Flow-Aware Multi-Topology Adaptive Routing (FAMTAR) is a new approach to multipath and adaptive routing in IP networks which enables automatic use of alternative paths when the primary one becomes congested. It provides more efficient network resource utilization and higher quality of transmission compared to standard IP routing. However, thus far it has only been evaluated through simulations. In this paper we share our experiences from building a real-time FAMTAR router and present results of its tests in a physical network. The results are in line with those obtained previously through simulations and they open the way to implementation of a production grade FAMTAR router.
FAMTAR was developed to answer the aforementioned problems. This was possible thanks to the development of flow-aware traffic handling, such as Flow-Aware Networking (FAN) @cite_8 . There were attempts to increase the efficiency of routing with the use of FAN, as presented, for example, in @cite_7 . The technique of trunk reservation borrowed from the telephone network is proposed in this paper for route selection. It is assumed that a path for a flow is chosen based on the bandwidth it requires. Also, a simple intelligent routing for FAN is presented in @cite_2 , where it is assumed that only non-congested links are considered when forwarding packets. However, it is not specified how to inform all routers about the congested links. FAMTAR provides a solution to that problem. Moreover, FAMTAR is a general idea, not specific to FAN networks.
@cite_2 @cite_7 @cite_8
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A new algorithm for intelligent routing in Approximate Flow-Aware Networks (AFAN) is presented and analyzed in the paper. In contrast to basic AFAN, where cross-protect routers block excessive traffic under congestion, it assumes a possibility of using other routes to destination nodes based on the idea similar to load balancing. The analysis is provided for the AFAN concept, which is the newest version of Flow-Aware Networks (FAN). The simulation experiments, discussed in the paper, were provided for basic AFAN and for the network with one of two congestion control mechanisms, the Remove and Accept Most Active Flows (RAMAF) and Simple Congestion Control Mechanism (SCCM). These solutions allow for fast acceptance of streaming flows independently of the volume of traffic load in a network. The results are presented for four different simulation topologies and prove the advantages of the proposed intelligent routing approach. Moreover, it is shown that the SCCM ensures better transmission properties than the RAMAF. This paper compares two approaches to realizing adaptive routing in the Internet: flow-oblivious multi-path routing using optimal end-to-end congestion control and flow-aware routing using fair queueing to share bandwidth on one or several paths. Multi-path congestion control provides ideal performance, assuming protocols can be designed to approximate the optimal fluid model. Flow-aware networking is more robust and less dependent on user cooperation and provides satisfactory performance provided use of long paths is limited in heavy traffic by applying "trunk reservation". The paper addresses the issue of providing Quality of Service (QoS) guarantees in the Internet. After a brief discussion of Internet traffic characteristics, we consider the possibility of performing multiplexing with predictable performance for stream and elastic traffic using open–loop and closed–loop control, respectively. QoS depends essentially on providing sufficient capacity to handle expected demand. We argue that flow awareness is additionally necessary to ensure that traffic is directed over routes with available capacity and to avoid congestion collapse in case of overload. Proposed flow–aware controls allow simple volume–based charging and the development of an economic model similar to that of the telephone network.