Distributed systems in use today depend heavily on network communications between clients and servers. In this report, we describe the design and implementation of the network architecture (hardware, software and protocols) of the RAID-II system. RAID-II is a high speed network file server connected to an UltraNetwork. In order to support high bandwidth network transfers with the RAID-II server, we partitioned the networking software among the various processors in the system. Measurements of the system show that the RAID-II server can sustain 21 MB/s of data bandwidth to the Ultranet.