A Case for TCP Vegas and Gateways using Game Theoretic Approach

2003

Abstract--TCP congestion control has been the subject of significant research for more than two decades. Various algorithms including TCP Tahoe, TCP Reno. TCP NewReno. SACK. FACK. and their variations have been proposed to overcome the problem of network ...

Lecture Notes in Computer Science, 2005

TCP Vegas detects network congestion in the early stage and successfully prevents periodic packet loss that usually occurs in TCP Reno. It has been demonstrated that TCP Vegas achieves much higher performance than TCP Reno in many aspects. However, TCP Vegas cannot prevent unnecessary throughput degradation when congestion occurs in the backward path, it passes through multiple congested links, or it reroutes through a path with longer round-trip time (RTT). In this paper, we propose an aided congestion avoidance mechanism for TCP Vegas, called Aid-Vegas, which uses the relative one-way delay of each packet along the forward path to distinguish whether congestion occurs or not. Through the results of simulation, we demonstrate that Aid-Vegas can solve the problems of rerouting and backward congestion, enhance the fairness among the competitive connections, and improve the throughput when multiple congested links are encountered.

Theoretical Computer Science, 2008

We consider network congestion problems between TCP flows and define a new game, the Window-game, which models the problem of network congestion caused by the competing flows. Analytical and experimental results show the relevance of the Window-game to the real TCP game and provide interesting insight on Nash equilibria of the respective network games. Furthermore, we propose a new algorithmic queue mechanism, called Prince, which at congestion makes a scapegoat of the most greedy flow. Preliminary evidence shows that Prince achieves efficient Nash equilibria while requiring only limited computational resources.

While the demand for bandwidth increases exponentially with the growing number of internet based devices, traditional TCP algorithms are turning to be sub optimal. Delay-based congestion control algorithms which are designed to overcome this challenge, are proven to be more satisfactory than loss-based congestion algorithms. On the one hand, Loss base congestion detection technique depends solely on packet loss. On the other hand delay-based algorithms have the advantage of proactively detecting congestion occurrences based on packet delays and as a result avoiding unnecessary packet loss. TCP-Vegas as the most referred variant of delay-based algorithms is promised to achieve between 40 and 70 percent better throughput. However there is some problems which are preventing TCP-Vegas to become widespread. One of these problems is lack of fairness in bandwidth allocation while delay and loss-based connection share a link. In this paper we made some modifications on the original TCP-Vegas which enabled the new algorithm to compete fairly with loss-based algorithm.

Proceedings. Tenth International Conference on Parallel and Distributed Systems, 2004. ICPADS 2004., 2004

In this paper, we propose a router-based congestion avoidance mechanism (RoVegas) for TCP Vegas. TCP Vegas detects network congestion in the early stage and successfully prevents periodic packet loss that usually occurs in TCP Reno. It has been demonstrated that TCP Vegas outperforms TCP Reno in many aspects. However, TCP Vegas suffers several problems that inhere in its congestion avoidance mechanism, these include issues of rerouting, persistent congestion, fairness, and network asymmetry. By performing the proposed scheme in routers along the roundtrip path, RoVegas can solve the problems of rerouting and persistent congestion, enhance the fairness among the competitive connections, and improve the throughput when congestion occurs on the backward path. Through the results of both analysis and simulation, we demonstrate the effectiveness of RoVegas.

… . Conference Proceedings of …, 2003

In spite of the larger performance gain such as higher throughput and almost zero packet retransmissions compared to TCP Reno, TCP Vegas still has a few obstacles for it to be deployed in the Internet. Studies have shown unfair treatment to Vegas connections when they compete with Reno connections. Other issues identified with TCP Vegas are problems of rerouting, persistent congestion, and discrepancy in flow rate tied with starting times and link bandwidth. We reinvestigate these issues and propose modifications to the congestion avoidance mechanism of the TCP Vegas, with the slow-start and congestion recovery algorithms of Vegas remaining untouched. Unlike the solutions proposed in the recent past to deal with some of these issues, our solution is neither dependent on any critical parameter values nor on the buffer management scheme at the routers (e.g., RED). Our experiments show that the modified TCP Vegas (Vegas-A) is able to obtain a fairer share of the network bandwidth when competing with other TCP flows. We also show that Vegas-A can tackle rerouting issues and rectify Vegas's bias against higher bandwidth flows. At the same time, our experiments prove that Vegas-A preserves the properties of Vegas that have made it a noteworthy protocol.

2000

We consider network congestion problems between TCP flows and define a new game, the Window-game, which models the problems of network congestion caused by the competing flows. Analytical and experimental results show the relevance of the Window-game to real TCP congestion games and provide interesting insight into the respective Nash equilibria. Furthermore, we propose a new algorithmic queue mechanism, called Prince, which at congestion makes a scapegoat of the most greedy flow. We provide evidence which shows that Prince achieves efficient Nash equilibria while requiring only limited computational resources.

International Journal for Research in Applied Science and Engineering Technology, 2018

As TCP is more popular and dominant congestion control technique. TCP congestion control techniques assure reliable data transmission and detecting congestion based on packet loss or packet delay. When the network is heavily loaded there is a loss of network performance called congestion. There are two types of network that is Homogenous and Heterogeneous network and various TCP variants which can be evaluated using network simulators. There is not a fair bandwidth allocation in a homogeneous network, but fair in heterogeneous network and has a significantly lower delay. This paper will present various TCP Variants related to TCP Vegas.

wseas.us

The widely used reliable transport protocol TCP, is an end to end protocol designed for the wireline networks characterized by negligible random packet losses. This paper represents exploratory study of TCP congestion control principles and mechanisms. Modern implementations of TCP contain four intertwined algorithms: slow start, congestion avoidance, fast retransmit, and fast recovery. In addition to the standard algorithms used in common implementations of TCP, this paper also describes some of the more common proposals developed by researchers over the years. We also study, through extensive simulations, the performance characteristics of four representative TCP schemes, namely TCP Tahoe, New Reno and Vegas under the network conditions of bottleneck link capacities for wired network.