@Roalnd-Baldin thanks!
Good catch the 195/197. However, we still see hundreds on AWS. It’s probably us then. I’ll check the header.

NB-IoT provides security features based on known LTE technology. The security features cover three categories:

Confidentiality: The customer payload is encrypted between NB-IoT modem and Cellular IoT Serving Gateway Node (CSGN). Between the private APN and server, the traffic is protected using IPSec (device cannot be accessed from the Internet). Integrity & authentication: The NB-IoT device authenticates itself at the network, based on known LTE registration procedures (SIM based authentication) Availability: If a redundant APN has been ordered the APN is distributed across two geo-redundant CSGNs.