In this thesis, the performance of a state-of-the-art path capacity estimation algorithm is evaluatedin terms of its suitability for being part of a measurement-based admission controller in amilitary Internet Protocol (IP) network.
The strive towards Network Enabled Capability (NEC) in miltary organizations drives the needfor interconnecting all the actors taking part in an operation. The resulting network is an IPbased,heterogeneous Wide Area Network (WAN), comprising of a variety of fixed and mobilecommunication links with different capacities.
In military IP networks, Quality of Service (QoS) cannot be guaranteed when there is congestion.This is due to the use of IPsec, which forms a cryptographic boundary between the trafficsource and forwarding routers, thus rendering end-to-end resource reservation impossible. Thiscalls for the implementation of a congestion avoidance policy through Measurement-based AdmissionControl (MBAC).
Based on a literature study, the estimation algorithms combining the use of packet-pair dispersionand delay analysis, were found to be the most suited for providing low-intrusive, fast andreliable measurements of the path capacity. One of these algorithms, Ad Hoc Probe, was extensivelyevaluated in a test bed based on link technologies typically found in military networks.
A number of performance limiting factors were identified, including a lack of support forTime Division Multiple Access (TDMA)-based links, restrictions on the number of hops incontention-based Mobile Ad Hoc Networks (MANETs) and a minimum required capacity thatmade the algorithm unfit for use in networks containing narrowband, low-capacity links.