- 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 3771: RTP Paging Port
Port 3771 is assigned by IANA to paging-port (RTP Paging Port).
3771
How paging-port works
Voice & chatPort 3771 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 3771 dangerous?
We have no specific security note for port 3771. Its risk depends on the program actually listening on it. General advice for voice & chat services:
IANA registry entries for port 3771
| Service | Port | Transport | Description | Reference | Updated |
|---|---|---|---|---|---|
| paging-port | 3771 | TCP, UDP | RTP Paging Port | - | 2003-06 |
// source: IANA service name and port number registry
Which program uses port 3771, and is it reachable?
Linux
sudo ss -ltnup 'sport = :3771' # process listening on 3771
sudo lsof -nP -i :3771macOS
sudo lsof -nP -i :3771
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 3771 -State Listen | Select LocalAddress, OwningProcess Get-NetUDPEndpoint -LocalPort 3771 netstat -ano | findstr :3771
From another machine
nmap -p 3771 -sV <host> sudo nmap -sU -p 3771 <host> nc -zv <host> 3771
Block it in the firewall
sudo ufw deny 3771/tcp # Linux (ufw) New-NetFirewallRule -DisplayName "Block 3771" -Direction Inbound -LocalPort 3771 -Protocol TCP -Action Block # Windows
What is port 3771 used for?
Port 3771 is assigned by IANA to paging-port (RTP Paging Port).
Is port 3771 TCP or UDP?
Port 3771 is registered for TCP and UDP.
Is it safe to open port 3771?
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 3771 is open?
On Linux run "ss -ltnup 'sport = :3771'", on macOS "lsof -nP -i :3771", and on Windows "netstat -ano | findstr :3771" to see the local process. From another machine, "nmap -p 3771 <host>" shows whether it is reachable.