Troubleshooting Tips for the Cisco uBR904 Cable Modem

The following sections are provided:

Feature Summary on page 1

Prerequisites on page 3

Supported MIBs and RFCs on page 3

CMTS to Cable Modem Network Topology on page 4

Troubleshooting Tips on page 5

Command Reference on page 16

Debug Commands on page 42

What to do Next on page 54

Feature Summary

This document provides MSOs (multiple service operators) with a set of software tools for troubleshooting a cable modem for data-over-cable connections. These tools are Cisco IOS troubleshooting commands used for verifying communication between the cable modem and other peripheral devices installed in the HFC network, such as the headend Cisco uBR7246, a DHCP server, and TFTP server.

Benefits

A MAC layer system log file exists inside the cable modem, which provides you with a snapshot of detailed reasons why an interface might reset and all the negotiations that occurred between the cable modem and the CMTS (a Cisco uBR7246 positioned at the headend). Over 220 possible description fields exist in this log. The log is displayed using the show controller cable-modem 0 mac log EXEC command.

Debug does not need to be turned on to troubleshoot a cable modem.

Cable technicians can understand the progression of normal data-over-cable communication events, from which they can resolve faulty system connections.

A cable technician can remotely telnet into a Cisco uBR904 cable modem, which could be installed in a customer’s home, and perform simple diagnostic tasks.

Troubleshooting Tips for the Cisco uBR904 Cable Modem 1

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Cisco Systems UBR904 manual Feature Summary, Benefits

UBR904 specifications

The Cisco UBR904 is a versatile broadband access device designed to deliver high-speed internet and data services in various deployment scenarios, particularly suitable for cable operators and service providers. This device allows operators to provide broadband services over a wide area, utilizing advanced technologies to ensure reliability and performance.

One of the key features of the UBR904 is its capability to support multiple channels for upstream and downstream communication, allowing for greater bandwidth and improved network performance. With its integrated DOCSIS (Data Over Cable Service Interface Specification) compliance, the UBR904 enables operators to leverage existing coaxial cable infrastructures to deliver data services efficiently. This makes it an ideal choice for operators looking to expand their service offerings without the need for extensive infrastructure changes.

Equipped with a powerful processor and ample memory, the UBR904 is designed for high throughput and low latency, supporting IP data services, voice services, and video on demand. It utilizes advanced modulation techniques and error correction algorithms that enhance data transmission efficiency and reliability. This results in a robust platform capable of meeting the demands of high-density areas while accommodating future growth.

The UBR904 also features flexible management capabilities. It includes support for SNMP (Simple Network Management Protocol), enabling operators to monitor and manage network performance effectively. The device can be easily configured through a graphical user interface or command-line interface, providing system administrators with the tools needed for straightforward deployment and maintenance.

In addition to its core functionalities, the UBR904 integrates security features to protect network traffic and ensure user data integrity. This includes capabilities for secure tunneling and access control lists, which enhance the security of the broadband connection.

Furthermore, the Cisco UBR904 is designed with scalability in mind. Operators can easily scale their networks by adding additional modules or interfaces as demand grows. This ensures that the UBR904 can meet the evolving needs of service providers without necessitating a complete hardware overhaul.

In summary, the Cisco UBR904 is a robust, feature-rich broadband access device that combines high performance, advanced technologies, and scalability, making it an excellent choice for operators looking to deliver high-speed internet and data services across diverse environments. Its ease of use and extensive management features further enhance its appeal, positioning it as a key player in the broadband access market.