Click on the 'i' icon > You see a faint line appear, but no graph Reproducible: Always Using git hash 2333fd4
This is from the frameworks branch btw.
The traffic monitor is not still ported, so you have to wait for a while.
Git commit e20839806450cd018de2e7a24fb23a54a70fe6da by Jan Grulich. Committed on 27/07/2015 at 13:07. Pushed by grulich into branch 'master'. Add traffic monitor REVIEW:124485 M +141 -8 applet/contents/ui/ConnectionItem.qml http://commits.kde.org/plasma-nm/e20839806450cd018de2e7a24fb23a54a70fe6da