Knowledge base

Recent high-speed protocols for optical cabling have triggered the development of new types of optical fibers and their new categorization. The initial categorization of fibers was based on glass core/cladding diameter: 50/125 μm, 62,5/125 μm or 9/12 μm. Today's fibers have different transmission characteristics in spite of the same glass geometry. International standard have therefore introduced a new classification based on the fiber's performance level.

The principles of optical cabling selection in terms of performance and transmission properties are described here. These principles apply to all components: cables, pigtails, adapters and patch cords.When choosing cables, it is necessary to consider the selection of their construction, which must comply with the operational and installation conditions.

illustrations of cross-sections of optical cables

International standards have defined five cabling categories for horizontal cabling - Cat.5E, Cat.6, Cat.6_A, Cat.7, Cat.7_A and two categories for data centers - Cat.8.1, Cat.8.2. Despite of this fact there are only two transmission speeds for horizontal cabling - 1Gigabit/s (Cat.5E, Cat.6), 10Gigabit/s (Cat.6A). In case of data centers the situation is different. There are only two transmission speeds for two categories - 25Gigabit/s and 40Gigabit/s but both of them can be transmitted on both categories (Cat.8.1 and Cat.8.2).

illustrations of cross-sections of copper installation cables

Cat. 8 system allows 40Gigabit/s transmission speed, guarantees transmission of all standardized protocols including 25GBASE-T and 40GBASE-T up to 30m and ensures a bandwidth of 2GHz.

Cat. 6_A interoperable components allow for a 10 Gigabit/s transmission speed, guarantee transmission of all standardized protocols including 10GBASE-T and ensure a bandwidth of 500 MHz. Due to the possibility of using products from different manufacturers and brands, users and suppliers do not depend on a single purchase source.

The Cat. 6A / Class E_A system allows for a 10 Gigabit/s transmission speed, guarantees the transmission of all standardized protocols including 10GBASE-T and ensures a bandwidth of 500 MHz. This system is disadvantaged from a long-term perspective as only components from a certain manufacturer are suitable for this solution.

Cat. 6 shielded components allow for a 1 Gigabit/s transmission speed, guarantee the transmission of all standardized protocols up to 1000BASE-T and ensure a bandwidth of 250 MHz. Cat. 6 lost its significance when Cat. 6A was introduced in 2006.

Cat. 6 unshielded components allow for a 1 Gigabit/s transmission speed, guarantee the transmission of all standardized protocols up to 1000BASE-T and ensure a bandwidth of 250 MHz. Cat. 6 lost its significance when Cat. 6A was introduced in 2006.