Cable Modems
- Bridged mode
- Ethernet to DOCSIS
- UTP to COAX
- Routed mode
- NAT
- IPv6
- IP address on the outside and IP address on the inside
- Integrated Switch
- May or may not have the capabilities to do VLAN, tags, trunking, etc.
- Integrated AP
- Depends on your organization
- You may not want the integrated AP
Data Over Cable Service Interface Specification
- DOCSIS is a standard designed to make use of cable infrastructure to send data. It was designed to allow the existing cable TV infrastructure to provide high speed internet. This standard led to a dramatic expansion on the internet because anyone with cable tv could also receive high speed internet through the same cable.
- Integration standard for data over CATV
- Specification covers Layers 1-3
- DOCSIS is from the cloud to our cable modem.
- DOCSIS 3.1 deployed in Comcast 2016
- DOCSIS 4.0 brings symmetrical data transfer
- Cable modem is the client
- Cable Modem Termination System (CMTS) resides at "head end"
Inside the Wire
- Physical
- Frequency
- We can sent different signal at the same time
- QAM
- A high resolution way to send lots of different data at once
- Different resolutions, the higher ones provides much better throughput.
- Voltage
- Datalink
- Network
- IP address assignment
- Traffic shaping
- Traffic filtering