One of the research focuses in ECSL of SUNY at Stony Brook is real-time Multimedia streaming. This research consists of several projects in the area of video streaming, Ethernet bandwidth guarantee, timeliness guarantee on the kernel level and on switched Ethernet environment providing bandwidth guarantee in heterogeneous hosts environment. The presented work does not rely on the particular real-time streaming mechanism, but it focuses on the application level development of the Multimedia streaming environment, providing the complete solution from recording to indexing and streaming.
Stony Brook Video Server [VERN] is the push server that is optimized to read continuous video from RAID and deliver up to 89 simultaneous video streams 1.5 megabits/second each. The content access mechanism includes the optimized data placement on the disk array with continuous stripes placed on all disks, the disk access scheduler is based on the round-robin enhanced with CScan [NR93] to minimize the seek overhead and optimized buffering and delivering schemas. The specialized file encoding is used for fast-forward, rewind and seek. To adopt the system for different bandwidth requirements the multi-resolution is supported with separately encoded files. The network media to deliver SBVS streaming is Ethernet. The Ethernet system is cheap and widely used but it provides good performance only on light load with no real-time guarantee. To overcome these deficiencies SBVS project is merged with RETHER [Venkatramani]
RETHER is the implementation of the Datalink OSI Layer protocol on Ethernet with real-time guarantee. It is implemented as the modification of Ethernet subsystem in FreeBSD kernel with a separate connection setup module. While the Datalink layer to Network layer interface is preserved, applications may use the standard TCP/UDP protocols with real-time guarantee. RETHER is not just point-to-point connection protocol, but also includes s switch that delivers the stream over the network of switches. The Datalink layer (Ethernet) routing mechanism is developed and ARP is not used to resolve the Internet address. Each host in the system has the assigned ID which is used to route the packet using the Ethernet routing table, similar to that on an Ethernet switch. For the BSD kernel RETHER appears as a modified Ethernet device driver.
SBSVS project may be extended to build on SBVS and RETHER as the option to improve its video delivery performance and quality.