WO2001071975A2

WO2001071975A2 - Methods for identifying connections in a network

Info

Publication number: WO2001071975A2
Application number: PCT/IB2001/000435
Authority: WO
Inventors: Joshua Klipper; Aviv Prital
Original assignee: Adc Telecommunications Israel Ltd.
Priority date: 2000-03-23
Filing date: 2001-03-21
Publication date: 2001-09-27
Also published as: AU2001244430A1; WO2001071975A9; IL151606A0; WO2001071975A3

Abstract

Systems, structures, and methods are discussed that enhance network configuration. Because pieces of equipment on a network may reside over a large area in various premises or buried underground, it is difficult for an installer to determine during the process of installation whether there has been an undesired coupling between at least two elements on the network. The embodiments of the present invention allow an installer to verify in the field whether such an undesired coupling exists, and permit the installer to proceed to fix the problem. The embodiments of the present invention probe the network to form a route of the network and present the route to the installer. If the route is an undesired route, then the network includes at least one undesired coupling between at least two elements. The route can be further analyzed to determine undesired portions of the route. Each undesired portion of the route pinpoints the two elements that are improperly connected to each other.

Description

METHODS FOR IDENTIFYING CONNECTIONS IN A NETWORK

Technical Field The technical field relates generally to networks. More particularly, it pertains to learning of undesired couplings between elements in networks.

Copyright Notice - Permission A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyright rights whatsoever. The following notice applies to the software and data as described below and in the drawings attached hereto: Copyright ^® 1999, 2000, ADC Telecommunications Inc., All Rights Reserved.

Background

In 1876, telephones were introduced to the marketplace. They were sold in pairs to customers. To enable a pair of telephones to work, a customer would have to couple a wire between the pair of telephones. In the idiom of telecommunications, the pair of telephones that is coupled by the wire defines a network. And more particularly, that network defines a point-to-point topology because the network includes two interconnected elements, such as the two telephones. Because of the popularity of the telephone, within a year after 1876, cities were strung with wires over houses and trees in a jumble. It became clear that the point-to-point topology would become unfeasible. The opening of the first switching office in New Haven, Connecticut, in

1878 solved the problem. Customers would wire the telephone to the switching office. For one customer to communicate with another, the switching office would connect the two customers together. Thus, multiple customers would be interconnected through a single switching office. The network that is defined by this is known as an access network. More particularly, this access network defines a star topology because the access network includes multiple elements (customers) connecting to a single switching office.

Modern access networks have grown beyond wires to include fiber optic cables to accommodate the transmission of video and other types of data. Whereas older networks coupled by wires are better suited for simpler topologies, such as point-to-point and star topologies, modern networks using fiber optic cables tend toward a ring topology since the ring topology offers many benefits, such as lower insertion loss associated with the addition of network taps. However, it can be difficult for an installer to properly connect networks using fiber optic cables in a ring topology. The reason for the difficulty is because a ring topology may include multiple rings. A probability exists that an installer will couple a network element from one ring to a network element in another ring. Such an installation may render the access network inoperable, and would eventually lead to customers' frustration and expensive repairs.

Thus, what is needed are systems, methods, and structures for learning about network installations so as to inhibit undesired coupling between two network elements.

Summary Systems, methods, and structures that support learning about network installations are discussed. An illustrative aspect includes a system to enhance network configuration. The system comprises a network. The network includes at least two pieces of equipment. One of the at least two pieces of equipment is coupled to the other of the at least two pieces of equipment. The system further comprises a network manager to manage the network. The network manager generates a report. The report is indicative of physical interconnections of the at least two pieces of equipment. The report is available before the network is configured and can be used to identify improper physical interconnection.

Another illustrative aspect of the present invention includes a data strucmre to enhance network configuration. The data structure comprises at least one data member interface to represent a coupling relationship between at least two pieces of equipment. The data member interface includes a data member system to represent a system in a network, a data member cage to represent a cage in the system, and a data member slot to represent a slot in the cage. Another illustrative aspect of the present invention includes a method for enhancing network configuration. The method includes an act for identifying a physical relationship between at least two elements in a network. The method also includes an act for presenting the relationship so as to allow for identification of an undesired relationship between the at least two elements in the network.

Brief Description of the Drawings Figure 1 is a block diagram of a system according to one aspect of the present invention.

Figure 2 is a structure diagram of a data structure according to one aspect of the present invention.

Figure 3 is a process diagram of a method according to one aspect of the present invention.

