Optical Fiber Cabling
The '568-B.3 specification on optical fiber cabling consists of one recognized cable type for horizontal subsystems and two cable types for backbone subsystems:
- Horizontal - 50/125µm or 62.5/125µm multimode (two fibers per outlet).
- Backbone - 50/125µm or 62.5/125µm multimode or singlemode.
All optical fiber components and installation practices shall meet applicable building and safety codes.
Optical fiber patch cords:
- Shall be a two-fiber (duplex) cable of the same type as the cables to which they connect.
- Shall be configured so that "A" connects to "B" and "B" connects to "A".
Installation of optical fiber connecting hardware:
- Connectors shall be protected from physical damage and moisture.
- Optical fiber cable connecting hardware should incorporate high-density termination to conserve space and provide for ease of optical fiber cable and patch cord management upon installation.
- Optical fiber cable connecting hardware should be designed to provide flexibility for mounting on walls, in racks, or on other types of distribution frames and standard mounting hardware.
Optical fiber cabling installation:
- Siemon recommends that a minimum of 1m (3.28 ft.) of two-fiber cable (or two buffered fibers) be accessible for termination purposes.
- Testing is recommended to assure correct polarity and acceptable link performance. Clause 11 of '568-B.1 provides recommended optical fiber link performance testing criteria.
Optical fiber connections:
- Connector designs shall meet the requirements of the corresponding TIA FOCIS documents.
- Telecommunications outlet/connector boxes shall be securely mounted at planned locations.
- The telecommunications outlet/connector box shall have:
- Cable management means to assure a minimum bend radius of 25mm (1 in.) and should have slack storage capability.
- Provisions for terminating and housing a minimum of two optical fibers.
- Identification of fiber types:
- Multimode connector or a visible portion of it and adapters shall be identified with the color beige.
- Singlemode connector or a visible portion of it and adapters shall be identified with the color blue.
- The two positions in a duplex connector are referred to as "position A" and "position B".
Small form factor (sff) connectors:
- Qualified SFF duplex and multi-fiber connector designs may be used in the main cross-connect, intermediate cross-connect, horizontal cross-connect, consolidation points and work area.
- A TIA Fiber Optic Connect Intermateability Standard (FOCIS) shall describe each SFF design.
- The SFF design shall satisfy the requirements specified in Annex A of the '568-B.3 standard.
- Some advantages of SFF connectors include compact size, modular compatibility with the eight position modular copper interface, and adaptability to high-density network electronics.