BSR64K R6.3.1 TroubleshootingGuide

8/10/2019 BSR64K R6.3.1 TroubleshootingGuide

1/138

BSR 64000

Troubleshooting

Guide

Compass ID: 388931013 Version 4

Release 6.3.1


2/138

Notice

EXCEPT AS INDICATED IN THE APPLICABLE SYSTEM PURCHASE AGREEMENT, THE SYSTEM,

DOCUMENTATION AND SERVICES ARE PROVIDED "AS IS", AS AVAILABLE, WITHOUT WARRANTY OFANY KIND. MOTOROLA MOBILITY, INC. DOES NOT WARRANT THAT THE SYSTEM WILL MEETCUSTOMER'S REQUIREMENTS, OR THAT THEIR OPERATION WILL BE UNINTERRUPTED ORERROR-FREE, OR THAT ANY ERRORS CAN OR WILL BE FIXED. MOTOROLA MOBILITY, INC. HEREBYDISCLAIMS ALL OTHER WARRANTIES, EXPRESS OR IMPLIED, ORAL OR WRITTEN, WITH RESPECTTO THE SYSTEM AND SERVICES INCLUDING, WITHOUT LIMITATION, ALL IMPLIED WARRANTIES OFTITLE, NON-INFRINGEMENT, INTEGRATION, MERCHANTABILITY OR FITNESS FOR ANY PARTICULARPURPOSE AND ALL WARRANTIES ARISING FROM ANY COURSE OF DEALING OR PERFORMANCE ORUSAGE OF TRADE.

EXCEPT AS INDICATED IN THE APPLICABLE SYSTEM PURCHASE AGREEMENT, MOTOROLAMOBILITY, INC. SHALL NOT BE LIABLE CONCERNING THE SYSTEM OR SUBJECT MATTER OF THISDOCUMENTATION, REGARDLESS OF THE FORM OF ANY CLAIM OR ACTION (WHETHER INCONTRACT, NEGLIGENCE, STRICT LIABILITY OR OTHERWISE), FOR ANY (A) MATTER BEYOND ITSREASONABLE CONTROL, (B) LOSS OR INACCURACY OF DATA, LOSS OR INTERRUPTION OF USE, ORCOST OF PROCURING SUBSTITUTE TECHNOLOGY, GOODS OR SERVICES, (C) INDIRECT, PUNITIVE,INCIDENTAL, RELIANCE, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES INCLUDING, BUT

NOT LIMITED TO, LOSS OF BUSINESS, REVENUES, PROFITS OR GOODWILL, OR (D) DIRECT

DAMAGES, IN THE AGGREGATE, IN EXCESS OF THE FEES PAID TO IT HEREUNDER FOR THE SYSTEMOR SERVICE GIVING RISE TO SUCH DAMAGES DURING THE 12-MONTH PERIOD PRIOR TO THE DATETHE CAUSE OF ACTION AROSE, EVEN IF COMPANY HAS BEEN ADVISED OF THE POSSIBILITY OFSUCH DAMAGES. THESE LIMITATIONS ARE INDEPENDENT FROM ALL OTHER PROVISIONS OF THISAGREEMENT AND SHALL APPLY NOTWITHSTANDING THE FAILURE OF ANY REMEDY PROVIDEDHEREIN.

All Motorola Mobility, Inc. products are furnished under a license agreement included with the product. If you areunable to locate a copy of the license agreement, please contact Motorola Mobility, Inc.

No part of this publication may be reproduced in any form or by any means or used to make any derivative work (suchas translation, transformation, or adaptation) without written permission from Motorola Mobility, Inc.

Motorola Mobility reserves the right to revise this publication and to make changes in content from time to timewithout obligation on the part of Motorola Mobility to provide notification of such revision or change. MotorolaMobility provides this guide without warranty of any kind, implied or expressed, including, but not limited to, theimplied warranties of merchantability and fitness for a particular purpose. Motorola Mobility may make

improvements or changes in the product(s) described in this manual at any time.

MOTOROLA and the Stylized M Logo are trademarks or registered trademarks of Motorola Trademark Holdings,LLC. All other trademarks are the property of their respective owners.

2011 Motorola Mobility, Inc. All rights reserved.

Compass ID: 388931013 Version 4

Release 6.3.1

Published: 12/11


3/138

Compass ID: 388931013 Version 4 iii

Contents

Contents

Preface

Scope ............................................................................................................................................. ixAudience........................................................................................................................................ix

Documentation Set ........................................................................................................................ ix

Conventions..................................................................................................................................xii

Notes, Cautions, Warnings ..........................................................................................................xiii

If You Need Help.........................................................................................................................xiii

Telephone Support............................................................................................................xiii

Online Support..................................................................................................................xiv

Motorola BSR Customer Website......................................................................xiv

1 Introduction

Overview .....................................................................................................................................1-1

Understanding Basic Troubleshooting ........................................................................................1-2

Discovering Problems .................................................................................................................1-3

Viewing Symptoms .....................................................................................................................1-3

Isolating the Problem ..................................................................................................................1-4

Solving the Problem ....................................................................................................................1-4

Evaluating the Solution ...............................................................................................................1-5

2 Checking Physical EquipmentOverview .....................................................................................................................................2-1
http://bsr64k-r5.2.0-troubleshootingguidetoc.pdf/http://bsr64k-r5.2.0-troubleshootingguidetoc.pdf/


4/138

BSR 64000 Troubleshooting Guide Release 6.3.1

iv Compass ID: 388931013 Version 4

Checking Physical Network Connections ...................................................................................2-2

Turning On the BSR 64000.........................................................................................................2-2

Determining BSR 64000 Operational Status...............................................................................2-3

Interpreting Resource Module LED Displays.............................................................................2-6

Supervisor Resource Module LEDs .................................................................................2-7

Module LEDs.....................................................................................................2-7

Fan Status LEDs.................................................................................................2-7

Alarm LEDs .......................................................................................................2-8

2:8 CMTS Resource Module LEDs .................................................................................2-9

Module LEDs.....................................................................................................2-9

Per-Port LEDs..................................................................................................2-10

2:8 CMTS Standby Resource Module LEDs .................................................................2-11

Module LEDs...................................................................................................2-11

Per-Port LEDs..................................................................................................2-12

TX32 Resource Module LEDs .......................................................................................2-13Module LEDs...................................................................................................2-13

Per-Port LEDs..................................................................................................2-15

TX32 Standby Resource Module LEDs .........................................................................2-16

Module LEDs...................................................................................................2-16

Per-Port LEDs..................................................................................................2-17

RX48 Resource Module LEDs.......................................................................................2-17

Module LEDs...................................................................................................2-17

Per-Port LEDs..................................................................................................2-19

Diagnostic Ethernet Port LEDs........................................................................2-20

RX48 Standby Resource Module LEDs.........................................................................2-20

Module LEDs...................................................................................................2-20

Per-Port LEDs..................................................................................................2-21

