×

Prevention of denial of service (DoS) attacks on session initiation protocol (SIP)-based systems using return routability check filtering

  • US 8,966,619 B2
  • Filed: 11/08/2006
  • Issued: 02/24/2015
  • Est. Priority Date: 11/08/2006
  • Status: Active Grant
First Claim
Patent Images

1. A method comprising:

  • receiving an attack on a Session Initiation Protocol (SIP)-based device; and

    applying a return routability check filter to the attack, wherein applying the return routability check filter includes;

    receiving a first SIP request message from a source;

    storing, in a content-addressable memory (CAM) table, an identifier of the source indicated in the first SIP request message;

    transmitting a challenge to the source to authenticate the source;

    receiving additional SIP request messages;

    determining, for each of the additional SIP request messages, if the CAM table includes an entry that matches an identifier of the corresponding additional SIP request message;

    determining, for each of the additional SIP request messages that includes an identifier that matches an entry in the CAM table, if the corresponding additional SIP request message includes a correct response to the challenge;

    blocking the additional SIP request messages that include an identifier that matches an entry in the CAM table and do not include the correct response to the challenge; and

    removing the identifier of the source from the CAM table when one of the additional SIP request messages includes an identifier that matches an entry in the CAM table and includes the correct response to the challenge.

View all claims
  • 3 Assignments
Timeline View
Assignment View
    ×
    ×