I have a XBOX One and I use an RB450g with the latest OS version. My XBOX One NAT type is STRICT. This basically prevents most online multiplayer features of the XBOX One. Does anyone have a XBOX One with open NAT using RB450g, if so please post config.

Have you tried upnp ??
http://wiki.mikrotik.com/wiki/Manual:IP/UPnP

I have UPnP setup as outlined and it works flawlessly with my XBox 360. However it does not work with my XBox One, my XBox One reports Strict NAT type while my XBox 360 reports open. Any help much appreciated.

Have you tried upnp ??
http://wiki.mikrotik.com/wiki/Manual:IP/UPnP

Yes I have UPnP working with my XBox 360 and it shows open NAT. However my XBox One console on the exact same network shows STRICT NAT. Any help much appreciated.

Have you tried upnp ??
http://wiki.mikrotik.com/wiki/Manual:IP/UPnP

Unfortunately UPnP properly implemented and it does not work with XBox One. The RouterBaord routers are NOT compatible with the XBox One. We will be migrating away from Routerboard brand and have begun referring all clients to follow suit.