Installation guide

CHAPTER

4-1

Cisco uBR7100 Series Universal Broadband Router Software Configuration Guide

OL-2238-03

Configuring Basic Broadband Internet Access

This chapter describes the parameters of configuring and maintaining basic broadband Internet access.

The chapter contains these sections:

• “Overview of Basic Broadband Internet Access” section on page 4-1

• “Typical Routing Configuration For High Speed Internet Access” section on page 4-2

• “Transparent Bridging Configuration” section on page 4-8

• “Integrated Routing and Bridging Configuration” section on page 4-10

• “Baseline Privacy Interface” section on page 4-13

Overview of Basic Broadband Internet Access

A Cisco uBR7100 series router and an intermediate frequency (IF)-to-RF upconverter are installed at the

headend or distribution hub to transmit digital data. The Cisco uBR7100 series router downstream ports

transmit IF signals to the upconverter, which translates the downstream signals to RF for broadcast.

Receivers, scramblers, and descramblers then process the TV signals to encode or decode signals as

needed for broadcast. Modulators format the analog TV and digital signals.

The analog and digital signals then pass through the RF combiner. The signals are broadcast from the

headend through optical transmitters to fiber nodes.

Amplifiers, coaxial cable, and taps carry the signals to the subscriber premises. Signals are processed as

follows:

• Tuners that handle MPEG video, audio and broadcast services in STBs, TVs, and VCRs receive

one-way analog signals.

• CMs, or tuners in EuroDOCSIS STBs that handle IP data, receive digital data signals:

–

Two-way CMs transmit RF signals back through amplifiers to optical fiber receivers at the

headend. These receivers pass the upstream signal to upstream ports on the Cisco uBR7100

series router where they are processed.

–

Telco return CMs transmit over the PSTN. Refer to Telco Return for the Cisco CMTS for

additional information.

Figure 4-1 on page 4-2 illustrates this general signal flow and associated processes in the CMTS.