Valerie Maguire

 

IEEE Std 802.3br™ “Standard for Ethernet Amendment 5: Specification and Management Parameters for Interspersing Express Traffic” was developed by the IEEE P802.3br Interspersing Express Traffic Task Force and approved by the IEEE-SA Standards Board on June 30, 2016. Ethernet use in industrial (e.g. factory, process, and building automation) and automotive networks is growing with more than a dozen purposeful industrial protocols currently serving these networking needs. This amendment addresses prioritization of express and non-express frames in converged traffic environments where control data is time‑sensitive and often requires minimum latency.

Goals and Objectives for Interspersing Express Traffic operation:

  • Preserve the IEEE 802.3 Ethernet frame format at the MAC
  • Preserve minimum and maximum MAC frame size of the current IEEE 802.3 standard
  • Use the Clause 4/Annex 4A MAC without alteration
  • Require no changes to PHYs
  • Support full duplex operation only
  • Preserve MAC/PLS service interface
  • Do not degrade  Mean Time to False Packet Acceptance (MTTFPA) at the MAC Service Interface
  • The latency to initiate the transmission of an express frame shall be less than two times the minimum packet size plus IPG
  • Assure that both ends of the link support Interspersing Express Traffic (IET) mode before enabling it
  • Provide a primitive at the MAC client service interface to inhibit the transmission of non-express frames
  • Provide two MAC client service interfaces at each end of the IET link, as the means to distinguish between the express and the non-express frames
  • Minimum IET frame size shall be greater than or equal to 64 bytes
  • IET frames will be constructed such that they will not be recognized as valid MAC frames by a non-IET-capable device

The IEEE 802.3 Distinguished Minimum Latency Traffic in a Converged Traffic Environment Call‑For‑Interest Consensus Presentation can be found here: http://www.ieee802.org/3/DMLT/public/nov12/CFI_01_1112.pdf

The Project Authorization Request (PAR), approved on November 13, 2013, can be found here: http://www.ieee802.org/3/DMLT/PAR_5C_Objectives/8023-DMLT-SG-1311-Winkel-PAR-2013-11-13r3.4.pdf

 

TIA-1152 copper field testingField test instruments are used to test installed balanced twisted-pair cabling specified in the TIA family of structured cabling Standards.

ANSI/TIA-1152-A “Requirements for Field Test Instruments and Measurements for Balanced Twisted-Pair Cabling” was developed by the TIA TR-42.7 Copper Cabling Subcommittee and published in November, 2016. This Standard provides requirements for field test instruments, as well as measurement methods to compare field instrument  measurements against laboratory equipment measurements collected in accordance with TIA-568-C.2.

Significant changes from the previous edition include:

  • Field tester requirements have been refined
  • External references to other standards have been updated
  • Specifications for Level 2G testers to test category 8 permanent links and channels up to 2000 MHz have been added

ANSI/TIA-1152-A Content

  • Test Instruments
  • Annexes addressing Typical Measurement Accuracy of Reference Laboratory Measurement Systems, Derivation of Level 2G Source Match and Reflection Tracking Terms, and Guidance for the Applicability of Resistance and Resistance Unbalance Measurements

Accuracy Levels

TIA-1152-A specifies requirements for four levels of field test devices based upon increased reporting and measurement accuracy:

  • Level IIe
  • Level III
  • Level IIIe
  • Level 2G
Click here for archive information on ANSI/TIA-1152.
 

This Standard specifies performance and transmission requirements for premises optical fiber cable, connectors, connecting hardware, and patch cords. Transition methods used to maintain optical fiber polarity and ensure connectivity between transmitters and receivers using simplex, duplex, and array connectivity are also described.

ANSI/TIA-568.D-3 “Optical Fiber Cabling Components” was developed by the TIA TR-42.11 Optical Systems Subcommittee and published in October, 2016. Significant changes from the previous edition include:

  • Optical fiber polarity information and optical fiber test measurement requirements now reside in TIA-568.3-D
  • Passive optical network components are specified
  • The polarity of cords and connectivity methods supporting parallel optical signals for transceiver interfaces and array connector patch cords and cables that exclusively employ two rows of fibers per plug are described
  • Array connectivity of arbitrary row width following patterns of the illustrated 12‑fiber row components are allowed
  • Specifications for wideband multimode fiber (commonly referred to as “OM5″) have been added
  • The use of OM1, OM2, and OS1 cables is no longer recommended
  • The maximum allowable OM3 and OM4 attenuation at 850 nm has been lowered to 3.0 dB/km
  • The minimum return loss of singlemode connections and splices has been raised from 26 dB to 35 dB
  • The insertion loss of reference-grade test connections is described and accommodated
  • Encircled flux launch conditions are specified for testing multimode connector performance at 850 nm
  • Multimode connector performance is no longer specified at 1300 nm
  • The minimum durability for all array connections is specified at 500 mating cycles
  • Specifications for outside plant microduct cable have been added

