Method and apparatus for emulating a digital cross-connect switch network

• US 5,748,617 A
• Filed: 05/01/1996
• Issued: 05/05/1998
• Est. Priority Date: 05/01/1996
• Status: Expired due to Term

• Current Assignee: Verizon Patent and Licensing Incorporated (Verizon Communications Inc.)
• Original Assignee: MCI Incorporated (Verizon Communications Inc.)
• Inventors: McLain, John V. Jr.
• Primary Examiner(s): Hsu, Alpus H.
• Assistant Examiner(s): Yao, Kwang Bin
• Application Number:
  US08/641,459
• Time in Patent Office: 734 Days
• Field of Search: 370/241, 370/242, 370/244, 370/250, 370/251, 370/252, 370/248, 370/249, 340/825.03, 340/826, 340/827, 364/550, 364/578, 395/500, 395/183.04, 395/183.05, 395/183.08, 395/183.09
• US Class Current: 370/244
• CPC Class Codes: H04M 3/2254 in networks
• CPC Class Codes: H04M 3/323 for the arrangements providing the connection (test connection, test call, call simulation)

Abstract

A method and apparatus for emulating a digital cross-connect (DXC) network fully tests a telecommunication network monitoring and control system (MCS). The communication and behavior of a digital cross-connect switching network are emulated in the presence and absence of selected network configurations, failures, and/or normalizations. A communication module communicates with the MCS through emulator control links using a communications protocol substantially identical to a communications protocol used in the emulated digital cross-connect network. A configuration database stores configuration data representing the current behavior of the DXC nodes. A topology database stores topology data representative of the topology of the emulated DXC network. An emulator message generator generates messages emulating communications from DXC nodes to the MCS. An emulator link selector further selects an enabled emulator control link depending upon whether respective emulated network control links are enabled. Intelligent emulator responses are generated and sent based on the current configuration and/or topology data which take into account any selected user-input to emulate solicited and unsolicited responses by actual digital cross-connect network nodes to MCS commands and audits. Simulated multi-tasking and dynamic user-interface control options are included. Finally, different types of digital cross-connect switching networks and systems are emulated to test an MCS including: DXC 3/3, DXC 3/1, and/or DXC 1/0 networks.

Claims

1. An emulator apparatus for emulating a digital cross-connect switch network to allow testing of a communication network monitor and control system (MCS) in the presence and absence of a selected network failure, the emulator apparatus comprising:

a communication module which communicates with the MCS over at least one emulator control link using a communications protocol substantially identical to a communications protocol used in the digital cross-connect switch network to communicate to the MCS;

a memory unit for storing emulated network data representative of the behavior and topology of the emulated digital cross-connect switch network in the presence and absence of the selected network failure; and

a processor coupled to said communication module and said memory unit, said processor sending emulator messages for the MCS to said communication module based on said emulated network data, said emulator messages emulating solicited and unsolicited messages that would be sent from the digital cross-connect switch network being emulated to the MCS in the presence and absence of the selected network failure.

2. The emulator apparatus of claim 1, wherein said emulated network data includes configuration data identifying the transmission behavior of DXC nodes in the digital cross-connect network and topology data identifying logical trunks extending through corresponding ports in the said nodes.

3. The emulator apparatus of claim 2, wherein said processor further comprises:

a control link servicer which detects incoming MCS messages sent to the emulator apparatus by the MCS;

a user-interface servicer which detects user inputs received through a user-interface, said processor updates at least one of said configuration data and said topology data to emulate the presence and absence of selected network failures identified by user-inputs; and

an emulator message generator, wherein said emulator message generator generates emulator messages in response to said incoming MCS messages detected by said control-link servicer based on at least one of said configuration data and said topology data, said emulator messages matching messages which would be sent from DXC nodes in the emulated digital cross-connect network in response to the detected incoming MCS messages.

4. The emulator apparatus of claim 3, wherein said processor further determines whether said generated emulator messages correspond to DXC nodes which are transmitting based on said configuration data, said processor sending emulator messages generated by the emulator message generator only for transmitting nodes.

