All ports
Port1720/UDP
h323hostcallPort
1720
Protocol
UDP
Category
Registered
Service
h323hostcall
What is port 1720?
Port 1720/UDP is a Registered port, registered with IANA for specific applications. It is associated with the h323hostcall service.
H.323 Call Control Signalling
Useful commands
nmapnmap -p 1720 -sV example.comnetcatnc -zv example.com 1720curlcurl -v http://example.com:1720/telnettelnet example.com 1720bash(echo > /dev/udp/example.com/1720) 2>/dev/nullFirewall commands
UFWAllow
sudo ufw allow 1720/udpDeny
sudo ufw deny 1720/udpiptablesAllow
sudo iptables -A INPUT -p udp --dport 1720 -j ACCEPTDeny
sudo iptables -D INPUT -p udp --dport 1720 -j ACCEPTfirewalldAllow
sudo firewall-cmd --permanent --add-port=1720/udpWindowsAllow
netsh advfirewall firewall add rule name="Open Port 1720" dir=in action=allow protocol=UDP localport=1720Security Risks
- Unauthorized access to the service
- Data exposure if the service is unauthenticated
- Outdated versions with vulnerabilities
- Incorrect service configuration
Frequently Asked Questions
What service runs on port 1720/UDP?
Port 1720/UDP is associated with the h323hostcall service. H.323 Call Control Signalling
Is it safe to expose port 1720 to the Internet?
It depends on the service and configuration. Port 1720 (h323hostcall) is a Registered port. If you need to expose it, keep the service updated, use strong authentication, and configure a firewall. It's always recommended to restrict access by IP when possible.
How do I check if port 1720 is open?
You can use nmap: `nmap -p 1720 -sV example.com`, netcat: `nc -zv example.com 1720`, or the bash command: `(echo > /dev/udp/example.com/1720) 2>/dev/null && echo "Open" || echo "Closed"`.
How do I open or close port 1720 on my firewall?
On Linux with UFW: `sudo ufw allow 1720/udp` (open) or `sudo ufw deny 1720/udp` (close). With iptables: `sudo iptables -A INPUT -p udp --dport 1720 -j ACCEPT`. On Windows: `netsh advfirewall firewall add rule name="Open Port 1720" dir=in action=allow protocol=UDP localport=1720`.
What applications and services use port 1720?
Port 1720/UDP is used by the h323hostcall service. Specific uses depend on the software and configuration. Check our related tools section for more information.