Multiplex communications – Wide area network – Packet switching
Patent
1989-06-15
1991-05-28
Olms, Douglas W.
Multiplex communications
Wide area network
Packet switching
370 941, 370 54, 370 61, 34082503, 3408255, H04Q 1104
Patent
active
050200526
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a telecommunication packet switching network to transmit packets of information through switching modules included therein, said switching modules being interconnected and each having a plurality of receive ports to receive said packets, a plurality of transmit ports to transmit said packets, and means to select one of their transmit ports and to transfer packets arriving at one of their receive ports to said selected transmit port, said network including at least one first switching module able to select one of its transmit ports without using routing information included in said packets, and at least one second switching module wherein said selection is controlled by routing information included in said packets.
Such a packet switching network is already known in the art, e.g. from the article "Design of a Broadcast Packet Switching Network" by J. S. TURNER, published in the "Proceedings of INFOCOM '86" of April 1986, pages 667 to 675. This known network comprises a first part and a second part which are connected in cascade and include the above mentioned first and second switching modules respectively. Each of these first switching modules is able to freely select one of its transmit ports with the purpose of evenly distributing the traffic load over the first network part.
A drawback of this system is that packets belonging to a same communication generally follow different paths in the first part of the network. As a result, the order of arrival of these packets at their destination may be different from the order in which they were supplied to the network.
An object of the present invention is to provide a packet switching network of the above type but which while having the above mentioned advantage of traffic distribution does not present the last mentioned drawback, i.e. wherein the order of arrival at their destination of the packets belonging to a same communication is the same as the one in which these packets were supplied to the network.
This object is achieved due to the fact that said first switching module, only for the first packet of a communication, selects one of its transmit ports without using routing information contained in this packet, whereas for the following packets belonging to the same communication it selects one of its transmit ports by using routing information relating to the route followed by said first packet.
Another characteristic feature of the present packet switching network is that said network comprises a first and a second part which are connected in cascade and include said first and second switching modules respectively.
In this way the first switching modules may freely select a path through the first network part for the first packet and thus evently distribute the traffic on this part. Because the same path is used by all the packets belonging to the same communication as this first packet and following the latter, not only the traffic distribution remains unaffected but also the order of transmission of these packets is maintained.
Another characteristic feature of the present invention is that said selection of said transmit port without using said routing information occurs at random.
The present invention also relates to a data processing system wherein input data streams are multiplexed to form a multiplexed output data stream on at least one output of the system.
Such a data processing system is for instance useful in the above packet switching system and is already known from the above mentioned article. If no precautions are taken the traffic load on this output may become too high and then adversely affect the quality of the output data stream.
Another object of the present invention is to provide a data processing system of the last mentioned type, but wherein a traffic overload on an output is prevented.
This object is achieved due to the fact that it includes processing means to allow an input data stream as part of said output data stream or not, depending on the result of a comparison of the total traffic load
REFERENCES:
patent: 4561090 (1985-12-01), Turner
patent: 4692917 (1987-09-01), Fujioka
patent: 4734907 (1988-03-01), Turner
patent: 4837761 (1989-06-01), Isono et al.
patent: 4891802 (1990-01-01), Jasmer et al.
IEEE Infocom '86, Fifth Annual Conference, "Computers and Communications Integration Design, Analysis, Management", Miami, Fla., 8-10 Apr. 1986, IEEE (New York, U.S.), J. S. Turner: Design of a Broadcast Packet Network: pp. 667-675.
Bulletin Scientifique de l'A.I.M, vol. 88, No. 2, Jun. 1975, (Liege, BE), T. E. Beeforth et al.: "Further Work on Data Communication Systems at the Unversity of Sussex", pp. 140-146.
The Post Office Electrical Engineers' Journal, vol. 70, No. 4, Jan. 1978 (London, GB), P. T. F. Kelly et al.: "The Telecommunications Network for EURONET", pp. 208-216.
DePrycker Martin L. F.
DeSomer Michel P. M.
ALCATEL N.V.
Hsu Alpus H.
Olms Douglas W.
Van Der Sluys Peter C.
LandOfFree
Packet switching network does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Packet switching network, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Packet switching network will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-41029