General Troubleshooting Guidelines

General troubleshooting procedure

General planning for troubleshooting

Effective troubleshooting depends in part on measures that you take before you experience trouble in your network. Cambium recommends the following measures for each site:

  • Identify troubleshooting tools that are available at your site (such as a protocol analyzer).
  • Identify commands and other sources that can capture baseline data for the site. These may include:
    • Ping
    • Tracert or traceroute
    • Link Capacity Test results
    • Throughput data
    • Configuration tab captures
    • Status tab captures
    • Session logs
    • Web browser used
  • Start a log for the site
    • Include the following information in the log:
    • Operating procedures
    • Site-specific configuration records
    • Network topology
    • Software releases, boot versions and FPGA firmware versions
    • Types of hardware deployed
    • Site-specific troubleshooting processes
    • Escalation procedures
  • Capture baseline data into the log from the sources listed above

General fault isolation process

Effective troubleshooting also requires an effective fault isolation methodology that includes the following:

  • Attempting to isolate the problem to the level of a system, subsystem, or link, such as
    • AP to SM
    • AP to CMM4
    • AP to GPS
    • Backhaul(BH)
    • Backhaul(BH) to CMM4
    • Power
  • Researching Event Logs of the involved equipment
  • Interpreting messages in the Event Log
  • Answering the questions listed in the following sections.
  • Reversing the last previous corrective attempt before proceeding to the next.
  • Performing only one corrective attempt at a time.

Questions to help isolate the problem

When a problem occurs, attempt to answer the following questions:

  • What is the history of the problem?
    • Have we changed something recently?
    • Have we seen other symptoms before this?
  • How wide-spread is the symptom?
    • Is the problem on only a single SM? (If so, focus on that SM.)
      • Is the problem on multiple SMs? If so
      • is the problem on one AP in the cluster? (If so, focus on that AP)
      • is the problem on multiple, but not all, APs in the cluster? (If so, focus on those APs)
      • is the problem on all APs in the cluster? (If so, focus on the CMM4 and the GPS signal.)
  • Based on data in the Event Log
    • does the problem correlate to External Hard Resets with no WatchDog timers? (If so, this indicates a loss of power. Correct your power problem.)
    • is intermittent connectivity indicated? (If so, verify your configuration, power level, cables and connections and the speed duplex of both ends of the link).
    • does the problem correlate to loss-of-sync events?
  • Are connections made via shielded cables?
  • Does the GPS antenna have an unobstructed view of the entire horizon?
  • Has the site grounding been verified?