Conference Papers

Permanent URI for this collectionhttps://idr.nitk.ac.in/handle/123456789/28506

Browse

Author: search.filters.author.Patil, S.D.

Search Results

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    On the robustness of AQM mechanisms against non-responsive traffic
    (Institute of Electrical and Electronics Engineers Inc., 2017) Patil, S.D.; Tahiliani, M.P.
    Active Queue Management (AQM) mechanisms have come a long way, with an initial goal to avoid congestion to the recent most focus on reducing queue delay. The benefits of using AQM mechanisms at routers are being thoroughly studied nowadays, mainly to avoid the problem of bufferblaat. Although a lot of work has focused on analyzing the behavior of AQM mechanisms, the nature of traffic used while deriving inferences is mainly responsive (TCP), with small numbers of unresponsive flows (UDP) used in the background. The usage of UDP in Internet has increased significantly in the recent past, owing to a great demand for time sensitive multimedia applications. Since UDP flows do not respond to congestion signals, controlling the queue length at routers by using AQM mechanisms becomes a non-trivial task. In this paper, we study the robustness of popular AQM mechanisms in the presence of a large number of unresponsive UDP flows using ns-2. Further, we provide guidelines to effectively tune the AQM knobs and enhance their robustness against non-responsive UDP flows. © 2016 IEEE.
  • No Thumbnail Available
    Item
    FQ-PIE Queue Discipline in the Linux Kernel: Design, Implementation and Challenges
    (Institute of Electrical and Electronics Engineers Inc., 2019) Ramakrishnan, G.; Bhasi, M.; Saicharan, V.; Monis, L.; Patil, S.D.; Tahiliani, M.P.
    Proportional Integral controller Enhanced (PIE) is an Active Queue Management (AQM) mechanism to address the bufferbloat problem. AQM mechanisms tackle bufferbloat by dropping or marking packets before the buffers fill up, but typically do not ensure fairness between responsive and unresponsive flows that share the same bottleneck link i.e., unresponsive flows can starve responsive flows when they co-exist. Recently, there has been an active interest in integrating flow protection mechanisms with AQM mechanisms to collectively tackle the problem of bufferbloat and fairness. There exist two such algorithms: Flow Queue Controlled Delay (FQ-CoDel) and Flow Queue Proportional Integral Controller Enhanced (FQ-PIE) that integrate flow protection with AQM mechanisms. Flow protection is achieved by dividing the incoming flows into separate queues and then applying CoDel/PIE algorithm on respective queues. Although FQ-CoDel is available in the mainline of Linux, there does not exist a model for FQ-PIE. In this paper, we discuss the design and implementation of FQ-PIE in the Linux kernel. We test and evaluate our proposed model of FQ-PIE in different scenarios by comparing the results obtained from it to those obtained for PIE and FQ-CoDel. Besides evaluating the fairness among responsive and unresponsive flows, we also evaluate the fairness among different types of responsive flows, such as when CUBIC TCP shares the same bottleneck link as TCP BBR. We also assess the benefits of integrating flow protection with AQM mechanisms in terms of reducing the latency for thin, latency sensitive flows when they coexist with thick, latency tolerant flows. © 2019 IEEE.