Figures 4A-4C illustrate tabular and pictorial diagrams of data according to one aspect of the present invention.

Detailed Description In the following detailed description of exemplary embodiments of the invention, reference is made to the accompanying drawings that form a part hereof, and in which is shown, by way of illustration, specific exemplary embodiments in which the invention may be practiced. In the drawings, like numerals describe substantially similar components throughout the several views. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments may be utilized and structural, logical, electrical, and other changes may be made without departing from the spirit or scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims. The embodiments of the present invention focus on enhancing network configuration by learning about the physical coupling between at least two elements on the network so as to ascertain whether undesired physical couplings exist. Although modern networks have built-in capabilities to generate alarms if undesired conditions exist in various layers of the network, it is difficult to generate such alarms at the lowest layer of the network— the physical layer— because the network cannot distinguish between a desired physical connection and an undesired physical connection.

One technique that has been used to detect undesired physical connections is the use of a trace byte. The trace byte is part of the overhead of a network to identify improper connections at the physical layer. However, the trace byte can be used only after the network is configured. Thus, if the network is improperly connected prior to configuration, the network may or may not generate alarms or may generate misleading alarms regarding improper connections upon powering- up of the entire network. Some of the alarms that may not be generated include Loss of Frame (LOF) or Loss of Pointer (LOP).

The embodiments of the present invention attempt to learn about the physical coupling relationship between each element on the network prior to configuration. This information is then presented to the operator of the network to help the operator quickly identify any installation problems. The discussion of the embodiments of the present invention is now presented below.

Figure 1 is a block diagram of a system according to one aspect of the present invention. System 100 includes an access network 102. The system 100 includes a switching office 110, and a number of premises, such as premises 104, 106, and 108. These premises include any premises that can house telecommunications equipment. The switching office 110 and premises 104, 106, and 108 include a number of pieces of equipment, such as a piece of equipment HOo- The term "equipment" means the inclusion of telecommunications equipment such as access multiplexers or data link controllers, or other devices. In the idiom of telecommunications, a piece of equipment can be called an "element" of the access network 102.

The access network 102 is arranged in a topology that includes a ring topology. In various embodiments, the access network 102 can be other topologies, such as point-to-point, star, or tree. The ring topology of the access network 102 includes a number of rings. One of the rings includes the piece of equipment 110o, a piece of equipment 104₀, a fiber optic cable 102₀ that couples the piece of equipment 110₀ and the piece of equipment 104₀; a piece of equipment 106o, a fiber optic cable 102ι that couples the piece of equipment 104₀ and the piece of equipment 106₀; a piece of equipment 108₀, a fiber optic cable 102₂ that couples the piece of equipment 106₀ and the piece of equipment 108₀; and a fiber optic cable 102₃ that couples the piece of equipment 108o and the piece of equipment 110₀. Another ring includes a piece of equipment 110_f , a piece of equipment 104] , a fiber optic cable 102 that couples the piece of equipment 110₁ and the piece of equipment 104ι; a piece of equipment 106ι, a fiber optic cable 102₅ that couples the piece of equipment 104, and the piece of equipment 106] ; a piece of equipment 108ι, a fiber optic cable 102₆ that couples the piece of equipment 106| and the piece of equipment 108ι; and a fiber optic cable 102₇ that couples the piece of equipment 108ι. and the piece of equipment 110i .

The switching office 110 may include a network manager that manages the access network 102. The network manager may include a software application for managing the access network 102. Because a possibility exists that an installer may have installed the access network 102 improperly, it is beneficial to identify physical connection for the pieces of equipment in the access network 102. Once this information is obtained, whether the access network 102 is improperly installed can be inferred. In one embodiment, the network manager identifies physical connection of the pieces of equipment by sending a test packet down to one of the rings of the access network 102. For illustrative purposes only, suppose the network manager at the switching office 110 sends a test packet from the piece of equipment 110₀. The test packet will travel along the fiber optic cable 102₀ to the piece of equipment 104₀. An identification of the piece of equipment 104₀ is recorded. In one embodiment, the identification is recorded in the test packet. The test packet then travels along the fiber optic cable 102] to arrive at the piece of equipment 106₀. The piece of equipment 106o is also recorded. In one embodiment, this is recorded in the test packet. The test packet then travels the fiber optic cable 102₂ to arrive at the piece of equipment 108₀. The piece of equipment 108₀ is also recorded. In one embodiment, this is recorded in the test packet. And finally, the test packet travels along the fiber optic cable 102₃ to arrive back at the piece of equipment 110₀. Each of the pieces of equipment visited by the test packet is recorded and is analyzed by the network manager. The recorded pieces of equipment define a route taken by the test packet. If the route is a route that would form a desired topology, then the route is a desired route describing desired couplings or relationships between the pieces of equipment or elements in the access network 102. The system 100 includes a toll office 122 (or a tandem office). The toll office 122 is coupled to the switch office 110 through a toll connecting trunk 122₀. The toll office 122 is also coupled to another switch office 120 through another toll connecting trunk 122] . The switch office 120 is part of an access network 112. The access network 112 includes a number of premises, such as premises 114, 116, and 118. The access network 112 is arranged in a topology that includes a ring topology. However, the access network 112 includes a defective ring topology due to improper installation.