ANSI/TIA-568.3.D Content

  • Optical Fiber Cable
  • Connecting Hardware
  • Cords, Array Cables, and Transitions
  • Optical Fiber Transmission Performance and Test Requirements
  • Annexes addressing Optical Fiber Connector Performance Specifications, Grandfathered Fiber and Cable Types, Maintaining Optical Fiber Polarity, Optical Branching Component Performance Specifications, and Guidelines for Field‑Testing Length, Loss, and Polarity of Optical Fiber Cabling

ANSI/TIA-568.3-D Duplex Polarity

Consecutive‑fiber positioning and reverse-pair positioning are the two methods specified to maintain polarity for duplex polarity systems. Consecutive‑fiber positioning is implemented by installing the fiber adapters in opposite orientations on each end of the link (i.e., A-B, A-B… on one end and B-A, B-A… on the other) and then attaching fibers to the adapters in consecutive order (i.e., 1,2,3,4…) on both ends of the link. Reverse‑pair positioning is implemented by installing the fiber adapters in the same orientation on each end of the link (i.e., A-B, A-B… or B-A, B-A…) and then attaching fibers to the adapters in consecutive order (i.e., 1,2,3,4…) on one end of the link and in reverse‑pair order (i.e., 2,1,4,3…) on the other end of the link.

ANSI/TIA-568.3-D Array Polarity

The purpose of an array connectivity polarity method is to create an optical path from the transmit port of one multi‑fiber device to the receive port of another multi‑fiber device. Different methods may be employed to achieve this goal. It is recommended that one polarity method be selected in advance and maintained consistently throughout an installation. Three sample polarity methods, referred to as Methods A, B, and C, are described in TIA-568.3‑D. Method A requires to use of of a different patch cord at one end of the link to maintain polarity. Method B uses the same patch cord at both ends of the link, but requires that the adapter (sometimes referred to as the cassette) be reversed at one end so that the fiber that originated in position 1 is mapped to the end position (e.g. position 12 or 24). Method C is a variant of Method A, but with the polarity crossover implemented in the trunking cable instead of via the patch cord. Both Methods B and C have the advantage of using the same patch cords at both ends of the link.

Click here for archive information on ANSI/TIA-568-C.3.

 

The 2017 edition of the NFPA 70® National Electrical Code® (NEC) contains a new Article 840, Part VI requirement addressing premise powering of communications equipment over communications cable. This requirement only applies when the power supplied is greater than 60W (e.g., it does not apply to IEEE 802.3 Type 1 (15W), Type 2 (30W), and Type 3 (60W) PoE implementations). In this case, the maximum ampacity that may be carried by a cable conductor is determined by the conductor gage (AWG) size, number of 4-pair cables in a bundle, and the mechanical temperature rating of the cable as provided in Table 725.144 of the NEC and excerpted below. Note that this table is based on an ambient temperature of 30° C (86° F).

As an example, the maximum ampacity of one 24 AWG category 5e conductor, mechanically rated to 60° C and contained within a bundle of 62-91 cables, is 400 mA (800 mA per pair). Since the developing IEEE P802.3bt Type 4 90W application is targeting an operating current of 960mA per pair, this example product and installation configuration would not be compliant to the NEC requirements for support of this application. To overcome this restriction, the NEC provides a provision to use a limited power or LP-rated cable jacket to support increased ampacity. Another alternative allowed by the NEC is to use cables having larger diameter conductors and/or a higher temperature rating to reach the desired ampacity capability.

Siemon recommends the use of its shielded category 6A and category 7A cables (having 23 AWG and 22 AWG sized conductors, respectively) for support of 60W and higher power applications because these cables offer the same application support capability as LP-rated cables with the added benefits of greater heat dissipation, power efficiency, bandwidth, and noise immunity. Note that these cables are mechanically rated to 75° C (167° F) and, according to the NEC table (refer to the cells highlighted in yellow), are suitable for support of at least 500 mA per conductor/ 1 A per pair current levels in bundle configurations of up to 192 cables in 30° C (86° F) ambient temperature environments. Siemon has developed bundling recommendations for a much broader range of ambient temperatures. Following these bundling guidelines ensures that an -LP rated cable is not required to support greater than 60W applications within the environments for which Siemon cables are rated.

