KDE Network Manager is suppose to have notification options for Connection Activated or Deactivated are missing here. I am on Kubuntu 14.04 LTS fully updated. You can see in the picture that some of the items are missing.
Different version of the KDE Network Manager widget have various number of the notifications.
Kubuntu 12.04 LTS - KDE 4.8 has:
Kubuntu 14.04 LTS - KDE 4.13 has:
Kubuntu 15.04 - KF5 / plasma 5 has:
With the 14.04 LTS, KDE 4.13,the Connection Activated' or 'Deactivated' are shown by the 'Active connection state changed'.