Fiber Optic Leased Lines for Business

Copper-based leased lines have been the go-to solution for connecting business sites and for dedicated access to the Internet. However, copper’s days are numbered as big data, HD video and a migration out of the corporate data centers and into the cloud accelerate. The era of fiber-everything is approaching. Fortunately, prices are lower and options greater than ever before.

Fiber optic leased lines have been employed for decades by major corporations and businesses, like video production and distribution, that can’t function without the bandwidth fiber affords. Nearly all of this bandwidth has been supplied by a telephone industry standard called SONET for Synchronous Optical NETworking.

SONET picks up where T-carrier stops. T1 is good for 1.5 Mbps and up to 12 Mbps when multiple T1 lines are bonded. T3, often called DS3, is a 45 Mbps service, although it can be rate limited to 10 or 20 Mbps to lower costs. DS3 stands at the crossroads between copper and fiber. DS3 bandwidth is most often carried on a multiplexed SONET service for most of the transport distance and then converted to coaxial copper connections at the customer site.

SONET fiber optic lines start with OC-3 at 155 Mbps. Like DS3, OC-3 can be rate limited to offer fractional OC-3 bandwidth at 50 or 100 Mbps. Most often it is leased as a full rate OC-3 service.

Other SONET service levels offer increasing bandwidth. OC-12 runs at 622 Mbps. OC-24 is a Gigabit service running at 1.2 Gbps. It is not widely offered. The next popular SONET service is OC-48 at 2.5 Gbps. OC-192 steps this up to 10 Gbps. OC-768 is a 40 Gbps line service that has been popular as a carrier backbone but now offered to businesses in some areas.

Note the big gaps in bandwidth between the SONET optical carrier levels. If you need a Gigabit connection, you may have to order an OC-48 service even though it has twice the bandwidth you require. We’ll take a look at how Carrier Ethernet is far more scalable and can give you fine degree of granularity for selecting just the right bandwidth for your applications.

Another thing about SONET is that it is a TDM or Time Division Multiplexed technology. This means that the signal is a string of bits divided into small channels and carefully synchronized to communicate with other SONET lines. Why this arrangement? It is the telephony legacy of SONET. It was designed to be compatible with Bell’s T-Carrier standards that are also TDM-based. Each channel in a T1 line or OC-768 is 64 Kbps to support one telephone call. Of course, these channels can now be combined so that you can use the entire line capacity less overhead to transport your data packets.

Since SONET is not a packet switched protocol, you need a protocol converter to translate between TDM and Ethernet in order to get your network data from place to place. That is generally a plug-in module for your router. Each SONET level has a specifically designed module that is unique to that optical carrier level.

What SONET has going for it is a long history and extensive deployment worldwide. You don’t have to worry about the intricacies of protocol conversion or signal interfacing, as they problems were solved long ago. SONET is most popular when deployed in rings of two redundant fibers that can switch in under 50 Msec to keep the data flowing even when faults in the system occur. Most metropolitan and long haul fiber optic networks are set up in the SONET ring topology for reliability.

What now competes with SONET is Ethernet over Fiber (EoF). Yes, this is the familiar Ethernet protocol that runs on your LAN but extended for long haul transport. The extended protocol is called Carrier Ethernet.

The advantages of Carrier Ethernet include easy and rapid scalability, a packet oriented protocol directly compatible with nearly all company networks and edge routers, and a considerable cost savings compared with SONET. Typical service levels start at 10 Mbps, the standard Ethernet service level. Other popular options are 100 Mbps Fast Ethernet, 1000 Mbps Gigabit Ethernet (GigE) and 10,000 Mbps or 10 Gigabit Ethernet (10 GigE).

You aren’t limited to these particular service levels. You can pretty much pick any bandwidth you like as long as the Ethernet Port installed at your facility can support the maximum speed you require. Easy scalability also means that you can often simply call your service provider and request an increase in bandwidth. It’s likely to be available in a matter of days if not hours.

Ethernet over FIber was almost unknown even a few years ago but now widely deployed. If available at your location, you’ll find that the cost per Mbps is much lower than SONET, perhaps half the cost for the same bandwidth. This is why Carrier Ethernet is rapidly taking over the fiber optic transport market, although SONET prices have also been plunging in response to the new competition.

Does your company require higher bandwidths that you can get from copper wireline services? Are you using fiber now but wondering if you can get a better price? Do you have a new application and want to get the best deal on bandwidth? If any of these apply, get competitive quotes on SONET and Ethernet fiber optic leased lines available for your business location.

How To Find Better Metro E Service Prices

Metro E or Metro Ethernet services are available in most cities. Businesses with a strong presence in a particular metropolitan area can use Metro E to good advantage in linking their various satellite offices, warehouses, factories, retail outlets and so on. The big issue is how can these companies be sure they are getting the best prices on the Metro Ethernet services they put on contract.

Metro Ethernet is a subset of the MAN or Metropolitan Area Network. Metro networks sprung up to address the needs of local businesses who didn’t necessarily need connections to other cities and states. What they really need is a way to connect from their headquarters location to their remotely located data center or backup data center miles away. Other connections are needed for branch offices and other operational locations.

This need for high performance, but local, network connections led to the rise of MAN operators. Like telcos or ISPs, they provide a set of services. In this case, it is most often access to a fiber optic ring that encircles the city and includes key suburbs, office and industrial parks. Last mile connections are provided from each business subscriber to the fiber ring. These can be fiber optic links or twisted pair copper connections depending on the bandwidth needed.

