Specifications

Bridging and Routing Features for the Cisco uBR904 Cable Modem 1
Bridging and Routing Features for the
Cisco uBR904 Cable Modem
The following sections are provided:
• Feature Summary, page 1
• Prerequisites, page 4
• Supported MIBs and RFCs, page 4
• Functional Description, page 5
• Configuration Options, page 7
• Configuration Tasks, page 8
• Configuration Examples, page 17
• Command Reference, page 19
• What to Do Next, page 37
Feature Summary
The Cisco uBR904 cable modem is a fully-functional Cisco IOS router and standards-based
Data-Over-Cable Service Interface Specification (DOCSIS) cable modem designed for use in small
office/home office data-over-cable applications. It enables the delivery of secure, high-speed
connections over small to medium-sized LANs. Downstream speeds up to 27 Mbps are supported
using the 64-QAM modulation technique, or 40 Mbps using 256-QAM. On the upstream, the
Cisco uBR904 can deliver 5 Mbps using Quadrature Phase-Shift Keying (QPSK) or 10 Mbps using
16-QAM.
The Cisco uBR904 is a compact device that supports the direct connection of up to four PCs and has
the familiar features and programming interface of other routers in Cisco’s extensive line of small-
and medium-sized business product offerings. The Cisco uBR904 provides packet data transport and
network address translation for TCP/IP applications between home or office computers and the cable
headend.
You can configure your cable modem to act as a bridge or as a router. See Figure 1 and Figure 2. For
more detailed descriptions of these options, see the “Configuration Options” section on page 7.