Results 1  10
of
47
Effective bandwidth of general Markovian traffic sources and admission control of high speed networks
 IEEE/ACM Transactions on Networking
, 1993
"... Absfruct The emerging highspeed networks, notably the ATMbased Broadband ISDN, are expected to integrate through statistical multiplexing large numbers of traffic sources having a broad range of burstiness characteristics. A prime instrument for controlling congestion in the network is admission ..."
Abstract

Cited by 267 (5 self)
 Add to MetaCart
Absfruct The emerging highspeed networks, notably the ATMbased Broadband ISDN, are expected to integrate through statistical multiplexing large numbers of traffic sources having a broad range of burstiness characteristics. A prime instrument for controlling congestion in the network is admission control, which limits calls and guarantees a grade of service determined by delay and loss probability in the multiplexer. We show, for general Markovian traffic sources, that it is possible to assign a notional effective bandwidth to each source which is an explicitly identified, simply computed quantity with provably correct properties in the natural asymptotic regime of small loss probabilities. It is the maximal real eigenvalue of a matrix which is directly obtained from the source characteristics and the admission criterion, and for several sources it is simply additive. We consider both fluid and point process models and obtain parallel results. Numerical results show that the acceptance set for heterogeneous classes of sources is closely approximated and conservatively bounded by the set obtained from the effective bandwidth approximation. Also, the bandwidthreducing properties of the Leaky Bucket regulator are exhibited numerically. For a source model of video teleconferencing due to Heyman et al. with a large number of states, the effective bandwidth is easily computed. The equivalent bandwidth is bounded by the peak and mean source rates, and is monotonic and concave with respect to a parameter of the admission criterion. Coupling of state transitions of two related asynchronous sources always increases their effective bandwidth. 1.
A new approach for allocating buffers and bandwidth to heterogeneous, regulated traffic in an ATM node
 IEEE Journal on Selected Areas in Communications
, 1995
"... AbstractA new approach to determining the admissibility of variable bit rate (VBR) traffic in buffered digital networks is developed. In this approach all traffic presented to the network is assumed to have been subjected to leakybucket regulation, and extremal, periodic, onoff regulated traffic ..."
Abstract

Cited by 150 (9 self)
 Add to MetaCart
AbstractA new approach to determining the admissibility of variable bit rate (VBR) traffic in buffered digital networks is developed. In this approach all traffic presented to the network is assumed to have been subjected to leakybucket regulation, and extremal, periodic, onoff regulated traffic is considered; the analysis is based on fluid models. Each regulated traffic stream is allocated bandwidth and buffer resources which are independent of other traffic. Bandwidth and buffer allocations are traded off in a manner optimal for an adversarial situation involving minimal knowledge of other traffic. This leads to a singleresource statisticalmultiplexing problem which is solved using techniques previously used for unbuffered traffic. VBR traffic is found to be divisible into two classes, one for which statistical multiplexing is effective and one for which statistical multiplexing is ineffective in the sense that accepting small losses provides no advantage over requiring lossless performance. The boundary of the set of admissible traffic sources is examined, and is found to be sufficiently linear that an effective bandwidth can be meaningfully assigned to each VBR source, so long as only statisticallymultiplexable sources are considered, or only nonstatisticallymultiplexable sources are considered. If these two types of sources are intermixed, then nonlinear interactions occur and fewer sources can be admitted than a linear theory would predict. A qualitative characterization of the nonlinearities is presented. The complete analysis involves conservative approximations; however, admission decisions based on this work are expected to be less overly conservative than decisions based on alternative approaches. I.
Simple Performance Models of Differentiated Services Schemes for the Internet
, 1999
"... Schemes based on the tagging of packets have recently been proposed as a lowcost way to augment the single class best effort service model of the current Internet by including some kind of service discrimination. Such schemes have a number of attractive features, however, it is not clear exactly wh ..."
Abstract