 

 

It is well understood that deploying 30 W and higher remote powering applications, such as Power over Ethernet (PoE) and Power over HDBaseT (POH), over balanced twisted-pair cabling produces a small degree of heat build-up within bundled horizontal cables. This heat build-up does not affect safety, but can affect transmission performance and long-term mechanical reliability. This can vary over differing cable categories and constructions as, for example, cables with larger conductors inherently have less heat build-up due to lower resistance and cables with metallic elements have less heat build-up due to superior heat dissipation properties. Different pathway styles (i.e. conduit versus free air) can also affect heat build-up within cable bundles.

Managing cable bundle size is important to ensure that heat build-up does not exceed the mechanical rating of the cables and that appropriate channel length de-rating is applied to offset additional insertion loss due to increased ambient temperature. While ISO/IEC TR 29125 and TIA TSB-184-A are under development to address recommendations for cabling supporting remote powering applications, these technical bulletins are generic in nature and not directly applicable to Siemon cables, which, depending on cable type, can support higher mechanical temperature ratings and offer superior heat dissipation.

The table below depicts recommended bundle sizes for Siemon horizontal cables supporting a variety of remote powering applications. Note that these bundling recommendations are applicable to cables installed in all pathway types, so they are more conservative than would be specified for cables in free air (i.e. non-conduit) installations. Consult the infrastructure design experts at Siemon for information on bundle size recommendations for cables installed in open pathways.

When in doubt about cable mechanical or heat dissipation capability, installation environment, or remote powering application, a conservative practice is to limit maximum bundle size to 24 cables. With the exception of the few instances noted below, this easy to remember practice addresses the majority of media, environmental, and application scenarios.

 

 

Q:         When will the 2.5G/5GBASE-T Ethernet Standard be ratified?  The IEEE 802.3bz™ “Standard for Ethernet Amendment: Media Access Control Parameters, Physical Layers and Management Parameters for 2.5 Gb/s and 5 Gb/s Operation” was approved by the IEEE-SA Standards Board on September 22, 2016.

Q:         Will the installed base of category 5e and 6 cabling support 2.5G/5GBASE‑T? 2.5G/5GBASE‑T operates over “defined use cases and deployment configurations” of category 5e/class D and category 6/class E cabling. Neither 2.5G nor 5GBASE-T are intended to operate over the entire installed base of category 5e/class D and category 6/class E cabling.

Q:         How will I know if my installed category 5e or category 6 cabling plant will support 2.5G/5GBASE-T? TIA is developing TSB-5021 and ISO/IEC is developing ISO/IEC TR 11801-9904 to address the evaluation of installed category 5e/class D and category 6/class E cabling for possible support of 2.5GBASE-T and 5GBASE-T. Extended frequency characterization (i.e. performance above 100 MHz for category 5e/class D cabling), signal to alien crosstalk assessment, and additional field test qualification measurements will be described within these documents. It is important to keep in mind that these field assessment methods are still under development and will likely prove to be very time-consuming and onerous to implement and may not be fully conclusive.

Q:         Is 2.5G/5GBASE-T operation covered by Siemon’s category 5e and category 6 system warranties? Because support of 2.5G/5GBASE-T by category 5e/class D and category 6/class E cabling is dependent upon environmental (e.g. alien noise levels) and installation (e.g. channel length and cable bundling) conditions, Siemon can only guarantee support of the  2.5GBASE-T and 5GBASE-T applications with category 6A/class EA and higher performing cabling systems.

 Q:        What grade of cabling should be installed to ensure guaranteed support of 2.5G/5GBASE-T? Siemon recommends that category 6A/class EA and higher grades of cabling be specified to support all new IEEE Std 802.11ac™-2013 based enterprise wireless access point uplink connections, even if it is anticipated that 2.5GBASE-T or 5GBASE-T equipment will be deployed. A recommendation to install category 6A/class EA or better cabling for all new installations intended to support 2.5G/5GBASE-T also appears in the developing TSB-5021 and ISO/IEC TR 11801-9904 drafts. Since category 6A/class EA and higher performing cabling is also guaranteed to support 10GBASE‑T, this design approach maximizes the lifecycle of the cabling infrastructure.

