Archive for December, 2009

Packet Analysis and VoIP: Useless?

December 23, 2009

Many people think you need to “look inside the packets” with a network analyzer to be able to debug & troubleshoot VoIP problems.  I would argue that this is rarely the case, as network analyzers are useful in a small handful of cases and most involve troubleshooting application configuration problems.

If you look at an overnight courier like UPS, their operating model has a lot of similarities to a large VoIP network.  Clients send & receive hundreds of thousands of packages across their network on a nightly basis.

If you look at how they operate, they don’t tear open packages to try to determine why a shipment went missing or why it is late. They learned a long time ago that they needed to “watch their entire network” and have tracking systems that can insure:

  1. That the packages make it to their destination (no packages lost)
  2. The packages all reach their destination on-time (low transit latency/delay)
  3. The packages reach their destination on-time as a regular occurrence (high degree of predictability with their service/low jitter)

When running a VoIP network, it’s rarely beneficial to “look inside the packets” to see the voice contents. What’s needed is the ability to “watch the entire network” so problems can be pinpointed when, where, and why they occur for fast remediation.