EP0490446A1
Expired / Lapsed
EP
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Dynamic call routing system
Assignee: Koninklijke PTT Nederland NV
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Filing: 1991-12-10
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Granted: —
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Expires: 2011-12-10
Abstract
Abstract Network congestions can largely be combated by preventing a congested point being approached right back at that network location where a new connection is initiated. To combat network congestions, at certain (important) points (A) at which new connections are initiated, the chosen (intermediate or final) destinations are automatically subjected to an investigation as to whether the chosen destination is or is not available at that instant. In a dynamic filter (F), destinations which appear to be unavailable are recorded for a certain, optionally variable, relaxation time in order thereby to hold back calls intended for such congested destinations for said relaxation time.
Inventors
- 👤 Daniel Bolte Bezemer
- 👤 Jan Henk Eelse Hofstee
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 22:59
CPC Classifications
H; H04; H04Q; H04Q3/00; H04Q3/64; H04Q3/66
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
281 words
Transmission system comprising a transmission network for the transmission of transmission signals between peripheral systems connected to said transmission network, in which, prior to such a transmission of transmission signals between a first peripheral system and a second peripheral system, said first peripheral system emits a call code signal to the transmission network, which call code signal comprises a code indicating said second peripheral signal, after which the transmission network or the second peripheral system sends back a 'positive' or 'negative' status code signal, indicating whether said second peripheral system is, or is not, accessible or available, respectively, characterised by at least one filter device (F) connected to the first peripheral system (A) and to the transmission network (T), which filter device comprises means for recording and for storing, during a relaxation time, comparison code signals corresponding to said call code signals emitted by the first peripheral system or to a portion of such a call code signal, in response to which the transmission network has sent back a 'negative' status code signal indicating 'inaccessible' or the called second peripheral systems has sent back a 'negative' status code signal indicating 'unavailable', which filter device furthermore comprises means for comparing a call code signal emitted by said first peripheral system with the comparison code signals then recorded and for not transmitting said call code signal in the event of apparent correspondence between said call code signal or a portion thereof and one of said comparison code signals during said comparison, but for transmitting said call code signal in the event of apparent noncorrespondence between said call code signal or a portion thereof and one of said comparison code signals during said comparison.
Claim 2
Dependent Claim
118 words
Transmission system according to Claim 1, characterised by a multiplicity of the said filter devices (F1..3), each filter device relating to a section (T1..3) of the transmission network, and also by a filter selection device (SEL) connected, on the one hand, to the first peripheral system (A) and, on the other hand, to each of said filter devices (F1..3) and comprising means for receiving the call code signals emitted by the first peripheral signal and, on the basis of such a call code signal, selecting and connecting, to the first peripheral system, the filter device which relates to said section of the transmission network to which the second peripheral system indicated by the call code signal is connected.
Claim 3
Dependent Claim
47 words
Transmission system according to Claim 1, characterised in that the relaxation time (t) assigned to a particular comparison code signal is made the longer, the greater the number of call code signals emitted by the first peripheral system (A) and corresponding to said comparison code signal is.
Claim 4
Dependent Claim
60 words
Transmission system according to Claim 1, characterised in that the relaxation time (t) assigned to a particular comparison code signal is made longer, the greater the number of 'negative' status code signals received back, after the emission of call code signals corresponding to said comparison code signal, from the transmission network (T) or from the second peripheral system (B) is.
Claim 5
Dependent Claim
58 words
Transmission system according to Claim 1, characterised in that the relaxation time (t) assigned to a particular comparison code signal is terminated after the receipt of a 'positive' status code signal, indicating that the second peripheral system is available again, from the second peripheral system (B), indicated by the call code signal corresponding to said comparison code signal.
Claim 6
Dependent Claim
67 words
Transmission system according to Claim 1, characterised in that the filter records comparison code signals which correspond to call code signals emitted by the first peripheral system (A), in response to which a 'negative' status code indicating 'inaccessible' or 'unavailable' has been received back a particular number of times from the transmission network (T) or from the called second peripheral systems (B) during a certain detection time.
Claim 7
Dependent Claim
21 words
Transmission system according to Claim 6, characterised in that the said detection time is equal to the said relaxation time (t).
Claim 8
Dependent Claim
72 words
Transmission system according to Claim 1, characterised in that the status code signals sent back contain not only an indication relating to the accessibility or availability of the called second peripheral system, but also a code corresponding to the respective call code signal, and in that said code is recorded in the filter device (F) as comparison code in the event of the inaccessibility or unavailability of the called second peripheral system.
Claim 9
Dependent Claim
87 words
Transmission system according to Claim 1, characterised in that the status code signals sent back contain not only an indication relating to the accessibility or availability of the called second peripheral system but also, in the event of a 'negative' status code signal, an error location code indicating the location in the transmission network (T) or second peripheral system (B), from which the 'negative' status code signal is sent back, and in that said error location code is recorded in the filter device (F) as comparison code.
Claim 10
Dependent Claim
30 words
Transmission system according to Claim 1, characterised in that the comparison code signals are stored in the filter device (F) in their chronological sequence of recording in said filter device.
Claim 11
Dependent Claim
289 words
Transmission system according to Claim 1, characterised in that the said filter device (F1..3) is provided with a switching device (SWTCH) connected to the first peripheral system (A) and to the transmission network (T) and comprising means for transmitting, or not transmitting, a call code signal (call) from the first peripheral system to the transmission network under the control of a switching control signal (s); a comparison code signal generator (GEN) which comprises means for recording as comparison code signals (comp) and storing, during a relaxation time (t) comparison codes which correspond to said call codes sent to said second peripheral systems (B) or to a section of such a call code, in response to which a 'negative' status code signal indicating 'inaccessibile' or 'unavailable' has been received back from the transmission network or from the called second peripheral system, which comparison code signal generator furthermore comprises means for generating the then recorded comparison code signals when a call code signal is emitted by the first peripheral system; a comparison device (COMP) connected to the first peripheral system, to the comparison code signal generator and to the switching device, and comprising means for comparing the call code signal originating from the first peripheral system with the comparison code signals generated by the comparison code signal generator, and also means for generating the said switch control signal with a value such that the call code signal originating from the first peripheral system is not transmitted by the switching device if the call code signal corresponds fully or partially to one of said comparison code signals and that said call code signal is in fact transmitted if the call code signal does not correspond to one of the comparison code signals.
References Cited (Backward Citations)
US3536842A
Cited
EP0291815A1
Cited
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