 

IEEE 802.3cd™ “Standard for Ethernet Amendment: Media Access Control Parameters, Physical Layers and Management Parameters for 200 Gb/s and 400 Gb/s Operation” is currently under development by the IEEE P802.3cd 50 Gb/s, 100 Gb/s, and 200 Gb/s Ethernet Task Force and anticipated to publish in September, 2018.  Server interconnects in the data center, which represent the highest number of equipment connections, require cost effective solutions. Advances in cost optimized single-lane solutions and higher speed multi-lane transmission solutions warrant reevaluating the signaling technology for 50 Gb/s and 100 Gb/s Ethernet. In addition, servers virtualizing more applications are driving additional bandwidth into the network and network uplinks need to progress to higher speeds to match server speeds. 200 Gb/s can support network infrastructure and oversubscription rates similar to 40 Gb/s and 100 Gb/s Ethernet as servers migrate from 25 Gb/s to 50 Gb/s, while also enabling data center fabric topology.  This amendment will define twelve Physical Layer (PHY) specifications and management parameters for 50 Gb/s, 100 Gb/s, and 200 Gb/s operation over backplanes and twinaxial copper cables. These solutions will support optional Energy Efficient Ethernet (EEE).

The new PHY specifications and attachment interfaces under development are as follows:

50GBASE-CR: 50 Gb/s transmission over one lane (2 twisted coaxial pairs) of shielded twinaxial copper cabling, with reach up to at least 3 m

50GBASE-FR: 50 Gb/s serial transmission over one wavelength  (2 fibers total)  for operation over singlemode optical fiber cabling with reach up to at least 2 km

50GBASE-KR: 50 Gb/s transmission over one lane of an electrical backplane, with a total insertion loss of less than 30 dB at 13.28125 GHz

50GBASE-LR:  50 Gb/s serial transmission over one wavelength  (2 fibers total)  for operation over singlemode optical fiber cabling with reach up to at least 10 km

50GBASE-SR:  50 Gb/s transmission over one lane (2 fibers total) for operation over multimode fiber optical fiber cabling with reach up to at least 100 m

50 Gigabit Attachment Unit Interface (50GAUI-1):  50 Gb/s one lane interface used for chip-to-chip or chip-to-module interconnections

50 Gigabit Attachment Unit Interface ( 50GAUI-2, LAUI-2):  50 Gb/s two lane interfaces used for chip-to-chip or chip-to-module interconnections

100GBASE-CR2: 100 Gb/s transmission over two lanes (4 twisted coaxial pairs) of shielded twinaxial copper cabling, with reach up to at least 3 m

100GBASE-DR: 100 Gb/s serial transmission over one wavelength (2 fibers total)  for operation over singlemode optical fiber cabling with reach up to at least 500 m

100GBASE-KR2: 100 Gb/s transmission over two lanes of an electrical backplane, with a total insertion loss of less than 30 dB at 13.28125 GHz

100GBASE-SR2: 100 Gb/s transmission over two lanes (4 fibers total) for operation over multimode fiber optical fiber cabling with reach up to at least 100 m

200GBASE-CR4: 200 Gb/s  transmission over four lanes (8 twisted coaxial pairs) of shielded twinaxial copper cabling, with reach up to at least 3 m

200GBASE-KR4: 200 Gb/s transmission over four lanes of an electrical backplane, with a total insertion loss of less than 30 dB at 13.28125 GHz

200GBASE-SR4: 200 Gb/s transmission over four lanes (8 fibers total) for operation over multimode fiber optical fiber cabling with reach up to at least 100 m

The current focus of the IEEE P802.3cd 50 Gb/s, 100 Gb/s, and 200 Gb/s Ethernet Task Force is circulation of their draft document for Task Force review and comment resolution.

The IEEE 802.3 50 Gb/s Ethernet over a Single Lane and Next Generation 100 Gb/s and 200 Gb/s Ethernet Call-For-Interest Consensus Presentation can be found here: http://www.ieee802.org/3/cfi/1115_1/CFI_01_1115.pdf

The Project Authorization Request (PAR), approved on May 12, 2014, can be found here: http://www.ieee802.org/3/cd/P802.3cd.pdf

The project objectives, approved on May 23, 2016, with changes from September 19, 2016, (refer to: http://www.ieee802.org/3/cd/P802d3cd_objectives_v4.pdf) are as follows:

