Fiber Distributed Data Interface 2
application | HTTP | IMAP | SMTP | DNS | ... |
transport | TCP | UDP | |||
Internet | IP ( IPv4 , IPv6 ) | ||||
Network access | FDDI-2 |
FDDI-2 is a further development of FDDI and is also suitable for the transmission of isochronous data streams (see asynchronous start-stop transmission).
Why FDDI-2
In the synchronous mode of FDDI there are waiting times for the reservation of the bandwidth , whereby the bandwidth can only be guaranteed in connection with a maximum delay . This delay can be with
The order in which the data is sent can also differ from the order in which the data is received ( buffer required). The delay is therefore a maximum of 100 ms, which is an extremely bad prerequisite for a possible dialogue.
development
In 1984 the development of FDDI-2 began with the aim of providing a guaranteed bandwidth with isochronous data streams as an add-on for FDDI. For this purpose, 16 wide band channels (WBC) with 6.144 mbps each were defined.
WBC (Wide Band Channels)
- The 16 channels may be used individually or combined, and between at least 2 stations for duplex connections are used
- The WBCs can be isochronous (FDDI-2) or z. B. synchronous (FDDI) can be used
- If the WBCs are used isochronously (FDDI-2), the data rate can be divided into multiples of 8kbps as a virtual connection (channels with 16, 64, 128, 1536 or 2048kbps)
- The specific bandwidth is requested via the station management (SMT - see FDDI)
- The maximum number of WBCs for isochronous traffic is set at the time of initialization
In 1994, FDDI-2 was standardized by the American National Standards Institute (ANSI) and guarantees reliable transport in real time (even with a full video signal and 24 frames per second). FDDI-2 is therefore particularly suitable for the transmission of continuous data. The big problem that FDDI systems cannot be connected to the FDDI-2-LAN contributed significantly to the fact that FDDI-2 was later supplanted by B-ISDN and ATM .
Communication options with FDDI-2
literature
- Dieter Conrads: data communication. Procedure - Networks - Services, 2nd edition, Friedrich Vieweg & Sohn Verlag, Wiesbaden 1989, ISBN 978-3-528-04589-0 .
- Barry Raveendran Greene, Philip Smith: Cisco ISP Essentials. Cisco System Inc., Indianapolis 2002, ISBN 1-58705-041-2 .
- Dieter Conrads: Telecommunications. Basics - Procedures - Networks, 5th edition, Friedrich Vieweg & Sohn Verlag, Wiesbaden 2004, ISBN 3-528-44589-0 .
- Dirk Traeger, Andreas Volk: LAN practice of local networks . Springer Fachmedien, Berlin / Heidelberg, ISBN 978-3-519-06189-2 .
- Bernhard Albert: FDDI and FDDI-II. Architecture - Protocols and Performance, Artech House, London 1994, ISBN 978-0-89006-633-1 .
Web links
- Difference Between FDDI 1 and FDDI 2 (accessed December 15, 2017)