Summary

Cisco.com

• Cable networks can offer voice and integrated data as well as analog and digital video.

• Cisco high-speed cable Internet equipment use the HFC system.

- One 810-MHz channel carries downstream traffic from the headend to subscribers.

- Another 37-MHz channel carries upstream signals from the subscriber toward the headend.

• DOCSIS is the cable service interface standard for data carried across RF interfaces.

• The DOCSIS CMTS communicates through channels with cable modems located in subscriber homes.

© 2004 Cisco Systems, Inc. All rights reserved. BCRAN v2.1—4-15

Quiz

Use the practice items here to review what you have learned in this lesson. The correct answers follow in the Quiz Answer Key.

Q1) CATV, commonly called cable TV, was invented to solve what consumer problem?

A) no data communications

B) cost-effectiveness

C) poor TV reception

D) not enough channels

Q2) The downstream video traffic emanates from the headend and is injected into a trunk cable at signal strength above _____ .

Q3) The_is the beginning of the cable distribution network.

A) headend

C) cable system

Q4) The subscriber drop includes_.

A) the set-top box

C) every thing up to the utility pole feeder

D) the backyard pedestal

Q5) Which of the following does not affect signal strength through coaxial cable?

A) weather

B) outside noise

C) temperature changes

D) topology

Q6) An individual cable modem subscriber may experience access speeds from_.

Q7) The upstream frequencies coming from the customer are in the range of_.

D) all of the above

Q8) _defines specific bandwidths for data signals (200 kHz, 400 kHz, 800 kHz,

1.6 MHz, and 3.2 MHz) that the cable operator can use.

A) Euro-DOCSIS

B) DOCSIS

C) NTSC

Q9) The location where the cable company aggregates, combines, mixes, and modulates all signals to send them downstream is called_.

A) headend

B) DOCSIS

C) NTSC

Q10) _is the TV system used in most of Europe.

A) Euro-DOCSIS

B) DOCSIS

C) NTSC

Q11) In what path are signals demodulated back to digital?

A) upstream

B) downstream

C) CMTS

Q12) Where does a PC receive an IP address in a CMTS?

A) from headend

B) from DHCP server

C) from TFTP server

D) from DOCSIS

0 0

Post a comment