  • Support full-duplex operation only
  • Preserve the Ethernet frame format utilizing the Ethernet MAC
  • Preserve minimum and maximum FrameSize of current IEEE 802.3 standard
  • Support optional Energy-Efficient Ethernet operation
  • Provide appropriate support for OTN
  • Support a MAC data rate of 50 Gb/s and 100 Gb/s
  • Support a BER of better than or equal to 10-12 at the MAC/PLS service interface (or the frame loss ratio equivalent) for 50 Gb/s and 100 Gb/s operation
  • Support a MAC data rate of 200 Gb/s
  • Support a BER of better than or equal to 10-13 at the MAC/PLS service interface (or the frame loss ratio equivalent) for 200 Gb/s operation
  • Define single-lane 50 Gb/s PHYs for operation over:
    • Copper twin-axial cables with lengths up to at least 3m
    • Printed circuit board backplane with a total channel insertion loss of ≤ 30dB at 13.28125 GHz
    • MMF with lengths up to at least 100 m
    • SMF with lengths up to at least 2 km
    • SMF with lengths up to at least 10 km
  • Define a two-lane 100 Gb/s PHY for operation over:
    • Copper twin-axial cables with lengths up to at least 3 m
    • Printed circuit board backplane with a total channel insertion loss of ≤ 30dB at 13.28125 GHz
    • MMF with lengths up to at least 100 m
    • Define a single lane 100 Gb/s PHY for operation over duplex SMF with lengths up to at least 500 m
  • Define four-lane 200 Gb/s PHYs for operation over:
    • Copper twin-axial cables with lengths up to at least 3 m
    • printed circuit board backplane with a total channel insertion loss of ≤ 30dB at 13.28125 GHz
    • Define 200 Gb/s PHYs for operation over MMF with lengths up to at least 100m
 

IEEE 802.3cc™ ”Standard for Ethernet Amendment: Physical Layer and Management Parameters for Serial 25 Gb/s Ethernet Operation Over Single-Mode Fiber” is currently under development by the IEEE P802.3cc 25 Gb/s Ethernet over Single-Mode Fiber Task Force and is anticipated to publish in October, 2017. The project will define the Physical Layer (PHY) specifications and management parameters for  support of 25 Gb/s over a pair of singlemode fibers beyond the 100 m reach limitation of 25GBASE-SR.  25 Gb/s PHYs for operation over singlemode optical fiber will provide optimized switch/router connectivity and facilitate 25 Gb/s migration from the data center to campus, metropolitan, and wide area environments.

The two new PHY specifications under development are:

25GBASE-LR: 25 Gb/s over one lane (i.e. 2 fibers total) of singlemode optical fiber cabling with reach up to at least 10 km

25GBASE-ER: 25 Gb/s over one lane (i.e. 2 fibers total) of singlemode optical fiber cabling with reach up to at least 40 km

The current focus of the IEEE P802.3cc 25 Gb/s Ethernet over Single-Mode Task Force is circulation of their draft document for Task Force review and comment resolution.

The IEEE 802.3 25 Gb/s Ethernet Over Single Mode Fiber Call-For-Interest Consensus Presentation can be found here: http://www.ieee802.org/3/cfi/1115_2/CFI_02_1115.pdf

The Project Authorization Request (PAR), approved on May 12, 2016, can be found here: http://www.ieee802.org/3/cc/P802.3cc.pdf

The project objectives, approved on January 21, 2016, (refer to: http://www.ieee802.org/3/cc/P802_3cc_Objectives.pdf) are as follows:

  • Support a MAC data rate of 25 Gb/s
  • Support full-duplex operation only
  • Preserve the Ethernet frame format utilizing the Ethernet MAC
  • Preserve minimum and maximum Frame Size of current IEEE 802.3 standard
  • Support a BER of better than or equal to 10-12 at the MAC/PLS service interface (or the frame loss ratio equivalent)
  • Support optional Energy-Efficient Ethernet operation
  • Provide physical layer  specification which support 25 Gb/s operation over at least 10 km on SMF
  • Provide physical layer specification which support 25 Gb/s operation over at least 40 km on SMF
  • Provide appropriate support for OTN
 

Early in the 40GBASE-T Ethernet application development process, it became understood that cabling specified to a bandwidth greater than 1,000 MHz would be required to support 40 Gb/s and higher transmission speeds.  This informative International Technical Report provides initial guidelines for next generation channels specified to 1,600 MHz.  It has subsequently been determined that cabling specified to 2,000 MHz is required to support both 25GBASE-T and 40GBASE-T.

