Troubleshooting High-Speed Data Service

What are two features that were added in Data Over Cable Service Interface Specification (DOCSIS) 3.1 to extend the viability of hybrid fiber/coax (HFC) network into the next decade?

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

Which step in the troubleshooting process requires a discussion with the customer to gather more detail about the problem?

Step 1: Identify the problem.

Which Data over Cable Service Interface Specification (DOCSIS) layer is used by cable modem termination system (CMTS) to differentiate between cable modems?

The DOCSIS Media Access Control (MAC) Layer.

What was introduced in Data Over Cable Service Interface Specification (DOCSIS) 3.0 to allow enough bandwidth for upstream carriers from previous DOCSIS versions?

The option to increase the top frequency of the upstream to 85MHz.

When analyzing a problem, what can the technician learn by asking the customer to show or demonstrate the problem?

The symptoms of the problem can be viewed, and any unusual screens or customer entries can be identified.

How does Internet protocol (IP) multicast differ from IP broadcast?

IP multicast traffic is only sent to specific modem addresses on the network; IP broadcast traffic is sent to all modems on the network.

What would be the downstream throughput if two quadrature amplitude modulation (QAM) channels with a throughput of 38 megabits per second (Mbps) were bonded?

76 Mbps.

When using a digital signal analyzer to troubleshoot data throughput in the Data Over Cable Service Interface Specification (DOCSIS) network, what is the minimum modulation error ratio (MER) into the cable modem for a 256- quadrature amplitude modulation (QAM) carrier?

32 dB or greater.

In a Data Over Cable Service Interface Specification (DOCSIS) network, why is the data throughput over the return or upstream path typically less than the throughput of data over the forward or downstream path?

Compared to the downstream path, the narrower bandwidths and lower orders of modulation used to transport data over the return path cause the downstream and upstream data throughput to be unequal or asymmetrical.

What layers of the Open Systems Interconnection (OSI) reference model are specific to cable networks and are present only between Data Over Cable Services Interface Specification (DOCSIS) modems and the cable modem termination system (CMTS)?

Layers 1 through 4 (Physical layer, Data Link Layer, Network Layer, and Transport Layer) are applied between the DOCSIS modem and CMTS.