Abstract: A method and system for tracing interne protocol packets is disclosed. One aspect of the method involves generating traceback packets containing information relating to their origin, destination, and encountered devices. The generated traceback packets can differ depending on the network configuration and Internet traffic scenarios. Another aspect involves analyzing incoming Internet traffic and generating traceback packets based on the performed analysis. Another aspect involves discovering a denial-of-service attack. Another aspect involves modifying operational parameters in response to the attack. One aspect of the system involves traceback servers, which can collect and provide traceback information to the public or on a private network. Another aspect involves the dissemination of traceback information to interested and/or authorized parties.

Abstract: A system is disclosed which can measure and control the absolute phase angles of individual coherent Frequency-Division-Multiplexed (FDM) carriers which have been combined to form a composite signal. User-specified phase relationships for the carriers are predetermined to produce an optimum peak factor (peak power to average power ratio) of the composite signal for a given application. In the preferred embodiment, phase relationships chosen to minimize peak factor can dramatically reduce the presence of intermodulation distortion products which can be detrimental to present communication architectures, such as Community Antenna Television (CATV).