Computing end-to-end QoS Paths in the Internet Considering Multiple Alliances

International audienceValue added services like VoIP, videoconferencing and IPTV need end-to-end Quality of Service (QoS) guarantees in order to work correctly. As the Internet is a collection of Autonomous Systems (AS), most of the time the communication endpoints belong to different ASes, so that all the ASes traversed by the communication must cooperate in order to offer end-to-end guarantees. Yet each AS is usually unwilling to disclose any detail about its internal network. To address this confidentiality issue we propose a system where each AS publishes a list of offers, specifying the QoS guarantees between its entry and exit points, without specifying anything else about its internal network. As proposed in several works, it is also possible for ASes to form alliances, which can be seen as "macro ASes" that publish the available offers between the entry and exit points of the alliance. In this paper we present ACQA, an algorithm that can find end-to-end paths satisfying given QoS constraints by combining the offers of several alliances and/or ASes