Cisco Systems UBR924 CMTS to Cable Modem Network Topology

List of Terms

Troubleshooting Tips for the Cisco uBR924 Cable Access Router 7

CMTS to Cable Modem Network Topology

Figure 1 shows the physical relationship between the devices in the HFC network and the

CiscouBR924 cable access router.

Figure1 Sample Topology

IP-related

ATM, FDDI, 100BT...

100BT

Analog TV

Digital TV

Upconvertor

ISP @ home...

DS-RF 54-860 Mhz

Fiber

Transceiver

80 km

Fiber node

(Telephone pole,

underground box)

Distribution

amplifier Top

amplifier

1000 ft

Drop box

Cisco u BR904

cable modem

100BT

100BT

100BT

Proxy server

ISP

WAN

Cisco

uBR7246

CMTS MSD: Maintenance Service

Organization, Cable companies

13304

Contents

Main Troubleshooting Tips for the Cisco uBR924 Cable Access Router Feature Summary Benefits Restrictions Platforms Prerequisites Supported MIBs and RFCs List of Terms Page Page List of Terms Troubleshooting Tips for the Cisco uBR924 Cable Access Router 7 CMTS to Cable Modem Network Topology Figure1 Sample Topology Troubleshooting Steps Step 1Understand How Basic Initialization Works Page . Step 2Connect to the Cisco uBR924 the cable service company prior to installation at the subscriber site. Step 3Display the Cisco uBR924s MAC Log File Step 3Display the Cisco uBR924s MAC Log File 12 Cisco IOS Release 12.0(5)T Step 4Interpret the MAC Log File and Take Action Event 1Wait for the Link to Come Up Event 2Scan for a Downstream Channel, then Synchronize Event 3Obtain Upstream Parameters Event 4Start Ranging for Power Adjustments Event 5Establish IP Connectivity Event 6Establish the Time of Day Event 7Establish Security Event 8Transfer Operational Parameters Event 9Perform Registration Event 10Comply with Baseline Privacy Event 11Enter the Maintenance State Step 5Use Additional Troubleshooting Commands Command Reference show controllers cable-modem show controllers cable-modem Troubleshooting Tips for the Cisco uBR924 Cable Access Router 21 Following is sample output for the show controllers cable-modem 0 command: Table2 briefly describes some of the fields shown in the display. For more information, see the Page Page Page show controllers cable-modem bpkm Page show controllers cable-modem des DES engine registers are displayed in the following example: Table4 briefly describes some of the fields shown in the display. For more information, see the Page show controllers cable-modem filters MAC and SID filter information is displayed in the following example: Table5 briefly describes some of the fields shown in the display. For more information, see the Page show controllers cable-modem lookup-table show controllers cable-modem lookup-table Troubleshooting Tips for the Cisco uBR924 Cable Access Router 35 The mini-slot lookup table is displayed in the following example: show controllers cable-modem lookup-table 36 Cisco IOS Release 12.0(5)T Page show controllers cable-modem mac Example 1 If the DHCP server cannot not be reached, the error will look like this in the MAC log: Example 2 Example 3 Page Page Example 4 Page Page Example 5 Page Table8 describes the fields shown in the display. Page Page Page show controllers cable-modem phy show controllers cable-modem phy 54 Cisco IOS Release 12.0(5)T Physical transmit registers are displayed in the following example: Page show controllers cable-modem tuner Page Debug Commands debug cable-modem bpkm Page debug cable-modem bridge Page debug cable-modem error Page debug cable-modem interrupts Page debug cable-modem mac Example 1 Example 2 Example 3 Page Page Page debug cable-modem map