Port 2000: SCCP
Port 2000 is SCCP, Cisco's Skinny Client Control Protocol used by Cisco IP phones to talk to a Cisco Unified Communications Manager. It is a lightweight alternative to SIP within Cisco VoIP deployments.
| Port number | 2000 |
|---|---|
| Service | Cisco Skinny Client Control Protocol |
| Protocol | TCP |
| Category | VoIP & streaming |
| Default encryption | No |
How do I check whether port 2000 is open?
Port 2000 carries TCP, so a connection either completes its handshake or it does not, which makes the check definitive.
| Question | Command | What to know |
|---|---|---|
| Is it open on a remote host? | nc -vz example.com 2000 | A TCP handshake either completes or it does not, so netcat gives a definitive answer in one line. |
| Same check on Windows | Test-NetConnection example.com -Port 2000 | Built into PowerShell. TcpTestSucceeded in the output is the answer; telnet is not installed by default on modern Windows. |
| What is listening locally? | ss -tlnp | grep ':2000 ' | Lists the process bound to port 2000 on Linux. On macOS use lsof -nP -iTCP:2000 -sTCP:LISTEN, on Windows netstat -ano | findstr :2000 |
Replace example.com with the host you are testing. A blocked port and a port with nothing listening on it look identical from the outside, so if a service should be running, check locally before blaming the firewall.
Frequently asked questions
What is port 2000 used for?
Port 2000 is SCCP, Cisco's Skinny Client Control Protocol used by Cisco IP phones to talk to a Cisco Unified Communications Manager. It is a lightweight alternative to SIP within Cisco VoIP deployments.
Is port 2000 TCP or UDP?
Port 2000 (SCCP) uses TCP.
Is port 2000 secure?
Port 2000 is not encrypted by default. Where possible, use an encrypted alternative or tunnel it over TLS or a VPN.
Should I open port 2000 on my firewall?
Only if you specifically need SCCP. Expose it to the smallest set of trusted sources, and never open database or Windows-service ports to the whole internet.