Design of the Network Multimedia File System protocol: a protocol for remote access of networked multimedia files

With multimedia communication growing in popularity, it has become important to develop techniques that will allow a multimedia application to access multimedia files from local as well as remote sites. This thesis describes the methodology used in the design of the Network Multimedia File System (NMFS) protocol. The protocol provides “transparent access to shared files across networks” much like Sun’s Network File System (NFS) protocol. However, NMFS differs from NFS in that it provides a connection-oriented service that allows the user to specify quality of service (QOS) parameters and reserve resources to achieve the desired QOS. NMFS is an application layer protocol and is intended to work with existing multimedia applications, unaltered, on multiple platforms. NMFS will provide real-time delivery of multimedia data over networks both designed and not designed to carry multimedia traffic. A unique feature of this protocol is that it uses an anticipated delivery schedule (ADS) to guide prefetch of portions of files that are likely to be requested in the future. This prefetched data is stored in a local buffer which reduces the need to transfer the data over the variable latency network when the application actually requests it. Thus NMFS provides most unaltered application programs with almost constant latency accesses over a network with variable latency.