Results 1  10
of
19
Adversarial models for prioritybased networks
 Networks
, 2005
"... In this article, we propose several variations of the adversarial queueing model and address stability issues of networks and protocols in those proposed models. The first such variation is the priority model, which is directed at static network topologies and takes into account the case in which pa ..."
Abstract

Cited by 15 (5 self)
 Add to MetaCart
(Show Context)
In this article, we propose several variations of the adversarial queueing model and address stability issues of networks and protocols in those proposed models. The first such variation is the priority model, which is directed at static network topologies and takes into account the case in which packets can have different priorities. Those priorities are assigned by an adversary at injection time. A second variation, the variable priority model, is an extension of the priority model in which the adversary may dynamically change the priority of packets at each time step. Two more variations, namely the failure model and the reliable model, are proposed to cope with dynamic networks. In the failure and reliable models the adversary controls, under different constraints, the failures that the links of the topology might
Instability of FIFO in the permanent sessions model at arbitrarily small network loads
 In Proceedings of SODA’07
, 2007
"... ..."
Deciding the FIFO Stability of Networks in Polynomial Time (full version
 Technical report: Frankfurter InformatikBerichte, No 3/2005, ISSN
, 2006
"... Abstract. FIFO is the most prominent queueing strategy due to its simplicity and the fact that it only works with local information. Its analysis within the adversarial queueing theory however has shown, that there are networks that are not stable under the FIFO protocol, even at arbitrarily low rat ..."
Abstract

Cited by 7 (0 self)
 Add to MetaCart
(Show Context)
Abstract. FIFO is the most prominent queueing strategy due to its simplicity and the fact that it only works with local information. Its analysis within the adversarial queueing theory however has shown, that there are networks that are not stable under the FIFO protocol, even at arbitrarily low rate. On the other hand there are networks that are universally stable, i.e., they are stable under every greedy protocol at any rate r<1. The question as to which networks are stable under the FIFO protocol arises naturally. We offer the first polynomial time algorithm for deciding FIFO stability and simplepath FIFO stability of a directed network, answering an open question posed in [1,4]. It turns out, that there are networks, that are FIFO stable but not universally stable, hence FIFO is not a worst case protocol in this sense. Our characterization of FIFO stability is constructive and disproves an open characterization in [4]. 1
The impact of failure management on the stability of communication networks
 In 10th International Conference on Parallel and Distributed Systems
, 2004
"... In this work we deal with communication networks in which links may fail. We propose an adversarial model for describing the traffic pattern occurring in this type of faulty systems and study properties concerning their stability, specially under (nontrivial) underloaded worsecase scenarios. We sh ..."
Abstract

Cited by 6 (2 self)
 Add to MetaCart
(Show Context)
In this work we deal with communication networks in which links may fail. We propose an adversarial model for describing the traffic pattern occurring in this type of faulty systems and study properties concerning their stability, specially under (nontrivial) underloaded worsecase scenarios. We show that, depending on how the system is organized and prepared to deal with failures, the dynamics of the system change and thus the conditions for stability. We propose three different ways of failure management and study how they influence on the stability of faulty communication networks under the adversarial model proposed. We show that some failure managements can provoke the instability of even very simple networks. 1.
Deciding stability in packetswitched FIFO networks under the Adversarial Queuing model in polynomial time
 In 19th International Symposium on Distributed Computing (disc’05
, 2005
"... Abstract. In spite of the importance of the fifo protocol and the research efforts invested in obtaining results for it, deciding whether a given (packetswitched) network is stable under fifo has remained an open question for several years. In this work, we address the general case of this problem ..."
Abstract

