TCP Port 1720 – h323hostcall

About TCP Port 1720

The Internet Assigned Numbers Authority (IANA) registers port 1720 for h323hostcall. The IANA description reads: ‘H.323 Call Control Signalling’. This port appears in 3 IDS rules and does not have notable malware activity indicators in our data.

IDS Rule References

3 IDS / security rules reference TCP port 1720. Treat that number as context, not a danger score. Many detection rules are written against groups of ports rather than one service, web ports especially, so common web alternate ports inherit large counts while genuinely sensitive services can show few rules or none. Presence in IDS rules does not mean traffic on this port is malicious.

Rule categories (top 2): trojan-activity (2), network-scan (1).

Sample rule descriptions for TCP port 1720:

• POLICY-OTHER Polycom Botnet inbound connection attempt
• POLICY-OTHER Polycom Botnet inbound connection attempt
• ET SCAN H.323 Scanning device

Data Sources

This information is compiled from: IANA Service Name and Transport Protocol Port Number Registry, Emerging Threats Open Ruleset (BSD 2-Clause / GPLv2 per SID range), and Snort Community Rules (GPLv2).