Diagnostic Ethernet Port LEDs........................................................................2-21

Ether-FlexTMResource Module LEDs............................................................................2-22

Module LEDs...................................................................................................2-22

GIG-E Port LEDs.............................................................................................2-22

Ethernet (10/100) Port LEDs ...........................................................................2-23

Rebooting an Individual Resource Module...............................................................................2-24


5/138

Release 6.3.1 Contents

Compass ID: 388931013 Version 4 v

3 Troubleshooting the CMTS

Overview .....................................................................................................................................3-1

Using Flap Lists to Troubleshoot CM Problems.........................................................................3-2

Viewing Flap List Statistics to Identify Network Health .................................................3-2

Interpreting Flap List Statistics ........................................................................................3-5

Tips for Administrating Flap Lists .................................................................................3-10

Resolving HFC Network Performance Problems .....................................................................3-11

Downstream Signal Reflected on Upstream Path ..........................................................3-11

Slow Performance Detected on Upstream Port..............................................................3-11

Too Many CPE Hosts on Subscriber CM ......................................................................3-15

Resolving Problems on the Upstream Path ...............................................................................3-16

Bad Upstream Signal-to-noise Ratio Detected ..............................................................3-16

Upstream Power Level Too Low or High .....................................................................3-19

Resolving Problems on the Downstream Path..........................................................................3-21

Bad Downstream Signal-to-Noise Ratio Detected ........................................................3-21Downstream Power Level Too Low or High ................................................................3-23

Resolving Cable Modem Problems ..........................................................................................3-24

Misconfigured Authentication String or Key ................................................................3-24

CM Does Not Reply to Station Maintenance Requests .................................................3-26

CM is Offline .................................................................................................................3-26

CM Cannot Obtain an IP Address ..................................................................................3-28

Provisioning Problems Cause CMs Not to Register ......................................................3-29

CM Does Not Respond to SNMP Messages .................................................................3-33

4 Troubleshooting Basic Routing Problems

Overview .....................................................................................................................................4-1

Resolving Host Connectivity Problems ......................................................................................4-2

Default Gateway Configuration Problems ......................................................................4-2

Misconfigured or Missing Default Routes .......................................................................4-3

Incomplete DNS Host Table ............................................................................................4-3

DNS Not Running ............................................................................................................4-4

Handling Routing Problems........................................................................................................4-4

Problem Router ................................................................................................................4-4

Misconfigured Router.......................................................................................................4-6


6/138


vi Compass ID: 388931013 Version 4

Routing Interface Down ...................................................................................................4-7

Handling a Misconfigured Access List ......................................................................................4-8

Access List and Filter Misconfigurations ......................................................................4-10

Handling UDP Broadcast Forwarding Problems .....................................................................4-11

Missing or Misconfigured IP Helper-address Specification...........................................4-11

UDP Broadcast Misconfiguration .................................................................................4-12

Resolving PPP Link Over SONET Failures .............................................................................4-12

5 Troubleshooting RIPOverview .....................................................................................................................................5-1

Handling Routing Table Problems ..............................................................................................5-2

Misconfigured or Missing Network Router Table Entries ...............................................5-2

Misconfigured Route Filtering .........................................................................................5-2

Split Horizon is Disabled .................................................................................................5-3

Handling RIP Version Inconsistencies ........................................................................................5-4Misconfigured Version of RIP Running on BSR ............................................................5-4

Misconfigured Version of RIP Running on Specified Interface.......................................5-5

6 Troubleshooting OSPF

Overview .....................................................................................................................................6-1

Handling OSPF-designated Interface Problems..........................................................................6-2

Handling Router Neighbor Misconfigurations ............................................................................6-2

Misconfigured Router.......................................................................................................6-3

Mismatched OSPF Parameters ........................................................................................6-3

Mismatched IP MTU ........................................................................................6-4

Resolving Missing Routes in Routing Table...............................................................................6-6

RIP Routing Information Incorrectly Redistributed into OSPF.......................................6-6

ABR Configured Without Area 0 Interface .....................................................................6-7

7 Troubleshooting BGP

Overview .....................................................................................................................................7-1

Handling BGP Routing Problems ...............................................................................................7-2

Missing Neighbor Table Entry ........................................................................................7-2

Misconfigured Access List ..............................................................................................7-2


7/138

Release 6.3.1 Contents

Compass ID: 388931013 Version 4 vii

Missing Network Destination Advertisement .................................................................7-3

Handling BGP Peer Misconfigurations ......................................................................................7-4

8 Troubleshooting Multicast Routing

Overview .....................................................................................................................................8-1

Hosts are Not Receiving Video ..................................................................................................8-1

Check Connection Between IGMP and Hosts..................................................................8-2

IGMP Configuration Problems .........................................................................8-2

Misconfigured IGMP Access Group .................................................................8-2

Some IGMP Hosts Are Not Receiving Multicast Services ...............................8-3

Check Connections Between Multicast Routers .............................................................8-4

9 Troubleshooting SONET

Overview .....................................................................................................................................9-1

Resolving Fault LED Issues........................................................................................................9-2LOS Determination ..........................................................................................................9-2

LOS Resolution ................................................................................................................9-3

LOF Determination ..........................................................................................................9-3

LOF Resolution ................................................................................................................9-4

LOP Determination ..........................................................................................................9-4

LOP Resolution ................................................................................................................9-5

Failed POS Module ..........................................................................................................9-6

Fail LED Blinks and Lights Repeatedly...........................................................................9-6

Handling Data Loss on SONET Link .........................................................................................9-6

Data Loss Determination..................................................................................................9-6

Data Loss Resolution........................................................................................................9-8

A Cable ModemRegistration Process

Introduction ................................................................................................................................A-1

Scanning ..........................................................................................................................A-1

Initial Ranging.................................................................................................................A-2

Establishing IP Connectivity ...........................................................................................A-3

Establishing Time of Day................................................................................................A-3


8/138


viii Compass ID: 388931013 Version 4

TFTP Connectivity ..........................................................................................................A-3

Registration......................................................................................................................A-4

Baseline Privacy ..............................................................................................................A-4

Periodic Ranging .............................................................................................................A-4

Data Exchange .................................................................................................................A-5

Index


9/138

Compass ID: 388931013 Version 4 ix

Preface

Scope

This document describes how to troubleshoot the Motorola Broadband Services

Router 64000 (BSR 64000) including hardware, applications, servers, databases,

and routing. This guide uses the term networkto refer to subscriber cable modems, theBSR family of products, cables and equipment, and host servers.

Audience

This document is for use by those persons who will install and configure the

BSR 64000 product. Only trained service personnel should install, maintain, or

replace the BSR 64000.

Documentation Set

The following documents comprise the BSR 64000 documentation set:

n BSR 64000 Quick Start Guide

The quick start guide provides a "roadmap" to the tasks involved in physically

installing the BSR 64000 product, physically connecting it to your network/HFC

infrastructure, and performing configuration tasks to enable the BSR 64000 to

operate in your networking environment.


