Apparatus and method for automatically determining the topology of a local area network

Claims

We claim:

1. Apparatus for automatically determining the topology of a local area network of interconnected hubs which utilize contention control, with individual hubs having at least three data ports, each of which is for coupling the hub in a star configuration to either a data terminal device or another hub in the local area network, said apparatus comprising:

(1) transmit means at each of the hubs for transmitting hub messages over the local area network, said transmit means including

(a) originate means for transmitting said hub messages which originate at an associated hub and contain an identifying address of said associated hub;

(b) repeat means for transmitting said hub messages received by said associated hub over the local area network which originated from other ones of said hubs of the network, said repeat means comprising a timing unit for retiming data to account for transmission distortion;

(2) port identifying means at each of the hubs for identifying which of said data ports of said associated hub has received which of said hub messages transmitted by other of said hubs of the local area network;

(3) control means coupled to said local area network for receiving topology data reported from each of said hubs, said topology data reported for each data port of a particular reporting hub, said topology data identifying a particular one of said data ports of said particular reporting hub and said topology data identifying addresses associated with other hubs which originated network messages received by said particular reporting hub over said particular one of said data ports; and

(4) processing means for determining the overall topology of the local area network by utilizing and combining said received topology data from each of said reporting hubs.

2. The apparatus of claim 1 wherein said originate means periodically transmits one of said hub messages originating at said associated hub.

3. The apparatus of claim 1 wherein said control means receives said topology data in response to topology request messages which the control means transmits over the local area network to the hubs.

4. The apparatus of claim 3 wherein said control means transmits separate ones of said topology request messages to each of said hubs.

5. The apparatus of claim 4 wherein said control means monitors which of said hubs has responded to said topology request message and transmits additional topology request messages directed to any of the hubs for which a response in said topology data is not received by said control means.

6. The apparatus of claim 1 wherein each of said hubs includes a plurality of modules, with each of said modules having at least one of said data ports and wherein said hub includes monitoring means for identifying a particular one of said modules and a particular data port of said modules over which said hub has received said hub messages originating from other one of said hubs in the local area network.

7. The apparatus of claim 6 wherein said modules are of different types having varying capabilities and wherein said monitoring means is also a means for identifying said type of module and wherein said topology data further includes type data indicative of the type of modules in said particular reporting hub.

8. The apparatus of claim 7 wherein said monitoring means identifies a particular one of said modules and a particular one of said ports by determining a physical location of said module in said hub.

9. The apparatus of claim 8 wherein said hub includes a chassis having an electrical backplane for interconnecting said modules and said modules may be inserted in said chassis in any one of predetermined locations along said backplane, with said monitoring means determining said physical location of said module in said hub by sensing the predetermined location where said modules are inserted.

10. In a communication network arrangement having a plurality of communication hubs coupled together wherein each of said hubs contains a plurality of communication ports for coupling with other hubs of said plurality of hubs, an apparatus for determining a topology of said communication network, said apparatus comprising:

circuitry for transmitting a plurality of first identifying messages, each of said first identifying messages originating from an originator hub and destined to other of said plurality of hubs, each of said plurality of first identifying messages comprising an address of said originator hub;

logic for recording into a link identification dataset for said each hub, a list associating individual ports of said each hub with addresses of originator hubs that originated identifying messages that were received over said individual ports; and

logic for generating said topology of said communication network based on said link identification datasets, said logic for generating said topology comprising logic for analyzing said identification datasets to construct an ancestor dataset comprising a topology level number and an ancestor list for individual hubs.

11. An apparatus for determining a topology of said communication network as described in claim 10 further comprising link transmit circuitry for transmitting said link identification dataset from said each hub to said logic for generating said topology.

12. An apparatus for determining a topology of said communication network as described in claim 11 wherein said link transmit circuitry is initiated in response to an activation message from a control console adapter coupled to said communication network.

