US4750175A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Network diagnostic apparatus and method
Assignee: Cisco Technology Inc
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Filing: 1986-08-29
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Granted: 1988-06-07
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Expires: 2006-08-29
Abstract
Abstract A system for testing a data processing network and diagnosing malfunctions therein is disclosed. It is assumed that the data processing network includes a plurality of processing units coupled by communication paths in which each processing unit communicates with one or more other processing units in the data processing network by sending and receiving data packets over one or more of the communication paths. The system includes probes and a local processor for creating modified data packets from the data packets present on the network communication paths. The modified data packets allow a central processing unit which is communication with the local processor to diagnose network errors while maintaining the security of the data contained in the original data packets.
Inventors
- 👤 William D. Brenneman
- 👤 Robert D. Hodges
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:41
CPC Classifications
H; H04; H04L; H04L43/00; H04L43/50; G; G06; G06F; G06F11/00; G06F11/07; G06F11/08; G06F11/22; G06F11/2273; G06F11/2294; G06F11/26; G06F11/273; G06F11/2736; G06F11/277
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
256 words
A system for detecting and diagnosing malfunctions in a data processing network wherein a plurality of processing units are coupled by communication paths over which each processing unit communicates with one or more other processing units in said data processing network by sending and receiving data packets, each said data packet comprising a message component and a format component, said format component comprising information for detecting errors in transportation and information specifying the format of said data packet, and said message component comprising information to be delivered to a processing unit, said system comprising means for detecting data packets at a predetermined point on one of said communication paths; local processing means coupled to said detecting means for processing said detected data packets, said local processing means comprising; means for separating each detected data packet into format and message components; means for generating a modified data packet for each said detected data packet, said modified data packet comprising data specifying the format component of said detected data packet and a replacement message comprising information for determining if the message component of said detected data packet was erroneously transmitted, wherein the message component of said data packet can not be ascetained from said modified data packet; and means for coupling said local processing means to a telephone line, said coupling means including means for transmitting a said modified data packet and information specifying the predetermined point at which said data packet was detected, over a telphone line in response to a signal received on said telephone line.
Claim 2
Independent Claim
256 words
A system for detecting and diagnosing malfunctions in a data processing network wherein a plurality of processing units are coupled by communication paths over which each processing unit communicates with one or more other processing units in said data processing network by sending and receiving data packets, each said data packet comprising a message component and a format component, said format component comprising information for detecting errors in transportation and information specifying the format of said data packet, and said message component comprising information to be delivered to a processing unit, said system comprising means for detecting data packets at a predetermined point on one of said communication paths; local processing means coupled to said detecting means for processing said detected data packets, said local processing means comprising; means for separating each detected data packet into format and message components; means for generating a modified data packet for each said detected data packet, said modified data packet comprising data specifying the format component of said detected data packet and a replacement message comprising information for determining if the message component of said detected data packet was erroneously transmitted, wherein the message component of said data packet can not be ascetained from said modified data packet; and means for coupling said local processing means to a telephone line, said coupling means including means for transmitting a said modified data packet and information specifying the predetermined point at which said data packet was detected, over a telphone line in response to a signal received on said telephone line.
Claim 3
Independent Claim
279 words
A system for detecting and diagnosing malfunctions in a data processing network wherein a plurality of processing units are coupled by communication paths over which each processing unit communicates with one or more other processing units in said data processing network by sending and receiving data packets, each said data packet comprising a message component and a format component, said format component comprising information for detecting errors in transmission and information specifying the format of said data packet, and said message component comprising information to be delivered to a processing unit, said system comprising means for detecting data packets at a predetermined point on one of said communication paths; local processing means coupled to said detecting means for processing said detected data packets, said local processing means comprising; means for separating each detected data packet into format and message components; means for generating a modified data packet for each said detected data packet, said modified data packet comprising data specifiying the format component of said detected data packet and a replacement message comprising information for determining if the message component of said detected data packet was erroneously transmitted; means for coupling said local processing means to a telephone line, said coupling means including means for transmitting a said modified data packet and information specifying the predetermined point at which said data packet was detected, over a telephone line in response to a signal received on said telephone line; and means coupled to said local processing means for coupling signals to a communication path in said data processing network at a predetermined point on said communication path, said coupling means being responsive to control signals received over said telephone line.
