Warning! This is an implementation hint article. Read this first.
The meaning of InitialTerminationTime in CreatePullPointSubscription command is not very clearly defined in the spec. However it can be roughly interpreted as:
- If InitialTerminationTime defined in relative time, the camera should automatically extend the actual termination time by the value specified with InitialTerminationTime each time the camera respond to a PullMessageRequest.
- Due to the principle stated here, in later versions of NVR software, an new template ET02 is added to accomodate this particular blurred spec issue.
This interpretation can be extrapolated by following spec reading (ONVIF-Core-Specification-v230.pdf, with annotation in colors):