13. In a communication network arrangement having a plurality of communication hubs coupled together wherein individual hubs contain a plurality of communication ports for coupling with other hubs of said plurality of hubs, a computer implemented method for determining a topology of said communication network, said method comprising the steps of:

transmitting a plurality of first identifying messages, each of said first identifying messages originating from an originator hub and destined to other of said plurality of hubs, each of said plurality of first identifying messages comprising an address of said originator hub;

recording into a link identification dataset for said each hub, a list associating each particular port of said each hub with addresses of originator hubs that originated identifying messages that were received over said each particular port; and

generating said topology of said communication network based on link identification datasets of said plurality of hubs, said step of generating said topology comprising the further step of analyzing said identification datasets to construct an ancestor dataset comprising a topology level number and an ancestor list for said each hub.

14. A method for determining a topology of said communication network as described in claim 13 further comprising the step of transmitting, for said each hub, said link identification dataset to said step of generating said topology.

15. A method for determining a topology of said communication network as described in claim 13 wherein said step of transmitting is initiated in response to an activation message from a control console adapter coupled to said communication network.

16. In a communication network arrangement having a plurality of communication hubs coupled together wherein individual hubs contain a plurality of coupling ports for coupling with other of said plurality of hubs, an apparatus for determining a topology of said communication network, said apparatus comprising;

means for transmitting a plurality of first identifying messages, each of said first identifying messages originating from an originator hub and destined to other of said plurality of hubs, each of said plurality of first identifying messages comprising an address of said originator hub;

means for receiving said plurality of first identifying messages over particular ports of said hubs;

means for recording, into a link of identification dataset for each hub, a list associating particular ports of said each hub with addresses of originator hubs that originated identifying messages that were received over said particular ports of said hubs; and

means for generating said topology of said communication network based on said link identification datasets comprising:

means for receiving an individual link identification dataset from individual hubs of said communication network;

means for determining a root hub of said individual hubs of said communication network;

means for constructing an ancestor table based on each link identification dataset received, said ancestor table including, for each individual hub, a topology level number and a list of ancestor hubs; and

means for constructing a topology of said communication network based on said ancestor table and said root hub.

17. An apparatus for determining a topology of said communication network as described in claim 16 wherein said means for recording comprises means for generating an individual link identification dataset for individual hubs, of said plurality of hubs.

18. An apparatus for determining a topology of said communication network as described in claim 16 wherein said means for generating said topology comprises;

means for receiving said link identification dataset;

means for determining a root hub of said plurality of hubs;

means for constructing an ancestor table based on said link identification dataset, said ancestor table including, for individual hubs, a topology level and a list of ancestors; and

means for constructing a topology of said communication network based on said ancestor table.

19. In a communication network arrangement having a plurality of communication hubs coupled together wherein each of said hubs contains a plurality of communication ports for coupling with other hubs of said plurality of hubs, an apparatus for determining a topology of said communication network, said apparatus comprising:

(1) means for constructing a link dataset for each hub of said plurality of hubs, said means for constructing a link dataset operable within said each hub and comprising:

(a) means for generating identification messages from said each hub and to other of said plurality of hubs, each identification message comprising an origination address specifying said each hub that originated said identification message;

(b) means for receiving identification messages that originated from other hubs through particular ports of said each hub; and

(c) means for recording a listing, for said each hub, associating port numbers of said particular ports with origination addresses of identification messages that were received over said particular ports of said each hub; and

(2) means for generating said topology of said communication network based on each link dataset constructed comprising:

(a) means for generating an ancestor table based on said transmitted link datasets wherein said ancestor table comprises, for said each hub, an ancestor list and a topology level number; and

(b) means for generating said topology of said hubs of said communication network based on said ancestor table.

20. An apparatus for determining a topology of said communication network as described in claim 19 where said means for constructing a link dataset and said means for transmitting said link dataset are operable within a network management module of said each hub.

21. An apparatus for determining a topology of said communication network as described in claim 19 wherein said means for generating said topology is operable within a control console adapter of said communication network.

