[NETWORK] 2000’s style ISP with the cisco uBR u7114

Following the dial-up Internet access, here is how to do it using a CMTS (Cable Modem Termination System) and a DOCSIS 1.x modem.

Pre-requisites:

  • 1XCMTS – in this example we will use a Cisco UBR 7114, since this model has an RF upconverter included, so we won’t need additional hardware on the CMTS. More info about the uBR7100 series here
  • Since the cable modem only has one RF interface, we will need a DOCSIS compliant Diplex filter. I used the Televes CoaxData 1Gbps TV-Data diplexer filter 2-68 MHz/87-2150MHz.

Televes Diplex

  • Since the signal is pretty strong and can damage the cable modem, I used 4X20dB attenuators on the cable connecting the OUT port of the Diplex Filter and the RF in port on the cable modem.
  • One DOCSIS 1.x compliant cable modem. I used the Thomson TCM420

CM Thompson

  • 3 Coax cables with F-male connectors on both ends.

 

Now that we have all the hardware, we have to connect the F cables to: DS0 RF and US0 on the 7114 CMTS. Both cables will go to the diplex filter.

DS0 to the 87-2150 port and US0 to the 2MHz-68MHz port. The cable modem will be connected on the center port of the diplex filter after adding the 4x20dB attenuators.

Note: the Internet link will be provided via the 100Mbps FE port on the CMTS.

Now for the config file on the CMTS, here is a sample:

Enjoy!