ISO/IEC 11801
The International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC) publish the ISO/IEC 11801 standard predominantly used in Europe. This standard was released in 1995 and is similar in many ways to the ANSI/TIA-568-C standard upon which it is based. The second edition was released in 2002 and is largely in harmony with ANSI/TIA-568-C. However, the ISO/IEC 11801 standard has a number of differences in terminology. Table 1 shows the common codes and elements of an ISO/IEC 11801 structured cabling system.
Differences between ANSI/TIA-568-C and ISO/IEC 11801
Differences between ANSI/TIA-568-C and ISO/IEC 11801 Ed. 2 include the following:
- ISO/IEC 11801 allows for an additional media type for use with backbone and horizontal cabling and 120 ohm UTP.
- The term consolidation point is much broader in ISO/IEC 11801; it includes not only transition points for under-carpet cable to round cable (as defined by ANSI/TIA-568-C), but also consolidation point connections.
Element | Code | Description |
|---|---|---|
Building distributor | BD | A distributor in which building-to-building backbone cabling terminates and where connections to interbuilding or campus backbone cables are made. |
Building entrance facilities | BEF | Location provided for the electrical and mechanical services necessary to support telecommunications cabling entering a building. |
Campus distributor | CD | Distributor location from which campus backbone cabling emanates. |
Equipment room | ER | Location within a building dedicated to housing distributors and application-specific equipment. |
Floor distributor | FD | A distributor used to connect horizontal cable to other cabling subsystems or equipment. |
Horizontal cable | HC | Cable from the floor distributor to the telecommunications outlet. |
Telecommunications room | TC | Cross-connection point between backbone cabling and horizontal cabling. May house telecommunications equipment, cable terminations, cross-connect cabling, and data networking equipment. |
Telecommunications outlet | TO | The point where the horizontal cabling terminates on a wall plate or other permanent fixture. The point is an interface to the work area cabling. |
Consolidation point | CP | The location in horizontal cabling where a cable may end, which is not subject to moves and changes, and another cable starts leading to a telecommunications outlet, which easily adapts to changes. |
Work-area cable | None | Connects equipment in the work area (phones, computers, etc.) to the telecommunications outlet. |
ISO/IEC 11801 Ed. 2 specifies a maximum permanent link length of 90 meters and a maximum channel link of 100 meters. Patch and equipment cord maximum lengths may be adjusted by formulas depending on the actual link lengths. Terminology differences between ANSI/TIA-568-C and ISO/IEC 11801 Ed. 2 include the following:
- The ISO/IEC 11801 Ed. 2 definition of the campus distributor (CD) is similar to the ANSI/TIA-568-C definition of a main cross-connect (MC).
- The ISO/IEC 11801 Ed. 2 definition of a floor distributor (FD) is defined by ANSI/TIA-568-C as the horizontal cross-connect (HC).
Classification of Applications and Links
ISO/IEC 11801 Ed. 2 defines classes of applications and links based on the type of media used and the frequency requirements. ISO/IEC 11801 Ed. 2 specifies the following classes or channels of applications and links:
Class A For voice and low-frequency applications up to 100kHz.Class B For low-speed data applications operating at frequencies up to 1MHz.Class C For medium-speed data applications operating at frequencies up to 16MHz.Class D Concerns high-speed applications operating at frequencies up to 100MHz.Class E Concerns high-speed applications operating at frequencies up to 250MHz.Class EA Concerns high-speed applications operating at frequencies up to 500MHz.Class F Concerns high-speed applications operating at frequencies up to 600MHz.Class FA Concerns high-speed applications operating at frequencies up to 1000MHz.Optical Class An optional class for applications where bandwidth is not a limiting factor.
