a high bandwidth Ethernet service (10 GigE) or 10 Gbps or 40 Gbps SONET.

Why lease a wavelength instead of dark fiber? For one thing, you may not need the entire capacity of the fiber or all those wavelengths you can create yourself. There’s considerable capital cost in purchasing the WDM systems for each end of the fiber that you can avoid by just leasing the wavelengths you need by the month. Capital expense and network management then become the service provider’s problem.

Dark fiber may not be available for the entire route you have in mind or you may be planning to install your own fiber in a particular area. Until it is ready, you can make good use of existing capability by leasing wavelength services as long as needed.

Dark fiber, wavelength services, Gigabit Ethernet or OCx SONET. Which is right for your needs? Get comparative pricing and availability of fiber optic services now to do a good trade off analysis.



Note: Photo courtesy of Sandia National Labratories.

New Data Center Networking Solutions

Data management and storage requirements for enterprise level organizations continue to increase. In addition, a majority of enterprise IT departments now replicate data between data centers. This has created a need for new and more cost effective bandwidth services, especially at 10 Gbps and above. Level 3 is addressing these needs with an enhancement of its existing data center networking solutions.

What’s different about data center connectivity compared to other business requirements? Data centers are far more concentrated than other computing resources. This is especially true for storage, a prime driver for offsite data centers in the first place. What this does is increase the need for high bandwidth connections between the concentration of storage and the concentration of users. It also influences the connectivity required.

What you need for last mile connections to an MPLS network or private lines to link business locations can usually be handled by T-Carrier, SONET/SDH or Carrier Ethernet line services. Data centers need higher bandwidth connections, but may also need special SAN protocols including Fibre Channel, Infiniband, ESCON and FICON.

SAN stands for Storage Area Networks. These are large collections of disk drives that connect directly to the application servers. SAN networks have traditionally been very localized, with the disk arrays physically near the servers. But what do you do when you need to duplicate data between data centers?

Many companies operate two or more data centers, sometimes a half-dozen or more. Some of this is due to mergers and acquisitions of formerly independent organizations with their own IT infrastructures. Much is driven by a need for disaster protection and recovery. When your business is critically dependent on its electronic data, normal backup processes aren’t adequate. You can have multiple copies of your files locked up locally and still be put out of business by a fire, tornado, flood, earthquake, hurricane or other disaster that destroys whole buildings and everything in them.

This means that you want to have copies of your critical data dispersed geographically. Establishing independent data centers in two or more cities far apart means than a disaster that takes out one center probably won’t knock out everything. There’s also an advantage to content providers in having the servers and data content located close to the customers. Latency is reduced and performance is increased due to less network congestion. A challenge is how to make sure the data is replicated exactly at all locations.

This is where long distance SAN networking comes into play. You need high levels of bandwidth but also support for SAN protocols to keep everything synchronized. FCoE or Fiber Channel over Ethernet is a popular protocol for transmitting Fibre Channel frames over 10 Gbps Ethernet connections. WDM or Wavelength Division Multiplexing avoids having to layer protocols to connect facilities. Each wavelength in a fiber optic link can be assigned its own protocol, regardless of what is running on other wavelengths in the same beam.

Level 3 Communications has expanded its data center networking portfolio to include SAN fiber channel protocol, dark fiber and managed fiber solutions. This is in addition to dedicated bandwidth services from 1 Gbps to more than 40 Gbps, including 10 Gbps EVPL or Ethernet Virtual Private Line service. They offer low latency route guarantees and an international service footprint, including a presence at key public exchange facilities.

Are you concerned with managing multiple high performance data centers? Would you like to have more options and/or better pricing for all your telecom connectivity needs? If so, get complementary consulting help and pricing and availability for high bandwidth networking services.



Note: Photo of data center servers courtesy of WikimediaCommons

WDM Wavelength Services Offer Expandability

If your need is for high bandwidth, security and flexibility, you should take a look at wavelength services. This is more than the typical fiber optic bandwidth service. It’s almost like owning the network facilities yourself.

The thing about fiber optic transmission is that it offers almost limitless bandwidth. That’s a foreign concept to anyone who’s been tied to copper wireline services. It’s also an odd notion for those who pick a fiber optic service level and sign a contract for it. If you order OC3 SONET service, what you get is a line that runs at 155.52 Mbps with a payload of 148.608 Mbps. You don’t have to fill the pipe continuously, but the capacity is there all the time. If you need more bandwidth, you only recourse is to add an additional service or upgrade to something like OC12 or Gigabit Ethernet.