Claim 4
Independent Claim
279 words
A system for detecting and diagnosing malfunctions in a data processing network wherein a plurality of processing units are coupled by communication paths over which each processing unit communicates with one or more other processing units in said data processing network by sending and receiving data packets, each said data packet comprising a message component and a format component, said format component comprising information for detecting errors in transmission and information specifying the format of said data packet, and said message component comprising information to be delivered to a processing unit, said system comprising means for detecting data packets at a predetermined point on one of said communication paths; local processing means coupled to said detecting means for processing said detected data packets, said local processing means comprising; means for separating each detected data packet into format and message components; means for generating a modified data packet for each said detected data packet, said modified data packet comprising data specifiying the format component of said detected data packet and a replacement message comprising information for determining if the message component of said detected data packet was erroneously transmitted; means for coupling said local processing means to a telephone line, said coupling means including means for transmitting a said modified data packet and information specifying the predetermined point at which said data packet was detected, over a telephone line in response to a signal received on said telephone line; and means coupled to said local processing means for coupling signals to a communication path in said data processing network at a predetermined point on said communication path, said coupling means being responsive to control signals received over said telephone line.
Claim 5
Independent Claim
281 words
A system for dectecting and diagnosing malfunctions in a data processing network wherein a plurality of processing units are coupled by communiation paths over which each processing unit communications with one or more other processing units in said data processing network by sending and receiving data packets, each said data packet comprising a message component and a format component, said format component comprising information for detecting errors in transmission and information specifying the format of said data packet, and said message component comprising information to be delivered to a processing unit, said system comprising means for detecting data packets at a predetermined point on one of said communciation paths; local processing means coupled to said detecting means for processing said detected data packets, said local processing means comprising; means for separating each detected data packet into format and message components; means for generating a modified data packet for each said detected data packet, said modified data packet comprising data specifying the format component of said detected data packet and a replacement message comprising information for determining if the message component of said detected data packet was erroneously transmitted; and means for coupling said local processing means to a telephone line, said coupling means including menas for transmitting a said modified data packet and information specifying the predetermined point at which said data packet was detected, over a telephone line in response to a signal received on said telephone line, wherein said local processing means further comprises alarm means comprising means for detecting improper signal patterns on a specified one of said communication paths and means for generating signals on said telephone line in response to detecting a said improper signal pattern.
Claim 6
Independent Claim
281 words
A system for dectecting and diagnosing malfunctions in a data processing network wherein a plurality of processing units are coupled by communiation paths over which each processing unit communications with one or more other processing units in said data processing network by sending and receiving data packets, each said data packet comprising a message component and a format component, said format component comprising information for detecting errors in transmission and information specifying the format of said data packet, and said message component comprising information to be delivered to a processing unit, said system comprising means for detecting data packets at a predetermined point on one of said communciation paths; local processing means coupled to said detecting means for processing said detected data packets, said local processing means comprising; means for separating each detected data packet into format and message components; means for generating a modified data packet for each said detected data packet, said modified data packet comprising data specifying the format component of said detected data packet and a replacement message comprising information for determining if the message component of said detected data packet was erroneously transmitted; and means for coupling said local processing means to a telephone line, said coupling means including menas for transmitting a said modified data packet and information specifying the predetermined point at which said data packet was detected, over a telephone line in response to a signal received on said telephone line, wherein said local processing means further comprises alarm means comprising means for detecting improper signal patterns on a specified one of said communication paths and means for generating signals on said telephone line in response to detecting a said improper signal pattern.
Claim 7
Dependent Claim
148 words
The system of claim 3 wherein said specified communication path comprises a plurality of conductors, each said conductor coupling digital signals between two processing units in said data processing network, and wherein said detecting means comprises: means for detecting said digital signals at a predetermined point on each of N selected conductors chosen from said plurality of conductors; means for assigning one of S states to each said conductor in response to the digital signals so detected wherein S is greater than 2; means for generating a number having radix S, said number including a plurality of digits, one said digit corresponding to each one of said N selected conductor, each said digit being determined by the state of said conductor; and means for comparing said generated number with a plurality of numbers and generating a signal if said generated number matches any of said plurality of numbers.
