CyberHunter
// Voice & chat

Port 4455: PR Chat User

Port 4455 is assigned by IANA to prchat-user (PR Chat User).

4455

How prchat-user works

Voice & chat
callercalleeprchat-user callercalleeprchat-user

Port 4455 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
01 Security

Is port 4455 dangerous?

We have no specific security note for port 4455. Its risk depends on the program actually listening on it. General advice for voice & chat services:

  • 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).
02 Registry

IANA registry entries for port 4455

ServicePortTransportDescriptionReferenceUpdated
prchat-user 4455 TCP, UDP PR Chat User - -

// source: IANA service name and port number registry

03 Check it

Which program uses port 4455, and is it reachable?

Linux

sudo ss -ltnup 'sport = :4455'      # process listening on 4455
sudo lsof -nP -i :4455

macOS

sudo lsof -nP -i :4455

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 4455 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 4455
netstat -ano | findstr :4455

From another machine

nmap -p 4455 -sV <host>
sudo nmap -sU -p 4455 <host>
nc -zv <host> 4455

Block it in the firewall

sudo ufw deny 4455/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 4455" -Direction Inbound -LocalPort 4455 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 4455 used for?

Port 4455 is assigned by IANA to prchat-user (PR Chat User).

Is port 4455 TCP or UDP?

Port 4455 is registered for TCP and UDP.

Is it safe to open port 4455?

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 4455 is open?

On Linux run "ss -ltnup 'sport = :4455'", on macOS "lsof -nP -i :4455", and on Windows "netstat -ano | findstr :4455" to see the local process. From another machine, "nmap -p 4455 <host>" shows whether it is reachable.

05 Related