Selecting the Right Network Troubleshooting Tool Part One: The Packet Analyzer
November 10, 2015
You have no intention of outsourcing your network maintenance needs to a third party management service. Instead, you’re going to roll up your sleeves and perform network maintenance the old fashioned way—that is, in house, right alongside your own network staff.
This is a great decision, as you and your staff will continue to be the closest ones to your network, ensuring that you maintain total control over all of the minute management details needed to keep your system up and running.
Keep in mind, however, that if you choose to go this route you’re going to need to use the right network troubleshooting tools; and with so many from which you can choose, the process can seem a bit overwhelming.
In this series, we’ll highlight several common network troubleshooting tools that are available, starting with a packet analyzer:
What it is: A packet analyzer—sometimes referred to as a packet capture device— is an instrument used to measure healthy data packets as they pass through a single location on the network.
What it’s useful for: It’s excellent for locating problems at Open System Interconnection (OSI) layers four through seven, transport to application. A packet analyzer is also useful for locating differentiated services code point (DSCP) tagging problems and VoIP codec issues. It can tell you about conversations that exist between agents and what ports are used.
What it’s bad for: The problem is that packet analyzers can only see valid, healthy packets. All bad packets get discarded by the switch or router before they make it to the packet analyzer, which means you only get part of the picture when assessing your network’s conditions. It can’t see where or why packets went missing – it can only confirm that there are missing packets. As a result, it’s poor at locating problems at layers one through three of the network, or the physical to network layers.
We often describe a packet analyzer like monitoring a traffic jam from an overpass. You can gain a lot of details from looking at the cars below; but you won’t be able to see a mile down the road to the actual cause of the traffic jam.
So keep in mind that a packet analyzer is a great tool for confirming that you have a network problem; but it won’t let you know where, or why, they are happening.