Environment
Onomondo app: Traffic Monitor
Device-to-server communication via TCP / UDP
Issue
Source IP on UDP datagrams does not match SIM IP.
I cannot identify SIM IPs via UDP packets sent to the server.
I am trying to enrich the data that we have in our system in a way such that we can determine the SIM card used when receiving data, but the SIM IP is not the one I see in the Onomondo app.
Solution
Use OpenVPN for direct access. This will allow you to identify the SIM IP.
Remember to enable VPN access in the Users tab.
Workaround:
Add device IMEI or ICCID to the UDP / TCP payload.
Get SIM information via Onomondo API.
Look up IMEI or ICCID in the JSON output to map it to a SIM.
Cause
All requests from Onomondo SIMs come from one of the public Onomondo SIM subnets. This is for enhanced security, but might not be ideal if you want to identify SIMs by source IP.