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:
Feb. 02, 1999
Filed:
Sep. 12, 1996
Robert E Thomas, Hudson, MA (US);
Koichi Tanaka, Kawasaki, JP;
Peter J Roman, Hopkinton, MA (US);
Wing Cheung, Sudbury, MA (US);
Shinichi Mizuguchi, Kawasaki, JP;
Cabletron Systems, Inc., Rochester, NH (US);
Abstract
In a network node having a host system coupled to a network by an adapter, VC-specific congestion is detected and reported to the host system. The host memory includes rx slots or buffers, each corresponding to one of one or more supported slot types. Per-VC slots consumed counters are maintained to count slot consumption for each active VC. Free buffer FIFOs are maintained for each of the one or more slot types, which have a predetermined congestion threshold associated therewith. Entries in each free buffer FIFO correspond to an rx slot posted by the host system. When a new rx slot or buffer in host memory is to be allocated to an incoming cell received on a given VC, the slots consumed counter is compared to the predetermined congestion threshold. If they are equal, the VC is at threshold level and the incoming cell is discarded and a report is sent to the host system. If the slots consumed counter is below threshold, a new rx slot is allocated for the reception of the data and the slots consumed counter is incremented. If the VC is credit-based flow control enabled and the slots consumed counter is below threshold, a credit is returned. If the VC is credit-based flow control enabled and the slots consumed counter is greater than or equal to the threshold, the credit return is deferred until the counter falls below threshold.