No abstract

Abstract-In network tomography, we seek to infer link status parameters (delay, congestion, loss rates etc.) inside a network through end-to-end measurements at (external) boundary nodes. As can be expected, such approaches generically suffer from identifiability problems; i.e., status of links in a large number of network topologies is not identifiable. We introduce an innovative approach based on linear network coding that overcomes this problem. We provide sufficient conditions on network coding coefficients and training sequence under which any logical network is guaranteed to be identifiable. In addition, we show that it is possible to locate any congested link inside a network during an arbitrary amount of time by increasing size of transmitted packets, leading to raise in complexity of the method. Further, a probability of success is provided for a random network. OPNET is used to implement the concept and confirm the validity of the claims -simulation results confirm that LNC correctly detects the congested link in situations where standard probing based algorithm fails.

Abstract-This paper addresses the issue of verifying transport protocol's parallel routing functionality on a vehicle gateway system. The focus of the paper is to construct a conflict-free input parameter model for testing this functionality. The input parameter model shall support the reduction of combinations to be tested and serves as a basis for automatic test case generation from a large space of input parameters. In the proposed approach, defined similarity criteria are used to cluster system input parameters represented as transport protocol routing instances into groups which stimulate similar behavior in the gateway when transport protocol routing is established. Subsequently, the two conflict-handling methods sub-models and avoid are utilized to prohibit invalid combinations of transport protocol routing instances. The proposed approach is applied on a complex example of real gateway with five buses, 390 transport protocol routing instances and diverse conflicts to illustrate its applicability.