Introduction to DOCSIS

Which DOCSIS version was the first to provide an option for raising the top frequency of the upstream spectrum to 85 megahertz (MHz) in order to create enough bandwidth for upstream carriers from modems running on previous DOCSIS modems?

DOCSIS 3.0

What features were introduced with the 3.1 Version of (DOCSIS 3.1) to increase the downstream and upstream data throughput?

Orthogonal frequency division multiplexing (OFDM) and low-density parity-check (LDPC).

What requirements were needed for PacketCable to deliver a quality and reliable telephone service over a DOCSIS access network?

Quality of Service (QOS) controls, enhanced security and adaptive equalization in the upstream path.

The First version of DOCSIS was approved as an international standard by what organization?

The International Telecommunication Union (ITU)

Which Open Systems Interconnection (OSI) reference model layers does the Media Access Control (MAC) Layer in the Data Over Cable Service Interface Specification (DOCSIS) overlap so that the media access control (MAC) can be used by the cable modem termination system (CMTS) to differentiate between cable modems?

The physical and data link layers

What communications access technology does the first version of DOCSIS (DOCSIS 1.0) use to send data upstream over the networks radio frequency (RF) return path?

Time Division Multiple Access (TDMA)

Where do DOCSIS modems receive their configuration files, billing system messages and access control messages from?

From the CMTS (headend) which interfaces with the operations support system (OSS) and acts as a proxy or messenger that transfers messages and files between the modems and the respective servers.

Why are the data throughput rates for both downstream and upstream in DOCSIS networks asymmetrical?

Because the narrower bandwidths and lower orders of modulation for the return path carriers cause the DOCSIS downstream and upstream data raters to be unequal or asymmetrical

What Criteria does the DOCSIS certification process ensure

Compliance with the DOCSIS standard and interoperability between suppliers.

Which Layers of the Open Systems Interconnection (OSI) reference model are specific to cable networks and are present only between DOCSIS modems and the CMTS?

Layers 1-4 (Physical Layer, Data Link layer, Network layer, and transport layer) are applied between the DOCSIS Modem and CMTS.