Appendix; Docsis And Cmts Architectural Overview; Docsis Specification Summary - Cisco uBR10012 Software Configuration Manual

DOCSIS and CMTS Architectural Overview

This appendix provides a brief overview of general DOCSIS architecture and enhancements, all of which
highlight the power and performance of the Cisco uBR10000 series CMTS.
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For a more comprehensive explanation of DOCSIS concepts and features, refer to these documents on
Cisco.com:
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At the time of publication, the DOCSIS 1.1 specification is still being finalized. This document cites
Note
DOCSIS 1.0 and DOCSIS 1.1 specifications located at
http://www.cablelabs.com/cablemodem/specifications/.

DOCSIS Specification Summary

Data is modulated and demodulated using the North American DOCSIS specifications, with downstream
6-MHz channels in the 54- to 860-MHz range and upstream ranges of 5 to 42 MHz. The cable interface
supports NTSC channel operation, using standard (STD), Harmonic Related Carrier (HRC), or
Incremental Related Carrier (IRC) frequency plans conforming to EIA-S542.
NTSC uses a 6 MHz-wide modulated signal with an interlaced format of 25 frames per second and 525
lines per frame. NTSC is compatible with the Consultive Committee for International Radio (CCIR)
Standard M. PAL, used in West Germany, England, Holland, Australia, and several other countries.
Cisco 6-MHz products can be used in Cisco 8-MHz cable plants. The products, however, operate at
Note
a maximum downstream bandwidth of 27 Mbps, ignoring 2 MHz of available channel width, and
limiting upstream channel choices to the range below 42 MHz.
The DOCSIS radio frequency (RF) specification defines the RF communication paths between the
CMTS and CMs (or CMs in STBs). The DOCSIS RF specification defines the physical, link, and
network layer aspects of the communication interfaces. It includes specifications for power level,
frequency, modulation, coding, multiplexing, and contention control. Cisco offers products that support
all DOCSIS error-correction encoding and modulation types and formats, and products that support
DOCSIS Annex B operations.
OL-1520-05
"DOCSIS Specification Summary" section on page A-1
"CMTS Traffic Engineering" section on page A-5
DOCSIS 1.1 for Cisco uBR7200 Series Universal Broadband Routers
Cable FAQs
A P P E N D I X
Cisco uBR10012 Universal Broadband Router Software Configuration Guide
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