Packet data switching apparatus

Details Packet data switching apparatus Packet data switching apparatus

1998-11-13

2002-12-03

Lee, Thomas (Department: 2185)

Electrical computers and digital data processing systems: input/

Input/output data processing

Input/output data buffering

C710S005000, C710S036000, C710S120000

Reexamination Certificate

active

06490640

ABSTRACT:

TECHNICAL FIELD
This invention relates to a switching device, and in particular to an ATM switching device which exhibits fairness in the way in which it handles incoming traffic at different inputs.
DESCRIPTION OF RELATED ART
One proposed solution to the problem of allocating network resources to the users of an integrated services network for packet-based traffic is known as Weighted Fair Queuing, in which arriving data packets are reordered so that they are retransmitted with a degree of fairness in the processor sharing system. See, for example, Parekh & Gallagher “A Generalized Processor Sharing Approach to Flow Control in Integrated Services Networks: The Single-Node Case” IEEE/ACM Transactions on Networking, Vol. 1, No. 3, June 1993. Such a system, however, can be very complex to implement.
U.S. Pat. No. 5,455,825 discloses a switch for digital communications networks, including a queuing system. When incoming cells or packets arrive, they are provided with numerical tags, calculated in accordance with a desired scheduling algorithm, and placed in a queue. A queue and search module, designed for VLSI implementation, selects the cells or packets for transmission based on the tags. Thus, the queue is searched, and, for each destination, the cell with the smallest tag value is sent for transmission. Such searching can, however, be time-consuming.
SUMMARY OF THE INVENTION
The present invention seeks to provide a switching device which provides fair queuing between its different input connections. In one aspect, this is achieved by storing received input data in a memory, together with an associated pointer, the pointer being indicative of a priority which is to be given to transmission of the data. The pointers are accessed through an array, which groups together the calls which have the same transmission, avoiding the need for lengthy searching. In another aspect, fair queuing is provided until the number of cells from a single input connection, awaiting transmission, exceeds a threshold number. Further cells from that input connection are then treated in a non-fair way.


REFERENCES:
patent: 4757529 (1988-07-01), Glapa et al.
patent: 4780870 (1988-10-01), McHarg et al.
patent: 5291482 (1994-03-01), McHarg et al.
patent: 5383182 (1995-01-01), Therasse et al.
patent: 5455820 (1995-10-01), Yamada
patent: 5455825 (1995-10-01), Lauer et al.
patent: 5610914 (1997-03-01), Yamada
patent: 5619500 (1997-04-01), Hiekali
patent: 5629928 (1997-05-01), Calvignac et al.
patent: 5651003 (1997-07-01), Pearce et al.
patent: 5689508 (1997-11-01), Lyles
patent: 5719853 (1998-02-01), Ikeda
patent: 5818840 (1998-10-01), Adams
patent: 5835491 (1998-11-01), Davis et al.
patent: 5901147 (1999-05-01), Joffe
patent: 0 405 530 (1991-01-01), None
patent: 0 471 344 (1992-02-01), None
patent: 0581486 (1994-02-01), None
patent: 0676878 (1995-10-01), None
patent: 0 681 385 (1995-11-01), None
patent: 0 681 385 (1996-08-01), None
patent: 0 405 530 (1996-09-01), None
patent: 0 471 344 (1997-02-01), None
patent: 0 405 530 (1999-01-01), None
Williams, K., Patents ACT 1977: Search Report Under Section 17(5); Mar. 27, 1996; United Kingdom Patent Office; pp. 1-3; In re: Application No. GB 9526688.8.
International Search Report; PCT/EP 96/05866; dated May 7, 1997.

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