We were recently asked to compare the cost of Category 5 UTP (Unshielded Twisted Pair) and fiber optic cabling for a local area network in a library which want to have 1.0 Gbps bandwidth to the desktop at some time in the future without replacing cabling. Given recent drops in fiber optic cable prices, the time seemed right to seriously consider the technology.
Cat 5 cable prices have been stable for the last two years at an average of $249 per node or outlet. Therefore, there was no need to obtain new quotes. In order to obtain current pricing for fiber optic cable, we contacted 3M, a major manufacturer, who quoted $378 per node, approximately 52 percent more than Cat 5.
We did some further checking with companies that install both types of cabling. They recommended using 70 percent as the differential because more skilled installers are required for fiber optic cabling. Therefore, labor costs are higher.
In addition to the cost of cabling there is the cost of switches. Fiber optic switches generally cost 50 to 80 percent more than Cat 5 switches.
Both Cat 5 and fiber optic cabling can accommodate up to 1.0 Gbps bandwidth per standard. (The 1.0 Gbps standard for Cat 5 cabling, officially designated IEEE 802.3ab, was ratified in June 1999). Fiber optic has the potential for supporting 10 Gbps in the future. Cat 5 is limited to 100 meters, while fiber optic cabling can be stretched for tens of kilometers.
There are now 120 companies in the Gigabit Ethernet Alliance that are committed to supporting Gigabit Ethernet over Cat 5 Copper. Cisco, Hewlett-Packard, FlowWise Networks, Foundry Networks, and Alteon Web Systems have begun to ship Gigabit switches and network interface products. 3Com Corp. and Cabletron have slated shipments beginning in November. Among the offerings will be switch cards that can be installed in existing 10/100 Mbps switches to upgrade them to Gigabit speed. Prices begin at $249 to utilize fiber optic to the desktop, well below the cost of replacing the switches completely.
Sixteen vendors not only exhibited their Gigabit Ethernet over Cat 5 copper at the NetWorld+Interop in Atlanta in September, but demonstrated the interoperability of the components. Network World, a trade publication, decided to subject the switches of seven vendors to more rigorous testing. It retained the Tolly Group to do the testing and reported in its September 13, 1999 issue (pp. 81-86) that the product not only conformed to the standard, but worked well together.
The difference in cost and the lack of need for multiple Gigabits to the desktop are the reasons most libraries use Cat 5 to the desktop. The difference in potential bandwidth and the distance limitations of Cat 5 are the primary reasons more and more large libraries are using fiber optic as the backbone for their local area networks.