5. The emulator apparatus of claim 4, wherein said configuration data includes a node transmission field representing whether each DXC node in the digital cross-connect network is emulated as a transmitting or non-transmitting node.

6. The emulator apparatus of claim 3, wherein said at least one emulator control link emulates respective at least one network node control links used to couple DXC nodes in the digital cross-connect network to the MCS.

7. The emulator apparatus of claim 6, wherein said at least one emulator link includes a first emulator control link and a second emulator control link, said first and second emulator control links emulating corresponding first and second network control links between DXC nodes in the digital cross-connect switch network and the MCS;

and wherein said processor further comprises;

an emulator link selector which selects at least one of said first and second emulator control links depending upon whether corresponding first and second network control links are enabled at a DXC node based on said configuration data, said communication module sending emulator messages generated by the emulator message generator over said at least one selected emulator primary and secondary control link.

8. The emulator apparatus of claim 7, wherein said configuration data includes first and second link active fields which identify whether respective first and second network node control links are emulated as transmitting or non-transmitting links for each DXC node in the digital cross-connect network.

9. The emulator apparatus of claim 3, wherein said processor switches control transparently between said control-link servicer and said user-interface servicer to service said at least one emulator control link and user-inputs in a pseudo-parallel sequence simulating multi-tasking.

10. The emulator apparatus of claim 9, wherein:

said user-interface servicer comprises a first program module for executing a first task to service said user-interface, said first program module having a control switch call after each partial logic unit of work in said first task;

said control link servicer comprises a second program module for executing a second task to service incoming MCS messages received over said at least one emulator control link; and

said processor further comprises a simulated multi-task controller for transparently switching control between said user-interface servicer and said control link servicer;

wherein said simulated multi-tasking controller switches control from said user-interface servicer to said control link servicer when said control switch call is read during execution of said first program module and an incoming MCS message is detected, and switches control from said control link-servicer back to said user-interface servicer to resume said first task after a partial logical unit of work in the second task has been executed by said control link servicer.

11. The emulator apparatus of claim 3, wherein said incoming MCS messages include session connect, keep alive, initialization, alarm audit, configuration status, and cross-connect commands.

12. The emulator apparatus of claim 3, wherein said emulator messages sent to the MCS include session connected, control implementation confirmation, control not implemented with reason code, solicited status of alarm, solicited status of node configuration, and unsolicited alarm messages.

13. The emulator apparatus of claim 2, wherein said topology data includes initial baseline topology data created from at least one of an external database, the MCS, and manual user-input.

14. The emulator apparatus of claim 1, wherein said communication module comprises at least one logical router, each logical router being connected between said processor and a respective emulator control link, and wherein each logical router multiplexes messages for a respective group of DXC nodes in the digital cross-connect network.

15. The emulator apparatus of claim 1, wherein said communication protocol comprises a standard data communication protocol including at least one selected from the following group of standard data communications protocols:

X.25, IP, TCP, Frame-Relay, ATM, SMDS, Ethernet, FDDI, ISDN, SDLC, and BISDN.

16. The emulator apparatus of claim 1, wherein said processor provides sub-second responses to the MCS and a user-interface.

17. The emulator apparatus of claim 1, wherein the emulator apparatus is run on a stand-alone personal computer connected to the MCS.

18. The emulator apparatus of claim 1, wherein user-inputs are entered through a user-interface for controlling the emulator apparatus.

19. The emulator apparatus of claim 18, wherein said user inputs include dynamic configuration inputs identifying changes in DXC node behavior or the topology of the emulated digital cross-connect network, and said processor updates said emulated network data in accordance with said dynamic configuration inputs.

20. The emulator apparatus of claim 1, wherein said processor detects user inputs identifying a selected network failure and generates an outage script file representative thereof.

21. The emulator apparatus of claim 20, wherein said selected network failure represents at least one of a partial trunk failure, total trunk failure, equipment failure, and node failure.

22. The emulator apparatus of claim 1, wherein said processor executes a user-selected outage script file, corresponding to a selected network failure, and sends emulator alarm messages to the MCS which emulate the behavior of DXC nodes in the digital cross-connect network in the presence of the selected network failure.

