Pros and con of fiber-to-the-desk

Sept. 1, 1997
Q: I attended the "Do we need zone cabling?" panel discussion at the bicsi conference in June. I left with the message that individual 4-pair drops were a better design choice than a 25-pair Category 5 cable. Comments?

4-pair vs. 25-pair cabling

Q: I attended the "Do we need zone cabling?" panel discussion at the bicsi conference in June. I left with the message that individual 4-pair drops were a better design choice than a 25-pair Category 5 cable. Comments?

Ross Bedbrook, RCDD

Bell Canada

Moose Creek, ON, Canada

A: Ah, yes, as moderator of that session, I remember it well. Brian Moffitt of Lucent Technologies presented a slide depicting a "600-Pair Consolidation Point," which George Weller of Steelcase later described as a "King Kong" consolidation point. amp`s Ken Hall concluded that "bicsi should drive zone cabling practices to ensure [that they are] designed and installed properly." Terry Cobb of Datacom Technologies explained that in a 4-pair cable, near-end crosstalk is measured from pair to pair, but in a 25-pair cable, near-end crosstalk is measured using a power-sum technique. Bob Jensen of dbi then reminded the group that there are no 25-pair connectors recognized in the tia/eia-568a standard; no field-test instruments available to test power-sum near-end crosstalk on 25 pair-cable; and no cabling install-ation requirements provided on how to break out the 25-pair into 4-pair bundles while minimizing crosstalk.

As for me, I am sticking to my closing statement at the session: "It sounds as if we still have some work to do on this one."

Donna Ballast is a communications analyst at the University of Texas

at Austin and a bicsi registered communications distribution designer (rcdd). Questions can be sent to her at Cabling Installation & Maintenance or at PO Drawer 7580, University of Texas, Austin, TX 78713; tel: (512) 471-0112, fax: (512) 471-8883, e-mail: [email protected].

Sponsored Recommendations

March 28, 2025
Bringing University of Tennesee's campus up to speed.
March 28, 2025
CommScope’s FiberGuide® Design Pro helps you design a complete fiber raceway for your data center or central office using 2D and 3D technology. This video guides you through the...
March 28, 2025
CommScope and Equinix work hand in hand to provide client connectivity across the globe