I've only seen it on the VMG8x24-B10A's and VMG1312-B10A's.
This with the BCM63168 chipset makes those 2 modems the highest syncing I've used.
I've tried a number of other BCM63168 modems (Billions, Netgear, TP-Link,) and none of them sync as high as the 2 Zyxel models with the noise filter.
A number of other members find the exact same.
Others well be in a better position to explain the technical wonders of this.