10/138


x Compass ID: 388931013 Version 4

n BSR 64000 Chassis Installation Guide

This guide provides detailed instructions for physically installing the BSR 64000

product including: procedures for rack mounting, making physical network cable

connections, connecting DC power, and for determining the status of the BSR

64000 after applying power to it. This document also provides a description of the

BSR 64000 chassis, its hardware components and modules.

n BSR 64000 Module Installation Guide

This guide contains procedures for installing additional and replacement

Resource and I/O Modules in a BSR 64000 chassis and for making physical cable

connections to the modules.

n BSR 64000 Command Line Interface Users Guide

For users, this guide describes the structure of the BSR 64000 Command Line

Interface (CLI) and its various command modes. It also provides rules and

guidelines for navigating through the CLI.

n BSR 64000 Command Reference Guide

This guide contains individual descriptions of the entire set of commands that

comprise the BSR 64000 Command Line Interface (CLI). These commands are

used to interface with, configure, manage, and maintain the BSR 64000.

n BSR 64000 System Administration Guide

For system administrators, this guide provides detailed procedures for performing

initial configuration tasks including setting up: user accounts and passwords;

telnet and console access; system logging; and associated servers such as DHCP,

DNS, etc.

n BSR 64000 CMTS Configuration and Management Guide

This guide provides the instructions and procedures for configuring and

managing BSR 64000 CMTS operation.

n BSR 64000 Routing Configuration and Management Guide

This guide contains the instructions and procedures for configuring and managing

BSR 64000 routing operation, including RIP, OSPF, and BGP.


11/138

Release 6.3.1 Preface

Compass ID: 388931013 Version 4 xi

n BSR 64000 SNMP Configuration and Management Guide


managing BSR 64000 Simple Network Management Protocol (SNMP) operation.

It also describes SNMP MIBs; provides information that describes standard and

proprietary MIB support; describes how to walk MIBs; and how to compile and

load SNMP MIBs.

n BSR 64000 BGP/MPLS VPN Configuration Guide


managing the BSR 64000 to support and implement Border Gateway Protocol/MultiProtocol Label Switching Virtual Private Networks (BGP/MPLS VPNs).

n BSR 64000 Troubleshooting Guide

This guide contains instructions and procedures for troubleshooting typical

configuration problems that might be encountered using the BSR 64000. It also

offers suggestions for information to record, and have available should the need

arise to call Motorola support for assistance with BSR 64000 operationalproblems.

n BSR 64000 Release Notes

These documents are specific to each release of the BSR 64000 product (software

and hardware). Release notes provide information about features not documented

or incorrectly documented in the main documentation set; known problems and

anomalies; product limitations; and problem resolutions.


12/138


xii Compass ID: 388931013 Version 4

Conventions

This document uses the conventions in the following table:

Convention Example Explanation

angle brackets < > ping

ping 54.89.145.71

Arguments in italic and enclosed by angle

brackets must be replaced by the text the

argument represents. In the example,

54.89.145.71replaces . When

entering the argument, do not type the anglebrackets.

bar brackets [ ] disable[level] Bar brackets enclose optional arguments. The

example indicates you can use the disable

command with or without specifying a level.

Some commands accept more than one

optional argument. When entering the

argument, do not type the bar brackets.

bold text cable relay-agent-option Boldface text must be typed exactly as it

appears.

brace brackets {} page{on| off} Brace brackets enclose required text. The

example indicates you must enter either onor

offafter page. The system accepts the

command with only one of the parameters.

When entering the text, do not type the brace

brackets.

italic text boot system Italic type indicates variables for which you

supply values in command syntax descriptions.

It also indicates file names, directory names,

document titles, or emphasized text.

screen display Wed May 6 17:01:03

2000

This font indicates system output.

vertical bar | page{on| off} A vertical bar separates the choices when a

parameter is required. The example indicatesyou can enter either command:

page onorpage off

When entering the parameter, do not type the

vertical bar or the brace brackets.


13/138

Release 6.3.1 Preface

Compass ID: 388931013 Version 4 xiii

Notes, Cautions, Warnings

The following icons and associated text may appear in this document.

If You Need Help

Support for your BSR 64000 hardware and software is available via telephone and the

Internet.

Telephone Support

If you need assistance while working with the BSR 64000, contact the Motorola

Technical Response Center (TRC):

The Motorola TRC is on call 24 hours a day, 7 days a week.

When calling for technical support, please have the following information available:

n Your customer information, including location, main contact, and telephone

number

n BSR product and modules

Note:A note contains tips, suggestions, and other helpful information, such

as references to material not contained in the document, that can help you

complete a task or understand the subject matter.

Caution: The exclamation point, within an equilateral triangle, is intended toalert the user to the presence of important installation, servicing, andoperating instructions in the documents accompanying the equipment.

Warning: This symbol indicates that dangerous voltage levels are present

within the equipment. These voltages are not insulated and may be of

sufficient strength to cause serious bodily injury when touched. The symbolmay also appear on schematics.

U.S. 1-888-944-HELP (1-888-944-4357)

International +215-323-0044


14/138


15/138


16/138


1-2 Compass ID: 388931013 Version 4

Understanding Basic Troubleshooting

The basic steps you need to troubleshoot network problems are as follows:

1. Identify the cause or symptom of the problem, which can be any undesired result

or behavior. SeeDiscovering Problems on page 1-3, to learn how to identify

problems.

2. Isolate the cause or symptom of the problem and try to determine its scope. For

example, determine if it is the whole HFC network, a particular subnetwork on

the HFC network, or just one subscriber that is experiencing the problem. See

Isolating the Problem on page 1-4, for more information.

3. Once the cause or symptom of a problem is isolated, make a list of

troubleshooting procedures that you plan to use. Refer to subsequent chapters in

this document for specific troubleshooting procedures you can use.

4. Document the changes and effects of changes as you perform troubleshooting

procedures, and note any new troubleshooting procedures that you use. This

simple precaution helps to avoid repeating steps, allows for future reference in

case the problem recurs, and is especially useful for troubleshooting intermittentproblems.

5. Determine if the problem is solved. Ensure that the troubleshooting procedure did

not cause new problems.

6. If the problem is not solved, try to identify problem causes more clearly, isolate

any additional causes, and perform additional troubleshooting procedures to

correct the problem.

Note: One or more symptoms or causes can be related to a single problem.


17/138

Release 6.3.1 Introduction

Compass ID: 388931013 Version 4 1-3

Discovering Problems

Ensure that you thoroughly understand the network so that you can establish abaseline from which to work, and distinguish the differences between normal and

abnormal activity on the network.

Perform the following steps to determine the source of problems:

Review release notes and technical bulletins to determine if there are any

incompatibilities or known problems.

Gather information for all the possible causes or symptoms to more quicklyisolate the problem.

Discover if the problem relates to another problem that you must solve first.

