Which layers of the OSI reference model are applied between DOCSIS modems and the CMTS?

The OSI reference model consists of seven layers, each responsible for different aspects of network communication. In the context of DOCSIS (Data Over Cable Service Interface Specification) modems and a CMTS (Cable Modem Termination System), the applicable layers are primarily involved in the physical and data link layers, as well as the network layer.

Layer 1, the Physical layer, is fundamental in this scenario as it concerns the transmission of raw bitstreams over a physical medium (in this case, coaxial cables). DOCSIS modems operate at this layer to facilitate signal modulation and demodulation.

Layer 2 is the Data Link layer, which manages node-to-node data transfer and error detection and correction. DOCSIS specifications detail how data is framed for transmission across the coaxial cable, signifying its critical role in ensuring reliable communication between modems and the CMTS.

Layer 3, the Network layer, is also pertinent since it deals with routing packets between devices, managing IP addressing and packet forwarding. Though primarily associated with higher-layer functionalities, the presence of Layer 3 is essential for the operation of broadband data services.

While Layers 4 and above, such as the Transport layer and Application layer, have important functions in general