One of the rings includes the piece of equipment 120₀, a piece of equipment 118₀, a fiber optic cable 112₀ that couples the piece of equipment 120₀ and the piece of equipment 1 18₀; a piece of equipment 116₀, a fiber optic cable 112| that couples the piece of equipment 118₀ and the piece of equipment 116₀; a piece of equipment 114₀, a fiber optic cable 112₂ that incorrectly couples the piece of equipment 116ι and the piece of equipment 114₀; and a fiber optic cable 112₃ that couples the piece of equipment 114₀ and the piece of equipment 120₀.

Another ring includes a piece of equipment 120ι, a piece of equipment 114|, a fiber optic cable 112₄ that couples the piece of equipment 120, and the piece of equipment 114ι; a piece of equipment 116ι, a fiber optic cable 112₅ that couples the piece of equipment 114| and the piece of equipment 116ι ; a piece of equipment 118], a fiber optic cable 102₆ that incorrectly couples the piece of equipment 106₀ and the piece of equipment 108₍; and a fiber optic cable 112₇ that couples the piece of equipment 118ι and the piece of equipment 120) .

The switching office 120 may include a network manager that manages the access network 112. For illustrative purposes only, suppose the network manager at the switching office 120 sends a test packet from the piece of equipment 120₀. The test packet will travel along the fiber optic cable 112₀ to the piece of equipment 118₀. The piece of equipment 118₀ is recorded. The test packet then travels along the fiber optic cable 112, to arrive at the piece of equipment 116Q. This is also recorded. Because of the improper installation, the test packet then travels the fiber optic cable 112₆ to arrive at the piece of equipment 118, . This is also recorded. And finally, the test packet travels along the fiber optic cable 112₇ to arrive at the piece of equipment 110] . In one embodiment, the identify of each of pieces of equipment is recorded in the test packet. The identity of each of the positions or pieces of equipment visited by the test packet is then sent to the network manager for analysis. Because the route of the test packet does not form a desired topology, there are undesired couplings or relationships between the pieces of equipment or elements in the access network 112. The precise locations of the undesired couplings may be obtained by studying the route of the test packet.

The access network 102 may be considered a fiber optic network because the access network 102 comprises pieces of equipment interconnected by the plurality of fiber optic cables 102₀, 102, , 102₂, 102 , 102₄, 102₅, 102₆, and 102₇. In one embodiment, the access network 102 includes an optical time division multiplexing network. In another embodiment, the optical time division multiplexing network includes a Synchronous Optical Network (SONET). In another embodiment, the optical time division multiplexing network includes a Synchronous Digital Hierarchy network (SDH). These rings may send information in one direction only (the direction of the arrow as shown). In one embodiment, the ring topology of the access network 102 includes a counter-rotating dual-ring topology. Another equivalent term for the access network 102 includes "the local loop." Other equivalent terms for the switching office 110 include "end office" and "local central office." Figure 2 is a structure diagram of a data structure according to one aspect of the present invention. The structure 200 includes a data member interface 202. The data member interface 202 represents a coupling relationship between at least two pieces of equipment in a network. The data member interface 202 includes a data member system 204. The data member system 204 represents a piece of equipment or an element on a network. The data member interface 202 includes a data member cage 206. The data member cage 206 represents a particular hardware cage in the system as represented by the data member system 204. The data member interface 202 includes a data member slot 208. The data member slot 208 represents a particular slot in the hardware cage in the system.

Typically, each piece of equipment in a network includes a number of connections, such as an output connection and an input connection. Thus, the structure 200 may be instantiated twice. The first instantiation is to represent the output connection and the second instantiation is to represent the input connection. The data members system, cage, and slot of the first instantiation contain information about another piece of equipment on the network to which a packet will be forwarded. The data members system, cage, and slot of the second instantiation contain information about another piece of equipment on the network from which a packet will be received.

