Browse Prior Art Database

Copy Function for Asynchronous Transfer Model Swap

IP.com Disclosure Number: IPCOM000115911D
Original Publication Date: 1995-Jul-01
Included in the Prior Art Database: 2005-Mar-30
Document File: 2 page(s) / 35K

Publishing Venue

IBM

Related People

Luijten, RP: AUTHOR

Abstract

This is an implementation of linear multicast for ATM switching systems.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 92% of the total text.

Copy Function for Asynchronous Transfer Model Swap

      This is an implementation of linear multicast for ATM switching
systems.

      The ATM standards define ATM switching by associating the
Virtual Patch/Virtual Channel (VPi/VCi) value of a cell at a switch
input adapter with a switch output port and replacing the VPi or
VPi/VCi field in the cell with a new value.  The cell is then sent
out on the given output port.

      This implementation calls for associating the incoming VPi/VCi
value with additional information (typically 'copy bits' in a
lookup-table) that indicates that the incoming cell must be copied to
one or more destinations, which are also indicated in the lookup
table.  Also, the VPi/VCi is swapped and the cell is sent out on the
associated output port of the switch (as before).

      This mechanism allows setting up a linear multicast tree for a
connection, where the cell may be copied to resources in the node
with special control functions, with very little added cost.

      An example of an entry (for one connection) in a lookup table
(located on the input adapter) is shown below.  These entries are
associated with values of VPi and VCi, for which a connection has
been set up.
  o  New VPi value
  o  New VCi value
  o  Switch output port address
  o  Copy Code bits:
       b'00'  discard cell
       b'01'  send cell to switch only
       b'10'  send cell to microprocessor only
       b'11' ...