UDP 1718
Synopsis
- UDP port 1718 is used by H.323 Gatekeeper Discovery (H.323 GkDiscovery), the mechanism endpoints use to locate an H.323 gatekeeper.
- Cisco IOS Gatekeeper (in Cisco Unified Communications/voice deployments) listens and responds on UDP 1718 for discovery requests.
- GNU Gatekeeper (GnuGk) implements H.323 gatekeeper discovery on UDP 1718.
- RADVISION ECS Gatekeeper (later sold by Avaya) supports H.323 discovery on UDP 1718 in enterprise video/voice networks.
- Polycom H.323 video endpoints (e.g., RealPresence/HDX series) can send gatekeeper discovery messages to UDP 1718.
- Lifesize H.323 video conferencing endpoints also support gatekeeper discovery via UDP 1718.
- Historically, port 1718 has been involved in H.323 parsing vulnerabilities (notably 2004 multi-vendor ASN.1 flaws affecting products from Microsoft, Cisco, Nortel/RADVISION), enabling denial-of-service or code execution via crafted discovery/RAS packets, so it is sometimes probed by attackers.
Observed activity
Last 30 days
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