Registered · Cross-platform

1720 H.323 call signaling

TCP Yes
UDP
SCTP
DCCP

What it is

H.323 Q.931 call setup.

When / why

VoIP/video call establishment.

Protocol status detail

TransportStatusMeaning
TCP Yes Assigned by IANA and standardized, specified, or widely used on this port.
UDP Not applicable for this transport.
SCTP Not applicable for this transport.
DCCP Not applicable for this transport.

Port range

Registered (1024–49151). Assigned by IANA on request; usable without elevated privileges on most systems.

Browse all ports →

Firewall rules for port 1720

Copy-ready inbound rules for the active transports. Replace every <source> placeholder with the specific host, subnet, or CIDR that should reach this port.

ufw

sudo ufw allow proto tcp from <source> to any port 1720

Allow TCP 1720 (H.323 call signaling). Replace <source> with the network/host that should reach it.

firewalld

sudo firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<source>" port port="1720" protocol="tcp" accept'

Allow TCP 1720 (H.323 call signaling) from <source>. Run 'firewall-cmd --reload' afterwards.

nftables

nft add rule inet filter input ip saddr <source> tcp dport 1720 accept

Allow TCP 1720 (H.323 call signaling). Assumes table 'inet filter' with an 'input' chain.

iptables

sudo iptables -A INPUT -p tcp -s <source> --dport 1720 -j ACCEPT

Allow TCP 1720 (H.323 call signaling). Persist with iptables-save/netfilter-persistent.

Azure NSG

az network nsg rule create -g <resource-group> --nsg-name <nsg> -n Allow-h323callsignaling-1720 --priority 1000 --access Allow --direction Inbound --protocol TCP --source-address-prefixes <source> --destination-port-ranges 1720

Inbound rule for 1720 (H.323 call signaling). Set <source> to a CIDR; lower priority number = higher precedence.

AWS Security Group

aws ec2 authorize-security-group-ingress --group-id <sg-id> --ip-permissions IpProtocol=tcp,FromPort=1720,ToPort=1720,IpRanges="[{CidrIp=<source-cidr>}]"

Inbound TCP 1720 (H.323 call signaling). Replace <source-cidr> (e.g. 10.0.0.0/16).

GCP firewall

gcloud compute firewall-rules create allow-h323callsignaling-1720 --direction=INGRESS --action=ALLOW --rules=tcp:1720 --source-ranges=<source-cidr> --network=<network>

Ingress rule for 1720 (H.323 call signaling). Scope with --source-ranges and optionally --target-tags.

Windows netsh

netsh advfirewall firewall add rule name="Allow H.323 call signaling 1720/TCP" dir=in action=allow protocol=TCP localport=1720 remoteip=<source>

Inbound TCP 1720 (H.323 call signaling). Set remoteip to a host/subnet; 'any' is discouraged.

Windows PowerShell

New-NetFirewallRule -DisplayName "Allow H.323 call signaling 1720/TCP" -Direction Inbound -Action Allow -Protocol TCP -LocalPort 1720 -RemoteAddress <source>

Inbound TCP 1720 (H.323 call signaling). Replace <source> with a host or subnet.

Rules are generated only for transports marked active for this port. They default to an inbound allow with an explicit source placeholder — never any. Review direction, scope, and rule precedence before applying in production.