Hello ,
This setup is supported as per Juniper to have redundant device on different sites . To give a brief heads up :
> The control and the FAb link will be connected using L2 device as per this setup . So you need to enable Jumbo frames on the connected switch to have then UP .
> A fiber connection is required for the Control Link between the nodes .
Rest everything follows the same way and the above document will give you a detailed information .