IBM trunk cable recommendations
The 62.5/125μm multimode optical fiber was initially recommended by IBM® and the American National
Standards Institute (ANSI) as the fiber of choice for long wavelength applications. Single Mode
fiber is now recommended for all new installations. For short wavelength applications at limited
distances, 50/125μm multimode optical fiber is preferred.
Note: Single mode and multimode cables cannot coexist in the same fiber optic channel link.
Additionally, we recommend that multimode cables of different core sizes (62.5μm and 50μm) should
not coexist in the same link.
For short wavelength applications at limited distances,
50.0/125 multimode optical fiber may be used. See Specifications. Maximum distances vary based on application and
fiber specifications. Obtain all attaching product specifications before selecting fiber for a trunk
installation. Various IBM products can use other fiber sizes to accommodate customer requirements worldwide.
For example, 50/125 multimode fiber is used extensively in Japan and some European countries.
However, use of these alternative fibers may not optimize distance capabilities.The 9- to 10- μm single mode optical fiber supports higher data rates and longer distances; therefore IBM considers it the direction for future products. See Specifications.
If you plan to install a multimode optical fiber trunk, IBM recommends that you also consider installing single mode optical fiber at the same time to support future high-bandwidth applications. See Fiber optic channel attachment options.