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Method of Dynamically Validating Cross-Point Switch Connections

IP.com Disclosure Number: IPCOM000100136D
Original Publication Date: 1990-Mar-01
Included in the Prior Art Database: 2005-Mar-15
Document File: 4 page(s) / 118K

Publishing Venue

IBM

Related People

Kaiser, JM: AUTHOR [+2]

Abstract

Disclosed is a method for validating the connections made and broken in a cross-point switch which is used in an electronic high-speed data switching unit which establishes short-term, dynamic connections for passing full-duplex data between pairs of ports.

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

Method of Dynamically Validating Cross-Point Switch Connections

       Disclosed is a method for validating the connections made
and broken in a cross-point switch which is used in an electronic
high-speed data switching unit which establishes short-term, dynamic
connections for passing full-duplex data between pairs of ports.

      The data from one port to another is routed via a cross-point
matrix switching element connected to all the port adapters.  The
output of each port is connected to the input of its connection
partner (i.e., if ports 1 and 3 are to be connected, paths through
the matrix will be established from 1 to 3 and from 3 to 1).

      Fig. 1 shows an output port and how one of the N input ports
(4) is selected to be connected to the output port.  A connect
register (1) holds the input port number to be connected, which is
decoded by a decoder (2).  The decoded outputs feed an N way AND/OR
(3) which will select one input port.  Unless a decoder failure
causes multiple outputs, only one input port will be selected for
each output port. (Multiple inputs can be detected due to the data
errors that result from the ORing of multiple inputs.)

      However, the same input port could be connected to two or more
different outputs and go undetected.  This article describes how this
can be detected if this were to occur.

      Fig. 2 shows a logical view of the N connect registers. They
are initialized so that the ith register contains the number I (i.e.,
 each output port selects its own input port (A of Fig. 2).  If ports
1 and 3 are now connected, the registers would appear as in (B) and
then, if 1 and 4 were connected before 1 and 3, were disconne...