A Guide to Wide Area Networking (WAN)

Multiple locations that cut across large areas such as cities, countries or continents are connected via a Wide Area Network (WAN). Organizations will typically connect their Local Area Networks to one another using a WAN.

The complexity of WAN setup configurations vary in complexity and is guided by a number of factors; these include:

● Bandwidth requirements
● Distance between locations
● Number of locations
● Reliability
● Security

Connections run the gamut from individual users connecting to simple cloud services such as a Gmail account to massive networks connecting multiple locations and data centers. One good example of the latter is Wells Fargo. With well over 30,000 Automated Teller Machines and over 8,000 branches, the company connects all these using a WAN. Organizations with this kind of networking requirements require state-of-the-art security and reliability due to the increase of cyber-attacks against financial institutions. The Central Bank of Russia was in the news recently, having lost the equivalent of $31 Million to online thugs.

Reliability of networks is vital. Networks, especially with regard to financial institutions, should always be available and have minimal downtime. There would be a crisis if, for example, a bank’s customers could not access their money.

Government departments, educational institutions, retail chains, medical centers and many other types of organizations depend on different forms of WAN to collaborate, share resources and conduct e-commerce. For example, just about every nation in the world has a WAN that connects its institutions of higher learning to research – a national research and educational network.

Necessity is the mother of invention. Over the last decade, there has been an explosion in the number of new applications with high bandwidth requirements. These include cloud services, video conferencing, remote diagnostics, video surveillance and much more. This has led to the demand and subsequent development of higher speed WANs. For example, in the medical industry genomic companies are churning out massive amounts of genomic which must be transmitted and stored in data centers. By some estimates, the data these companies are producing will balloon to 2 to 40 exabytes every year over the next decade.
Let’s now examine some of the technologies used for WANs.
Wide Area Networking Technologies

There are several technologies used for WANs, these include:
● Internet
● Leased lines
● Dark fiber
● Wavelength services
● Carrier Ethernet

The Internet

Unknown to many, the Internet is actually the largest, cheapest and most easily accessible WAN. The Internet connects millions of computers around the world. According to Internet World Stats, as at December 2018, there were 4.1 billion Internet users in the world. This compared to 3.9 billion users in mid-2018 and about 3.7 billion users in late 2017.
However, despite the ease of access and low cost of the Internet there are a few drawbacks. For example the public Internet doesn’t come with quality of service guarantees. There is high latency, loss of data packets and several other performance related issues. This makes it unsuitable for critical applications that require high performance and uptime.

Furthermore, due to its very nature of being public and easily accessible, it is also the least secure. Anyone with some technical training and criminal inclination can easily access unsecured data transmitted over the Internet. The last US elections where Russia was accused of hacking the US Democratic National Committee (DNC) serves as a stark reminder of just how risky it is to transmit sensitive information over the public Internet.

Internet Based VPNs

One of ways to deal with the security challenges of the public Internet is a Virtual Private Network (VPN). This technology creates a secure network over the Internet or a private network. The complexity of VPNs ranges from simple point to point connections that connect a remote computer to a secure server to massive VPNs used by organizations to enable employees to connect to an Intranet.

VPNs have been used by journalists, bloggers and the general population in countries that censor the Internet, such as China, North Korea, Iran and Sudan. VPN communication is less likely to be intercepted and users can use the technology to access blocked websites. This is because VPN makes use of encryption when transmitting data. Data leaving one point is encrypted before transmission and then decrypted at the receiving point. Furthermore, VPN technology allows a user to mask their IP location appearing like they are in a different location from their true location.

However, despite all these advantages of VPN, the quality of data transmitted via VPN is still lower than what you would have over public Internet.
Private Wide Area Network Solutions
Private Wide Area Networks solutions solve the problem of security and quality of service. Below are the most common private WAN solutions.
Leased Lines (T1/E1)
Leased lines are private two-way dedicated lines connecting two or more connections. Organizations deploy leased lines to transmit data, voice and video between two or more locations.

Dedicated Internet access is made possible using leased lines sold by Internet Service Providers (ISPs). With leased lines, it is possible to have symmetric upload and download speeds with no fluctuation regardless of the number of users connected to the ISP at any time. Providers have a number of different types of leased lines.

T1 leased lines have a capacity of 1.544 Mbps and come with 24 voice channels where each channel is equivalent to a DS0. The E1 leased line is the European version and has a capacity of 2.048 Mbps and 32 voice channels. T3 leased lines have a capacity of 44.7 Mbps while E3 lines have a capacity of 34.4 Mbps.

Typically, leased lines have been delivered over twisted pairs of copper wire in a local loop. Today, most leased lines are delivered over optical fiber and other last mile technologies.

Dark Fiber Services

Communication services are evolving at a frenetic pace. The demands for higher capacity are outstripping what traditional leased lines can deliver. This is where dark fiber comes into play. But, what exactly is Dark Fiber?