Cited by 62 (0 self)
 Add to MetaCart
Schemes based on the tagging of packets have recently been proposed as a lowcost way to augment the single class best effort service model of the current Internet by including some kind of service discrimination. Such schemes have a number of attractive features, however, it is not clear exactly what kind of service they would provide to applications. Yet quantifying such service is very important to understand the benets and drawbacks of the different tagging schemes and of the mechanisms in each scheme (for example how much RIO contributes in the Assured scheme), and to tackle key performance and economic issues (e.g. the difference in tariff between different service classes would presumably depend on the difference in performance between the classes). Our goal in this paper is to obtain a quantitative description of the service provided by tagging schemes. Specically, we describe and solve simple analytic models of two recently proposed schemes, namely the Assured Service scheme ...
Analysis, Approximations and Admission Control of a MultiService Multiplexing System with Priorities
 In Proc. IEEE INFOCOM '95
, 1995
"... We consider an ATM system with an architecture which is designed to accommodate users with very different quality of service requirements. In the base case with only two services, sources which require low loss belong to a High Priority class, and share a FCFS buffer, which has priority access to th ..."
Abstract

Cited by 53 (3 self)
 Add to MetaCart
We consider an ATM system with an architecture which is designed to accommodate users with very different quality of service requirements. In the base case with only two services, sources which require low loss belong to a High Priority class, and share a FCFS buffer, which has priority access to the trunk. A Low Priority class of sources with typically less stringent requirements on loss have a separate FCFS buffer, which receives the timevarying, residual bandwidth, if any, of the trunk. By administering admission control and restricting the combination of sources to an admissible set, the service guarantees for both classes may be satisfied. The sources are bursty and stochastic fluid models are used to handle burstscale congestion effects. Our contributions are: (i) we develop simple, fast and robust analytic approximations for the queue distributions in the two buffers; (ii) for admission control, we calculate the admissible set by using our analytic approximations and find that...
A Quantitative Study of Differentiated Services for the Internet
 IEEE GLOBECOM
, 1999
"... The Differentiated Services architecture provides router mechanisms for aggregate traffic, and edge mechanisms for individual flows, that together can be used to build services with varying delay and loss behaviors. In this paper, we compare the loss and delay behaviors that can be provided using th ..."
Abstract

Cited by 42 (2 self)
 Add to MetaCart
The Differentiated Services architecture provides router mechanisms for aggregate traffic, and edge mechanisms for individual flows, that together can be used to build services with varying delay and loss behaviors. In this paper, we compare the loss and delay behaviors that can be provided using the services based on combinations of two router mechanisms, threshold dropping and priority scheduling and two packet marking mechanisms, edgediscarding and edgemarking. In the first part of our work, we compare the delay and loss behaviors of the two router mechanisms coupled with edgediscarding for a wide range of traffic arrivals. We observe that priority scheduling provides lower expected delays to preferred traffic than threshold dropping. In addition, we find that a considerable additional link bandwidth is needed with threshold dropping to provide same delay behavior as priority scheduling. We further observe little difference in the loss incurred by preferred traffic under both ro...
Folding Algorithm: A Computational Method for Finite QBD Processes with LevelDependent Transitions
 IEEE Trans. Commu
, 1994
"... This paper presents a new computational method for steady state analysis of finite QBDprocess with leveldependent transitions. The QBD state space is defined in twodimension with N phases and K levels. Instead of formulating solutions in matrixgeometric form, the Foldingalgorithm provides a tech ..."
Abstract

Cited by 34 (20 self)
 Add to MetaCart
This paper presents a new computational method for steady state analysis of finite QBDprocess with leveldependent transitions. The QBD state space is defined in twodimension with N phases and K levels. Instead of formulating solutions in matrixgeometric form, the Foldingalgorithm provides a technique for direct computation of ßP = 0, where P is the QBD generator which is an (NK) \Theta (NK) matrix. Taking a finite sequence of fixedcost binary reduction steps, the Klevel matrix P is eventually reduced to a singlelevel matrix, from which a boundary vector is obtained. Each step halves the matrix size but keeps the QBD form. The solution ß is expressed as a product of the boundary vector and a finite sequence of expansion factors. The time and space complexity for solving ßP = 0 is therefore reduced from O(N 3 K) and O(N 2 K) to O(N 3 log 2 K)andO(N 2 log 2 K), respectively. The Foldingalgorithm has a number of highly desirable advantages when it is applied to queueing an...
Multiple Time Scale Regulation and Worst Case Processes for ATM Network Control
, 1995
"... Recent research on congestion control in high speed ATM networks has sought to extract statistical multiplexing efficiencies while guaranteeing quality of service. To facilitate network control, traffic regulators are positioned at network edges, with Leaky Bucket regulation ubiquitous. We consider ..."
Abstract

