ATM Forum Approves Five New Physical Layer Specifications.end users with a wide variety of standardized media for ATM, the ATM Forum A membership organization founded in 1991 to promote ATM networking technology. It worked with ANSI and the ITU to set standards. Its first specification in 1992 defined the User-Network Interface (UNI). In 2004, the Forum merged with the MPLS and Frame Relay Alliance. has approved five new specifications: UNI for E3, a Cell-based Transmission Convergence Sublayer for Clear Channel Interfaces, a 155 Mbps interface for Category 3 unshielded twisted pair See twisted pair. (hardware) unshielded twisted pair - (UTP) Normal telephone wire (in the USA). It may be used for computer to computer communications, e.g. using a version of Ethernet or localtalk. It is much cheaper than standard "full-spec" Ethernet cable. (UTP UTP (uridine triphosphate): see uracil. (Unshielded Twisted Pair) See twisted pair. UTP - unshielded twisted pair ) cable, a 622 Mbps optical interface for multimode fiber An optical fiber with a larger core than singlemode fiber. It is the most commonly used fiber for short distances such as LANs. Light can enter the core at different angles, making it easier to connect the light source to broader light sources such as LEDs. , and Utopia Level 2. The E3 UNI will enable vendors supplying products to the European market to incorporate ATM into existing E3 equipment. The 155 Mbps over UTP-3 cabling offers a high speed interface while providing a migration path for 51 Mbps. The carrierless amplitude and phase modulation phase modulation: see modulation. Varying the angle of a wave in a carrier in order to transmit analog or digital data. For digital signals, phase modulation (PM) is widely used in conjunction with amplitude modulation (AM). (CAP) technology used for these two UTP-3 specifications minimize installation costs by enabling connections over existing voice grade cabling. The 622 Mbps optical interface provides very high bit rates for computer-to-computer applications, minimizing transfer time for high volume files or other high volume data. The interface allows vendors to use existing multimode fiber and specifications for both LEDs and short wavelength lasers. The Cell-based Transmission Convergence Sublayer for Clear Channel Interfaces provides a means to transport ATM cells in the payload of any available transport mechanism. Examples include V.35, EIA/TIA EIA/TIA Electronic Industries Alliance/Telecommunication Industries Association 449/530, and EIA/TIA 612/613 (HSSI (High-Speed Serial Interface) A serial interface with transmission rates up to 52 Mbps. It is often used to connect one or more LAN routers and network devices to a T3 line, which provides 44.736 Mbps. ) or even RS-232. Utopia Level 2 is a follow-up to an earlier Utopia specification. It provides functional requirements See information requirements and functional specification. (specification) functional requirements - What a system should be able to do, the functions it should perform. for interconnections between physical layer chips and ATM level chips. Additionally, the data path for Level 2 accommodates 622 Mbps bit rates. "We are making progress in providing specifications for many different kinds of physical media. This will ensure that users have access to a wide variety of standardized media for ATM," said Rick Townsend, chair of the Physical Layer Working Group of the ATM Forum Worldwide Technical Committee. The specifications are available through the ATM Forum. To receive an order form call the ATM Forum's Fax on Demand Service at 415/688-4318, email info@atmforum.com or access the ATM Forum's World Wide Web at http://www.atmforum.com. Formed in October 1991, the ATM Forum's worldwide membership currently includes more than 800 organizations, representing all sectors of the computer and communications industries, as well as government agencies, research organizations and end users. The Forum's charter is to speed the development and deployment of ATM products and services. Activities include the development and recommendation of interoperability specifications and the promotion of industry cooperation and awareness. CONTACT: The ATM Forum Jenni Brumfield, 408/486-2504 jbrumfield@baynetworks.com Drusie Demopoulos, 408/486-2511 drusie_demopoulos@baynetworks.com |
|
||||||||||||||
Printer friendly
Cite/link
Email
Feedback
Reader Opinion