A network of processing devices includes a medium for low-latency interfaces for providing point-to-point connections between each of the processing devices. A switch within each processing device is arranged to facilitate communications in any combination between the processing resources and the local point-to-point interfaces within each processing device. A networking layer is provided above the low-latency interface stack, which facilitates re-use of software and exploits existing protocols for providing the point-to-point connections. Higher speeds are achieved for switching between the relatively low numbers of processor resources within each processing device, while low-latency point-to-point communications are achieved using the low-latency interfaces for accessing processor resources that are external to a processing device.