The structure 200 can be instantiated iteratively to contain all the couplings or relationships between pieces of equipment or elements in a network. Such information stored in the structure 200 can then be presented in various formats, such as tabular formats or pictorial formats. Figure 3 is a process diagram of a method according to one aspect of the present invention. The process 300 includes an act 302 for identifying a relationship between at least two elements in a network. The act of identifying 302 includes an act of recording an identification of equipment or network element as a packet travels from one element to another element on the network. The act of identifying 302 includes an act of forming a route from the result of the act of recording. In one embodiment the act of forming a route uses the information recorded in the packet. In one embodiment, the route defines a relationship between at least two elements on the network. The act of identifying 302 includes an act of determining if the route is an undesired route. If the route is an undesired route, then the relationship between the at least two elements on the network includes an undesired relationship.

In another embodiment, the act of identifying 302 includes an act 304 for storing an identification of an element in a packet that travels from one element to another element on a network. The act of storing 304 may store a number of identifications as the packet travels. This set of identifications defines a route. If the route is an undesired route, then the relationship between the at least two elements on the network includes an undesired relationship. In one embodiment, the act of identifing 302 is executed through a software application running on a Data Communication Channel of a network. The network is selected from a group consisting of a Synchronous Optical Network and a Synchronous Digital Hierarchy network. In another embodiment, the act of identifying 302 can be iterated. In another embodiment, the act of identifying 302 can be iterated until no new relationships among elements on the network is learned with a test packet.

The process 300 includes an act 306 for presenting the relationship so as to allow identification of an undesired relationship between at least two elements on the network. The act of presenting 306 includes presenting the information in a tabular format or in a pictorial format.

Figures 4A-4C illustrate tabular and pictorial diagrams of data according to one aspect of the present invention. Figure 4 A illustrates a tabular diagram 400 A. The tabular diagram 400A can be formed and presented to a user after at least one relationship between two elements on a network is learned. The user can use the tabular diagram 400A to determine if an undesired coupling exists between at least two elements on the network. The tabular diagram 400A includes row 402 A for representing the system. The system includes an element on the network, such as a computer, a telephone, or other devices. The tabular diagram 400A includes row 404 A for representing a cage in the system. The tabular diagram 400A includes row 406A for representing a slot in the cage. The tabular diagram 400A includes a number of columns, such as columns 408 A. Each of these columns represents an element on the network. Column 408 A represents an element 1. Column 408A includes a number of cells, such as cells 408A₀, 408A| , and 408A . These cells 408 A₀, 408A), and 408 A₂ contain information about another element with which element 1 has a coupling relationship.

Similarly, column 410A represents an element 2. Column 410A includes a number of cells, such as cells 410A₀, 410A| , and 410A₂. Column 412A represents an element 3. Column 412A includes a number of cells, such as cells 412A₀, 412Aι , and 412A₂. Column 414A represents an element 4. Column 414A includes a number of cells, such as cells 414A₀, 414A, , and 414A₂.

Optionally, the information that is used to form the tabular diagram 400 can be used to form a pictorial diagram as shown in Figures 4B and 4C . Figure 4B illustrates a network 400B in a ring topology that has a desired relationship between each element in the network 400B. The network 400B includes a first ring. The first ring includes an interface 408B₀ that is coupled to an interface 410B i . The coupling relationship between the interface 408B₀ and the interface 410Bι is represented by a line 402B₀. The line 402Bo has an arrowhead illustrating the direction in which packets flow in the first ring of the network 400B. The first ring includes an interface 412B₀ that is coupled to the interface 410B| through the line 402B| . The first ring includes an interface 414B] that is coupled to the interface 412B₀ through the line 402B₂. The first ring includes a relationship between the interface 414B| and the interface 408B₀ through the line 402B₃. The network 400B includes a second ring. The second ring includes an interface

408B, that is coupled to an interface 414B₀ through a line 402B . The second ring includes an interface 412B] that is coupled to the interface 414Bo through the line 402B₅. The second ring includes an interface 410B₀ that is coupled to the interface 412Bι through the line 402B₆. The first ring includes a relationship between the interface 410B₀ and the interface 408B) through the line 402B₇.