Claim 8
Dependent Claim
77 words
The system of claim 4 wherein S is equal to 4 and wherein said first state is assigned to a conductor having a steady potential below a first predetermined potential, said second state is assigned to a conductor having a steady potential above a second predetermined potential, said third state is assigned to a conductor having an oscillating potential, said oscillations occurring in a predetermined frequency range, and said fourth state is assigned to all other conductors.
Claim 9
Dependent Claim
288 words
In a data processing network in which a plurality of processing units are coupled to each other by communication paths, each said processing unit communicating with one or more of said other processing units by sending and receiving data packets comprising a message component and a format component, said format component comprising information for detecting errors in transmission and information specifying the format of said data packet, and said message component comprising information to be delivered to a processing unit, said data processing network including means for detecting data packets at least one predetermined location in one of said communication paths and means for coupling signals to said communication path at said predetermined location, said data processing network also including local processor means for receiving commands over a telephone circuit and executing said commands, said commands including commands for processing and storing detected data packets and commands for coupling signals to said predetermined location in said communication path, a method for detecting and diagnosing malfunctions comprising the steps of: detecting data packets at said predetermined location in said communication path; separating each detected data packet into format and message components; generating a modified data packet for each said detected data packet, said modified data packet comprising data specifying the format component of said detected data packet, and a replacement message comprising information for determining if the message component of said detected data packet was erroneously transmitted, wherein the message component of said data packet may not be ascertained from said modified data packet; and transmitting data over a telephone circuit, said data specifying a modified data packet and the predetermined point at which said detected data packet was detected, in response to one of of said received commands.
Claim 10
Dependent Claim
288 words
In a data processing network in which a plurality of processing units are coupled to each other by communication paths, each said processing unit communicating with one or more of said other processing units by sending and receiving data packets comprising a message component and a format component, said format component comprising information for detecting errors in transmission and information specifying the format of said data packet, and said message component comprising information to be delivered to a processing unit, said data processing network including means for detecting data packets at least one predetermined location in one of said communication paths and means for coupling signals to said communication path at said predetermined location, said data processing network also including local processor means for receiving commands over a telephone circuit and executing said commands, said commands including commands for processing and storing detected data packets and commands for coupling signals to said predetermined location in said communication path, a method for detecting and diagnosing malfunctions comprising the steps of: detecting data packets at said predetermined location in said communication path; separating each detected data packet into format and message components; generating a modified data packet for each said detected data packet, said modified data packet comprising data specifying the format component of said detected data packet, and a replacement message comprising information for determining if the message component of said detected data packet was erroneously transmitted, wherein the message component of said data packet may not be ascertained from said modified data packet; and transmitting data over a telephone circuit, said data specifying a modified data packet and the predetermined point at which said detected data packet was detected, in response to one of of said received commands.
Claim 11
Dependent Claim
288 words
In a data processing network in which a plurality of processing units are coupled to each other by communication paths, each said processing unit communicating with one or more of said other processing units by sending and receiving data packets comprising a message component and a format component, said format component comprising information for detecting errors in transmission and information specifying the format of said data packet, and said message component comprising information to be delivered to a processing unit, said data processing network including means for detecting data packets at least one predetemrined location in one of said communication paths and means for coupling signals to said communication path at said predetermined location, said data processing network also including local processor means for receiving commands over a telephone circuit and executing said commands, said commands including commands for processing and storing detected data packets and commands for coupling signals to said predetermined location in said communication path, a method for detecting and diagnosing malfunctions comprising the steps of: detecting data packets at said predetermined location in said communication path; separating each detected data packet into format and message components; generating a modified data packet for each said detected data packet, said modified data packet comprising data specifying the format component of said detected data packet, and a replacement message comprising information for determining if the message component of said detected data packet was erroneously transmitted; transmitting data over a telephone circuit, said data specifying a modified data packet and the predetermined point at which said detected data packet was detected, in response to one of said received commands; and coupling signals to said predetermined point in said communication path in rsponse to one of said received commands.