23. The emulator apparatus of claim 1, wherein said processor detects a user input selecting an outage script file for normalization, said outage script file corresponding to a selected network failure, and sends emulator clear alarm messages to the MCS which emulate the behavior of DXC nodes in the digital cross-connect network during normalization of the selected network failure.

24. The emulator apparatus of claim 1, further comprising a user-interface module for displaying emulator control options at the user-interface including at least one of outage selection, normalization/clear alarms, view communication log, view trace log, and view real-time message display;

wherein said processor responds to a user-input identifying an emulator control option and executes a corresponding emulator control routine.

25. The emulator apparatus of claim 1, wherein said processor maintains a communication log file which includes all incoming MCS commands sent to the emulator apparatus and all outgoing solicited and unsolicited emulator messages sent from the emulator apparatus to the MCS.

26. The emulator apparatus of claim 1, wherein said processor maintains a trace log file which includes error messages generated by said processor during operation of the emulator apparatus.

27. The emulator apparatus of claim 1, wherein the digital cross-connect network comprises a DXC 3/3 network, a hybrid DXC 3/3 and 3/1 network, or a DXC 1/0 network.

28. A computer-implemented method for emulating a digital cross-connect network to test a network monitoring and control system (MCS), comprising the steps of:

storing emulated network data representative of the behavior and topology of the digital cross-connect network being emulated;

establishing connectivity with the MCS over at least one emulator control link;

detecting incoming MCS messages; and

sending emulator messages over said at least one emulator control link to the MCS in response to said incoming MCS messages based on said emulated network data, said emulator messages emulating messages that would be sent from DXC nodes in the digital cross-connect network being emulated to the MCS in response to said detected incoming MCS messages.

29. The method of claim 28, further comprising the steps of:

detecting user inputs identifying a modification in at least one of the behavior or topology of the emulated digital cross-connect network;

updating said emulated network data to represent said modification; and

sending emulator messages in response to said detected user-inputs, said emulator messages emulating solicited and unsolicited messages sent from DXC nodes when the digital cross-connect network is configured according to said modification.

30. The method of claim 29, wherein said modification comprises a selected network failure, said selected network failure representing at least one of a partial trunk failure, total trunk failure, equipment failure, and node failure.

31. The method of claim 28, wherein said storing step comprises the steps of:

storing configuration data representative of the behavior of each DXC node in the digital cross-connect network being emulated; and

storing topology data representative of the topology of the digital cross-connect network being emulated.

32. The method of claim 31, further comprising the step of:

selecting an emulator control link corresponding to an enabled network control link based on said configuration data; and

wherein said sending step sends messages to the MCS over the respective emulator control link selected in said selecting step, thereby, emulating messages sent from DXC nodes over corresponding enabled network control links to the MCS.

33. The method of claim 28, further comprising the steps of:

executing an outage script file corresponding to a selected network failure; and

sending emulator alarm messages to the MCS which emulate the behavior of DXC nodes in the digital cross-connect network in the presence of the selected network failure.

34. The method of claim 28, further comprising the steps of:

executing an outage script file corresponding to a selected network failure to normalize the digital cross-connect network; and

sending emulator clear alarm messages to the MCS which emulate the behavior of DXC nodes in the digital cross-connect network during normalization of the selected network failure.

35. The method of claim 28, further comprising the steps of:

displaying emulator control options at a user-interface, said emulator control options including at least one of outage selection, normalization/clear alarms, view communication log, view trace log, and view real-time message display;

detecting a user-input selecting one of said emulator control options; and

executing a corresponding emulator control routine.

36. The method of claim 28, further comprising the steps of:

detecting user inputs identifying a selected network failure; and

generating an outage script file which identifies near-side port alarms for DXC nodes having near-side ports facing said selected network failure.

37. The method of claim 28, wherein the digital cross-connect network comprises a DXC 3/3 network, a hybrid DXC 3/3 and 3/1 network, or a DXC 1/0 network.