UDP 20000
Synopsis
- DNP3 (Distributed Network Protocol) commonly uses UDP port 20000 in SCADA/ICS deployments for communication between masters and outstations/RTUs. Examples include devices and software from Schweitzer Engineering Laboratories (SEL relays), ABB RTUs, GE Multilin relays, Schneider Electric SCADAPack RTUs, and SCADA platforms/drivers like Inductive Automation Ignition’s DNP3 driver and AVEVA (ClearSCADA/Geo SCADA).
- Asterisk-based PBXs (e.g., Asterisk, FreePBX) use UDP ports 10000–20000 for RTP media; thus UDP port 20000 often carries RTP audio/video streams in default configurations.
- Security note: DNP3 over UDP historically lacks authentication/encryption, and UDP/20000 exposed to the internet is frequently scanned; insecure implementations can allow data reads or even control commands, so deployments typically tunnel or use Secure DNP3/VPNs.
Observed activity
Last 30 days
Detailed chart