Multiplex communications – Data flow congestion prevention or control – Control of data admission to the network
Patent
1995-01-06
1997-11-25
Olms, Douglas W.
Multiplex communications
Data flow congestion prevention or control
Control of data admission to the network
370253, 370463, H04J 314, H04L 1256
Patent
active
056919751
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to a method and apparatus for control in an asynchronous transfer mode (ATM) network providing a variable-bit-rate (VBR) service, and more particularly to a method and apparatus for call admission control, cell flow rate monitoring, and internetwork connection in an ATM network providing a VBR service.
BACKGROUND ART
In an ATM multiplexing transmission apparatus, call admission control is performed to prevent degradation in the quality of service (QOS) due to cell losses caused by a buffer overflow, delays, etc., resulting from an increase in traffic. For this purpose, the variation of QOS caused by an increase in traffic after multiplexing is evaluated using UPC (utilization parameter control) parameters with the peak and average rates defined.
In Prior Art (1), according to Hatono, Kawakita, and Mizuno, "Hierarchic fluid approximation model for ATM traffic analysis," IEICE Technical Report SSE91-152, pp. 13-18, March 1992, bursty cell arrivals are approximated by a fluid, and using a stochastic differential equation expressing the variation of the cell length in a buffer, the distribution of the cell length is obtained, from which the cell loss rate is determined.
In Prior Art (2), according to Hirano and Watabe, "Evaluation of burst traffic multiplexing characteristics in ATM switching," Trans. IEICE (B-1), Vol. J72-B-I, No. 4, pp. 264-271, April 1989, and H. Heffes and D. Lucantoni, "A Markov modulated characterization of packetized voice and data traffic and related statistical multiplexer performance," IEEE Jour. SEl. Areas Commun. Vol. SAC-4, No. 6, pp. 833-846, 1986, a cell arrival process is considered using a Markov model, and from a state transition equation in state space expressing simultaneously the state of each call source and the cell length in a buffer, the cell length in a stationary state is obtained, from which the cell loss rate and time delay are calculated.
In Prior Art (3), according to Nakagawa, "Analysis of VBR pass/channel characteristics defined by deterministic parameters," IEICE Technical Report CAS91-150, pp. 1-6, March 1992, and Y. Miyao, "A Call Admission Control Scheme in ATM Networks," Proc. of ICC' 91, pp. 14.5.1-14.5.6, June 1991, the upper bound of the number of cell arrivals or the arrival rate is evaluated using the Chernoff upper bound, thereby obtaining the upper limit of the cell loss rate.
Each of the above prior art examples has a shortcoming of its own: with Prior Art (1), there is no guarantee that QOS will be evaluated on the safe side; with Prior Art (2), the amount of calculation involved is so large that it is difficult to obtain the result within a practical time; and with Prior Art (3), the upper limit to be evaluated is large, so that the gain after multiplexing becomes small. Furthermore, Prior Art (3) has the shortcomings that it is not possible to evaluate delays among QOS, and that when priorities are allocated among call classes, QOS evaluation on a priority class basis is not possible.
An ATM cell flow rate monitoring unit is a device used to measure the number of cells passing through a given point on a transmission path in a given time interval, detect transmission path breakage, failures of switching nodes such as exchanges, cross connects, multiplexers, etc., failures of a UPC monitoring unit, etc., and alert the network control unit to the occurrence of such failures.
In the prior art relating to such an apparatus, according to Chaki, Shinozaki, et al., "A proposal of ATM network resource management for high-speed data," IEICE Technical Report SSE91-150, pp. 1-6, March 1992, the number of arriving cells is continuously monitored in order to detect the occurrence of congestion along a transmission path and to perform necessary control, and when the measured cell discard rate has exceeded a predetermined value continuously for a predetermined length of time, then the path is judged as being congested, and the necessary control is performed.
According to Okatsu, Matsunaga, and Ueda, "A study on
REFERENCES:
patent: 5224091 (1993-06-01), Brandt
patent: 5231633 (1993-07-01), Hluchyj et al.
patent: 5268900 (1993-12-01), Hluchyj et al.
patent: 5313579 (1994-05-01), Chao
patent: 5367523 (1994-11-01), Chang et al.
patent: 5388097 (1995-02-01), Baugher et al.
Arai, Hideaki et al., An Analysis of Call Admission Control in the ATM Network, Theses by IECE, vol. J72-B+I, No. 11, Nov. 25, 1989, pp. 1000-1007.
Chujo Takafumi
Hamada Takeo
Fujitsu Limited
Jung Min
Olms Douglas W.
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