Internet-Security.com UDP port 1719 details

UDP port 1719 is used by the H.323 protocol for RAS (Registration, Admission, and Status) signaling between endpoints and gatekeepers. Real-world implementations that listen on 1719 include GNU Gatekeeper (GnuGk), RADVISION/Avaya Scopia ECS Gatekeeper, and Cisco gatekeeper products such as Cisco IOS Gatekeeper and Cisco VCS/Expressway. H.323 endpoints like Polycom/Poly RealPresence Group and HDX codecs, Tandberg/Cisco TelePresence endpoints, Lifesize systems, and legacy clients such as Microsoft NetMeeting use 1719 to register with a gatekeeper. After registration, call setup typically uses TCP 1720, while 1719 remains the RAS channel. Attackers sometimes scan UDP/1719 to enumerate H.323 gear, and historic H.323 stack flaws (notably 2004 ASN.1 parsing bugs across multiple vendors) have been exploited for denial-of-service or code execution.

UDP 1719