Most Metro networks were constructed using dual SONET rings with a working ring and a protection ring carrying traffic in opposite directions. Standard SONET ring protection offers an automatic failover within 50 mSec if the main ring fails for any reason. This self-healing capability improves the resiliency of SONET fiber optic networks to survive equipment failures and severed lines called “backhoe fade.”

SONET services include OC3, OC12 and OC48 telecom services. DS3 is also often available multiplexed on OC3 services. One issue with SONET is that the service levels aren’t very granular. There a big step, for instance, between OC3 at 155 Mbps and OC12 and 622 Mbps.

Metro Ethernet, also called Carrier Ethernet, addresses many of the limitations of legacy SONET services. Metro E may be provided as a service on SONET networks called Ethernet over SONET. This way the underlying network can be kept in place avoiding large construction costs. Some newer metropolitan networks are IP based to begin with. They offer Ethernet services by default.

One issue is ease of interfacing with the MAN. Ethernet is the standard protocol of company LANs. With an Ethernet connection to the MAN, you simply plug an Ethernet patch cord, fiber or copper, between your network edge router and the carrier’s demarcation connection. SONET requires a special interface card to do the protocol conversion between Ethernet, a network protocol, and SONET, a telecommunications protocol. SONET interfaces are unique OC3, OC12, OC48 and so on. Ethernet interfaces are ports with maximum speeds. A typical Ethernet port is 100 Mbps, 1000 Mbps or 10 Gbps. These support any network speed up to the maximum the installed port can handle. This make it easy for service providers to offer an almost infinite selection of bandwidths to their customers.

Since everything stays in the Ethernet protocol end to end, Metro E can be used to bridge multiple company LANs in the metro area. This is called Ethernet LAN service or E-LAN. You can also get point to point private line connections called Ethernet Line service or E-Line.

Metro E also addresses another limitation of SONET, which is historically high costs. Ethernet services of similar bandwidth are often half the price of their SONET equivalent. Extensive scalability also means that companies can select a bandwidth level closer to what they actually need instead of being cramped for speed or having to order way more than can be practically put to use.

How can you be sure that you are getting the best Metro Ethernet or even SONET MAN service prices? The best way is to work through a bandwidth broker that represents dozens of top tier service providers. Not only do you save time with one-stop shopping, but it is likely that you’ll get quotes from competitive carriers that you may not even be aware of.

Are you currently using metropolitan area network services or have a new requirement for metro bandwidth? If so, get prices and availability of Metro E and SONET network services from providers that serve your business locations.



Note: Photograph of Pittsburgh skyline part of a panorama courtesy of Wikimedia Commons.

SONET Rings To Support Ethernet

The hot bandwidth service these days is Carrier Ethernet. Everybody wants it once they see the cost advantage over the WAN connection they have now. The big question is can they get it?

In most cases, the answer is yes for a couple of reasons. First, new competitive carriers are rapidly building out their fiber optic core networks based on IP from the start. These networks are tailor made for Carrier Ethernet services. It’s relatively easy to get a point to point Ethernet connection between two distant business locations and use it to link their respective LANs. The result is one larger bridged LAN that enables all employees to be on essentially the same corporate network.

The other reason that Ethernet WAN services are so readily available is that established SONET fiber optic networks are being pressed into service to deliver Ethernet to the customer. This is known as Ethernet over SONET or EoS. The core of the network is still SONET, but operations at that level are invisible to you. As far as you are concerned, your connection is Ethernet all the way.

There’s no reason that SONET can’t transport Ethernet, ATM or other protocols. It was designed as a transport technology and has been adapted over the years to carry whatever traffic required hauling. The origins of SONET, like T-Carrier, are with the telephone industry. The name is an acronym for Synchronous Optical NETwork. Note the term synchronous. That tells you SONET is set up to be a highly synchronized network. The designed is based on multiplexing thousands of small channels called DS0s that each hold one telephone call. These DS0 building blocks can be combined to create T1 and T3 lines or SONET services such as OC-3, OC-12 and OC-48.

The beauty of synchronization for circuit switched architectures based on time division multiplexing is that everything is orchestrated so tightly and you can easily multiplex and demultiplex channels and higher level services. The device that does this is called an ADM or Add/Drop Multiplexer. An ADM can drop off a T1 line, DS3, OC3 or other service at your door from a much higher speed fiber line that carries traffic for many customers.

How does Ethernet squeeze into those tiny telephone channels? It takes some doing, considering that each DS0 carries exactly 64 Kbps. That’s about the speed of an old dial-up modem. What the industry has done is replace the telephone oriented channels with large concatenated frames and various mapping techniques to more efficiently carry Ethernet packets. SONET networks can now readily carry Ethernet services from standard 10 Mbps Ethernet to 100 Mbps Fast Ethernet, 1000 Mbps Gigabit Ethernet (GigE), and 10 Gigabit Ethernet (10GigE).

A feature of most SONET networks that makes them highly reliable is their twin ring design. Two separate fiber strands are used simultaneously. Each carries the same traffic, but in opposite directions. If a fault occurs in the working ring, the network switches over to the protection ring within 50 mSec. This self-healing property works best when the two rings are widely separated so that a single backhoe cut or equipment fault doesn’t take out both rings at once.

Ethernet over SONET and native IP networks are making Carrier Ethernet services of all speeds readily available for businesses looking to upgrade their bandwidth connections at reasonable costs. How much are we talking? Find out with an instant online Ethernet Fiber quote for 10 Mbps to 1 Gbps service levels. Higher bandwidths and SONET services quotes need some manual effort but will be sent to you promptly.

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.