How does iDMSS Plus push notification work

[tomas21]

I'm trying to figure out how the push notification works for Dahua ip cams without a DVR based on a situation below.

I thought my mobile phone had to actively be able to communication with my home Dahua cameras but I discovered something...

While not home, on Verizon LTE, and not VPN'd into my home network... i got a push notification to my mobile device. I don't understand how the camera that detected motion was able to send a push notification to my mobile device based on my setup at home. I do not have a DVR but have the cameras all configured to capture motion and send to a local FTP server.

Thoughts?

 

[nayr]

Dahua runs a cloud NVR service and it probably relays push's out via that so the phone wont need direct access to the camera to be notified.. dunno havent set it up yet.

thats how blackberry push's notifications, i dont think I trusted them anymore than I do Dahua.. but I digress, they could use it as potential vector for privacy abuse.

My cams are on there own vlan and I block outgoing internet connections on that network, I run a local NTP/DNS/FTP server and use VPN so they have no need for internet access.

 

[tomas21]

Dahua runs a cloud NVR service and it probably relays push's out via that so the phone wont need direct access to the camera to be notified.. dunno havent set it up yet.

thats how blackberry push's notifications, i dont think I trusted them anymore than I do Dahua.. but I digress, they could use it as potential vector for privacy abuse.

ya I'm real curious because I didn't setup any cloud settings. How does it know to link my phone to my cams for push notification?

 

[nayr]

your phone grabs the camera's hardware id when it logs in the first time on setup.. the mobile app probably connects to Dahua and says: here I am and these are the devices I am configured for, maby a one way hash of username/password.

then the camera, when it has an alert and is configured to push it connects to Dahua and says: I am <hardwareid> with token <username/password hash> and I need you to push this out to any listening devices... then Dahua makes a connection to your phone (the push part, instead of phone making connection to Dahua) and relays the video... The Mobile app just has a listening port open to dahua's servers and updates its IP with dahua when needed.

Thats how I suspect it works, its transparent to you and there is nothing to setup as long as both cameras can reach Dahua's push proxy... if they have an outage then push notifications will fail.

I will do some packet captures and gather more info once I got a Dahua NVR and everything all setup; none of my cams will push.

 

[tomas21]

I don't have a Dahua DVR setup only Dahua cams. If you give me some instructions I can fire up wireshark and see what happens when motion push notifications go out from any of my 2 Dahua cams.

 

[nayr]

you'd need a switch with port mirroring to get the packets of another machine directed to you, or an old network hub.. other-words you have to watch the packets traverse your router to see if there "calling home".. (or setup a pc router with 2 network interfaces bridged and wireshark running)

if you have an old hub plug your computer and the cameras into the hub and run a wireshark capture filtering the addresses of your cameras while you trigger a push event.. and dig through looking for any non-local traffic.

Would want to do this for both the mobile app and the camera to see what both are sending.

 

[tomas21]

HI Nayr,

Did you ever figure out how the push service works on Dahua cameras setup on the iGMSS Plus iPhone app?

 

[nayr]

nope, never got me a Dahua NVR with this functionality.. just didnt seem worth the cost.. I open the phone app a few times a year, usually when I am on vacation and I want to move the PTZ's to check on things... I also have my IP cameras firewalled off from internet access, they can only talk to devices on the same vlan and nothing else.

My HA software has IPCamera support, so I just have it push a jpeg photo when an event fires off that's in view of a camera.. works fine, even with 2G phone speeds out in the middle of nowhere.