Record all configuration parameters that relate to the problem.

Determine if the network configuration has changed recently, such as the addition

or removal of components, upgrading, or reconfiguration.

Identify aspects that causes or symptoms have in common to determine if they are

related.

Look for network patterns in the causes. What time of day did these problems

occur? What events were logged? What network thresholds were transgressed?

Record any changes that occurred since the network was last functioning

correctly. Changes in network activity may relate to a configuration change.

Record any changes that occurred since the last time the BSR was operating

properly. Investigate any configuration changes that might be related to theproblem.

Viewing Symptoms

Perform the following tasks to view and compare symptoms that are related to a

problem:

Repeat the conditions that led to the symptom. Consider any errors or failures thatcan cause a particular symptom, and test them to see if they are causing the

symptom.

Determine if any symptoms are related. Are there unexpected or undesired results

in more than one area? If so, find the areas in common and the variables that

affect them. The source of the problem is often found in similar areas.


18/138



Focus on one symptom or a set of related symptoms of a problem. However, do

not completely disregard other symptoms, because what may appear to be an

unrelated problem may actually be related based on other symptoms.

Isolating the Problem

A problem can have one or more causes. To identify the cause of unwanted behavior,

use the following techniques:

Isolate the problem. For example, isolate a problem to one part of the network or

to a specific access module. Find the functions that are working correctly.

Retrace the steps that were taken, and return the network to its condition before

the problem first appeared. Once the network is in a known condition, take

incremental steps and observe the network to learn when and where the problems

occur.

Determine if there have been any additions, changes, or upgrades to the network.

If so, consider any consequences the changes could have had on the network, and

whether they affect the current situation.

Solving the Problem

Different problems require different actions and solutions, but follow these basic steps

to fix any problem:

1. Identify the course of action and the steps you plan to take.

2. Decide what tools are necessary to fix the problem on the network. For example,

you can use the CLI as a tool to look at events and set SNMP traps. You can use a

cable tester to check physical media connections.

3. Perform each step for the course of action.

4. Verify the result of each action using the available CLI show commands. For

example, if you enabled a port, use the appropriate show ip interface brief

command in Privileged EXEC mode to verify that the port is enabled.

5. If more than one possible action exists, select the easiest one first to quickly

eliminate possibilities, or select the action that appears most likely to solve the

problem first, even if it is the most time-consuming or difficult to perform.


19/138

Release 6.3.1 Introduction


Evaluating the Solution

Once you find the solution, test it to ensure that no new symptoms or problems occur.If new symptoms or problems do occur, repeat the troubleshooting process to

determine the cause. If problems or symptoms recur, create a standard test plan to

evaluate fixes.


20/138


21/138


2Checking Physical Equipment

Overview

This chapter describes how to turn on the BSR 64000 and observe system startup to

determine if the system boots properly. The process also involves checking physical

connections and observing LEDs on the BSR products. In addition, you should check

power and network connections anytime you install new hardware or whenever a

problem occurs.Topics in this chapter include:

Checking Physical Network Connections

Turning On the BSR 64000

Determining BSR 64000 Operational Status

Interpreting Resource Module LED Displays

Rebooting an Individual Resource Module

BSR 64000 T bl h ti G id R l 6 3 1


22/138



Checking Physical Network Connections

Check network connections for loose, broken, or disconnected cables. Inspect thecable terminating connectors for damage.

Use the following techniques to troubleshoot physical cables on the network:

Use the Command Line Interface (CLI) showcommands to view port and slot

information.

Use a cable tester to test the network cables for damage.

Verify that all the networks associated with the BSR are within properspecifications.

Use cable testing equipment to measure or ensure that the correct distances for

cable runs are in place.

If the BSR 64000 is installed, ensure that all modules are seated correctly in the

chassis.

Replace any suspected defective modules or devices with known working spare

modules or devices.

Refer to the system documentation or service contract information for

replacements and on-site spares.

Turning On the BSR 64000

To apply power to the BSR 64000, complete the following tasks:

1. Verify that the electrical connections to the BSR 64000 are secure.

2. Turn on the DC power supply connected to the BSR 64000.

Release 6 3 1 Checking Physical Equipment


23/138

Release 6.3.1 Checking Physical Equipment


3. Turn on each BSR 64000 Power Entry Module by placing its power switch in the

ON (I) position. You can access the Power Entry Module power switches through

the plastic shield that covers the DC power connections. See Figure 2-1.

Figure 2-1 Accessing BSR 64000 Power Switches

Determining BSR 64000 Operational Status

To determine BSR 64000 status following power up do the following:

Visually check the operational status of the cooling units. All fans in the bottomFan Module and the blowers in the top Blower Module should be turning and the

Fan Status LED labeled OK on the front panel of the SRM should be lit green for

both the top (TOP) Blower Module and bottom (BOT) Fan Module.

Power Entry Module B

Power Switch

Power Entry Module A

Power Switch

bsr64k036a

BSR 64000 Troubleshooting Guide Release 6 3 1


24/138



Observe the LEDs on the SRM, CMTS, TX32, RX48, and NIM (HSIM) Modules

after the booting process completes. The LED display on these modules will vary

until the BSR 64000 is booted. When the booting process completes, the LEDswill display as described in Table 2-1.

Table 2-1 BSR 64000 LED Display States Following Successful Booting

Module LED LED Display State

Supervisor Resource

Module (SRM)

Module LEDs:

Fail Off

Status Green (Active SRM)

or

Blinking Green (Standby SRM)

(SRM Redundant Systems Only)

Alarm Off

Fan Status LEDs (TOP and BOT (bottom) Fan Module):

OK Green

Fail Off

Alarm LEDs:

MIN (Minor) Off

MAJ (Major) Off

CRIT (Critical) Off

2:8 CMTS Resource

Module

Module LEDs:

Fail Off

Status Green

Alarm Off

Upstream and Downstream Port LEDs:

Link Off (unconfigured) orGreen

Fault Off



25/138



2:8 CMTS Standby

Resource Module

Module LEDs:

Fail Off

Status Blinking Green

Alarm Off

Upstream and Downstream Port LEDs:

Link Off Fault Off

TX32 Resource Module Module LEDs:

Fail Off

Status Green

Alarm Off

Downstream Port LEDs:


Fault Off

TX32 Standby Resource

Module

Module LEDs:

Fail Off


Alarm Off

Downstream Port LEDs:

Link Off

Fault Off

RX48 Resource Module Module LEDs:

Fail Off

Status Green

Alarm Off

Upstream Port LEDs:


Fault Off





26/138

g


Interpreting Resource Module LED Displays

The following sections describe the LED displays of the following BSR 64000

Resource Modules:

Supervisor Resource Module LEDs

2:8 CMTS Resource Module LEDs

2:8 CMTS Standby Resource Module LEDs

TX32 Resource Module LEDs

TX32 Standby Resource Module LEDs

RX48 Resource Module LEDs

RX48 Standby Resource Module LEDs

Ether-FlexTMResource Module LEDs

RX48 Standby Resource

Module

Module LEDs:

Fail Off


Alarm Off

Upstream Port LEDs:

Link Off Fault Off

Ether-Flex Resource

Module andEther-Flex

Standby Resource

Module

Module LEDs:

Fail Off

Status Green

Alarm Off

GIG-E Port LEDs:

Link Green

ACT (Activity) Off orBlinking Green

10/100 Port LEDs:


ACT (Activity) Off orBlinking Green





27/138


Supervisor Resource Module LEDs

The SRM has the following groups of LEDs that indicate its operational status and the

status of other chassis components:

Module LEDs

Fan Status LEDs

Alarm LEDs

The subsections that follow describe the display states of these LED groups.

