BY DAVID SZCZEPANIK
Students at universities are among the most demanding consumers of bandwidth on a network. With thousands of students demanding access to high-bandwidth applications, and demand surging at peak times of day, universities must have robust networks that offer bandwidth, speed, reliability, and upward scalability to meet ever-increasing demands. So it's no surprise that universities are leading-edge adopters of technology that have embraced the move toward all-fiber networks.
Georgetown University (GU) is no exception. Installing a fiber backbone in 1989, GU brought fiber to many of its dorms with an FDDI network. In 1997, this backbone was upgraded with an ATM network, connecting buildings at 155 Mbits/sec. And now, the university is pursuing an aggressive strategy of bringing multiple fiber drops to each student dorm room or apartment, giving each student direct fiber connections from their desktop or laptop.
Although multimode optical fiber has been the de facto standard for backbone and riser applications among universities-and other premises-network applications-for some time, the higher cost of fiber electronics has been a barrier to bringing fiber all the way to the workstation or desktop. Coupled with the fact that copper infrastructure is capable of handling current needs, many network managers who have hybrid fiber/unshielded twisted-pair (UTP) systems have left their horizontal copper cables intact.
Rich Kogut, Georgetown's chief information-technology architect has a different point of view. While he admits that Category 5E UTP would probably suffice for GU's current data-transmission needs, he's basing his decisions to go with fiber on the university's future needs. "In the foreseeable future, we anticipate 100 Mbits/sec, then Gigabit Ethernet to the desk. We will soon have an optical premises-network infrastructure in place to accommodate both-and more," he explains.
At Georgetown, Kogut had two major priorities: First, complete the network upgrades in student residences, providing each and every tenant with optical-fiber connectivity right from their rooms; second, build a data-communications infrastructure for the university that would accommodate future protocol advancements, without incurring additional costs necessary to support the more advanced applications that will evolve over the next decade.
Like many other network managers, Kogut was leery of the costs and complexity associated with upgrading to new grades of copper, which include significant recabling, installation of active electronics, and testing and employee retraining-a real possibility given the development and active marketing of Category 6 UTP. On the other hand, "fiber has sufficient bandwidth to do everything students need to accomplish today and in the foreseeable future," says Kogut. "Since fiber is scalable, it allows us to leverage our investments by adding function and capacity as needed. With Cat 5E or 6 UTP, you can't leverage your investment."
Kogut also is approaching his upgrade with an innovative approach: He's using media converters-little black boxes that can be seen on floors under beds, on desktops, and mounted on walls under desks-to leverage the university's investment in LAN electronics. As a result, Kogut is able to expand the capabilities of his network without making the currently operational network products obsolete. By installing media converters, he's also able to minimize disruption and downtime to his network.
Media converters enable interconnectivity between dissimilar media. They are easy to install: Simply connect a fiber patch cord to the converter's optical jack, and since they function as physical-layer devices, they do not interfere with any upper-level protocol information. The media converters also provided a convenient way to utilize the university's existing 10Base-T ports on PCs and laptops (with PCMCIA cards), facilitating the upgrade to fiber without investing in more expensive fiber network interface cards and the labor costs necessary to install them.
So for network managers seeking to migrate incrementally to fiber, media conversion enables the strategic and incremental locations of new fiber, while they save on premises-network expenses.
In college dorms, space is at a premium. Given the choice between wiring closets and extra dorm rooms, students will always get the nod. When looking at the 35 main campus buildings considered for fiber-to-the-workstation upgrade, Kogut and his team knew that in some buildings, the need to add intermediate distribution frames (IDFs), or telecommunications closets, would be a problem in dorms already squeezed for space.
Here, deploying fiber offers an advantage that's unheard of with copper (which has a 100-m distance limit). Because optical fiber can support link lengths of 300-plus meters, Georgetown was able to use a more centralized approach, with only one IDF per floor and eliminating the need for placing active equipment in multiple closets. "Using fewer IDFs translates into either having room for additional students or not," says Paul Correia, GU's current-projects/engineering manager.
Adds L. David Ansara, a project engineer who provides infrastructure support, "Homerunning electronics to one room is a big plus. If there's a problem, I can quickly troubleshoot the problem with two technicians. What took me two hours to remedy with UTP cabling, I can usually accomplish in 15 minutes with fiber."
Having fewer IDFs also translates into a sometimes overlooked source of cost savings: The network needs less backup power and less security and fire-suppression equipment; HVAC and related power costs are less. Depending on the number of IDFs eliminated, these hidden heating and/or cooling costs can be significant.
Additionally, Kogut used small-formfactor (SFF) connectors in his network, also reducing costs. Since SFF connectors are so small, system designers are able to fit twice the number of transceivers onto the same board, allowing double the port counts currently available on optical hubs, routers, and switches. Boosting a typical configuration of 12 ports to 24 ports helps translate into overall cost reductions.
While all-fiber-based solutions are still perceived as having higher initial installed costs, for networks like Georgetown's, the bottom line must be based on a number of factors: migration costs, space utilization and related costs, maintenance costs, and network reliability and performance. Planning long-term, fiber seems an enlightened decision, and one that continues to prevail at Georgetown University. Two more buildings are currently being upgraded with fiber and more are planned for the first quarter of this year.
Dave Szczepanik is product marketing manager at Sun Conversion Technologies. He wrote this article on behalf of the TIA Fiber Optics LAN Section (FOLS). FOLS member companies include 3M/Volition, Allied Telesyn International, AMP Netconnect, Belden Wire & Cable, Berk-Tek, CommScope, Corning, LANcast, Leviton Voice and Data Div., Lucent Technologies, Micro Linear, Ortronics, Panduit, the Siemon Co., Siecor, Sumitomo Electric Lightwave, Sun Conversion Technologies, and Transition Networks. Visit the FOLS Website at www.fols.org.