You have version 3 firmware. The latest is version 4. I'm running a fairly old 5216-4ks2 with version 4 firmware and as of a couple months ago it worked with P2P, although the smartPSS and DMSS apps had to be upgraded with newer versions. Be careful if upgrading the firmware. There are V1 and V2 hardware versions of the 5216-4ks2, and the V1 hardware cannot use the newer V4 firmware. Ironically, the V3 firmware firmware won't tell you which hardware version NVR you have (the V4 firmware does tell). I believe you can find out from the part number sticker on the NVR case. My V1 NVR say its part number is 1.0.01.23.10840. I vaguely remember the V2 stickers say something to that effect, but don't remember the details.