Figure 4C illustrates a network 400C in a ring topology that has at least one undesired relationship between two elements. The network 400C includes elements similar to Figure 4B. For clarity purposes, the discussion of similar elements as presented above is incorporated here in full. There are at least three undesired relationships as shown in the network 400C. The first undesired relationship includes the coupling between the interface 4 IOC, and 408Cι through the line 402C₇. The second undesired relationship includes the coupling between the interface 408C] and 4 IOC, through the line 402C₀. The third undesired relationship includes the coupling between the interface 408C₀ and 414C₀ through the line 402C₄.

The user can use the tabular diagram 400A or the pictorial diagrams 400B and 400C to determine if an undesired coupling exists between at least two elements on the network. The tabular diagram 400A and the pictorial diagrams 400B and 400C also allow the user to determine the location of the undesired coupling.

Conclusion The embodiments of the present invention allow an installer in the field to determine whether there has been an incorrect coupling between two network elements. The embodiments of the present invention pinpoint the position of the problem, and permit the installer to ameliorate the incorrect coupling. The embodiments of the present invention allow such a problem to be corrected early in the installation of a network given that attempts to fix the network after installation may be expensive. The hereinbefore discussion of the embodiments of the present invention focus on a ring topology, but a particular network topology does not limit the embodiments of the present invention, and other types of topology may benefit from the embodiments of the present invention.

Although the specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement which is calculated to achieve the same purpose may be substituted for the specific embodiments shown. This application is intended to cover any adaptations or variations of the present invention. It is to be understood that the above description is intended to be illustrative, and not restrictive. Combinations of the above embodiments and other embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention includes any other applications in which the above structures and fabrication methods are used. Accordingly, the scope of the invention should only be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. For example, other tabular and graphical depictions can be used to present the physical interconnections detected. Further data of the physical interconnections can be gathered using other mechanisms prior to configuration of the system.

Claims

We claim:

1. A system to enhance network configuration, the system comprising: a network that includes at least two pieces of equipment, wherein one of the at least two pieces of equipment is coupled to an other of the at least two pieces of equipment; and a network manager that is adapted to identify and report physical connections between the at least two pieces of equipment before the network is configured.

2. The system of claim 1, wherein the network includes a fiber optic network.

3. The system of claim 2, wherein the fiber optic network includes an optical time division multiplexing network.

4. The system of claim 3, wherein the optical time division multiplexing network includes a Synchronous Optical Network.

5. The system of claim 3, wherein the optical time division multiplexing network includes a Synchronous Digital Hierarchy network.

6. The system of claim 1, wherein the at least two pieces of equipment is coupled in a ring topology.

7. The system of claim 1, wherein the network manager includes an application program that sends out packets that traverse the network and gather data of the physical connections.

8. A data structure to enhance network configuration, the data structure comprising: at least one data member interface to represent a coupling relationship between at least two pieces of equipment, the data member interface includes a data member system to represent a system in a network, a data member cage to represent a cage in the system, and a data member slot to represent a slot in the cage.

9. The data structure of claim 8, wherein the at least one data member interface is adapted to be instantiated to form a first and a second connection.

10. The data structure of claim 9, wherein the first connection represents one of the at least two pieces of equipment, and wherein the second connection represents the other of the at least two pieces of equipment.

11. The data structure of claim 8, wherein the network is selected from a group consisting of a Synchronous Optical Network and a Synchronous Digital Hierarchy network.

12. The data structure of claim 11, wherein the data structure is presented in a tabular format so as to allow a determination of a desired configuration of the network.

13. A method for enhancing network configuration, the method comprising: identifying a physical relationship between at least two elements in a network; and presenting the relationship so as to allow identification of an undesired relationship between the at least two elements on the network.

14. The method of claim 13, wherein identifying includes recording an identification of each network element that receives a packet as the packet travels from one of the at least two elements to the other of the at least two elements in the network.

15. The method of claim 14, and further comprising identifying a route from the stored identification values such that the route defines the relationship between the at least two elements in the network.

16. The method of claim 13, wherein identifying includes identifying the relationship using a Data Communication Channel protocol of a network selected from a group consisting of a Synchronous Optical Network and a Synchronous Digital Hierarchy network.

17. The method of claim 13, wherein the act of identifying is iterated.

18. The method of claim 20, wherein the act of identifying is iterated until no additional relationships among the elements on the network are identified on a given pass.

19. The method of claim 13, wherein presenting includes presenting information in a tabular form.

20. The method of claim 13, wherein presenting includes presenting information in a pictorial form.