Module LEDs

The SRM Module LEDs are visible on the module front panel and are labeled: Fail,

Status, and Alarm.

Table 2-2describes the possible display states of these LEDs during operation.

Fan Status LEDs

The SRM provides a set of Fan Status LEDs for each of the Fan Tray Modules

installed in the BSR 64000 chassis. These LEDs are visible on the module front panel

of the SRM and are labeled: OKand Fail. Table 2-3describes the possible display

states of the LEDs. Separate LED status is available for the top (TOP) and bottom

(BOT) Fan Tray Modules.

Table 2-2 Module LED Display States for the SRM

Fail Status Alarm Interpretation

Off Green Off Normal operating status. When operating in SRM redundant

mode, indicates that the SRM is the Active SRM.

Off Blinking

Green

Off Normal operating status. When operating in SRM redundant

mode, indicates that the SRM is the Standby SRM.

Off Green Red Failure. SRM is operating with an alarm condition.

Red Off Off Indicates a module hardware failure.

Red Off Red Failure. SRM is not operational.

Red Green Red Reset. SRM is booting.

Off Off Off Module is not receiving power.


28/138



29/138


2:8 CMTS Resource Module LEDs

2:8 CMTS Modules have two groups of LEDs that indicate the operational status of

the module. These LED groupings include:

Module LEDs

Per-Port LEDs

The following subsections describe the possible display states of these LED types.

Module LEDs

The Module LEDs are visible on the module front panel and are labeled: Fail,Status,

and Alarm.

Table 2-5describes the possible display states of these LEDs during non-redundant

2:8 CMTS operation and Table 2-6describes the possible states of these LEDs during

redundantoperation.

Table 2-5 Module LED Display States for 2:8 CMTS Resource Module

(Non-Redundant Operation)


Off Green Off Normal operating status.

Off Green Red Failure. Module is operating with an alarm condition. Note: This

sequence of LEDs occurs when an alarm condition is detected

on individual upstream and downstream ports.

Red Green Off Indicates a module hardware failure.

Red Off Red Failure. Module is not operational.

Red Off Off Failure. Power (-48 Vdc) is present at the midplane connector

but not at the module. May indicate a blown fuse on the module.

Off Off Off Module is not receiving power or is not secured in the chassis

through its module ejectors and integrated ejector switch.



30/138


Per-Port LEDs

Downstream ports and each upstream port have two LEDs associated with them to

indicate their operational status. These LEDs are visible on the module front panel

and are labeledLinkand Fault.

Table 2-6 Module LED Display States for a 2:8 CMTS Resource Module

(Redundant Operation)


Off Green Off Normal operating status. Module is providing service to the HFC

network.

Off Blinking

Green

Off A failure or other disruption has caused the 2:8 CMTS Standby

Module to assume service to the HFC network. The module

can be placed back in service by performing an administrative

switch-over from the 2:8 CMTS Standby Module to this module.

Off Blinking

Green

Red Failure. Module is operating with an alarm condition and service

to the HFC network is switched over to the 2:8 CMTS Standby

Module (if available).

Note: This sequence of LEDs occurs when an alarm condition

is detected on individual upstream and downstream ports.

Red Blinking

Green

Off Indicates a module hardware failure and service to the HFC

network is switched over to the 2:8 CMTS Standby Module.

Red Off Red Failure. Module is not operational and service to the HFCnetwork is switched over to the 2:8 CMTS Standby Module (if

available).



Red Green Red Reset. Module is booting.




31/138



32/138



Per-Port LEDs

The 2:8 CMTS downstream ports and each upstream port have two LEDs to indicate

their operational status. These LEDs are visible on the module front panel and arelabeledLinkand Fault.

Port LEDs are grouped vertically. A number to the right of each LED group indicates

the channel number associated with the group. The two downstream channels are

numbered 0 and 1, and the eight upstream channels are numbered 0 through 7.

Table 2-8 Module LED Display States for the 2:8 CMTS Standby Resource Module


Off Blinking

Green

Off Normal operating status. Module is in a Standby state.

Off Green Off Normal operating status. Module has assumed service for a

primary 2:8 CMTS module.

Off Green Red Failure. Module is operating with an alarm condition.Note: Thissequence of LEDs occurs when an alarm condition is detected

on individual upstream and downstream ports.





Red Green Red Reset. Module is booting.Off Off Off Module is not receiving power or is not secured in the chassis




33/138


Table 2-9describes the possible display states of these LEDs when the module has

assumed service for a primary 2:8 CMTS module. When the module is operating in

Standby mode, the LEDs should all be Off.

TX32 Resource Module LEDs

TX32 Resource Modules have two groups of LEDs that indicate the operational status

of the module. These LED groupings include:

Module LEDs

Per-Port LEDs


Module LEDs


and Alarm.

Table 2-9 2:8 CMTS Standby Module Downstream and Upstream

Per-Port LED Display States

Link Fault Interpretation

Green Off Normal operating status when module has assumed service for

a primary 2:8 CMTS module and the port is configured.

Green Red Operating with an alarm condition detected. Note:An alarm

condition detected for an individual port also causes the System

Alarm LED to light.

Off Red Failed port. Port is not operational.

Off Off Port is not configured. Note: Check module LEDs to determine

if the module is receiving power.



34/138



operation and Table 2-11describes the possible states of these LEDs during

redundantoperation.

Table 2-10 Module LED Display States for the TX32 Resource Module





sequence of LED occurs when an alarm condition is detected

on individual downstream ports.





Off Off Off Module is not receiving power or is not secured in the chassisthrough its module ejectors and integrated ejector switch.




Off Green Off Normal operating status. Module is capable of providing service

to the HFC network.

Off Blinking

Green

Off A failure or other disruption has caused the TX32 Standby

Module to assume service to the HFC network. The module can

be placed back in service by performing an administrative

switch-over from the TX32 Standby Module to this module.

Off Blinking

Green


to the HFC network is switched over to the TX32 Standby


Note: This sequence of LED occurs when an alarm condition is

detected on individual upstream and downstream ports.

Red Blinking

Green


network is switched over to the TX32 Standby Module (if

available).



