Interessant om even uit te zoeken ook:
Wat ik opmaak is dat de modem connect, de frequentie wordt bepaald door aftasten van het digitale signaal, er wordt geluisterd naar een "upstream channel descriptor" met daarin de "upstream frequency, modulation type and channel bandwidth"en vervolgens een packet (de "map"), waarin staat welke freq. te gebruiken om een upstreampakket retour te sturen. Daarna wordt er met oplopend voltage afgetast wat de juiste signaalverhouding is. (Once the CMTS detects the range request, it analyzes the power, frequency and timing of the range request and sends the cable modem a range response, which includes instructions for the modem to adjust its transmit power, frequency and timing as necessary. The CMTS does this ranging (station maintenance) for every cable modem in the DOCSIS network at least once every 30 seconds. This ensures that all cable modems are transmitting at the proper power, frequency and timing.)
Daarna wordt DHCP ingezet en dan:
"Trivial file transfer protocol (TFTP): Next, the cable modem must download the configuration file whose name it was given during the DHCP process. It does this by sending a TFTP read request to the IP address of the TFTP server, also obtained during the DHCP process. If the filename exists on the TFTP server, the file is downloaded to the cable modem. This file will provide the cable modem with settings such as the maximum subscriber data download and upload speeds, quality of service (QoS) settings, DOCSIS 1.1 settings, encryption settings, etc."
"Registration request: Finally, the cable modem will send a registration request to the CMTS along with a list of the modem's configuration settings. If the CMTS approves of the modem's settings, it will respond with a registration response indicating a successful registration. If the CMTS does not like the cable modem's settings, the CMTS has the ability to reject the cable modem with a registration rejection, and the cable modem will not be able to come online and transmit data."
Het lijkt erop dat er dus niet te "tamperen" valt met je cable modem! Helaas...