- Use strong credentials and TLS for signalling.
- Rate-limit registrations to stop extension scanning and toll fraud.
- Alert on unexpected chat protocols leaving servers (possible command and control).
Port 1336: Instant Service Chat
Port 1336 is assigned by IANA to ischat (Instant Service Chat).
1336
How ischat works
Voice & chatPort 1336 sets up the call (who calls whom), then the voice travels as a stream of audio packets.
- Transport
- TCP · UDP
- Exposure risk
- not rated depends on the program listening
- Encryption
- Unknownnot stated by the registry
- IANA status
- Assigned1 registered service
- Range
- Registered (1024-49151)
- Category
- Voice & chat
Is port 1336 dangerous?
We have no specific security note for port 1336. Its risk depends on the program actually listening on it. General advice for voice & chat services:
IANA registry entries for port 1336
| Service | Port | Transport | Description | Reference | Updated |
|---|---|---|---|---|---|
| ischat | 1336 | TCP, UDP | Instant Service Chat | - | - |
// source: IANA service name and port number registry
Which program uses port 1336, and is it reachable?
Linux
sudo ss -ltnup 'sport = :1336' # process listening on 1336
sudo lsof -nP -i :1336macOS
sudo lsof -nP -i :1336
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 1336 -State Listen | Select LocalAddress, OwningProcess Get-NetUDPEndpoint -LocalPort 1336 netstat -ano | findstr :1336
From another machine
nmap -p 1336 -sV <host> sudo nmap -sU -p 1336 <host> nc -zv <host> 1336
Block it in the firewall
sudo ufw deny 1336/tcp # Linux (ufw) New-NetFirewallRule -DisplayName "Block 1336" -Direction Inbound -LocalPort 1336 -Protocol TCP -Action Block # Windows
What is port 1336 used for?
Port 1336 is assigned by IANA to ischat (Instant Service Chat).
Is port 1336 TCP or UDP?
Port 1336 is registered for TCP and UDP.
Is it safe to open port 1336?
It depends on the program that listens on it. Open it only for a service you know and only to the networks that need it. Use strong credentials and TLS for signalling.
How do I check if port 1336 is open?
On Linux run "ss -ltnup 'sport = :1336'", on macOS "lsof -nP -i :1336", and on Windows "netstat -ano | findstr :1336" to see the local process. From another machine, "nmap -p 1336 <host>" shows whether it is reachable.