R. M. Karp, E. Koutsoupias, C. H. Papadimitriou, and S. Shenker, "Optimization problems in congestion control," in FOCS, 2000.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....is achieved even under this assumption. It is worth noting that all these papers deal with rates instead of windows of sequence numbers. 4. 2 Competitive analysis of TCP congestion control The problem of analyzing TCP congestion control using competitive analysis was suggested by Karp et al. [KKPS00], who attempted to find theoretical reasons for the empirically observed superiority of TCP to most of the proposed alternatives. In their model, a TCP session attempts to guess a threshold u (intuitively the ideal transmission rate for the session) and the network (modeled as an adversary) ....

R. Karp, E. Koutsoupias, C. Papadimitriou, and S. Shenker. Optimization problems in congestion control. In IEEE Symposium on Foundations of Computer Science, pages 66-- 74, 2000.

....a large, diverse collection of autonomous entities to interact, collaborate and compete. Game theory has emerged as an important tool to understand the complex interplay of the interests of these autonomous agents, and thus model and analyze the architecture and the functioning of the Internet [26, 18, 27, 29, 12]. Ideas from game theory have been used to design protocols [18, 20, 11, 29] and to gain insights into basic computer science problems [23, 1, 3, 21] Some of the application areas that have received extensive interest include problems relating to routing protocols for networks [27] such as ....

....and compete. Game theory has emerged as an important tool to understand the complex interplay of the interests of these autonomous agents, and thus model and analyze the architecture and the functioning of the Internet [26, 18, 27, 29, 12] Ideas from game theory have been used to design protocols [18, 20, 11, 29] and to gain insights into basic computer science problems [23, 1, 3, 21] Some of the application areas that have received extensive interest include problems relating to routing protocols for networks [27] such as congestion control[29, 12] bandwidth pricing [20] multicasting [11] and design ....

R. Karp, E. Koutsoupias, C.H. Papadimitriou and S. Shenker, \Optimization problems in Congestion Control", in Proceedings of 41 st FOCS, 2000.

....the widely used Transport Control Protocol (TCP) as an online competitive scheduling problem. While practitioners firmly believe that TCP performs well, we are able for the first time to prove this formally. In particular, we provide an answer to the following question posed by Karp et al. [KKPS00]: Of which problem is TCP congestion control the solution . First, we prove that even though TCP is an online, nonclairvoyant, and distributed algorithm, its user perceived latency or flow time is within a constant factor of that of the optimal offline algorithm when it is given a constant ....

....which use the transport control protocol (TCP) TMW97] There has been a lot of empirical evidence that TCP provides superior performance to most proposed alternatives. However, the reasons for the success of TCP have not been understood from a theoretical standpoint. Recently, Karp et al. [KKPS00] studied this problem and asked Of which problem is TCP congestion control the solution In this paper, we provide an answer to their question by proving that a simplified version of TCP allocates bandwidths to users in an efficient and fair way. Our results are proved by demonstrating that ....

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R. Karp, E. Koutsoupias, C. Papadimitriou, and S. Shenker. Optimization problems in congestion control. In IEEE Symposium on Foundations of Computer Science, pages 66-- 74, 2000.

....is the TCP packet size and RTT is the Round Trip Time. The analysis suggests a 75 efficiency of the protocol when the system is in equilibrium. Several, congestion control algorithms along with a cost analysis of their capacity to discover the available bandwidth, have been recently presented in [16]. x = y x y x k y k Efficiency Line y = B Bandwidth Limit Line Flow f1 Flow f2 Fig. 2. Vectorial representation of two flow convergence to fairness. Figure is based on [1] V. EXPERIMENTAL METHODOLOGY AND TESTBED . 4 ms 4 ms RED RED 17 ms FTP Senders FTP ....

R. Karp, E. Koutsoupias, C. Papadimitriou, and S. Shenker, "Optimization Problems in Congestion Control," in IEEE Symposium on Foundations of Computer Science, November 2000, pp. 66-- 74.

....the TCP packet size and RTT is the Round Trip Time . The analysis suggests a 75 efficiency of the protocol when the system is in equilibrium. Several congestion control algorithms along with a cost analysis of their capacity to discover the available bandwidth have been recently presented in [10]. Although the system efficiency is well defined and adequately measured, the algorithm s potential to achieve fairness needs further attention. From our perspective, fairness involves a punctual, a vertical and a horizontal aspect. The punctual represents the question whether the algorithm ....

R. Karp, E. Koutsoupias, C. Papadimitriou, and S. Shenker, "Optimization Problems in Congestion Control," in IEEE Symposium on Foundations of Computer Science, pp. 66--74, November 2000.

....which proved that this is indeed the case with respect to the algorithm we suggested. This analysis is given in the next chapter. There was also a focus on another major problem of determining the available bandwidth. This problem was inspired by some recent work done in a paper by Karp et al. [2]. The work basically reduced the problem to an algorithmic problem of determining the available bandwidth through query algorithms. In fact any congestion control algorithm controls the rate of sending packets by making estimates about the available bandwidth. The standard TCP algorithm : Additive ....

....UN adding a cost of V per unit time and therefore a total cost of V UN . Also here we are making N polls so that we should multiply this by N . Also we will divide this by T to average it out over the interval. Thus the average cost we de ne is 2 . This is a random variable whose expectation E[ 2 ] is what we seek as the cost. However in the present form this is dicult to evaluate so we take in consideration that N is large and so N = the expectation of the random variable which gives the inter polling times. What we basically aim to evaluate here is the quantity E[ For this we ....

