7.7.5 Multiple operator storage system  For any number of connections greater than two, a networked system of data storage and backup should be implemented. Such a networked system allows access to multiple users in accordance with the rules set down by the data management system. Small scale networks are relatively common and, with the right level of knowledge, easy and affordable to implement. Reasonable quantities of storage can be achieved with an enterprise level attached storage device. Storage technologies and products can be split into three main types: direct- attached storage (DAS), network-attached storage (NAS) and the storage area network (SAN). NAS has better performance and scalability than DAS and it is cheaper and simpler to configure than SAN. NAS technology is, from a cost benefit view, the most appropriate scalable technology for system of the size under discussion.  Most low cost NAS devices exhibit reduced bandwidth when compared to the more expensive devices resulting in slower access times, or a lower number of allowable simultaneous access availability. This should present no major problem to smaller collection as the requirement for simultaneous access remains low, especially if MP3 derivatives of the preservation master copies are used for access.  A typical small scale networked storage system may comprise of a server class desktop computer connected to a NAS device. The NAS would have the capability of mounting multiple hard disks in a RAID array. An average low cost NAS would hold between 0.5 and 20 terabytes of disk storage (noting the penalty for RAID is less storage than that indicated by the raw disk size). The digital audio workstations (DAW) access the NAS via an Ethernet switch or similar device which, if configured properly, has the effect of separating the storage facility from the office LAN (local area network) and improves the security of the storage facility. The HDDs would be backed up onto data tape.