Cited by 5 (0 self)
 Add to MetaCart
(Show Context)
Abstract. In spite of the importance of the fifo protocol and the research efforts invested in obtaining results for it, deciding whether a given (packetswitched) network is stable under fifo has remained an open question for several years. In this work, we address the general case of this problem and try to characterize the property of stability under fifo in terms of network topologies. Such a characterization provides us with the family of network topologies that, under the fifo protocol, can be made unstable by some adversarial traffic pattern. We show that the property of stability under fifo is decidable in polynomial time. 1
Adversarial queueing model for continuous network dynamics
 In 30th International Symposium on Mathematical Foundations of Computer Science (mfcs’05), volume 3618 of Lecture Notes in Computer Science
, 2005
"... In this paper we initiate the generalization of the Adversarial Queueing Theory (aqt) model to capture the dynamics of continuous scenarios in which the usually assumed synchronicity of the evolution is not required anymore. We propose an asynchronous model, named continuous aqt (caqt), in which pac ..."
Abstract

Cited by 5 (1 self)
 Add to MetaCart
(Show Context)
In this paper we initiate the generalization of the Adversarial Queueing Theory (aqt) model to capture the dynamics of continuous scenarios in which the usually assumed synchronicity of the evolution is not required anymore. We propose an asynchronous model, named continuous aqt (caqt), in which packets can have arbitrary lengths, and the network links may have different speeds (or bandwidths) and propagation delays. We show that, in such a general model, having bounded queues implies bounded endtoend packet delays and vice versa. From the network point of view, we show that networks with directed acyclic topologies are universally stable, i.e., are stable independently of the scheduling policies and the traffic patterns used in it, and that this even holds for traffic patterns that make links to be fully loaded. We also show that the characterization of the property of universal stability of networks is the same as in the aqt model and, therefore, decidable in polynomial time. Concerning packet scheduling policies, we show that the wellknown lis, sis, ftg and nfs scheduling policies remain universally stable in our model. However, we present other scheduling policies that are unstable under the caqt model, but universally stable under the aqt model. In this sense, the caqt model is strictly stronger than the aqt model. Additionally, we show that the network features considered in the caqt model, namely packet lengths, propagation delays and bandwidths, are important keynotes for the stability of the system.
Adversarial Queuing on the Multiple Access Channel
, 2006
"... ... where n is the number of stations, and show that fair latency is impossible to achieve for injection rates that are ω ( 1 log n). For channels without collision detection, we present a fullsensing protocol of fair latency for injection rates that are 1 at most c lg2, for some c> 0. We show t ..."
Abstract

Cited by 4 (3 self)
 Add to MetaCart
... where n is the number of stations, and show that fair latency is impossible to achieve for injection rates that are ω ( 1 log n). For channels without collision detection, we present a fullsensing protocol of fair latency for injection rates that are 1 at most c lg2, for some c> 0. We show that there exists an acknowledgmentbased protocol n 1 that has fair latency for injection rates that are at most cn lg2, for some c> 0, and develop n an explicit acknowledgmentbased protocol of fair latency for injection rates that are at most 1 27n2 ln n. Regarding impossibility to achieve just stability by restricted protocols, we prove that
A Systematic Construction of Instability Bounds in LIS Networks
, 2005
"... In this work, we study the impact of dynamically changing link slowdowns on the stability properties of packetswitched networks under the Adversarial Queueing Theory framework. Especially, we consider the Adversarial, QuasiStatic Slowdown Queueing Theory model, where each link slowdown may take o ..."
Abstract

Cited by 1 (0 self)
 Add to MetaCart
(Show Context)
In this work, we study the impact of dynamically changing link slowdowns on the stability properties of packetswitched networks under the Adversarial Queueing Theory framework. Especially, we consider the Adversarial, QuasiStatic Slowdown Queueing Theory model, where each link slowdown may take on values in the twovalued set of integers {1, D} with D> 1 which remain fixed for a long time, under a (w, ρ)adversary. In this framework, we present an innovative systematic construction for the estimation of adversarial injection rate lower bounds, which, if exceeded, cause instability in networks that use the LIS (LongestinSystem) protocol for contentionresolution. In addition, we show that a network that uses the LIS protocol for contentionresolution may result in dropping its instability bound at injection rates ρ> 0 when the network size and the high slowdown D take large values. This is the best ever known instability lower bound for LIS networks.