The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 25, 2005
Filed:
Feb. 02, 1998
Hans-jürgen Reumerman, Aachen, DE;
Thomas Meuser, Aachen, DE;
Veit Pietzuch, Buxtehude, DE;
Kai Klapdohr, Hamburg, DE;
Hans-Jürgen Reumerman, Aachen, DE;
Thomas Meuser, Aachen, DE;
Veit Pietzuch, Buxtehude, DE;
Kai Klapdohr, Hamburg, DE;
Koninklijke Philips Electronics N.V., Eindhoven, NL;
Abstract
A coupling device (switch) for a local network operating in the asynchronous transfer mode (ATM) which comprises a central cell memory (CCM) for buffer storage of packets (frames) formed by individual ATM cells and arriving on feed lines, a central memory control device for controlling the storage in the central cell memory (CCM) and the writing and reading processes of the packets into and from the central cell memory (CCM). The control device includes a counting circuit for counting the ATM cells arriving in the central cell memory (CCM) and a discarding circuit for discarding ATM cells packet by packet for preventing a congestion in the central cell memory (CCM). To enable an efficient buffer management also in the case of very small cell memories, in particular below 1000 cells, the central memory control device comprises at least one comparator device connected upstream of the central cell memory, which comparator device cooperates with the counting circuit and with a control logic such that, when a programmable threshold value (L) for the degree of filling of the central cell memory (CCM) is reached, a programmable number of links (VC) are defined on the basis of the sequence of arrival of the ATM cells assigned to the relevant link (VC), and in that each ATM cell of the packet belonging to the defined VC value is discarded before it arrives in the central cell memory.