22. In a communication network arrangement having a plurality of communication hubs coupled together wherein each of said hubs contains a plurality of coupling ports for coupling with other of said plurality of hubs, a computer implemented method for determining a topology of said communication network, said method comprising the steps of:

transmitting a plurality of first identifying messages, each of said first identifying messages originating from an originator hub and destined to other of said plurality of hubs, each of said plurality of first identifying messages comprising an address of said originating hub;

receiving said plurality of first identifying messages over particular ports of said hubs;

recording, into a link identification dataset, a list associating particular ports of said each hub with addresses of originator hubs that originated identifying messages that were received over said particular ports of said hubs; and

generating said topology of said communication network based on said link identification datasets by:

(a) receiving an individual link identification dataset from individual hubs of said communication network;

(b) determining a root hub of said plurality of hubs of said communication network;

(c) constructing an ancestor table based on each link identification dataset received, said ancestor table including, for individual hub, a topology level number and a list of ancestor hubs; and

(d) constructing a topology of said communication network based on said ancestor table and said root hub.

23. A method as described in claim 22 wherein said step of recording is operable within individual hubs of said plurality of hubs.

24. A method for determining a topology of said communication network as described in claim 22 wherein said step of recording comprises the step of generating an individual link identification dataset for individual hubs of said plurality of hubs.

25. In a communication network arrangement having a plurality of communication hubs coupled together wherein each of said hubs contains a plurality of coupling ports for coupling with other of said plurality of hubs, a computer implemented method for determining a topology of said communication network, said method comprising the steps of:

transmitting a plurality of first identifying messages, each of said first identifying messages originating from an originator hub and destined to other of said plurality of hubs, each of said plurality of first identifying messages comprising an address of said originating hub;

receiving said plurality of first identifying messages over particular ports of said hubs;

recording, into a link identification dataset, a list associating particular ports of said each hub with addresses of originator hubs that originated identifying messages that were received over said particular ports of said hubs; and

generating said topology of said communication network based on said link identification datasets by:

(a) receiving said link identification dataset;

(b) determining a root hub of said plurality of hubs; and

(c) onstructing an ancestor table based on said link identification dataset, said ancestor table including, for each hub, a topology level and a list of ancestors; and

(d) constructing a topology of said communication network based on said ancestor table.

26. In a communication network arrangement having a plurality of communication hubs coupled together wherein individual hubs contain a plurality of communication ports for coupling with other hubs of said plurality of hubs, a method for determining a topology of said communication network, said method comprising the steps of:

(1) constructing link dataset for each hub of said plurality of hubs, said step of constructing a link dataset operable within said each hub and comprising the further steps of:

(a) generating identification messages from said each hub that are destined to other of said plurality of hubs, each identification message comprising an origination address specifying a hub that originated said identification message;

(b) receiving identification messages that originated from other hubs through particular ports of said each hub; and

(c) recording a listing, for said each hub, associating port numbers of said particular ports with origination addresses of said identification messages that were received over said particular ports; and

(2) generating said topology of said communication network based on each link dataset by:

(a) generating an ancestor table based on said transmitted link datasets wherein said ancestor table comprises, for said each hub, an ancestor list and a topology level number; and

(b) generating said topology of said hubs of said communication network based on said ancestor table.

27. A method for determining a topology of said communication network as described in claim 26 wherein said step of generating said topology is operable within a control console adapter of said communication network.

28. The method as recited by claim 26 wherein said step of constructing a link dataset and said step of transmitting said link dataset are operable within a network management module of each hub.

29. A method for determining a topology of said communication network as described in claim 26 wherein said step of generating said topology is operable within a control console adapter of said communication network.

30. A method of generating a topology representing a configuration of hubs coupled within a communication network, individual hubs having a plurality of ports, said method comprising the steps of:

generating and sending identification messages from individual hubs to other hubs in said network, said identification messages identifying the generating hub;

receiving, at individual hubs, identification messages generated by other hubs from the network, said identification messages received via ports of said individual hubs;

creating individual listing datasets for individual hubs by associating each port of an individual hub with identifications of all generating hubs that generated identifying messages which were received over said each port;

collecting each listing dataset from individual hubs over the network; and

generating a topology based on each listing dataset by:

(a) creating an ancestor dataset based on each listing dataset for individual hubs, said ancestor dataset comprised of a listing of ancestor hubs and topology level for said individual hubs; and

(b) generating a topology of said network based on said ancestor dataset.

