The Network metric group contains per-node metrics regarding network activity. The metrics available are:

• Network in
• Network out

These metrics traffic can indicate if certain nodes are bearing more load due to traffic or repairs. This can otherwise be hidden under some circumstances (eg, uneven partition size or batch size).

Network in

This metric shows the difference between the number of bytes received over the network since the last metric.

You can also get this metric through the Monitoring API  with the query param metrics=n::networkindelta

Network out

This metric shows the difference between the number of bytes sent over the network since the last metric.

You can also get this metric through the Monitoring API  with the query param metrics=n::networkoutdelta