What you are using with fiber optic services is not the entire bandwidth of the fiber. In fact, you may be totally unaware that your signals are multiplexed with lots of others all traveling on the same fiber strand. If there is only one laser beam with a single color or wavelength shining through that fiber, it likely has a capacity of at least 10 Gbps. Chances are, though, that there are many different color beams all riding simultaneously down the fiber. They don’t interfere because they are different colors of light, called Lambdas, all in the infrared region of the spectrum. Each Lambda or wavelength has a carrying capacity as high as 10 Gbps. You can think of these as equivalent to individual high capacity lines. If the fiber optic strand were made of copper, each wavelength would be a separate pair of wires.

What if you could lease a wavelength instead of a copper wireline or a fixed bandwidth service on a fiber optic cable? The wavelength doesn’t care what modulation or data pattern you use. It’s just a pure light beam of one wavelength. There’s no fancy footwork required to convert between one protocol and another just to be compatible with what’s running on the line. That opens some interesting possibilities. You could use your leased wavelength to carry Gigabit Ethernet or Fast Ethernet, SONET OC3, OC12 or OC48, Fibre Channel, or ESCON.

Need to transport a variety of high bandwidth protocols? OK. Just lease multiple wavelengths and give each protocol its own Lambda. The won’t interfere. In fact, they won’t even known the other wavelengths exist.

This type of network transport is no longer a pipe dream. All you need to do is lease WDM Wavelength Services from a fiber optic network carrier such as AboveNet. What AboveNet has done is install a base of dark fiber in many metropolitan areas. It’s called dark because it hasn’t already be put into service with a particular fiber optic service in mind. It’s like a blank canvas ready to become any work of art. AboveNet “lights” the fiber as needed using WDM equipment to create their wavelength services.

WDM stands for Wavelength Division Multiplexing. It’s the technology that creates multiple wavelengths on a single fiber strand. This is a standardized process that ensures there is enough separation between the wavelengths that they won’t interfere and that different brands of networking equipment will work together. There are two flavors of WDM: CWDM or Coarse Wavelength Division Multiplexing and DWDM or Dense Wavelength Division Multiplexing. The difference is that DWDM squeezes more wavelengths, up to 160, onto a given fiber but at a higher cost than CWDM.

Is this affordable? AboveNet says that their CWDM service becomes competitive at the OC-3 service bit-rate. If you can use more bandwidth than that, you’ll save money with CWDM. Typical applications include connecting corporate headquarters with branch offices and data centers, or connecting multiple hospitals and medical centers for exchange of medical images and other health service records.

Has your business or organization become limited by the network services available? Perhaps it’s time to move up to wavelength services. Find out by getting prices and availability of fiber optic wavelength services for your locations. Complementary consulting by bandwidth experts is also available for serious applications.



Note: Image of light spectrum from prisms courtesy of Marcellus Wallace on Wikimedia Commons.

Metro Fiber Network Bandwidth For Denver

Bandwidth is booming in the Mile High City, or soon will be. AboveNet is installing nearly 100 route miles of dark and lit fiber to meet the mile-high bandwidth needs of Denver’s telecommunications, media, financial services, health care, retail and government users.

This could be a sign of things to come for nearly all metropolitan areas. The fact is that our productivity and economic growth is becoming more and more dependent on high levels of bandwidth to connect businesses, supplier, customers and remotely located employees. Copper can take us just so far. Then it’s time to connect with the nearly unlimited resources of glass fiber cables.

How much bandwidth are we talking about? AboveNet has fiber optic networks in cities nationwide that offer single wavelength service of 40 Gbps, 10 Gbps, 2.5 Gbps or 1 Gbps to extend a corporate LAN/WAN to multiple, metro area locations. You can have 40 Gbps fiber connectivity via an OC-768 handoff at your premises. That’s a level of bandwidth that was available only to carriers themselves not so long ago.

It should also be noted that each fiber strand can support more than one wavelength using a process called WDM or Wavelength Division Multiplexing. Each wavelength, or Lambda, is a slightly different color of laser light. Dozens or hundreds of wavelengths can travel through the same fiber without interfering. Each of those wavelengths can support up to 40 Gbps of bandwidth.

But is even this enough for the demands of major corporate or government users in a city the size of Denver? Well, those fiber cables that AboveNet is installing don’t just have one strand of fiber inside. These cables bundle 432 or 216 separate fibers within a large cable assembly. Multiply all those fiber strands times the number of wavelengths each fiber can support times the Gbps that each wavelength can carry and you’ve got some serious bandwidth. It’s more than is needed right now, so some fibers won’t be activated. These are the dark fiber that’s held in reserve for future needs or sold to organizations that want to have complete control over their communication resources by lighting their own fiber.

Do you have a need for metro or long haul fiber optic services from 40 Mbps to 40 Gbps? There are dark fiber and lit fiber optic services available now in most metropolitan areas from AboveNet and other high bandwidth competitive carriers. Prices are lower than they’ve ever been, thanks to improved technology and increased competition. You may be able to afford more bandwidth than you imagine. Find out with a competitive pricing quote and complementary consulting support from our Telarus bandwidth experts.