Patent ID: 8180032
Filing Date: 2012-05-15
Classification: H04L,H04M

Abstract:
1. A method of protecting a telephone number mapping server from a denial of service attack, the method comprising: receiving a first call initiation request message associated with a first attempt to place a first exception call from an unregistered end user device; determining that a behavior of making exception call attempts is excessive based on the first call initiation request message and based on a behavior of making call requests of the unregistered end user device; inhibiting querying of a telephone number mapping server in connection with the first call initiation request message based on the determination that the behavior of making exception call attempts by the unregistered end user device is excessive; storing a value in a database, the value indicating that making subsequent exception calls from the unregistered end user device is disabled; receiving a second call initiation request message associated with a second attempt to place a second exception call from the unregistered end user device; and inhibiting querying of the telephone number mapping server in connection with the second call initiation request message based on the value in the database.