The standard defines several link/channel classes and cabling categories of
twisted-pair copper interconnects, which differ in the maximum frequency for which a certain channel performance is required: • Class A: Up to 100 kHz using
Category 1 cable and connectors • Class B: Up to 1 MHz using
Category 2 cable and connectors • Class C: Up to 16 MHz using
Category 3 cable and connectors • Class D: Up to 100 MHz using
Category 5e cable and connectors • Class E: Up to 250 MHz using
Category 6 cable and connectors • Class EA: Up to 500 MHz using
category 6A cable and connectors (Amendments 1 and 2 to ISO/IEC 11801, 2nd Ed.) • Class F: Up to 600 MHz using
Category 7 cable and connectors • Class FA: Up to 1 GHz (1000 MHz) using
Category 7A cable and connectors (Amendments 1 and 2 to ISO/IEC 11801, 2nd Ed.) • Class BCT-B: Up to 1 GHz (1000 MHz) using with coaxial cabling for BCT applications. (ISO/IEC 11801-1, Edition 1.0 2017-11) • Class I: Up to 2 GHz (2000 MHz) using
Category 8.1 cable and connectors (ISO/IEC 11801-1, Edition 1.0 2017-11) • Class II: Up to 2 GHz (2000 MHz) using Category 8.2 cable and connectors (ISO/IEC 11801-1, Edition 1.0 2017-11) The standard link impedance is 100 Ω. (The older 1995 version of the standard also permitted 120 Ω and 150 Ω in Classes A−C, but this was removed from the 2002 edition.) The standard defines several classes of
optical fiber interconnect: • OM1*: Multimode, 62.5 μm core; minimum modal bandwidth of 200 MHz·km at 850 nm • OM2*: Multimode, 50 μm core; minimum modal bandwidth of 500 MHz·km at 850 nm • OM3: Multimode, 50 μm core; minimum modal bandwidth of 2000 MHz·km at 850 nm • OM4: Multimode, 50 μm core; minimum modal bandwidth of 4700 MHz·km at 850 nm • OM5: Multimode, 50 μm core; minimum modal bandwidth of 4700 MHz·km at 850 nm and 2470 MHz·km at 953 nm • OS1*: Single-mode, maximum attenuation 1 dB/km at 1310 and 1550 nm • OS1a: Single-mode, maximum attenuation 1 dB/km at 1310, 1383, and 1550 nm • OS2: Single-mode, maximum attenuation 0.4 dB/km at 1310, 1383, and 1550 nm • Grandfathered
OM5 OM5 fiber is designed for wideband applications using
SWDM multiplexing of 4–16 carriers (40G=4λ×10G, 100G=4λ×25G, 400G=4×4λ×25G) in the 850–953 nm range.
Category 7 Class F channel and
Category 7 cable are
backward compatible with Class D/Category 5e and Class E/Category 6. Class F features even stricter specifications for
crosstalk and system noise than Class E. To achieve this,
shielding was added for individual wire pairs and the cable as a whole. Unshielded cables rely on the quality of the twists to protect from EMI. This involves a tight twist and carefully controlled design. Cables with individual shielding per pair such as Category 7 rely mostly on the shield and therefore have pairs with longer twists. The Category 7 cable standard was ratified in 2002, and primarily introduced to support
10 gigabit Ethernet over 100 m of
copper cabling. Like the earlier standards, it contains four twisted copper wire pairs rated for transmission frequencies of up to 600 MHz. However, in 2006, Category 6A was ratified for Ethernet to allow 10 Gbit/s while still using the conventional
8P8C connector. Care is required to avoid signal degradation by mixing cable and connectors not designed for that use, however similar. Most manufacturers of active equipment and network cards have chosen to support the 8P8C for their 10 gigabit Ethernet products on copper and not
GG45,
ARJ45, or
TERA connectors as Class F would have originally called for. Therefore, the Category 6 specification was revised to Category 6A to permit this use; products therefore require a Class EA channel (ie, Cat 6A). some equipment has been introduced which has connectors supporting the Class F (Category 7) channel. Note, however, that Category 7 is not recognized by the
TIA/
EIA.
Category 7A Class FA (Class F Augmented) channels and
Category 7A cables, introduced by ISO 11801 Edition 2 Amendment 2 (2010), are defined at frequencies up to 1000 MHz. The intent of the Class FA was to possibly support the future 40 gigabit Ethernet:
40GBASE-T. Simulation results have shown that
40 gigabit Ethernet may be possible at 50 meters and 100 gigabit Ethernet at 15 meters. In 2007, researchers at
Pennsylvania State University predicted that either 32 nm or 22 nm circuits would allow for 100 gigabit Ethernet at 100 meters. However, in 2016, the
IEEE 802.3bq working group ratified the amendment 3 which defines 25GBASE-T and 40GBASE-T on Category 8 cabling specified to 2000 MHz. The Class FA therefore does not support 40G Ethernet. there is no equipment that has connectors supporting the Class FA (Category 7A) channel. Category 7A is not recognized in TIA/EIA.
Category 8 Category 8 was ratified by the TR43 working group under ANSI/TIA 568-C.2-1. It is defined up to 2000 MHz and only for distances up to 30 m or 36 m, depending on the patch cords used.
ISO/IEC JTC 1/SC 25/WG 3 developed the equivalent standard ISO/IEC 11801-1:2017/COR 1:2018, with two options: •
Class I channel (
Category 8.1 cable): minimum cable design
U/FTP or F/UTP, fully backward compatible and interoperable with Class EA (Category 6A) using
8P8C connectors; •
Class II channel (
Category 8.2 cable): F/FTP or S/FTP minimum, interoperable with Class FA (Category 7A) using
TERA or
GG45. == Abbreviations for twisted pairs==