Token ring local area network testing apparatus for obtaining beacon domain information

• US 5,363,366 A
• Filed: 01/11/1993
• Issued: 11/08/1994
• Est. Priority Date: 01/11/1993
• Status: Expired due to Fees

• Current Assignee: Fluke Corporation (Fortive Corp.)
• Original Assignee: Fluke Corporation (Fortive Corp.), Forte Networks (Fortive Corp.)
• Inventors: Fish, David G., Wisdom, Thomas S. Jr.
• Primary Examiner(s): Chin, Wellington
• Assistant Examiner(s): Jung, Min
• Application Number:
  US08/003,234
• Time in Patent Office: 666 Days
• Field of Search: 370/13, 370/16, 370/16.1, 370/85.4, 370/85.5, 370/17, 371/20.6, 371/29.1, 379/21
• US Class Current: 370/245
• CPC Class Codes: H04L 12/433 with asynchronous transmission, e.g. token ring, register insertion
• CPC Class Codes: H04L 12/437 Ring fault isolation or reconfiguration for SDH/SONET ring networks H04J3/085
• CPC Class Codes: H04L 43/50 Testing arrangements

Abstract

A token ring local area network (LAN) testing apparatus is provided. The apparatus includes hardware and software for keeping track of information related to the origination of a beacon frame that occurs due to a fault in the token ring. When a fault occurs in the token ring, a beacon frame is generated and this frame is useful in reporting the network domain or location that initiated the beaconing condition. This information is useful to the network manager in isolating the token ring fault. In addition to the first or original beacon frame, further or phantom beacon frames can be generated. These phantom beacon frames include those generated by other stations on the token ring experiencing a signal loss due to steps taken by the originating station as a result of the fault. These phantom domains are usually not beneficial to the network manager in isolating the fault on the token ring. The testing apparatus includes a software state machine for use in distinguishing the first beacon frame from phantom beacon frames. A display unit is able to display information from the first beacon frame and avoids displaying information associated with phantom beacon frames.

Claims

1. A method for monitoring a fault in a token ring local area network, comprising:

inserting a testing apparatus into a token ring;

obtaining an initial beacon frame by said testing apparatus indicative of a first fault in the token ring, with contents of said initial beacon frame including a source address and a nearest active upstream neighbor address;

receiving a subsequent beacon frame by said testing apparatus that occurs after said initial beacon frame, with contents of said subsequent beacon frame including a source address and a nearest active upstream neighbor address that are different from said source address and said nearest active upstream neighbor address of said initial beacon frame;

storing said source address and said nearest active upstream neighbor address of said initial beacon frame in memory;

checking for recovery of the token ring from the first fault; and

displaying said source address and said nearest active upstream neighbor address of said initial beacon frame.

2. A method, as claimed in claim 1, wherein:

said initial beacon frame is a first beacon frame received by said testing apparatus due to the first fault.

3. A method, as claimed in claim 1, wherein:

said obtaining step includes determining that the first fault has occurred in the token ring based on said contents of said initial beacon frame and said determining step includes comparing said contents of said initial beacon frame with predetermined information related to a token ring fault.

4. A method, as claimed in claim 3, wherein:

said determining step includes using a software state machine to determine whether said predetermined information corresponds to said contents of said initial beacon frame.

5. A method, as claimed in claim 1, further including:

changing contents of a status information memory storage from a first state to a second state when said initial beacon frame is received.

6. A method, as claimed in claim 5, wherein:

said changing step includes re-changing said contents of said status information memory storage from said second state to said first state after said recovery from the first fault occurs.

7. A method, as claimed in claim 1, further including:

ignoring all beacon frames received after said initial beacon frame related to the first fault by not storing and not displaying all of said beacon frames received after said initial beacon frame.

8. A method, as claimed in claim 1, wherein:

said displaying step includes displaying said source address and said nearest active upstream neighbor address of said initial beacon frame before said recovery occurs.

9. A method, as claimed in claim 8, wherein:

said displaying step includes indicating that recovery has occurred.

10. A method, as claimed in claim 1, wherein:

said checking step includes determining whether a frame of a configuration report server type was received.

11. A testing apparatus for monitoring a fault that occurs in a token ring local area network, comprising:

first means for obtaining contents from an initial beacon frame when a first fault is present on the token ring and for obtaining contents from a subsequent beacon frame when the first fault is present on the token ring, said contents of said initial beacon frame including a source address and a nearest active upstream neighbor address associated with the first fault and said contents of said subsequent beacon frame including a source address and a nearest active upstream neighbor address that are different from said source address and said nearest active upstream neighbor address of said initial beacon frame;

second means for determining that at least one of said source address and said nearest active upstream neighbor address of said subsequent beacon frame is different from at least one of said source address and said nearest active upstream neighbor address of said initial beacon frame;

third means for storing said source address and said nearest active upstream neighbor address of said initial beacon frame; and

fourth means for displaying said source address and said nearest active upstream neighbor address of said initial beacon frame.

12. An apparatus, as claimed in claim 11, wherein:

said second means includes means for selecting predetermined contents from said initial beacon frame.

13. An apparatus, as claimed in claim 11, wherein:

said second means includes status information memory storage for indicating that said initial beacon frame was received by said testing apparatus in connection with the first fault.

14. An apparatus, as claimed in claim 11, wherein:

said second means includes a software state machine for obtaining station address related information from said initial beacon frame.

15. An apparatus, as claimed in claim 11, wherein:

said second means includes means for ignoring all beacon frames that are received after said initial beacon frame has been received, wherein said means for ignoring avoids storing and avoids displaying all of said beacon frames received after said initial beacon frame.

16. An apparatus, as claimed in claim 15, wherein:

said initial beacon frame is a first beacon frame received by said first means related to the first fault.