In which message inactivity timer signalled to UE in LTE?

Hi Experts,
Please help to tell in which message inactivity timer signalled to UE in LTE.
How eNodeB knows UE is inactive to move it to idle state?
In ZTE I’ve seen we have separate inactivity timer for enodeb and UE.
For Nokia only common parameter inactivitytimer so need to check how UE come to know value configured.

Do you mean RRC inactivity timer?
If so, it is not communicated to UE.
eNodeB maintains this timer and releases RRC connection after timer expiry.
UE will go to inactive on eNodeB instructions.

Hope you people are talking about Discountinous Reception…

Yes, thanks for clarification. It mean only eNodeB controlled it.

No it’s not DRX.