As a result of competition in the long distance industry, businesses have a variety of long distance carriers (MCI, U.S. Sprint, AT&T, etc.) to choose from for the transport of a company’s voice and data traffic. By choosing to use more than one long distance vendor for service, businesses can safeguard themselves from a long-distance network disaster. This “vendor diversity” strategy provides a company with protection and continued communication in the event there should be an outage on either of the networks. The calls are simply re-routed to the secondary vendor.
Equally critical and prone to failure is the local telephone company network. Until 1984, there was no competition to the local phone company for service, and hence nowhere else to go in the event of a telephone company failure. Since then, deregulation and the divestiture of the Bell system have occurred, allowing for the beginnings of a new competitive service, Metropolitan Area Networks (MANs).
The focus of these new providers is to bring alternative service options when linking customers to their long distance carriers. MANs also provide a necessary and vital backup link to customers. Critical business fortunes cannot be left to a sole provider--the local telephone company.
MANs are one of the most recent phenomena in the competitive telecommunications industry, having emerged entirely in the past five years. A MAN is basically a public telecommunications network, employing fiber optic digital technologies, specializing in voice, data and video transmission services, as an alternative or supplement to local telephone company services.
MANs are primarily used by business customers with large telecommunications requirements and long distance carriers, both as a primary source of access facilities as well as a secondary source of access to and among the nation’s long distance carriers.
MANs are best suited to applications where large volumes of voice, data or video traffic must be exchanged between relatively local sites within the same metropolitan area. This makes these services a viable part of a company’s network disaster recovery plans for alternate access to carriers, changing to a back-up data center in the event of a disaster, or as a complete alternate access network.
In the beginning, the thrust of MAN service was clearly on fiber optics technology, flexibility and price as the means of differentiation from the local telephone company. Now, however, the trend has shifted towards differentiation based on quality, customer service, installation speed and perhaps most important, redundancy and diversity.
According to a recent study conducted by Donaldson, Lufkin, and Jenrette Securities Corporation, customers do not move their business to the alternate access vendor because of price, but rather because of the “insurance” value. The competitor to the phone company provides route diversity to minimize disruptions in the event of a telephone company cable cut or central office failure. This is particularly true of customers in the banking, brokerage and insurance industries that are highly dependent on voice and data facilities where a telephone company outage could prevent the customer from doing business.
Today’s customers apparently are less willing to incur the risk of “downtime.” The understanding of the technology that customers need and the logistics needed to carry it out combine to create the type of disaster recovery service that MANs are implementing throughout the country.
Most MAN networks are designed in a loop or ring configuration. This ring allows for the same traffic to flow on the ring in two different directions at all times (bi-directional rings). In the event that there is a cable cut or outage on one of the paths in the ring, the traffic is automatically rerouted to travel to the same destination in the opposite direction (Exhibit 1). This is called diversity.
Most MANs choose to employ fiber optic technology and optical hardware rather than copper wire for fiber’s many inherent benefits. The following are two critical benefits:
QUALITY: Fiber will transmit in excess of 20 miles without the signal having to be regenerated (distances of over 70 miles are possible). Each time the signal is regenerated in a copper system is another point for possible failure. Copper requires the use of a regeneration of the signal about every mile. Fiber is also not susceptible to induced noise, nor does it conduct electricity or attract lightning. In the unlikely event that lightning were to strike fiber or metal near fiber, the fiber would not conduct the electrical surge into the attached electronic equipment and the system would be protected. The fiber backbone within the encasing copper cable is also less susceptible to fire damage.
RELIABILITY: The amount of time services available to the customer is measured in “uptime” or network availability. MAN networks offer continuous network surveillance, both remote diagnostic testing and fault correction capabilities.
MAN standards and future development will provide interconnection among MANs as well as with Local Area Networks (LANs) and Wide Area Networks (WANs). Connectivity for businesses to worldwide telecommunications networks is a clear goal of MANs. However, the ultimate goal of MANs is, and will continue to be, to carry integrated, voice, data, video, and other broadband traffic, with the most secure and reliable technology available.
Businesses now have the opportunity to enhance their potential to survive a telecommunications crisis through the availability of MANs and other telecommunications vendors. No company can afford to lose time or money due to communications outages or failures.
Barbara Samson is the Vice President of the Association for Local Telecommunications Services and co-founder of Intermedia Communications of Florida, Inc. She is responsible for all external matters for ICI, as well as handling public relations for the company.
This article adapted from Vol. 3 No. 3, p. 29.