The Internet as we know it today has been optimised to transmit large amounts of data or “greedy streams” - the type of transmission involved in downloading large files or watching online TV. Up to recently, Internet research has primarily focused on speeding up transmission by increasing bandwidth so that more data can be transferred at a given time. The most common Internet protocol for transmitting data, TCP, works by apportioning available bandwidth among the users present at any given time. The downside is that this can cause latency, or delay, in data transmissions. For time-dependant applications such as Internet telephony and online gaming, time lags as short as a few hundred milliseconds can create big problems.
In real-time gaming against other players online, data is transmitted only when an action such as moving around or shooting at someone is performed. The same principle applies for stock market programs when placing orders or requesting share prices, for example, via the trading systems in use the Norwegian Stock Exchange. In such cases it is essential to avoid any delay.
Applications like these often generate what are called thin data streams. With thin streams only small amounts of data are transmitted at a time and there can be extended periods between data packages. Such thin streams cannot compete with greedy traffic for bandwidth. Thin streams almost invariably come up short against greedy traffic and users are left to cope with the resulting lag. We want a more balanced Internet where thin streams don’t always lose out. This can be achieved by adding speed to the mix, instead of only thinking about maximising throughput.
Locate the sources of increased delay and loss rates for thin streams along the entire path of a data packet. Develop mechanisms that reduce the latency for time-dependent thin-stream applications without having to change current Internet infrastructure.
The Research Council of Norway
- Coop. Assoc. for Internet Data Analysis (CAIDA)
- FUNCOM OSLO AS
- Universitetet i Oslo
- Karlstads Universitet
- UNINETT AS
- University of Kaiserslautern
- CISCO SYSTEMS NORWAY AS