Claim 12
Dependent Claim
288 words
In a data processing network in which a plurality of processing units are coupled to each other by communication paths, each said processing unit communicating with one or more of said other processing units by sending and receiving data packets comprising a message component and a format component, said format component comprising information for detecting errors in transmission and information specifying the format of said data packet, and said message component comprising information to be delivered to a processing unit, said data processing network including means for detecting data packets at least one predetemrined location in one of said communication paths and means for coupling signals to said communication path at said predetermined location, said data processing network also including local processor means for receiving commands over a telephone circuit and executing said commands, said commands including commands for processing and storing detected data packets and commands for coupling signals to said predetermined location in said communication path, a method for detecting and diagnosing malfunctions comprising the steps of: detecting data packets at said predetermined location in said communication path; separating each detected data packet into format and message components; generating a modified data packet for each said detected data packet, said modified data packet comprising data specifying the format component of said detected data packet, and a replacement message comprising information for determining if the message component of said detected data packet was erroneously transmitted; transmitting data over a telephone circuit, said data specifying a modified data packet and the predetermined point at which said detected data packet was detected, in response to one of said received commands; and coupling signals to said predetermined point in said communication path in rsponse to one of said received commands.
Claim 13
Independent Claim
143 words
A method for detecting malfunctions in a communication path including a plurality of conductors, each said conductor coupling digital signals between two processing units in a data processing network, a method for detecting a malfunction in said communication path comprising the steps of: detecting said digital signals at a predetermined point on N selected conductors, each said selected conductor being chosen from said plurality of conductors; assigning one of S states to each said conductor in response to the digital signals so detected wherein S is greater than 2; generating a number comprising a plurality of digits, one said digit corresponding to each said selected conductor, each said digit being determined by the state of said selected conductor; and comparing said generated number with a plurality of numbers and generating a signal if said generated word matches any of said plurality of numbers.
Claim 14
Independent Claim
143 words
A method for detecting malfunctions in a communication path including a plurality of conductors, each said conductor coupling digital signals between two processing units in a data processing network, a method for detecting a malfunction in said communication path comprising the steps of: detecting said digital signals at a predetermined point on N selected conductors, each said selected conductor being chosen from said plurality of conductors; assigning one of S states to each said conductor in response to the digital signals so detected wherein S is greater than 2; generating a number comprising a plurality of digits, one said digit corresponding to each said selected conductor, each said digit being determined by the state of said selected conductor; and comparing said generated number with a plurality of numbers and generating a signal if said generated word matches any of said plurality of numbers.
Claim 15
Dependent Claim
141 words
A means for detecting a malfunction in a communication path comprising a plurality of conductors, each said conductor coupling digital signals between two processing units, said detecting means comprising: means for detecting said digital signals at a predetermined point on each of N selected conductors chosen from said plurality of conductors; means for assigning one of S states to each said conductor in response to the digital signals so detected wherein S is greater than 2; means for generating a number having radix S, said number including a plurality of digits, one said digit corresponding to each one of said N selected conductor, each said digit being determined by the state of said conductor; and means for comparing said generated number with a plurality of numbers and generating a signal if said generated number matches any of said plurality of numbers.
Claim 16
Dependent Claim
141 words
A means for detecting a malfunction in a communication path comprising a plurality of conductors, each said conductor coupling digital signals between two processing units, said detecting means comprising: means for detecting said digital signals at a predetermined point on each of N selected conductors chosen from said plurality of conductors; means for assigning one of S states to each said conductor in response to the digital signals so detected wherein S is greater than 2; means for generating a number having radix S, said number including a plurality of digits, one said digit corresponding to each one of said N selected conductor, each said digit being determined by the state of said conductor; and means for comparing said generated number with a plurality of numbers and generating a signal if said generated number matches any of said plurality of numbers.
