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Cisco uBR7200 Series Universal Broadband Router Software Configuration Guide
OL-2239-05
Chapter 1 Overview of Cisco uBR7200 Series Software
Cisco uBR7200 Series Chassis Overview
System Interoperability
This section describes guidelines about the interoperability of certain features in the
Cisco uBR7200 series universal broadband routers. Additional DOCSIS interoperability is described in
the
“Supported Software Features for the Cisco uBR7200 Series” section on page 1-22
.
Cable Modem Interoperability
The Cisco uBR7200 series interoperates with the following cable modems:
•
DOCSIS-based two-way cable modems that support basic Internet access, VoIP, or Virtual Private
Networks (VPNs).
•
Telco-return Cable modems
To support telco return, use a Cisco uBR7200 series software image that contains “t” in its file name.
The telco-return cable modem must be DOCSIS-based or compliant and must be configured to
support telco return.
Note
Some third-party telco-return CMs cannot receive traffic over the same downstream
channel as CMs operating on a two-way data system. In these instances, segment your
cable plant to allow more than one downstream channel.
•
EuroDOCSIS cable modems or STBs with integrated EuroDOCSIS CMs using Cisco MC16E cable
interface line cards and Cisco IOS Release 12.1(2)EC1 or higher.
EuroDOCSIS operation support includes 8-MHz Phase Alternating Line (PAL) or Systeme
Electronique Couleur Avec Memoire (SECAM) channel plans.
Clock Synchronization
The Cisco uBR7200 series support clock hardware and software to enable high-quality delivery of IP
telephony services through synchronized data transmissions. To support the clock feature set, a
Cisco uBR7246 VXR chassis must be used. The Cisco uBR7246 VXR must contain a clock card and an
MC16S, MC16E, or MC28C cable interface line card. Only the MC16S, MC16E, and MC28C cable
interface line cards support the external clock reference from the clock card to distribute that signal to
CMs or STBs attached to the specific network segments. A chassis configured with an MC16S or
MC16E cable interface line card must be running Cisco IOS Release 12.1(2)EC1 or higher. A chassis
configured with an MC28C cable interface line card must be running Cisco IOS Release 12.1(3a)EC1 or
higher.
Each cable modem must also support VoIP applications and the clock reference feature set to enable
synchronized timing. The Cisco uBR924 cable access router, running Cisco IOS Release 12.0(7)T or
later, supports the clock reference feature set automatically.
