Network Outage

In August 2019, the FCC’s probe into the massive CenturyLink network outage indicated the cause was equipment failure starting with malformed packets. Read more about that here.

In general network design and configuration should avoid issues like this happening. But given the constant need to update network and equipment software to enable features and to enhance security, there is also a constant need to validate that things that are supposed to work still work.

The strategy to avoid situations like the one above is to simulate and emulate in the lab prior to network deployment of equipment or a software update.

A Traffic Generator like the Spirent TestCenter is used to simulate the traffic and a Network Emulator like the Calnex SNE is used to emulate the network effects to add realism to the test.

For example, to simulate and emulate the scenario that happened above, the setup below is used.

bad packets diagram

The traffic generator is used to create test packets with load, distribution and type as expected in the network. The Calnex SNE is then used to:

  1. Flip bits or bytes within a packet or overwrite them with to malform the payload.

  2. Add network latency, loss and jitter effects.

The traffic generator would then detect whether any catastrophic conditions such as the one that brought down the CenturyLink network happen or not.

With the Calnex SNE, you can go beyond testing to fully simulate and emulate to validate everything works correctly prior to deployment in a live network, thereby avoiding potentially disastrous consequences


Anand Ram
VP Business Development