ISO/IEC TR 11801-9901 “Generic Cabling for Customer Premises – Part 9901: Guidance for Balanced Cabling in Support of at Least 40 Gbit/s Data Transmission” was developed by ISO/IEC JTC 1/SC 25 (Subcommittee 25: Interconnection of Information Technology Equipment, of ISO/IEC Joint Technical Committee 1: Information Technology) and published in October, 2014.  This Technical Report provides performance for class I and class II balanced twisted-pair cabling containing two connections and up to 30 m of cords and cable specified from 1 to 1,600 MHz.  The contents of this report have been superseded by ISO/IEC 11801-1.

ISO/IEC TR 11801-9901 Content

  • Channel Requirements using Components with Enhanced Performance and Extended Frequency (Class I and Class II)
  • Channel Requirements for Category 6A and Category 7A Components
  • Annexes addressing Assessment of Cabling Capacity for 40 Gbit/s and Characterisation of a Channel using Standardised Components with Extended Frequency

ISO/IEC TR 11801-9901 Channel Descriptions

  • Class I channels are constructed from two Category 8.1 connectors, up to 26m of Category 8.1 cable and, two 2m Category 8.1 cords
  • Class II channels are constructed from two Category 8.2 connectors, up to 26m of Category 8.2 cable and, two 2m Category 8.2 cords
 

This International Standard will specify requirements for balanced twisted-pair copper (Classes A, B, C, D, E, EA, F, FA, I and II), coaxial (Class BCT-C), and optical fibre (OM1, OM2, OM3, OM4, wideband OM4, OS1a, and OS2) cabling systems used in office (ISO/IEC 11801-2), industrial (ISO/IEC 11801-3), home (ISO/IEC 11801-4), data centre (ISO/IEC 11801-5), distributed building (ISO/IEC 11801-6), and other premise environments. This Standard will specify the structure and minimum configurations of generic cabling, performance requirements of channels, links, connecting hardware, and cords, implementation requirements, conformance requirements and verification procedures, and interfaces. Requirements for cable performance are made via reference to applicable IEC Standards.

ISO/IEC 11801-1 “Generic Cabling for Customer Premises – Part 1: General Requirements” is currently under development by ISO/IEC JTC 1/SC 25 (Subcommittee 25: Interconnection of Information Technology Equipment, of ISO/IEC Joint Technical Committee 1: Information Technology) and anticipated to publish in early 2017. This Standard will cancel and replace 11801 Edition 2.2.

Significant changes from the previous edition include:

  • Class I and II channel and link requirements have been added
  • Category 8.1 and 8.2 connecting hardware and cord requirements have been added
  • Cabled OM1, OM2, and OS1 optical fibre is no longer recommended for new installations
  • Cabled wideband OM4 and OS1a optical fibre requirements have been added

ISO/IEC 11801-1 Content

  • Conformance
  • Structure of Generic Cabling
  • Channel Performance Requirements
  • Link Performance Requirements
  • Reference Implementation for Backbone Cabling Subsystems
  • Cable Requirements
  • Connecting Hardware Requirements
  • Cord Requirements
  • Annexes addressing Conformance Testing Procedures for Balanced Cabling of Classes A to FA, I and II and Optical Fibre Cabling, Mechanical and Environmental Performance Testing of Connecting Hardware for Balanced Cabling (Category 5 through 7A, 8.1, 8.2 and BCT‑B), Electromagnetic Characteristics, Acronyms for Balanced Cables, Supported Applications, and Optical Fibre Cable OM1, OM 2 and OS1
ISO/IEC 11801-1 Balanced Twisted-Pair Class Specifications
  • Class A is specified up to 100 kHz
  • Class B is specified up to 1 MHz
  • Class C is specified up to 16 MHz
  • Class D is specified up to 100 MHz
  • Class E is specified up to 250 MHz
  • Class EA is specified up to 500 MHz
  • Class F is specified up to 600 MHz
  • Class FA is specified up to 1 000 MHz
  • Class I and Class II are specified up to 2 000 MHz
ISO/IEC 11801-1 General Functional Elements
The general functional elements specified in ISO/IEC 11801-1 are the terminal equipment (TE) outlet, consolidation point (CP), subsystem cable 1 (divided into cable Y and cable Z if a consolidation point is present), distributor 1, other subsystem cables (e.g. 2, 3 and 4), and other distributors (e.g. 2, 3 and 4).
ISO/IEC 11801-1 Environmental Classification
1 = commercial, 2 = light industrial, 3 = industrial
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