Missing stats counters

Could someone explain, why there is only one field in most of stats counters? (and what does it show, tx or rx)?

At the same time, on the other router with the same ROS version (7.23.1) there are 2 fields for each counter. But packets counters are missing on this tab.

Judging by the field names "Tx&Rx" instead of "Tx/Rx" it shows the sum. :upside_down_face:

Oh, I didn't notice that, thanks. But anyway, it's still unclear, why they are different.

chipset features, not all chipsets have all details....