Claim 17
Independent Claim
276 words
A system for detecting and diagnosing malfunctions in a data processing network comprising a plurality of processing units coupled by communication paths over which each processing unit communicates with one or more other processing units in said data processing network by sending and receiving data packets, each said data packet comprising a message component and a format component, said format component comprising information for detecting errors in transmission, including at least one check sum, and information specifying the format of said data packet, and said message component comprising information to be delivered to a processing unit, a system for detecting and diagnosing malfunctions in said data processing network comprising: means for detecting data packets at a predetermined point on one of said communicaiton paths; local processing means coupled to said detecting means for receiving the data packets detected by said detecting means, said local processing means comprising; means for separating each detected data packet into said format and message components; means for generating a modified data packet for each said detected data packet, said modified data packet comprising data specifying the format component of said detected data packet, and a replacement message having a check sum equal to that of the message component of said detected data packet, wherein said message component of said data packet may not be ascertained from said modified data packet; and means for coupling said local processing means to a telephone line, said coupling means including means for transmitting a said modified data packet and information specifying the predetermined point at which said data packet was detected, over a telephone line in response to a signal received on said telephone line.
Claim 18
Independent Claim
276 words
A system for detecting and diagnosing malfunctions in a data processing network comprising a plurality of processing units coupled by communication paths over which each processing unit communicates with one or more other processing units in said data processing network by sending and receiving data packets, each said data packet comprising a message component and a format component, said format component comprising information for detecting errors in transmission, including at least one check sum, and information specifying the format of said data packet, and said message component comprising information to be delivered to a processing unit, a system for detecting and diagnosing malfunctions in said data processing network comprising: means for detecting data packets at a predetermined point on one of said communicaiton paths; local processing means coupled to said detecting means for receiving the data packets detected by said detecting means, said local processing means comprising; means for separating each detected data packet into said format and message components; means for generating a modified data packet for each said detected data packet, said modified data packet comprising data specifying the format component of said detected data packet, and a replacement message having a check sum equal to that of the message component of said detected data packet, wherein said message component of said data packet may not be ascertained from said modified data packet; and means for coupling said local processing means to a telephone line, said coupling means including means for transmitting a said modified data packet and information specifying the predetermined point at which said data packet was detected, over a telephone line in response to a signal received on said telephone line.
Claim 19
Independent Claim
299 words
A system for detecting and disagnosing malfunctions in a data processing network comprising a plurality of processing units coupled by communication paths over which each processing unit communicates with one or more other processing units in said data processing network by sending and receiving data packets, each said data packet comprising a message component and a format component, said format component comprising information for detecting errors in transmission, including at least one check sum, and information specifying the format of said data packet, and said message component comprising information to be delivered to a processing unit, a system for detecting and diagnosing malfunctions in said data processing network comprising: means for detecting data packets at a predetermined point on one of said communication paths; local processing means coupled to said detecting means for receiving the data packets detected by said detecting means, said local processing means comprising; means for separating each detected data packet into said format and message components; means for generating a modified data packet for each said detected data packet, said modified data packet comprising data specifying the format component of said detected data packet, and a replacement message having a check sum equal to that of the message component of said detected data packet; means for coupling said local processing means to a telephone line, said coupling means including means for transmitting a said modified data packet and information specifying the predetermined point at which said data packet was detected, over a telephone line in response to a signal received on said telephone line; and means coupled to said local processing means for coupling signals to a communication path in said data processing network at a predetermined point on said communication path, said coupling means being responsive to control signals received over said telephone line.
Claim 20
Independent Claim
299 words
A system for detecting and disagnosing malfunctions in a data processing network comprising a plurality of processing units coupled by communication paths over which each processing unit communicates with one or more other processing units in said data processing network by sending and receiving data packets, each said data packet comprising a message component and a format component, said format component comprising information for detecting errors in transmission, including at least one check sum, and information specifying the format of said data packet, and said message component comprising information to be delivered to a processing unit, a system for detecting and diagnosing malfunctions in said data processing network comprising: means for detecting data packets at a predetermined point on one of said communication paths; local processing means coupled to said detecting means for receiving the data packets detected by said detecting means, said local processing means comprising; means for separating each detected data packet into said format and message components; means for generating a modified data packet for each said detected data packet, said modified data packet comprising data specifying the format component of said detected data packet, and a replacement message having a check sum equal to that of the message component of said detected data packet; means for coupling said local processing means to a telephone line, said coupling means including means for transmitting a said modified data packet and information specifying the predetermined point at which said data packet was detected, over a telephone line in response to a signal received on said telephone line; and means coupled to said local processing means for coupling signals to a communication path in said data processing network at a predetermined point on said communication path, said coupling means being responsive to control signals received over said telephone line.
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