Docsis-Compliant Downstream Signals - Cisco 7246VXR - uBR Router Software Configuration Manual

Chapter 1 Overview of Cisco uBR7200 Series Software
Figure 1-2
Satellite
feed
Off-air
channels

DOCSIS-Compliant Downstream Signals

Downstream signals are modulated using 64 or 256 Quadrature Amplitude Modulation (QAM-64 or
QAM-256), based on the cable interface card used, your cable plant, and the significance of the data.
DOCSIS defines the messages and data types for CMTS to cable modem (or cable modem in an STB)
OL-2239-05
EuroDOCSIS and STB Architecture
PSTN
Internet
Hub
OC-3 (155-Mbps) to
OC-48 (2488-Mbps)
fiber ring
Hub Hub
Hub
Receiver
MPEG encoder
Remultiplexer
and modulators
Local streaming
media servers
Local streaming
media caches
Cisco uBR7200 Series Universal Broadband Router Software Configuration Guide
Regional streaming
media servers
Regional streaming
media caches
Streaming media
manager
PSTN
Cisco GSR 12000
high-speed router
Headend
Cisco subscriber
registration center
STB Internet
application servers
Proxy servers
Billing system
Cisco Universal
Broadband Router
(uBR7200)
RF
STB Internet
application servers
MPEG
VoD server
Web caches
DOCSIS and CMTS Interoperability
Satellite
feed
Receiver
MPEG
encoder
Remultiplexer
and modulators
Ad insertion
Firewall
High-speed
router
(Cisco
GSR 12000)
Regional data center
HFC
network
Node
STB
Off-air
channels
1-139