35/138


Per-Port LEDs

Downstream ports each have two LEDs associated with them to indicate their

operational status. These LEDs are visible on the module front panel and are labeled

Linkand Fault.

Port LEDs are grouped vertically. A number to the right each LED group indicates the

channel number associated with the group. The eight downstream channels are

numbered 0 through 7.


Red Off Red Failure. Module is not operational and service to the HFC

network is switched over to the TX32 Standby Module (if

available).






Table 2-12 TX32 Downstream Per-Port LED Display States


Green Off Normal operating status when configured.



Alarm LED to light.


Off Off Port is not configured.

Note: Check module LEDs to determine if the module is

receiving power.






36/138


TX32 Standby Resource Module LEDs

TX32 Standby Resource Modules have two groups of LEDs that indicate the

operational status of the module. These LED groupings include:

Module LEDs

Per-Port LEDs


Module LEDs

The Module LEDs are visible on the module front panel and are labeled: Fail,Status,and Alarm.

Table 2-13describes the possible display states of these LEDs when the module has

assumed service for a primary TX32 module. When the module is operating in


Table 2-13 Module LED Display States for the TX32 Standby Resource Module


Off Blinking

Green

Off Normal operating status. Module is in a Standby state.


primary TX32 module.

Off Green Red Failure. Module is operating with an alarm condition.Note: This

sequence of LED occurs when an alarm condition is detectedon individual upstream and downstream ports.










37/138


Per-Port LEDs

Downstream ports each have two LEDs associated with them to indicate their

operational status. These LEDs are visible on the module front panel and are labeledLinkand Fault.


channel number associated with the group. The eight downstream channels are

numbered 0 through 7.


RX48 Resource Module LEDs

RX48 Modules have two groups of LEDs that indicate the operational status of the

module. These LED groupings include:

Module LEDs

Per-Port LEDs


Module LEDsThe Module LEDs are visible on the module front panel and are labeled: Fail,Status,

and Alarm.

Table 2-14 TX32 Standby Downstream Per-Port LED Display States


Green Off Normal operating status when configured.



Alarm LED to light.




receiving power.



38/138



operation. Table 2-16describes the possible display states of these LEDs during

redundant operation.

Table 2-15 Module LED Display States for the RX48 Resource Module



Off Green Off Normal operating status when configured.



on individual upstream ports.





Off Off Off Module is not receiving power or is not secured in the chassisthrough its module ejectors and integrated ejector switch.




Off Green Off Normal operating status. Module is capable of providing service

to the HFC network

Off Blinking

Green

Off A failure or other disruption has caused the RX48 Standby

Module to assume service to the HFC network. The module can

be placed back in service by performing an administrative

switch-over from the RX48 Standby Module to this module.

Off Blinking

Green


to the HFC network is switched over to the RX48 Standby


Note: This sequence of LED occurs when an alarm condition is

detected on individual upstream and downstream ports.

Red Blinking

Green


network is switched over to the RX48 Standby Module (if

available).



39/138


Per-Port LEDs

Upstream port have two LEDs associated with them to indicate their operational

status. These LEDs are visible on the module front panel and are labeledLinkand

Fault.


channel number associated with the group. The eight upstream channels are numbered

0 through 7.


Red Off Red Failure. Module is not operational and service to the HFC

network is switched over to the RX48 Standby Module (if

available).






Table 2-17 RX48 Upstream Per-Port LED Display States


Green Off Normal operating status.



Alarm LED to light.




receiving power.






40/138


Diagnostic Ethernet Port LEDs

The RX48 front panel includes an RJ45 connector for use as a 1000BaseT diagnostic

Ethernet Port. The RJ45 connector includes two integrated LEDs, one green and oneyellow. The Green LED provides Link status of the port. The yellow LED indicates

port activity.

RX48 Standby Resource Module LEDs

RX48 Standby Modules have two groups of LEDs that indicate the operational status

of the module. These LED groupings include:

Module LEDs

Per-Port LEDs


Module LEDs


and Alarm.Table 2-18describes the possible display states of these LEDs when the module has

assumed service for a primary RX48 module. When the module is operating in


Table 2-18 Module LED Display States for RX48 Standby Resource Module


Off Blinking

Green

Off Normal operating status. Module is in Standby state.


primary RX48 Module.



on individual upstream ports.









41/138


Per-Port LEDs

Upstream port have two LEDs associated with them to indicate their operational

status. These LEDs are visible on the module front panel and are labeledLinkandFault.


channel number associated with the group. The eight upstream channels are numbered

0 through 7.


Diagnostic Ethernet Port LEDs

The RX48 Standby front panel includes an RJ45 connector for use as a 1000BaseTdiagnostic Ethernet Port. The RJ45 connector includes two integrated LEDs, one

green and one yellow. The Green LED provides Link status of the port. The yellow

LED indicates port activity.

Table 2-19 RX48 Standby Upstream Per-Port LED Display States


Green Off Normal operating status.



Alarm LED to light.




receiving power.



42/138


Ether-FlexTMResource Module LEDs

The Ether-FlexTMResource Module has the following groups of LEDs that indicate its

operational status and the status of other chassis components:

Module LEDs

GIG-E Port LEDs

Ethernet Port LEDs

The following subsections describe the possible display states of these LED groups.

Module LEDsThe Module LEDs are visible on the module front panel and are labeled: Fail,Status,

and Alarm.


GIG-E Port LEDs

Ether-FlexTMResource Modules support two optical ports (either single-mode or

multimode), labeled 0and 1. Each port has two LEDs associated with it to indicate the

ports operational status. The LEDs are visible on the module front panel and arelabeledLinkand ACT.

Table 2-20 Module LED Display States for the Gigabit Ethernet Resource Module



Off Green Red Failure. Module is operating with an alarm condition.







h b ( ) h i h f h i di h b


43/138


The number (0 or 1) to the right of each LED group indicates the port number

associated with the group. Table 2-21describes the possible display states of these

LEDs during operation.

Ethernet (10/100) Port LEDs

Ether-FlexTMResource Modules support eight 10/100 BASE-T Ethernet ports, labeled

0through 7. Each Ethernet port on the module has two LEDs associated with it to

indicate the ports operational status. The Ethernet port LEDs are visible on the

module front panel and are labeledLinkand ACT.

Port LEDs are grouped vertically. Table 2-22describes the possible display states of

the 10/100 Ethernet Port LEDs during operation.

Table 2-21 Gig-E Port LED Display States

Link ACT Interpretation

Green Flashing

Green

Normal operating status when configured and connected to an

external device. Link is established, and the ACT LED flashes to

show activity on the port.

Off Off Port is not configured, has failed, is not operational, or is notconnected.

Note:Check module LEDs to determine if the module is receiving

power.

Green Off Link without activity.

Table 2-22 8-Port 10/100 Port LED Display States

Link ACT Interpretation

Green Flashing

Green

Normal operating status when configured and connected to an

external device. Link is established, and the ACT LED flashes to

show activity on the port.

