ONVIF : How to form the DeviceIO web service address from the IP address of an ONVIF supported IP camera

Question

I have the IP address of an ONVIF supported IP camera,how do I form the address of the DeviceIO web service?

Answer 1

A robust way to do it is the following:

1. Probe the camera, by using the WS-Discovery
2. Extract the field XAddr from the ProbeMatch. Usually it is http://<ip_addr>/onvif/device_service, but it is not guaranteed always to be like this.
3. Verify if your camera supports GetCapabilities or it has the new GetServices.
4. Either from GetCapabilitiesRepsonse or GetServicesResponse verify if your device supports the Device I/O service and get the corresponding XAddr.

Beware that the initial handshake may be tricky, because if the camera only supports UsernameToken for authtentication, you'll need to syncronize your client with the device's clock. Have a look at the ONVIF Application Programmer's Guide for further details.