You can use e.g. nmap to get information about the UPNP service behind port 1900 by running
nmap -sU -p 1900 --script=upnp-info YourServerHere
In case of deCONZ the reply will look like:
PORT STATE SERVICE
1900/udp open upnp
| upnp-info:
| 192.168.0.26
| Server: Linux/3.14.0 UPnP/1.0 IpBridge/1.26.0
|_ Location: http://192.168.0.26:8090/description.xml
MAC Address: 22:DD:55:00:EE:68 (Unknown)
In case you disabled e.g. deconz, hue and the port is still in use I would expect to get a different content then.