CyberHunter
// Voice & chat

Port 9750: Board M.I.T. Synchronous Collaboration

Port 9750 is assigned by IANA to board-voip (Board M.I.T. Synchronous Collaboration).

9750

How board-voip works

Voice & chat
callercalleeboard-voip callercalleeboard-voip

Port 9750 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 9750 dangerous?

We have no specific security note for port 9750. 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 9750

ServicePortTransportDescriptionReferenceUpdated
board-voip 9750 TCP, UDP Board M.I.T. Synchronous Collaboration - 2006-01

// source: IANA service name and port number registry

03 Check it

Which program uses port 9750, and is it reachable?

Linux

sudo ss -ltnup 'sport = :9750'      # process listening on 9750
sudo lsof -nP -i :9750

macOS

sudo lsof -nP -i :9750

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 9750 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 9750
netstat -ano | findstr :9750

From another machine

nmap -p 9750 -sV <host>
sudo nmap -sU -p 9750 <host>
nc -zv <host> 9750

Block it in the firewall

sudo ufw deny 9750/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 9750" -Direction Inbound -LocalPort 9750 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 9750 used for?

Port 9750 is assigned by IANA to board-voip (Board M.I.T. Synchronous Collaboration).

Is port 9750 TCP or UDP?

Port 9750 is registered for TCP and UDP.

Is it safe to open port 9750?

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 9750 is open?

On Linux run "ss -ltnup 'sport = :9750'", on macOS "lsof -nP -i :9750", and on Windows "netstat -ano | findstr :9750" to see the local process. From another machine, "nmap -p 9750 <host>" shows whether it is reachable.

05 Related