Subscription service: the lifetime counter shall be reset on any subscription related request
In Subscription service the lifetime counter shall be reset on any subscription service request.
Whereas it is not indicated in the subscription states table, the following specification part 4 sentence indicates it:
If the timer expires the number of times defined for the Subscription lifetime without having received a Subscription Service request from the Client, the Subscription assumes that the Client is no longer present, and terminates.
Moreover UACTT tests it, including the Monitored Item Service request concerning the subscription. As a conclusion the lifetime counter shall be reset for any valid Subscription or Monitored Item Service request on a given subscription.