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R. Karp, E. Koustosoupias, C.Papadamitriou, and S.Shenker. Optimization problems in congestion control. FOCS, 2000. 26

....problems. The connection is made more meaningful by the fact that the two areas of game theory and approximation algorithms share common methodology both heavily use machinery from the theory of linear programming. Various aspects of this connection have been explored recently by researchers [8, 10, 15, 20, 21, 26, 27, 29]. In this paper we will consider the problem of sharing the cost of a jointly utilized facility in a fair manner. Consider a service providing company whose set of possible customers, also called users, is U . For each set S U C(S) denotes the cost incurred by the company to serve the users ....

P. Karp, Koutsoupias and Shenker. Optimization problems in congestion control. In Proceedings of the 41st FOCS, 2000.

.... strategies and responses of these agents in negotiations and resource allocations [14, 15, 18] Others use market based ideas to solve distributed computational problems [20, 21] Researchers in networking have proposed game theoretic techniques to deal with congestion control in the Internet [5, 7, 13, 17]. 2 Our paper is motivated by the algorithmic mechanism design paper of Nisan and Ronen [12] They investigate computational complexity and algorithmic issues in mechanism design, and raise some intriguing problems. Specifically, they asked the question that forms the basis of our work: Can the ....

....there is an increased need to design efficient protocols that motivate self interested agents 9 to cooperate. Example applications include resource allocation in computational grids [22] marketbased protocols for scheduling or task allocation [20, 21] and congestion control in the Internet [5, 7, 10, 17]. One of the most celebrated results in the field of mechanism design is the Vickrey ClarkeGroves protocol, which uses a payment scheme to motivate selfish agents to bid truthfully. In this paper, we focused on the algorithmic aspect of computing the VCG payments in the context of shortest path ....

R. Karp, E. Koutsoupias, C. Papadimitriou, and S. Shenker. Optimization problems in congestion control. In Proc. 41st Annu. IEEE Sympos. Found. Comput. Sci., 2000.

....network and u be the (unknown) threshold. Cost gentle = # u x for x u #(x u) for x u (1) Cost severe = # u x for x u u for x u (2) In the real world, we consider the case where an adversary is changing u with time. This model has been analyzed in by Karp, Papadimitrou and Shekner [1]. Notes for Lecture 25: 2 For the remainder of this lecture, we will consider only the static u case with a severe cost function. Let s analyze the worst case performance of di#erent algorithms under these conditions, starting with the most obvious approach. Binary Search: Naively, since there ....

Richard Karp, Elias Koutsoupias, Christos Papadimitriou, and Scott Shenker. (2000). Optimization Problems in Congestion Control. http://www.cs.ucla.edu/ elias/publications/paper-kkps00.ps

....This ingeniously simple scheme seems to work, and its users do not seem eager to abandon it for something more aggressive, but the origins of this apparent success and acquiescence are not well understood. One is justi ed to wonder: Of which game is TCP IP congestion control the Nash equilibrium [12] 3 If we see Internet congestion control as a game, we can be sure that its equilibrium is not achieved by rational contemplation, but by interaction and adaptation in an environment where conditions (and player populations) change rapidly (and in which changes in strategy incur costs) These ....

Karp, Koutsoupias, Papadimitriou, Shenker, \Optimization problems in congestion control," Proceedings of the 41st FOCS, 2000.

.... strategies and responses of these agents in negotiations and resource allocations [14, 15, 20] Others use market based ideas to solve distributed computational problems [21, 23] Researchers in networking have 2 proposed game theoretic techniques to deal with congestion control in the Internet [5, 6, 13, 19]. Our paper is motivated by the algorithmic mechanism design paper of Nisan and Ronen [12] They investigate computational complexity and algorithmic issues in mechanism design, and raise some intriguing problems. Specifically, they asked the question that forms the basis of our work: Can the ....

....there is an increased need to design efficient protocols that motivate self interested agents to cooperate. Example applications include resource allocation in computational grids [24] market based protocols for scheduling or task allocation [21, 23] and congestion control in the Internet [5, 6, 10, 19]. One of the most celebrated results in the field of mechanism design is the Vickrey (or VickreyClarke Groves) protocol, which uses a payment scheme to motivate selfish agents to bid truthfully. In this paper, we focused on the algorithmic aspect of computing the Vickrey payments in the context ....

R. Karp, E. Koutsoupias, C. Papadimitriou, and S. Shenker. Optimization problems in congestion control. In Proc. 41st Annu. IEEE Sympos. Found. Comput. Sci., 2000.

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R. M. Karp, E. Koutsoupias, C. H. Papadimitriou, and S. Shenker, "Optimization problems in congestion control," in FOCS, 2000.

No context found.

R. Karp, E. Koutsoupias, C. Papadimitriou, and S. Shenker. Optimization Problems in Congestion Control. In IEEE Symposium on Foundations of Computer Science, pages 66--74, November 2000.

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Richard M. Karp, Elias Koutsoupias, Christos H. Papadimitriou, and Scott Shenker. Optimization problems in congestion control. In IEEE Symposium on Foundations of Computer Science, pages 66--74, 2000.

No context found.

Richard M. Karp, Elias Koutsoupias, Christos H. Papadimitriou, and Scott Shenker. Optimization problems in congestion control. In IEEE Symposium on Foundations of Computer Science, pages 66--74, 2000.

No context found.

Richard M. Karp, Elias Koutsoupias, Christos H. Papadimitriou, and Scott Shenker. Optimization problems in congestion control. In IEEE Symposium on Foundations of Computer Science, pages 66--74, 2000.

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