To better understand Dark Fiber, it is important to have a good understanding of fiber optics. Fiber optic is undoubtedly more superior to twisted copper or wireless communication. This is despite the fact that the speed of light over fiber is relatively similar to that over copper. The advantages of fiber over twisted copper include:

● Fiber has a much bigger greater frequency range i.e. ~4THz in the C-band as compared to ~100MHz for CAT5 cable.
● Fiber is immune to electromagnetic interference and has lower signal tempering which makes it even more superior for communication.

This abundance of optical frequency bandwidth gives optical fiber near limitless capacity. Depending on the technology used, fiber optics can deliver up to 100 Gbps, these include Ethernet or Optical Transport Network (OTN). The capacity of the optical fiber is only limited by the transmission hardware. Dark Fiber, therefore, refers to this installed fiber that is not in use.
Organizations have the option to purchase or lease this “unlit” fiber from a provider. Dark Fiber is especially useful to organizations that are undergoing rapid growth and want to be able to quickly scale their bandwidth requirements. With Dark Fiber, such an organization can upgrade their bandwidth simply by upgrading their transmission hardware. This allows an organization to evolve technologically without having to rely on the provider. The only caveat is that the organization is usually responsible for monitoring and repairing the fiber infrastructure. Where the fiber network is long e.g. over 100 kms, the organization must be prepared to invest in optical amplifiers, regenerators and other maintenance equipment that must regularly monitored. Thus, where Dark Fiber is viable, the organization must have a clear understanding of all the operational challenges.

Case Study: University Of Colorado Health (UCHealth) Leased Dark Fiber
One good example of how an institution can lease Dark Fiber to quickly scale its bandwidth needs is The University of Colorado Health (UCHealth), a fast-growing health institution with four major hospitals or clinics.

The university plans to grow its affiliates and construct new facilities in the long-term. They are doing so in an ecosystem where technology is evolving fast. Most educational and health facilities have over the last decade migrated to the use of high definition image and video, Electronic Health Records and Telehealth amongst other technologies.

As the university’s high bandwidth needs continue to grow, they needed to invest in a scalable, reliable, secure, low latency and high capacity WAN solution. The obvious option was leasing Dark Fiber from a provider to meet these needs.

Optical Wavelength Services

Many large organizations with multiple locations around the world need dedicated, secure, high speed bandwidth but are not prepared for the upfront capital requirements of leasing fiber. One of the more affordable workarounds is making use of Optical Wavelength Services.

By making use of technology known as Dense Wavelength Division Multiplexing (DWDM), network providers are able to transmit multiple wavelength channels within a single fiber, and these can even be routed to different parts of the network. DWDM makes it possible to multiplex multiple laser light wavelengths onto a single fiber strand. For example in the C-band signals can be transmitted at the wavelength 1528.77nm, 1529.55nm….1567.95nm and so forth, in accordance with the rules defined by the International Telecommunication Union (ITU).
The current systems are able to transmit up to 128 different wavelengths within a single fiber strand and each channel has a capacity of up to 400Gbps.

Leasing wavelength services from a provider with a national or even global presence allows an organization to access high bandwidth at multiple locations around the world without having to invest in expensive leased fiber. Network operators deploy optical wavelength services using a number of technologies which include SONET/SDH, IP and Ethernet.

Case Study: An Information Services Company Wavelength Services
A large company dealing information services and offering its services in a wide range of industries was in the market for a reliable, high bandwidth connection between two if its data centers. Additionally, the company needed redundancy to guarantee continuous connectivity between the two centers that were geographically separated by over 1,000 miles.
To solve this problem, the company sought the services of XO Communications, a leading network provider in the US whose network covers more than 50 countries. XO Communications provided two fully managed 10 Gbps wavelengths using Ethernet to connect to the data centers.


MPLS is an acronym that stands for Multiprotocol Label Switching. MPLS VPN is a type a virtual private network where the network overlays a carrier’s private MPLS network as opposed to the public Internet. The effect of this is that the traffic flow is faster amongst other advantages. In the OSI model, the data link layer deals with protocols such as Ethernet and SONET/SDH capable to carrying data packets over simple LANs or point to point WANs. The network layer in OSI deals with IP packet routing across the entire network. MPLS sits somewhere in the middle and comes with extra data transportation features across the entire meshed network. While each router in a traditional IP networks performs a lookup in a routing table to establish where to send a data packet, with each router repeating the process until the packet reaches its destination, MPLS makes use of label switching. Essentially, the first router to receive the data packet examines the routing table and then determines the fastest and best route to the final destination and applies a “label” to data packet. This ensures that subsequent routers along the route do not need to look up the address of the next router. The result is greater efficiency in data transmission. In fact, different labels are assigned to packets with certain characteristics hence the use of the term “multi labeling”. The network treats packets according to their labels. For example, packets labeled as “voice” and “video” can be sent along routes with lower latency. This is difficult to achieve using traditional IP routing.

