Blogging about Kamailio SIP Server, Asterisk, FreeSWITCH, SIP, WebRTC, VoIP and more...
For research, I created honeypot what mimics vulnerable PBX.
For emulation, I used Kamailio nodes that send any calls to termination node and answers to OPTIONS and REGISTER.
For every INVITE I recorded From, To, UA, Call-ID, IP and call time.
Termination node has Kamailio with Flask app for preprocessing calls and Asterisk for topology hiding when calls sent to PSTN.
All calls with a cost of more than 2 cents per minute were rejected with code 486.
I used 4 sensor nodes located in NL, DE, SG and NYC.
For 18 days, 254805 INVITE were collected from 296 different IP’s. On average, 860 INVITEs were received from an IP.