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Adaptative Algorithm to Improve the Cell Tolerance of Clipper 1000

IP.com Disclosure Number: IPCOM000116617D
Original Publication Date: 1995-Oct-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 4 page(s) / 58K

Publishing Venue

IBM

Related People

Cukier, M: AUTHOR [+2]

Abstract

One ATM cell always belongs to a logical queue. CLIPPER 1000, handles up to 16K logical queues, so every logical queue is labelled by a 14 bits logical queue address.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 78% of the total text.

Adaptative Algorithm to Improve the Cell Tolerance of Clipper 1000

      One ATM cell always belongs to a logical queue.  CLIPPER 1000,
handles up to 16K logical queues, so every logical queue is labelled
by a 14 bits logical queue address.

      The moment where an ATM cell has to be emitted on the
communication line is coded in a memory called Time Division Memory
(TDM).  A free running counter addresses the TDM memory for which the
period corresponds to the time of emission of one ATM cell.

      The logical queues of the ATM cells to be emitted are coded in
the TDM.  If a logical queue corresponds to a fast transmission, it
appears more often than if the logical queue corresponds to a slow
transmission.  Ideally the distance between 2 consecutive addresses
should correspond to the desired interval of time between 2 cells.
This means that this interval should be constant, or within the
smallest possible tolerance.

      Every time the microprocessor writes into the TDM, it triggers
a background process intended to spread the content of the TDM as
regularly as possible all along the memory space.  To do this, the
word in the TDM is moved in order to be equidistant between the
previous and the next address corresponding to the same logical
queue.

An additional RAM stores the following information for each TDM
address:
  o  distance between current address and previous one (same LQ)
  o  distance between current address and next one (same LQ)

The...