31. A method of generating a topology as described in claim 30 further comprising the step of displaying on a computer display screen a generated topology of said network.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to local area networks and more particularly to apparatus and methods for monitoring the status of a local area network by producing a topology map of the network configuration and by producing a control console display image depicting the appearance of selected network hubs.

2. Background Art

Local area networks for interconnecting data terminal equipment such as computers are well known in the art. Such networks may include a large number of components which may be configured in a variety of ways.

Although equipment exists for monitoring the status of local area networks, such equipment is not capable of accurately monitoring and reporting network status in a manner which may be readily interpreted. For example, the network may include a large number of hubs or concentrators, each of which form the center of a star configuration. The concentrators may each be capable of servicing a large number of data terminal equipment such as personal computers. The network medium may be shielded twisted pair cable, unshielded twisted pair cable or fiber optic cable or a combination of all three. Further, each type of cabling may be supported by various types of modules located in each of the concentrators.

None of the conventional apparatus for monitoring and displaying the status of a network are capable of conveying the actual status of the network in a manner which can be easily comprehended by a user. The disclosed apparatus and method overcomes such limitations and allow the actual status of the network to be automatically monitored and displayed. The information displayed depicts in great detail the status of a network which can be easily comprehended by individuals with a minimum amount of training even if the network is relatively complex. Further, the status of the network is automatically updated. These and other advantages of the present invention will become apparent to those skilled in the art upon a reading of the Detailed Description of the Preferred Embodiment together with the drawings.

SUMMARY OF THE INVENTION

Apparatus and a method of monitoring the status of a local area network are disclosed. The network typically includes a plurality of hubs, such as concentrators, with each hub having data ports for coupling the hub in a star configuration to either data terminal equipment, such as personal computers, or for coupling the hub to another hub of the network. The network is of the type which utilizes network contention control such as the well known Carrier Sense Multiple Access With Collision Detection (CSMA/CD).

In one embodiment of the invention, the apparatus automatically determines the overall topology of the network, with the hubs having at least three data ports each. The apparatus includes a transmit means associated with each of the hubs having both originate and repeat means. The originate means functions to transmit messages over the network which originate at the associated hub and which contain an identifying address of the associated hub. The repeat means functions to transmit messages received by the associated hub over the network which originated from other hubs of the network.

Each of the hubs further includes port identifying means for identifying which of the data ports has received one of the messages transmitted by another hub of the network. In this manner, topology data regarding the connection of the various ports of the associated hub to other hubs of the network are obtained. The topology data from a single hub usually does not contain enough information to ascertain the overall network topology.

The apparatus further includes control means coupled to the network for receiving the topology data from each of the hubs in the network. The topology data identify a particular one of the data ports of the hub reporting the topology data and address of the other ones of the hubs which originated network messages received by the reporting hub over that particular port. Finally, the apparatus includes processing means for determining the overall topology of the network utilizing the received topology data.

In another embodiment of the invention, the apparatus monitors the status of each of the hubs of a star configured network by producing an image, on a control console display for example, which depicts the appearance of the actual hub.

Each hub of the network includes a chassis for receiving a plurality of modules. The modules have at least one port for connecting the data terminal equipment such as a computer to the hub, with the modules being of varying types. For example, some modules may be adapted for use with unshielded twisted pair cables and other modules may be adapted for use with optical cables.

The apparatus includes location means for producing location data indicative of the location of each of the modules in the hub chassis. An exemplary location means would include hard-wired slot identification bits located on the chassis which are transferred to any module inserted into the chassis slot associated with the hard-wired bits. Type means are further included for producing type data indicative of the type of each of the modules in the hub. An exemplary type means would include hard-wired bits on the module which indicate the type of module.

Finally, the apparatus includes display means for producing an image of the hub utilizing the location data and the type data, with the image depicting the location of the modules in the hub and the type of modules.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of an exemplary local area network of the type in which the subject invention can be used and which includes three concentrators or hubs and associated data terminal equipment.

FIG. 2 is schematic diagram of a local area network, having twenty-four concentrators, of the type in which the subject invention can be used.

FIG. 3 is an exemplary display produced in accordance with the present invention depicting a selected portion of the topology of the network of FIG. 2.

