# WHATPORT(2000)

## NAME

port 2000 — Cisco SCCP (Skinny) — Cisco SCCP — the "Skinny" call-control protocol between IP phones and Unified Communications Manager.

Protocol: TCP  
IANA registry

## DESCRIPTION

IANA registers 2000 as cisco-sccp, and Cisco's own firewall documentation states that Unified Communications Manager uses TCP port 2000, the default SCCP port, to serve SCCP clients. A Cisco IP phone opens a TCP connection here to register, then receives call setup, keypad, and display instructions over it while the media itself flows separately over RTP. It also shows up on Cisco routers and gateways running SCCP telephony features.

## EXPOSURE

**Do not expose.** SCCP is a cleartext call-control plane — exposing it invites call-setup abuse, toll fraud, and eavesdropping on who is calling whom; keep voice on its own VLAN.

## CHECK

```sh
nc -vz TARGET 2000
```

## SEE ALSO

- docs — [Cisco — Firewall Support of Skinny Client Control Protocol](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/sec_data_zbf/configuration/xe-16-6/sec-data-zbf-xe-16-6-book/sec-data-sccp.html) (cisco.com)
- iana — [IANA port registry — 2000 (cisco-sccp)](https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml?search=2000) (iana.org)

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HTML: <https://whatport.net/2000/> · JSON: <https://whatport.net/2000.json> · full dataset: <https://whatport.net/ports.json>