Q: My company is getting ready to move upstairs. The space we are moving into is already cabled with a Category 3 system throughout. The installers coming in to cable have suggested to our facilities manager that we do not need Category 5. Our server has a 10/100 card and our switch is upgradable to 10/100. We run 10Base-T. I have always used Category 5 and believe that, for performance issues, it is needed. However, this is a big added cost to our move. Should we have all Category 3 pulled and replaced with Category 5?
Babette Kleiman
RN Homecare
Woodland Hills, CA
A: The installers are right. A Category 3 cable system will support your 10Base-T network very well. But do you have any records on the installed cabling, such as the usual pass or fail on the primary field-test parameters: wire map, length, attenuation, near-end crosstalk? How long are they going to be there? When will the migration to 100Base-T start? Is there a window of time--such as Christmas break--that could be used for re- cabling in the future? These are the types of questions that will have to be answered before you can decide whether to re-cable today or in the future.
In the university environment, we can arrange to turn down an academic department, floor, or building during Christmas or spring break and re-cable. However, any 24-hour, seven-day-a-week operation would require a much different approach.
Among my personal credos are the following:
- Do not move any department into a workspace that is not cabled to support its projected voice, data, and video requirements for at least the next three years. It is so much easier and less expensive to install cable in an unoccupied space than in one full of office furniture and people trying to work. Logical but not always feasible--the budget rules.
- Never use a Category 3-compliant cabling system as a pull wire for Category 5. Category 3 cable is excellent for voice and low-speed data. Again, logical but not always achievable due to lack of space in telecommunications closets.
Donna Ballast is a communications analyst at The University of Texas at Austin and a BISCI registered communications distribution designer (RCDD). Questions can be sent to her at:
Cabling Installation & Maintenance or at PO Drawer 7580,
The University of Texas,
Austin, TX 78713;
tel: (512) 471-0112,
fax: (512) 471-8883,
e-mail: ballast@utexas.edu.
