CAN Request in FMS network

Hello,

It's been some time since i have been following this list. It is really
instructive and I have learned a lot with you.

I have a doubt regarding FMS and write operations. I am wondering if it is
possible to deploy a private CAN network connected to a OEM FMS. In the
private CAN network there will be internal requests but I hope it will not
go into the vehicle network.

Am i mistaken?
Kind regards

Alberto Álvarez