The supported protocols are mentioned on the product-info on the website, on the box of the device and in the manual. If, for some reason, the protocol you need is not supported, then you can either:
1. Live for it and wait for a firmware-release, supporting the protocol, or
2. Return the item and look for one that does support your required protocol, or
3. Live with it and use other means or work-arounds (and there are plenty)
Ad 1. If the product is older, then the chances of an appropriate firmware-upgrade diminish with time... This means that options 2 or 3 are probably the only way to go. I have not seen that many IP-cams that support your required protocol.
So I wish you good luck, whatever way you are going in the future.
P.S. The subject of this thread relates to the DCS920... But same limitations apply, alas.