Cited by 24 (1 self)
 Add to MetaCart
Recent research on congestion control in high speed ATM networks has sought to extract statistical multiplexing efficiencies while guaranteeing quality of service. To facilitate network control, traffic regulators are positioned at network edges, with Leaky Bucket regulation ubiquitous. We consider the composite of conventional Leaky Bucket regulators, one for each time scale. Over longer time scales the enforcement of traffic to the mean in the regulation is less stringent, in so far as the bucket is larger, while the mean rate is smaller. The regulated process is required to be compliant with all the Leaky Bucket regulators. In the approach taken here, traffic sources are assumed to be mutually independent but otherwise adversarial to the utmost extent permitted by regulators. To mitigate against an overly conservative design, small losses are allowed in accessing the shared unbuffered network resource. We rely on the Chernoff bound, which also gives an asymptotic, large deviations a...
Performance Analysis of the Dual Cell Spacer in ATM Systems
, 1995
"... In this paper we develop an analysis of the socalled Dual Cell Spacer. In contrast to a conventional spacer, which shapes a traffic stream only according to a given Peak Cell Rate, the Dual Cell Spacer takes into account the Peak Cell Rate as well as the Sustainable Cell Rate with the corresponding ..."
Abstract

Cited by 20 (7 self)
 Add to MetaCart
In this paper we develop an analysis of the socalled Dual Cell Spacer. In contrast to a conventional spacer, which shapes a traffic stream only according to a given Peak Cell Rate, the Dual Cell Spacer takes into account the Peak Cell Rate as well as the Sustainable Cell Rate with the corresponding Burst Tolerance. The analysis is carried out in the discretetime domain. Performance measures such as the cell rejection probability, the cell delay distribution and the cell interdeparture time distribution are derived. All results are of an exact nature. Numerical examples that compare the performance of the Dual Cell Spacer with that of a conventional spacer show a similar performance in terms of cell delay and cell loss for relatively small values of the Burst Tolerance. Using our analysis, both the Sustainable Cell Rate and the Burst Tolerance, which are used for traffic shaping in the Dual Cell Spacer, can be chosen adequately to achieve a given target cell rejection probability or ...
A Novel Approach to Estimating the Cell Loss Probability in an ATM Multiplexer Loaded with Homogeneous OnOff Sources
 IEEE Transactions on Communications
"... Estimating the cell loss probability in an ATM multiplexer is one of the most important problems concerning congestion control and bandwidth management in an ATMbased BISDN. We propose a new approach to estimating the cell loss probability in an ATM multiplexer. We use the Markov modulated determin ..."
Abstract

Cited by 17 (3 self)
 Add to MetaCart
Estimating the cell loss probability in an ATM multiplexer is one of the most important problems concerning congestion control and bandwidth management in an ATMbased BISDN. We propose a new approach to estimating the cell loss probability in an ATM multiplexer. We use the Markov modulated deterministic process (MMDP) to approximate the actual arrival process and then model the ATM multiplexer as an MMDP/D/1/K queueing system. Using queueing analysis, we derive a formula for the cell loss probability expressed in terms of the limiting probabilities of a Markov chain. We propose two approximation methods based on the results of the analysis. The actual arrival process is approximated by an (M+1) state MMDP in the first method and by a twostate MMDP in the second. The major advantages of both methods are simplicity, computational efficiency, and numerical stability. The most attractive feature of the second method is that the cell loss probability can be expressed in closed form. Nume...
Analysis of a Queueing Model with Delayed Feedback and its Application to the ABR Flow Control
, 1997
"... A common method for regulating the input flow in today's telecommunication networks is the implementation of reactive traffic control mechanisms. By limiting the user's access according to the current network load situation, the throughput is optimized while congestion is avoided. In ATM networks, f ..."
Abstract

Cited by 13 (3 self)
 Add to MetaCart
A common method for regulating the input flow in today's telecommunication networks is the implementation of reactive traffic control mechanisms. By limiting the user's access according to the current network load situation, the throughput is optimized while congestion is avoided. In ATM networks, for example, a ratebased feedback control is applied to dynamically adjust the transmission rates of connections belonging to the ABR service category. This paper presents a discretetime analysis of a queueing model with nondeterministic arrivals and delayed feedback. The binary feedback information is used to regulate the input flowbychanging the interarrival distribution accordingly. Applying this model, the performance of the ABR flow control can be studied with respect to the variabilityofthecell generation process.