VMG1312-B10A: QoS

The ZyXEL VMG1312 has QoS enabled by default with a set of default rules giving priorities to various protocols.

Initial findings show that the default settings may not ideal.

The affect of disabling QoS

Here we are running a backup job, an rsync (over ssh). Just after 7am QoS is disabled for around 30 minutes. The latency (blue) immediatly jumps up to an average of 350ms. It was less than 20ms with QoS enabled.

Standard QoS enabled, then disabled, then enabled

Problems with default settings

With the default settings, running an rsync over ssh backup, kills DNS lookups completely! SSH has a higher priority than DNS, and with all the SSH traffic DNS lookups can't get a word in edgeways.

2015-05-08 We're looking in to better config for the QoS settings.