Patent Number: 8,719,926

Title: Denial of service detection and prevention using dialog level filtering

Abstract: A method may include receiving a session initiation protocol (SIP) request message and determining whether a dialog exists corresponding to the request message. The method may also include determining whether the dialog is in a first phase or a second phase when a dialog exists corresponding to the session control protocol message and querying a table indicating valid protocol requests for the determined phase to determine whether the received request message is valid. The method may include rejecting the request message when determined that the request message is not valid.

Inventors: Ormazabal; Gaston S. (New York, NY), Schulzrinne; Henning G. (Leonia, NJ)

Assignee: Verizon Patent and Licensing Inc.

International Classification: G06F 11/00 (20060101)

Expiration Date: 5/06/12018