FIG. 4 is a schematic diagram of a local area network with the upper level concentrators connected to a common coaxial cable.

FIG. 5 is an exemplary display produced in accordance with the present invention depicting a selected portion of the topology of the network of FIG. 4.

FIG. 6 is a section of a display menu showing a portion of a main menu bar and an exemplary selected submenu.

FIG. 7 is a section of a display showing a detailed view image which depicts the actual appearance of the front panel of a selected network concentrator, including the location of modules in the concentrator and the type of modules.

FIGS. 8A-8F are enlarged views of selected portions of the FIG. 7 image showing details of the various type of modules.

FIG. 9 is similar to FIG. 7 except that another style of concentrator is depicted.

FIG. 10 is a block diagram of one of the network concentrators showing the network management module and host modules all connected to a common concentrator backplane together with various data terminal equipment in the network management control console connected to the concentrator.

FIG. 11 is a block diagram showing the network management interface for the host modules for interfacing the modules to the concentrator backplane.

FIG. 12 is a block diagram of a further exemplary network showing the interconnection of the concentrators of the network.

FIG. 13 is a Network Management Module List showing the various ports of each of the concentrators and the addresses of the other concentrators which transmit messages received over the ports.

FIG. 14 is a flow chart depicting the process whereby the link data are obtained from the concentrators to construct the FIG. 13 List.

FIG. 15 is a flow chart depicting the process whereby the link data of the FIG. 13 List are processed to form the Ancestor Table of FIG. 16.

FIG. 16 is a Ancestor Table constructed from the data contained in the FIG. 13 List.

FIG. 17 is a block diagram of a network where the up port of the highest level concentrators are connected together so that no concentrator will be assigned the Level 0 position of the topology display.

FIG. 18 is a simplified display image of the overall topology of a network based upon the data of the FIG. 16 Ancestor Table.

FIG. 19 is a functional block diagram of the network management module located in each of the network concentrators.

FIG. 20 is a functional block diagram of the control console adapter, the adapter being an expansion card used to convert a personal computer to a network management control console.

FIGS. 21A-21C are flow charts depicting the process for producing the detailed view of the concentrators such as depicted in FIGS. 7 and 9.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

Referring to the drawings, FIG. 1 is a diagram showing the physical connection of a typical simplified local area network. The depicted network function to interconnect six personal computers or PCs 20a-f. The network includes three concentrators 22a, 22b and 22c. The concentrators function as a hub in the star network topology and provide basic Ethernet functions. Many of the details which will be provided regarding the network are exemplary only, it being understood that the present invention may be utilized in connection with a wide variety of communication networks.

Each of the concentrators includes several plug-in modules 26 which connect to a backplane (not depicted) of each concentrator 22. There are various types of modules including host modules which have ports for connecting the associated module to data terminal equipment (DTE). For example, concentrator 22b includes a host module 26c having a port (not designated) connected to personal computer 20a by way of an interface device 24a. Device 24a is a transceiver (transmitter/receiver) used to link the computer 20a (DTE) or node to the network cable. Module 26c will typically have several other ports (not depicted) for connecting to other DTEs.

One of the DTEs, such as personal computer 20d, is designated as the network management control console (NMCC). The designated computer 20d is provided with a control console adapter (CCA), which is an expansion board which adapts the computer for use as a control console. As will be explained, a user can perform various network monitoring and control functions at the NMCC. A pointer device, such as a mouse 23 having primary and secondary control buttons 23a and 23b, respectively, is used for carrying out these functions.

Each concentrator 22a, 22b and 22c is provided with a network management module (NMM). The network management module NMM gathers data received on a port of a host module and transmits the data to other modules in the concentrator. Further, the network management module NMM will forward the received data to other concentrators in the network that may be connected to the concentrator.

The foregoing can be further illustrated by way of example. Assume the personal computer 20e has a message for computer 20b. Each computer or node in the network has an associated address. Messages directed to a particular computer will be decoded by a conventional network controller card installed in the computer and, if the destination address in the message matches the computer address, the message will be processed by the computer. The message originating from computer 20e will include a