Off Off Port is not configured, has failed, is not operational, or is not

connected.

Note:Check module LEDs to determine if the module is receiving

power.

Green Off Link without activity.


44/138


45/138


3Troubleshooting the CMTS

Overview

This chapter provides troubleshooting solutions tosomecommon DOCSIS network

problems with the following:

Using Flap Lists to Troubleshoot CM Problems

Resolving HFC Network Performance Problems

Resolving Problems on the Upstream Path

Resolving Problems on the Downstream Path

Resolving Cable Modem Problems




46/138



The BSR maintains a database of flapping CMs to assist in locating cable plant

problems. The flap list feature tracks the upstream and downstream performance of all

CMs on the network, without impacting throughput and performance between the CM

and BSR, or creating additional packet overhead on the HFC network.

Refer to theBSR 64000 CMTS Configuration and Management Guidefor more

information on configuring flap-list settings.

Viewing Flap List Statistics to Identify Network Health

Flap lists are used to collect statistics for determining CM problems on the network.

There are several different options for sorting flap list statistics. The CM flap list

keeps track of the CM MAC address, up and down transitions, registration events,

missed periodic ranging packets, upstream power adjustments on the BSR. This

section describes the different sorting options and describes the command output

fields.

CMs appear in the flap list when any of the following conditions are detected: The CM re-registers more frequently than the configured insertion time.

Intermittent keepalive messages are detected between the BSR and the CM.

The CM upstream transmit power changes beyond the configured power adjust

threshold.

Follow these steps to view flap list statistics by using different sorting options:

1. Issue the show cable flap-listcommand, in Privileged EXEC mode, to view allflap list statistics for CMs:

MOT:7A#show cable flap-list

The following is typical show cable flap-list command output:

Figure 3-1 show cable flap-list Command Output

MAC ID CableIF Hit Miss Ins CRC Pow Rng Flap Type Time

000b.0643.3b60 4/0 U1 1469 7 0 3 0 1 1 Rng FRI NOV 05 11:59:39

000b.0643.36c8 4/0 U1 1469 7 0 0 0 1 1 Rng FRI NOV 05 11:59:40

000b.0643.3b78 4/0 U1 1469 6 0 0 0 1 1 Rng FRI NOV 05 11:59:40

Release 6.3.1 Troubleshooting the CMTS

2. Issue the show cable flap-list sort-flap command, in Privileged EXEC mode, to


47/138


2. Issue the show cable flap list sort flapcommand, in Privileged EXEC mode, to

sort the flap list statistics in ascending order by the CM flap:

MOT:7A#show cable flap-list sort-flap

The following is typical show cable flap-list sort-flap command output:

Figure 3-2 show cable flap-list sort-flap Command Output

3. Issue the show cable flap-list sort-timecommand, in Privileged EXEC mode, to

sort the flap list statistics in ascending order by the time at which the CM flapoccurred:

MOT:7A#show cable flap-list sort-time

The following is typical show cable flap-list sort-time command output:

Figure 3-3 show cable flap-list sort-time Command Output

4. Issue the show cable flap-list sort-interfacecommand, in Privileged EXEC

mode, to sort the flap list statistics in ascending order by the cable upstream

interface on which the CM flap occurred:

MOT:7A#show cable flap-list sort-interface

MAC ID CableIF Hit Miss Ins Pow Rng Flap Type Time

0020.403d.a764 4/0 U0 5519 0 1 2877 0 2878 PAdj TUE JAN 13 07:58:24 2004

0050.f112.2144 3/1 UO 65 0 1 2566 0 794 PAdj TUE JAN 13 07:19:47 2004

0050.f112.2296 2/1 UO 18 0 1 1234 0 553 PAdj TUE JAN 13 07:21:05 2004

0010.9504.a92b 3/0 UO 148 0 1 2344 0 181 PAdj TUE JAN 13 07:34:32 2004


0020.403d.a764 4/0 U0 5519 0 1 2877 0 2878 PAdj TUE JAN 13 07:58:24 2004

0050.f112.2144 3/1 UO 65 0 1 2566 0 794 PAdj TUE JAN 13 07:34:32 20040050.f112.2296 2/1 UO 18 0 1 1234 0 553 PAdj TUE JAN 13 07:21:05 2004

0010.9504.a92b 3/0 UO 148 0 1 2344 0 181 PAdj TUE JAN 13 07:19:47 2004


The following is typical show cable flap-list sort-interface command output:


48/138


g yp p p

Figure 3-4 show cable flap-list sort-interface Command Output

Table 3-1identifies the flap list command output column field identifications:

Table 3-1 Flap List Command Output Identifications

Field Identification

MAC ID Lists the MAC addresses of the CMs sorted by the flap rate or mostrecent flap time. The first six digits in the CM MAC address indicate

the vendor ID of the CM manufacturer, followed by six digits indicating

a unique host address. Each CM MAC address is unique.

Cable IF Indicates the cable interface up/down flap. This is the cable interface

on the BSR 64000 CMTS module. It denotes the CMTS module slot

number, the downstream and the upstream port number. The flap list

data can be sorted based on the upstream port number which is

useful when isolating reverse path problems unique to certaincombining groups.

Hit The Hit and Miss column fields detect the intermittent upstream; the

keepalive hits versus misses is the number of times CMs do not

respond to the MAC layer keepalive messages. If there are a number

of misses, this points to a potential upstream problem.

Miss

Ins The Insertions Link process is used by a CM to perform an initial

maintenance procedure to establish a connection with the BSR. The

Ins column is the flapping CMs (re-) insertion count and indicates the

number of times the a CM starts and inserts into the network in an

abnormal way. An abnormality is detected when the time between link

re-establishment attempts is less than the user-configurable

parameter. This function can identify potential problems in the

downstream interface such as incorrectly provisioned CMs repeatedly

trying to re-establish a link.


0020.403d.a764 4/0 U0 5519 0 1 2877 0 2878 PAdj TUE JAN 13 07:58:24 20040050.f112.2144 3/1 UO 65 0 1 2566 0 794 PAdj TUE JAN 13 07:19:47 2004

0050.f112.2296 3/0 UO 18 0 1 1234 0 553 PAdj TUE JAN 13 07:21:05 2004

0010.9504.a92b 2/1 UO 148 0 1 2344 0 181 PAdj TUE JAN 13 07:34:32 2004


Table 3-1 Flap List Command Output Identifications


49/138


Interpreting Flap List Statistics

This section describes how to interpret flap list statistics in order to troubleshoot thecable network.

CM activity follows the sequence below:

Power-on

Initial maintenance

Station maintenance

Power-off

The initial link insertion is followed by a keepalive loop between the BSR and CM

and is called station maintenance. When the link is broken, initial maintenance is

repeated to re-establish the link.

Initial maintenance @ Time T1

Station maintenance

CRC Displays the count of CRC errors for each cable modem on the

flap-list. This count is also saved in the cable modem history record so

that the count remains valid if cable modems flap. The count is a sum

of all of the CRC errors for each service flow tied to a cable modem.

