Browse Prior Art Database

Method to Implement Flexible Striping of Ports in a Circuit-Switch

IP.com Disclosure Number: IPCOM000119711D
Original Publication Date: 1991-Feb-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 3 page(s) / 92K

Publishing Venue

IBM

Related People

Liu, L: AUTHOR [+2]

Abstract

Disclosed is a method to allow grouping of individual ports in a circuit-switch to allow striping of data across multiple ports of the switch.

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

Method to Implement Flexible Striping of Ports in a Circuit-Switch

      Disclosed is a method to allow grouping of individual
ports in a circuit-switch to allow striping of data across multiple
ports of the switch.

      The figure shows the relevant blocks of a switching system
where the disclosed method applies.  The switching system is a
non-blocking circuit-switch with a total of N ports.  Each port
attaches to an external duplex-link by means of a
transmitter/receiver pair.  The ports are interconnected through a
crosspoint matrix.  A matrix- controller controls the individual
crosspoints of the matrix to configure the switching paths in
response to requests for connections and disconnections received from
the ports.

      The disclosed method allows a number of the ports to be grouped
together and used as a single communication channel in a data
transfer, thus providing much higher bandwidths than afforded by a
single port.  Thus, the same switch can be used as a N-port switch
with an individual link-bandwidth of B; or as an N/K-port switch with
individual link- bandwidth of KB.  The group-size K is selected when
the switching system is configured.

      In the disclosed method, a connection between two groups is
requested individually by the member-ports of one of the groups.  The
matrix-controller processes these requests serially and connects each
port in the requesting group with the corresponding port in the
requested group. It is possible that connection-requests to a
particular port-group Z may be generated by two different port-groups
X and Y almost simultaneously.  Because of the asynchronous nature of
the connection-requests, the result could be that some ports in Z get
connected to ports in X, while some are connected to ports in Y.  The
disclosed method prevents this condition by incorporating mechanisms
in the matrix controller which prevent ports from one group to be
connected to two distinct groups at any time.  Such interlocks can be
provided in many different ways; one example is as follows:

      The matrix-controller maintains a busy bit for each p...