SANP: An algorithm for selecting end-to-end paths with QoS guarantees

The Internet has recently seen the emergence of new value added services (IPTV, VoIP, etc..), that require Quality of Service (QoS) guarantees. Given the nature of the Internet, most of the time, the source and the destination are connected to different providers, so that multiple ISPs must cooperate in order to offer end-to-end QoS guarantees. All this without revealing how each provider implements a given service and without forcing any provider to implement a specific path or solution within its own network. To address these challenges, we propose a distributed algorithm (SANP), which computes a set of feasible non-dominated paths between the source and the destination. The algorithm assumes only that each AS is willing to publish QoS guarantees offers and the corresponding price that it proposes between any two of its border routers. Contrary to other existing solutions, SANP does not assume that the sequence of ASes is known, instead it builds a sub-graph around the route used by existing routing mechanisms between the source and destination. The subgraph is obtained by merging the neighborhoods of all the nodes traversed by the request. To assess SANP, we compare the paths it finds with the all the feasible non-dominated paths that exist in the graph. Our simulations show that SANP finds a reasonable number of paths that are close to the optimal solution. By increasing the radius of the neighborhoods used to compute the subgraph it is possible to increase the number and the quality of the paths found by SANP, yet even for reasonably small values of the radius (3, 4, 5) the results are fairly good.