A data processing network includes a network of devices addressable via a system address space, the network including a computing device configured to execute an application in a virtual address space. A virtual-to-system address translation circuit is configured to translate a virtual address to a system address. A memory node controller has a first interface to a data resource addressable via a physical address space, a second interface to the computing device, and a system-to-physical address translation circuit, configured to translate a system address in the system address space to a corresponding physical address in the physical address space of the data resource. The virtual-to-system mapping may be a range table buffer configured to retrieve a range table entry comprising an offset address of a range together with a virtual address base and an indicator of the extent of the range.