Cross platform system link

I am trying to have a twelve player system link with 2 Xbox 360s and one Xbox one. I have 3 copies of reach. So far, the 360s are linking to each other and I can see the Xbox one in the lobby, but the “join party” option is grey and does not allow the Xbox one to join. Am I doing something wrong or is not possible to link them?

Thanks

AFAIK, Xbox One’s don’t support System Link functionality, regardless if you’re running Xbox360 software that does.

I actually got them to link once the 360s updated to the latest version of xbox live, they hooked right up!

Super news!!!
Great you could get it to work

i dunno. a direct link between my 360 and xbone has worked for reach, gears, and borderlands. but thats with only 2 consoles.

i dunno what a mix of 4 requires.

I have been trying to rectify this issue ever since backwards compatibility was introduced.
Let me just say that the issue I have spans multiple games all with the same result.Lets start with Halo 3 and Reach.
I have 4 xbox 360s and 4 xbox ones.Working setup:
System link works with all 8 systems happily when the Xbox Ones are connected through the wired port to the network.
The Xbox 360s can be wired or wireless, it does not matter.The issue that has yet to be resolved, Xbox One’s connected wirelessly can see the system link games but it fails to connect. It acknowledges that the NAT is open and refers you to Microsoft help for suport.I have used multiple routers, so it appears this problem exists within the Xbox one wireless communications.
I do not know enough to start tinkering with those settings. I would suggest that would be the first place to concentrate on if you seek to create a fully wireless system link game. I would love to know the solution. I have spent a lot of time searching for the answer to know avail.

Please don’t revive old topics, thanks.