Pow The Power Adjustment column field shows power adjustment

statistics during station maintenance polling. This column indicates

the number of times the BSR tells a CM to adjust the transmit power

more than the configured threshold. If constant power adjustments are

detected, an amplifier problem is usually the cause. The source of

failure is found by viewing CMs either in front or behind various

amplifiers.

Rng Response to RNG-RSP messages from affected CMs. The cable

modem is online and sent a periodic Ranging Request (RNG-REQ)

message to the CMTS, but it received an Abort Ranging reply from the

CMTS.

Flap Total of Pow, Rng, and Ins values. High flap-count CMs have highSIDs and may not register.

Type Type of error event which triggered the CM to flap.

Time Indicates the most recent time a flap has occurred for a particular CM.

Field Identification


Init maintenance @ Time T2


50/138


The Insand Flapcounters in the flap list are incremented whenever T2 T1 < N

where Nis the insertion-time parameter configured using the cable flap-listinsertion-timecommand. The default value for this parameter is 60 seconds.

Use the following cause or symptom observations to interpret flap list activity and

solve CM problems:

Table 3-2 Troubleshooting CM Problems

Cause or Symptom Problem

Subscriber CM shows a lot of flap list

activity

CM is having communication problems with

the BSR.

Subscriber CM shows little or no flap list

activity.

The CM is communicating with the BSR

effectively, however there is still a problem.

The problem can be isolated to the

subscribers CPE computer equipment or the

CM connection.

Ten percent of the CMs in the flap listshow a lot of activity.

These CMs are most likely having difficultiescommunicating with the BSR.

CMs have a lot of power adjustment

(P-Adj) errors.

CMs have problems with their physical

upstream paths or in-home wiring problems.

Use corresponding CMs on the same physical

upstream port interface with similar flap list

statistics to quickly resolve problems outside

the cable plant to a particular node or

geographic location.

All CMs are incrementing the insertion at

the same time.

There is a provisioning server failure.

A CM has more than 50 power

adjustments per day.

The CM has a suspect upstream path.

Corresponding CMs on the same physical

upstream port interface with similar flap list

statistics can be used to quickly resolve

problems outside the cable plant to aparticular node or geographic location.

A CM has roughly the same number of

hits and misses and contain a lot of

insertions.

There is a problematic downstream path. For

example, the downstream power level to the

CM may have a power level that is too low.

A high flap list insertion (Ins) time

number.

Intermittent downstream synchronization loss.

DHCP or CM registration problems.




51/138


Low miss/hit ratio, low insertion, low

P-adj, low flap counter and old

timestamp.

Indicates an optimal network situation.

High ratio of misses over hits (> 10%) Hit/miss analysis should be done after the

"Ins" count stops incrementing. In general, if

the hit and miss counts are about the same

order of magnitude, then the upstream may

be experiencing noise. If the miss count is

greater, then the CM is probably dropping out

frequently and not completing registration.

The upstream or downstream is perhaps not

stable enough for reliable link establishment.

Very low hits and miss counters and high

insertion counters indicate provisioning

problems.

High power adjustment counter. Indicates the power adjustment threshold is

probably set at default value of 2 dBadjustment. The CM transmitter step size is

1.5 dB, whereas the headend may command

0.25 dB step sizes. Tuning the power

threshold to 6 dB is recommended to

decrease irrelevant entries in the flap list. The

power adjustment threshold may be set using

the cable flap-list power-adjust threshold

command from Global Configuration mode. Aproperly operating HFC network with short

amplifier cascades can use a 2-3 dB

threshold.





52/138


High P-Adj (power adjustment) This condition can indicate that the fiber node

is clipping the upstream return laser. Evaluate

the CMs with the highest number of

correcteds and uncorrecteds first. If the CMs

are not going offline (Ins = 0), this will not be

noticed by the subscriber. However, they

could receive slower service due to dropped

IP packets in the upstream. This condition will

also result in input errors on the cableinterface.

High insertion rate. If link re-establishment happens too

frequently, then the CM is usually having a

registration problem. This is indicated by a

high Ins counter which tracks the Flap

counter.

Note: CMs go offline faster than the frequency hop period and can cause the

frequency to stay fixed while CMs go offline. Reduce the hop period to 10

seconds to adjust to the hop frequency period.



Table 3-3describes how to interpret flap list statistics:


53/138


Table 3-3 Flap List Statistic Interpretations

Field Description

Hit and Miss The HIT and MISS columns are keepalive polling statistics between the

BSR and the CM. The station maintenance process occurs for every CM

approximately every 10 seconds. When the BSR receives a response

from the CM, the event is counted as a Hit. If the BSR does not receive a

response from the CM, the event is counted as a Miss. A CM will fail to

respond either because of noise or if it is down. CMs which only log

Misses and zero Hits are assumed to be powered off.

Misses are not desirable since this is usually an indication of a return path

problem; however, having a small number of misses is normal. The flap

count is incremented if there are M consecutive misses where M is

configured in the cable flap-list miss-thresholdparameter. The

parameter value ranges from 1-12 with a default of 6.

Ideally, the HIT count should be much greater than the Miss counts. If a

CM has a HIT count much less than its MISS count, then registration is

failing. Noisy links cause the MISS/HIT ratio to deviate from a nominal 1%or less. High Miss counts can indicate:

Intermittent upstream possibly due to noise

Laser clipping

Common-path distortion

Ingress or interference

Too much or too little upstream attenuation

P-Adj The station maintenance poll in the BSR constantly adjusts the CMtransmit power, frequency, and timing. The Power Adjustments (P-Adj)

column indicates the number of times the CMs power adjustment

exceeded the threshold value. The power adjustment threshold may be

set using the cable flap-list power-adjust thresholdcommand with a

value range of 0-10 dB and a default value of 2 dB. Tuning this threshold

is recommended to decrease irrelevant entries in the flap list. Power

Adjustment values of 2 dB and below will continuously increment the

P-Adj counter. The CM transmitter step size is 1.5 dB, whereas the

headend may command 0.25 dB step sizes. Power adjustment flap

strongly suggests upstream plant problems such as:

Amplifier degradation

Poor connections

Thermal sensitivity

Attenuation problem


Table 3-3 Flap List Statistic Interpretations


54/138


Tips for Administrating Flap Lists

Follow these suggestions for administrating flap lists:

Write script(s) to periodically poll the flap list.

Analyze and identify CM trends from the flap list data.

Query the billing and administrative database for CM MAC address-to-street

address translation and generate reports. These reports can then be given to the

Customer Service Department or the cable plants Operations and Maintenance

Department. Maintenance personnel use the reports to see patterns of flapping

CMs, street addresses, and flap statistics that indicate which amplifier or feeder

lines are faulty. The reports also help troubleshoot problems

Documents

BSR64K R6.3.1 TroubleshootingGuide