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:
Apr. 28, 2009
Filed:
Nov. 17, 2003
Scott David D'souza, Ottawa, CA;
Dmitri Vinokurov, Ottawa, CA;
Scott David D'Souza, Ottawa, CA;
Dmitri Vinokurov, Ottawa, CA;
Alcatel Lucent, Paris, FR;
Abstract
A method and apparatus directed to detecting DoS (denial of service) attacks against SIP enabled devices. A substantial imbalance between an accounting of SIP INVITE (INV) and SIP 180 Ringing (N) messages indicates a DoS attack. Preferably the number (H) of INVITE messages including credentials (INV) that are sent from a user client in response to a 407 Authentication Required message from a proxy server are removed from the accounting before the balance is tested. If the equation INV+INV−H=N(where INVis the number of INVITE messages without credentials) is not true within a small margin of error then the presence of a current DoS attack on the proxy server is indicated by the inequality.