D-Link SECURICAM Network DCS-2120 User Manual page 120

Section  - Security
The Advanced > Network page displays the port settings for your camera. If necessary, these ports can be changed
if they are already in use by other devices (e.g. in a multiple camera environment).
Note: There are only two ports that are required to be
opened for the DCS-2120, HTTP port and RTSP port. Please
refer to page 122 on how to open ports in the router.
D-Link DCS-10 User Manual 10