Data Center Handbook, 2nd Edition

17FIBER CABLING FUNDAMENTALS, INSTALLATION, AND MAINTENANCE

Robert Reid

Panduit Corporation, Tinley Park, Illinois, United States of America

17.1 HISTORICAL PERSPECTIVE AND THE “STRUCTURED CABLING MODEL” FOR FIBER CABLING

17.1.1 What Is Point‐to‐Point (PtP) Cabling

Point‐to‐point (PtP) cabling refers to a data center (DC) cabling system comprised of “jumper” fiber cables that are used to connect one switch, server, or storage unit directly to another switch, server, or storage unit. A PtP cabling system is adequate for a small number of connections. However, as the number of connections in a data center increases, PtP cabling lacks the flexibility necessary when making additions, moves, or changes to data center infrastructure.

When the data centers were first built, end user terminals were connected via PtP connections. This was a viable option for small computer rooms with no foreseeable need for growth or reconfiguration. As computing needs increased and new equipment was added, these PtP connections resulted in cabling chaos with associated complexity and higher cost. Therefore, there is a downside to PtP cabling. However, the PtP cabling is surfacing again with the use of top of rack (ToR) and end of row (EoR) equipment mounting options. ToR and EoR equipment placement rely heavily on PtP cables, which can be problematic and costly if viewed as a replacement for standards‐based structured cabling systems (Fig. 17.1).

FIGURE 17.1 “Unstructured” cabling with PtP wiring. ...