Downstream is DSLAM to modem
Upstream is modem to DSLAM.
Usually it is more common to see downstream errors as traditionally it is downstream which uses the higher frequencies.
However VDSL has several frequencies bands (groups of tones), so it can depend on what tones are in use... or at what frequency there may be EMI/RFI type noise.
An awful lot of Upstream Errors can sometimes be indicative of a HR type fault, but this is also usually accompanied by crackling on the telephone line, or the line dropping when the phone is in use.
it would be nice to know a bit more about how the technology works though.
The
DMT section on the main website more info about the frequency allocations and how it works
In last day I have had about 430 upstream ES and no ES on downstream this can be normal then?
That figure over the course of a day is considered acceptable by the DLM.
One caveat to be aware of is that some modems don't always reset the upstream errors.