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.
- 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
- 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:
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! version 12.3 service timestamps debug datetime msec service timestamps log datetime msec no service password-encryption service udp-small-servers max-servers no-limit ! hostname Router ! boot-start-marker boot-end-marker ! ! no cable qos permission create no cable qos permission update cable qos permission modems cable time-server ! cable config-file platinum.cm service-class 1 max-upstream 128 service-class 1 guaranteed-upstream 10 service-class 1 max-downstream 10000 service-class 1 max-burst 1600 cpe max 8 timestamp ! no aaa new-model ip subnet-zero ! ! ip cef no ip domain lookup ip dhcp excluded-address 10.128.1.1 10.128.1.15 ip dhcp excluded-address 10.254.1.1 10.254.1.15 ip dhcp ping packets 1 ! ip dhcp pool CableModems network 10.128.1.0 255.255.255.0 bootfile platinum.cm next-server 10.128.1.1 default-router 10.128.1.1 option 128 ip 10.128.1.1 option 4 ip 10.128.1.1 option 2 hex ffff.8f80 option 11 ip 10.128.1.1 option 10 ip 10.128.1.1 dns-server 8.8.8.8 lease 1 0 10 ! ip dhcp pool hosts network 10.254.1.0 255.255.255.0 next-server 10.254.1.1 default-router 10.254.1.1 dns-server 8.8.8.8 domain-name ExamplesDomainName.com lease 1 0 10 ! ! ! ! ! ! ! interface FastEthernet0/0 ip address dhcp ip nat outside duplex auto speed auto ! interface FastEthernet0/1 no ip address shutdown duplex auto speed auto ! interface Cable1/0 ip address 10.254.1.1 255.255.255.0 secondary ip address 10.128.1.1 255.255.255.0 ip nat inside cable downstream annex B cable downstream modulation 64qam cable downstream interleave-depth 32 cable downstream frequency 111000000 cable downstream channel-id 0 no cable downstream rf-shutdown cable upstream 0 description Cable upstream interface, North cable upstream 0 frequency 37008000 cable upstream 0 power-level 0 cable upstream 0 channel-width 1600000 cable upstream 0 minislot-size 4 cable upstream 0 modulation-profile 1 cable upstream 0 admission-control 150 no cable upstream 0 shutdown cable upstream 1 channel-width 1600000 cable upstream 1 minislot-size 4 cable upstream 1 modulation-profile 1 cable upstream 1 shutdown cable upstream 2 channel-width 1600000 cable upstream 2 minislot-size 4 cable upstream 2 modulation-profile 1 cable upstream 2 shutdown cable upstream 3 channel-width 1600000 cable upstream 3 minislot-size 4 cable upstream 3 modulation-profile 1 cable upstream 3 shutdown no cable arp cable source-verify dhcp cable dhcp-giaddr policy no keepalive ! ip nat inside source list 1 interface FastEthernet0/0 overload ip classless no ip forward-protocol udp netbios-ns no ip http server no ip http secure-server ! ! access-list 1 permit 10.128.1.0 0.0.0.255 access-list 1 permit 10.254.1.0 0.0.0.255 cdp run ! ! ! line con 0 transport preferred all transport output all line aux 0 transport preferred all transport output all line vty 0 4 login transport preferred all transport input all transport output all line vty 5 15 login transport preferred all transport input all transport output all ! end |
Enjoy!