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Browse Prior Art Database

Transport of an 8KHZ Marker on 100 Mbps Asynchronous Transfer Mode User Network Interface

IP.com Disclosure Number: IPCOM000117628D
Original Publication Date: 1996-Apr-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 4 page(s) / 87K

Publishing Venue

IBM

Related People

Calvignac, J: AUTHOR [+5]

Abstract

Disclosed is a method for transporting an 8 kHz marker on the 100 Mbps ATM UNI defined in the Asynchronous Transfer Mode (ATM) Forum specification. The resulting interface remains compliant with the standard. It enables the transport of isochronous traffic for real delay Multimedia applications by synchronizing end stations communicating through LAN.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Transport of an 8KHZ Marker on 100 Mbps Asynchronous Transfer Mode
User Network Interface

      Disclosed is a method for transporting an 8 kHz marker on the
100 Mbps ATM UNI defined in the Asynchronous Transfer Mode (ATM)
Forum specification.  The resulting interface remains compliant with
the standard.  It enables the transport of isochronous traffic for
real delay Multimedia applications by synchronizing end stations
communicating through LAN.

      The ATM Forum has defined a high-speed User Network Interface
(UNI) exhibiting low implementation cost because based on widely
available FDDI interface technology.

The main characteristics of this interface are:
  o  100 Mbps throughput;
  o  4b/5b FDDI-based line coding;
  o  Explicit cell delineation.

      This interface presents interesting cost characteristics
because of the simple line encoding selected, and also because of its
simple data encoding:
  o  The "JK" symbol pair is used for symbol alignment
  o  Explicit cell delineation is performed by the "TT" symbol pair
      (Fig. 1)
  o  Idle link can carry idle ATM cells or "JK" symbol pairs: any
      number of "JK" symbol pairs can be placed in-between ATM
non-idle
      cells.
  o  ATM cells delineated by "TT" can be preceded by "JK" for maximum
      robustness (Fig. 2)

To date, this UNI has been adopted only in the WAN environment.  This
is mainly due to the fact that the simple cell framing is not in
accordance with the 125 us framing found in WAN interfaces, and also
because this interface does not carry all the control information
found in the overhead of the WAN interfaces.

      The disclosed method is based on the making o...