Results after running Princeton IoT Inspector for 2 hours

If you want to check it out, here is the web page. It only just became available for Windows 10 pretty recently.

Here is a link to a snapshot of the “communication endpoints” reported by the inspector after running it on my PC for 2 hours.

A few things of note.

  1. I have my primary DNS on my router set to so that’s what that entry is.
  2. The entry for local network I assume is Sense talking to my HS110s and my HS300. It’s interesting to me though that it’s the largest chunk of data.
  3. Obviously, it connects to
  4. There are two entries for Amazon. I assume Sense is running it’s server on AWS. Since this is the 2nd largest chunk of data, I assume this is Sense providing the energy information back to the mothership.
  5. Sense is sending data to After going to the site and poking around a bit, it seems like this service can be used in a variety of ways.
  6. Sense is sending data to Apple. The entry that is a ? has an IP that starts with 17.253.20 so it’s an Apple server as well.

For transparency, it would be awesome if someone from Sense could explain what data is being sent to Data Dog and how it’s being used. It appears to send data to them every 5 minutes.

I would also like to know why data is being sent to Apple, and what that data is. I have no Apple devices in my house whatsoever nor do I use any Apple services. It seems to send Apple a near constant stream of small data (like around 30 Kbps).


For anyone interested, here is the local network traffic for a single HS110. I have 3 HS110s on my network, and the chart looks identical for all 3.

Apparently, the HS300, even though it functions as 6 separate devices, transmits it’s data for all the plugs at the same time.

  • Sense uses AWS for cloud servers and online storage. Of note, any PII is kept is physically separate systems.
  • We use Datadog for Support-related diagnostics, tracking non-identifiable information like memory usage and Wi-Fi RSSI.
  • We’re actually currently using Apple for our NTP (time) server. It’s a bit of a vestigial holdover from the early days here, but we’ll be updating that soon.

Interesting. I have often wondered about NTP and IoT devices that have critical time stamping requirements … and I assume a Sense monitor fits that bill. I assume there is a balance between on-monitor time drift and the frequency of polling the NTP server? At what point do you install atomic clocks in the monitor like one sees in various weather stations and self-correcting time pieces?