MPLS VPN is ideal for organization seeking multiple location, complex and reliable WANs that have the capacity to support the convergence of many services including data, voice and video. Organizations seeking these kind of service are typically multinationals needing to connect multiple dispersed locations around the world. To achieve seamless connectivity across borders and vast expanses of ocean would be too complicated and expensive using dark fiber or wavelength services.

However, despite these touted advantages of MPLS VPN, the main criticism is that when compared to other emerging technologies, the cost of MPLS VPN is still high. The challenge for IT managers, therefore, is to carefully evaluate the benefits of setting up MPLS VPN vis-à-vis the cons before making a switch.

Case Study: IWG Plc Network Expansion
IWG Plc, formerly Regus, is a multinational corporation and the world’s largest provider of serviced offices, virtual offices, meeting rooms, and videoconferencing to clients on a contract basis. The company operates in 106 countries with more than 2,300 business centers.

A few years ago, the company needed a network upgrade to connect 400 business centers in the United States. The upgrade needed to be fully scalable, flexible and redundant. 犀利士
The company needed to be able to increase connection speed immediately on demand. To do so, IWG turned to Level 3 who provided them with an MPLS VPN solution that delivered 100Mbps to each center.

Carrier Ethernet

One of the most mature networks technologies in use is Ethernet. It has come a long way since 1983 when it was first ratified by The Institute of Electrical and Electronics Engineers (IEEE) 802.3 working group. During that nascent time, it was initially theorized to support a maximum rate of 10Mbps but that has now grown to a standard of 400Gbps and development of Tbps capable Ethernet technology is currently underway.

Today, just about every building and computer in the developed world is equipped with an Ethernet port and this is fast becoming the de facto standard in developing countries. The result is that the cost per port has fallen drastically and the telecommunications industry has widely adopted Ethernet to take advantage of its wide reach.

According to the Metro Ethernet Forum, Carrier Ethernet is defined as, “an ubiquitous, standardized, carrier-class service and Network defined by five attributes that distinguish it from familiar LAN based Ethernet”. The five attributes are as follows:

1. Quality of service
2. Reliability
3. Scalability
4. Service management
5. Standardization


MEF outlines two standard services needed for delivery of service to the end-user:

● E-Line – a point-to-point virtual Ethernet connection between two users in a network. An E-Line either be an EPL which is an actual physical connection or, an Ethernet Virtual Private Line (EVPL).
● E-LAN – a connection that connects multiple points to one another allowing users to connect to multiple locations at the same time.


The most common sense reason to use Carrier Ethernet is the ability to quickly and easily upgrade to a faster connection when needed.


In the event of downtime, recovery should happen in less than 50ms.

Quality of Service (QoS)

Carrier Ethernet comes with guaranteed service quality levels which are defined prior to taking up the service via Service Level Agreements (SLAs). Customers can even request different SLAs for services over the same provider network.

Service Management

With Carrier Ethernet, the network can be managed, monitored and diagnosed from a central point using neutral standards-based software obtained from a vendor.
As opposed to native Ethernet which is deployed over short distances, carrier Ethernet can be deployed over other network technologies. Examples of such implementations include:

● Ethernet over fiber
● Ethernet over SONET/SDH
● Ethernet over MPLS
● Ethernet over OTN
● Ethernet over WDM
● Ethernet over µWave

These enable Carrier Ethernet to be delivered over wide geographical distances, for example, in a Metro area or global WAN. The main criticism for Carrier Ethernet is that it is yet to become as widely available as MPLS.

Hybrid WAN | SD-WAN

IT managers continuously face demand for more bandwidth. Depending on the particular scenario, simply adding MPLS bandwidth can prove to be very expensive. The more cost effective solution is to develop a hybrid Wide Area Network (Hybrid WAN) by supplementing MPLS with a less costly solution such as Public Internet of 4G/LTE (long-term evolution). Using such a configuration, sensitive traffic can be routed over MPLS while regular traffic can travel over the cheaper connection option.

SD-WAN refers to Software Defined Wide Area Network. While Hybrid WAN is associated with SD WAN, it is not identical. SD WAN automates the management of WANs and is an extension of software defined networking (SDN). In SDN, the logic that decides how traffic is handled is separated from the data plane that forwards the traffic. Solutions such as DSL, 4G, MPLS, private lines, satellite broadband etc, are managed by SDN controllers. SDN decides on how traffic should be routed depending on the traffic requirements at any time. Thus, applications that need high reliability such as VOIP and video are prioritized and routed using the best path hence improving the quality of service.

SD-WAN also comes with higher security which makes transmitting data over the Internet much more secure. While many organizations have taken advantage of the cost benefits of SD-WAN, the majority still prefer to send their sensitive data over private networks.

Finding Suitable Wide Area Network Solutions | FiberGuide Consulting Services

The growing demand for information and communication services has put IT managers on a never ending quest to connect locations separated by great physical distances with ever expanding amount of bandwidth. Furthermore, the demand for additional bandwidth now comes with high expectations with regard to quality, reliability, latency, resilience and security. National and global carriers have responded by coming up with dozens of innovative solutions to meet the growing demand.

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