@inproceedings {Simula.ND.399,
	title = {Improving Disk I/O Performance on Linux},
	journal = {UpTimes - Proceedings of Linux-Kongress and OpenSolaris Developer Conference 2009},
	number = {2},
	year = {2009},
	month = {October},
	pages = {61-70},
	publisher = {German Unix User Group},
	type = {Workshop},
	abstract = {The existing Linux disk schedulers are in general efficient, but we have identified two scenarios where we have observed a non-optimal behavior. The first is when an application requires a fixed bandwidth, and the second is when an operation performs a file tree traversal. In this paper, we address both these scenarios and propose solutions which both increase performance.},
	isbn = {978-3-86541-358-1},
	author = {Carl Henrik {Lunde} and Espeland, H{\r a}vard and H{\r a}kon Kvale {Stensland} and Petlund, Andreas and Halvorsen, P{\r a}l},
	editor = {Wetter, Dirk}
}
@inproceedings {Simula.ND.407,
	title = {Improving File Tree Traversal Performance by Scheduling I/O Operations in User Space},
	journal = {Proceedings of the 28th IEEE International Performance Computing and Communications Conference (IPCCC)},
	year = {2009},
	pages = {145-152},
	publisher = {IEEE},
	type = {Conference},
	abstract = {Current in-kernel disk schedulers provide efficient means to optimize the order (and minimize disk seeks) of issued, in-queue I/O requests. However, they fail to optimize sequential multi-file operations, like traversing a large file tree, because only requests from one file are available in the scheduling queue at a time. We have therefore investigated a user-level, I/O request sorting approach to reduce inter-file disk arm movements. This is achieved by allowing applications to utilize the placement of inodes and disk blocks to make a one sweep schedule for all file I/Os requested by a process, i.e., data placement information is read first before issuing the low-level I/O requests to the storage system. Our experiments with a modified version of tar show reduced disk arm movements and large performance improvements.},
	isbn = {978-1-4244-5736-6},
	author = {Carl Henrik {Lunde} and Espeland, H{\r a}vard and H{\r a}kon Kvale {Stensland} and Halvorsen, P{\r a}l},
	editor = {Zhong, Sheng}
}
@inproceedings {Simula.ND.117,
	title = {Transparent Protocol Translation and Load Balancing on a Network Processor in a Media Streaming Scenario},
	journal = {Network and Operating System Support for Digital Audio and Video (NOSSDAV 2008)},
	year = {2008},
	month = {May},
	pages = {129-130},
	publisher = {ACM},
	type = {Workshop},
	abstract = {Today, major newspapers and TV stations make live and on-demand audio/video content available, video-on-demand services are becoming common and even personal media are frequently uploaded to streaming sites. The discussion about the best transport protocol for streaming has been going on for years. Currently, HTTP-streaming is usual although the transport of streaming media data over TCP is hindered by TCP{\textquoteright}s probing behavior, which results in the rapid reduction and slow recovery of the packet rates. On the other hand, UDP has been criticized for being unfair against TCP, and it is therefore often blocked by access network providers. To exploit benefits of both TCP and UDP, we have implemented a proxy that performs transparent protocol translation in such a way that the video stream is delivered to clients in a TCP-compatible and TCP-friendly way, but with UDP-like smoothness. The translation is related to multicast-to-unicast translation and to voice-over-IP proxies that translate between UDP and TCP. Furthermore, it is also similar to the use of proxy caching that ISPs employ to reduce bandwidth demands. The unique advantage of our approach is that we avoid full-featured TCP handling on the proxy server but still achieve live protocol translation at line-speed in a TCP-compliant, TCP-friendly manner. Although we discard packets just like a sender of non-adaptive video over TCP, we achieve higher user-perceived quality because our proxy can avoid receive queue underflows in the proxy, while also achieving the same average bandwidth as a TCP connection between proxy and client. In this demo, we present our prototype implemented on an Intel IXP2400 network processor. The prototype proxy does not buffer outgoing packets, yielding data loss in case of a congested TCP side. Comparing HTTP-streaming from a web-server and RTP/UDP-streaming from a video server shows that, in case of some loss, our solution using UDP from the server and a proxy that translates to TCP delivers a smoother stream at playout rate while the end-to-end TCP stream oscillates heavily.},
	isbn = {978-1-60588-157-6},
	author = {Espeland, H{\r a}vard and Carl Henrik {Lunde} and H{\r a}kon Kvale {Stensland} and Griwodz, Carsten and Halvorsen, P{\r a}l},
	editor = {Griwodz, Carsten and Wolf, Lars}
}
@inproceedings {Simula.ND.36,
	title = {Transparent Protocol Translation for Streaming},
	journal = {ACM International Multimedia Conference (ACM MM)},
	year = {2007},
	note = {(short paper) {\textcopyright} ACM, (2007). This is the author{\textquoteright}s version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution. The definitive version was published in Proceedings of the 15th international conference on Multimedia (2007), http://doi.acm.org/10.1145/1291233.1291407},
	month = {September},
	pages = {771-774},
	publisher = {ACM},
	type = {Annual},
	abstract = {The transport of streaming media data over TCP is hindered by TCP{\textquoteright}s probing behavior that results in the rapid reduction and slow recovery of the packet rates. On the other side, UDP has been criticized for being unfair against TCP connections, and it is therefore often blocked out in the access networks. In this paper, we try to benefit from a combined approach using a proxy that transparently performs transport protocol translation. We translate HTTP requests by the client transparently into RTSP requests, and translate the corresponding RTP/UDP/AVP stream into the corresponding HTTP response. This enables the server to use UDP on the server side and TCP on the client side. This is beneficial for the server side that scales to a higher load when it doesn{\textquoteright}t have to deal with TCP. On the client side, streaming over TCP has the advantage that connections can be established from the client side, and data streams are passed through firewalls. Preliminary tests demonstrate that our protocol translation delivers a smoother stream compared to HTTP-streaming where the TCP bandwidth oscillates heavily.},
	isbn = {978-1-59593-702-5},
	author = {Espeland, H{\r a}vard and Carl Henrik {Lunde} and H{\r a}kon Kvale {Stensland} and Griwodz, Carsten and Halvorsen, P{\r a}l},
	editor = {Lienhart, Rainer and Anand R. {Prasad}}
}
