(12) United States Patent ao) Patent No.: us 6,647,424 Bi
Pearson et al. (45) Date of Patent: Nov. 11,2003
(54) METHOD AND APPARATUS FOR
DISCARDING DATA PACKETS
(75) Inventors: Terry Pearson, Hollis, NH (US); Tom
Colley, Boxborough, MA (US); Larry
Manor, Londonderry, NH (US); Joe
Kidder, Arlington, MA (US); Linda
Cabeca, Waltham, MA (US)
(73) Assignee: Nortel Networks Limited, St. Laurent
( * ) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 0 days.
(21) Appl. No.: 09/314,563
(22) Filed: May 19, 1999
Related U.S. Application Data
(60) Provisional application No. 60/086,078, filed on May 20, 1998.
(51) Int. CI.7 G06F 15/16
(52) U.S. CI 709/232; 370/235
(58) Field of Search 370/397, 412,
370/235, 236, 321, 229, 419, 337; 709/232,
(56) References Cited
U.S. PATENT DOCUMENTS
5,313,455 A * 5/1994 van der Wal et al 370/232
A method, apparatus and article of manufacture for filtering a data packet. The data packet is classified a filter type according to a classification criteria. A size value of the data packet is added to a data count for the filter type. The filter type is compared to a committed information rate (CIR). The data packet is filtered if the data count exceeds the CIR or a burst rate. A status the data packet may optionally be altered if the data count exceeds the CIR. A priority of the data packet may optionally be reclassified if the data count exceeds the CIR.
19 Claims, 8 Drawing Sheets