Journal of High Speed Networks - Volume 11, issue 1

Authors: Petrovic, Slobodan S. | De, Subrata K.

Article Type: Research Article

Abstract: The Adaptive Stochastic Rate Allocation (ASRA) algorithm for ABR traffic management in ATM networks is presented. As the dynamics and parameters of the traffic flow process are poorly known, the adaptive feedback gain depends not only on the parameters' estimates, but is also modulated by current uncertainty of the parameters. Therefore, the control algorithm expresses its dual nature by simultaneously performing two functions: ceaseless estimation of parameters and the process control. The allowed cell rates of the ABR sources are dynamically shaped by the feedback messages based on the instantaneous queue size in the ATM switch output buffer. The ASRA …scheme is evaluated via simulation testing in comparison with the ERICA and BECN schemes. The requirements tested included: utilization, queuing delay, queuing delay variance, and queue size. The results of a simulation study suggest that the ASRA scheme can provide for higher priority VBR traffic, while retaining almost the same average utilization, considerably shorter average queue length, average queuing delay and particularly queuing delay variance in the ATM switch output buffer. The ASRA scheme's fairness in max‐min sense along with fast transient response is demonstrated. Show more

Keywords: ATM, ABR, rate control, feedback, bursty traffic

Citation: Journal of High Speed Networks, vol. 11, no. 1, pp. 1-22, 2002

Authors: Acampora, Anthony S. | Gholmieh, Ralph A. | Krishnamurthy, Srikanth

Article Type: Research Article

Abstract: In this paper, we consider a symmetric grid network consisting of N distinct nodes. The number of allowable calls (either the number of circuit switched calls or the maximum number of virtual connections such that QoS objectives are maintained) between any two nodes of the network is assumed to be a constant. We first determine this constant assuming that the network is fully loaded. Then, we find the maximum additional capacity needed on each link such that single link, and double link failures can be tolerated by rerouting calls around failed links. Results show that the maximum additional capacity needed …to recover from any single link, double link, or single node failure, with no loss of connections (except for those connections terminating at a failed node) scales as ${1/\sqrt{(N)}}$ . Thus, we conclude that rerouting, combined with an admission policy which blocks new call attempts such that a fraction of capacity proportional to ${1/\sqrt{(N)}}$ is reserved for failure recovery, provides totally failsafe operation in the presence of such failure events. Show more

Citation: Journal of High Speed Networks, vol. 11, no. 1, pp. 23-44, 2002

Authors: Wang, Bin | Hou, Jennifer C. | Han, Ching‐Chih

Article Type: Research Article

Abstract: Complement to our prior work in [21], we address in this paper the problem of dynamically establishing/terminating real‐time message streams in response to call setup/clear requests in single‐hop star‐coupled WDM optical networks. We consider a network architecture in which N stations are connected to a star coupler with W data channels (W≤N) and one control channel. Each of the W data channels is slotted and shared by the N stations by means of time division multiplexing. The control channel is used for stations to coordinate the call establishment and termination operations. We propose a distributed, dynamic slot allocation scheme …to allocate/de‐allocate time slots on the W data channels to message streams, with the objective of meeting message deadlines. To facilitate slot assignment, the proposed scheme first decomposes each message stream into a set of message sub‐streams, and groups the time slots on each wavelength channel into sub‐channels. In response to a call setup request, the proposed scheme then allocates one or more empty sub‐channels available over the W data channels to a message stream to fulfill its temporal requirement, subject to the source/destination constraints and that the temporal guarantees to existing message streams should not be violated. On the other hand, in response to a call clear request, the proposed scheme releases the slots allocated to the terminated message stream, and merges, if appropriate, empty sub‐channels to facilitate future message stream establishment. We formally prove the properties, and the correctness of, the proposed dynamic slot allocation scheme. Show more

Keywords: Dynamic channel setup and tear‐down, time constrained communications, quality of service (QoS), WDM star‐based lightwave networks, slot allocation

Citation: Journal of High Speed Networks, vol. 11, no. 1, pp. 45-66, 2002

Authors: Li, Guangzhi | Simha, Rahul

Article Type: Research Article

Abstract: This paper considers a network design problem introduced by Gerstel, Lin and Sasaki (INFOCOM'98) in which resource allocation is performed within a Wavelength Division Multiplexing (WDM) optical ring network to reduce overall equipment cost. The problem can be summarized as follows. The Add‐Drop Multiplexers (ADM's) that are used to terminate lightpaths in an optical (SONET/SDH) ring are expensive. A naive implementation would require ADM's for each wavelength at each node. However, by carefully assigning connections to wavelengths and routing the resulting lightpaths, one may avoid terminating all wavelengths at every node, and thereby reduce the number of ADM's needed. …While Gerstel et al. consider wavelength assignment with respect to this problem, they do not consider the additional complication of routing. In this paper, we consider joint routing and wavelength assignment, and show that the number of ADM's required is significantly less than the number resulting from applying the heuristics in Gerstel et al. Our algorithm analyzes connection requirements and, using a decomposition based on Euler paths, performs routing and wavelength assignment. Show more

Keywords: Optical networks, SONET/WDM, Routing and wavelength assignment, ADM's

Citation: Journal of High Speed Networks, vol. 11, no. 1, pp. 67-77, 2002