Method and apparatus for performing in-service quality of service testing

• US 6,147,998 A
• Filed: 12/17/1997
• Issued: 11/14/2000
• Est. Priority Date: 08/26/1997
• Status: Expired due to Term

• Current Assignee: NetScout Systems Incorporated
• Original Assignee: Visual Networks Technologies, Inc. (Fortive Corp.)
• Inventors: Kelley, Paul W., MacEachern, Stuart P., Beck, Ralph L.
• Primary Examiner(s): Vu, Huy D.
• Assistant Examiner(s): BOAKYE, ALEXANDER O
• Application Number:
  US08/992,755
• Time in Patent Office: 1,063 Days
• Field of Search: 370/241, 370/244, 370/250, 370/251, 370/252, 370/253, 370/395, 370/232, 370/397
• US Class Current: 370/395.1
• CPC Class Codes: H04L 2012/5616 Terminal equipment, e.g. codecs, synch.
• CPC Class Codes: H04L 2012/5625 Operations, administration and maintenance [OAM]
• CPC Class Codes: H04L 2012/5628 Testing
• CPC Class Codes: H04L 2012/5638 Services, e.g. multimedia, GOS, QOS
• CPC Class Codes: H04L 43/00 Arrangements for monitoring or testing data switching networks
• CPC Class Codes: H04L 43/106 using time related information in packets, e.g. by adding timestamps
• CPC Class Codes: H04Q 11/0478 Provisions for broadband connections

Abstract

An apparatus and method for determining the QoS of a communication system. In one embodiment a service verification equipment device (SVE) is placed into the communications link between the wide area network and the transmitting customer premise and an SVE is placed into the communications link between the wide area network and the receiving customer premise. The transmitting SVE inserts a test cell into the customer'"'"'s data stream over communications link which informs the receiving SVE that a test is commencing. After a predetermined number of customer data cells are sent, the transmitting SVE inserts a termination cell into the communications link at the end of the test. The receiving SVE then compiles data related to the QoS of the communications link and that data is analyzed to determine the QoS.

Claims

1. A method of testing QoS in an in-service communications link comprising the steps of:

inserting, by a transmitting service verification equipment device located at a transmitting customer premise, a test initiation cell having a standard header and a specific payload into a data stream from said transmitting customer premise;

receiving, by a receiving service verification equipment device located at a receiving customer premise, the data stream;

determining by the receiving service verification equipment that a cell in the data stream is the test initiation cell by reading the specific payload of the cell, said cell payload indicating that a test is being initiated;

continuing to transmit by the transmitting service verification equipment device a number of cells of the customer'"'"'s data stream;

receiving by said receiving service verification equipment device said number of cells of customer'"'"'s data stream;

collecting by said receiving service verification equipment device statistical data regarding the QoS of the communications link;

inserting, by said transmitting service verification equipment device located at a transmitting customer premise, a test termination cell having a standard header and a specific payload into a data stream of said customer indicating to said receiving service verification equipment device located at said receiving customer premise that said test is being terminated; and

analyzing said data collected by said receiving service verification equipment device to determine QoS.

2. The method of claim 1 further comprising the step of determining, by said receiving service verification device, that a cell is a test termination cell by reading the payload of the cell.

3. The method of claim 1 wherein the statistical data collected is a checksum of each of the number of cells of the customer'"'"'s data stream.

4. The method of claim 1 wherein the statistical data collected is a timestamp of each of the number of cells of the customer'"'"'s data stream.

5. The method of claim 4 wherein the timestamp is compressed by calculating elapsed time.

6. The method of claim 1 further comprising the step of transmitting the statistical data collected to a test management workstation.

7. A system for testing an in-service communications link between a first service customer located at a first service customer premise and a second service customer located at a second service customer premise, comprising:

a first service verification equipment device inserted between the first service customer and the in-service communications link passing data cells from the first service customer to the in-service communications link and passing to the in-service communications link a test initiation cell having a header identical to the data cells of the first service customer and having an unique payload;

a second service verification equipment device inserted between the in-service communications link and the second service customer passing data cells from the in-service communications link to the second service customer and recognizing the unique payload in the test initiation cell and not passing the test initiation cell on to the second service customer.

8. The system of claim 7 in which the first service verification equipment device passes a test termination cell having a header identical to the data cells of the first service customer and having a unique payload and in which the second service verification equipment device recognizes the unique payload in the test termination cell and does not pass the test initiation cell on to the second service customer.

9. The system of claim 8 in which the first service verification equipment device begins logging quality of service data after passing the test initiation cell and in which the second service verification equipment device begins logging quality of service data after receiving the test initiation cell.

10. The system of claim 9 in which the first service verification equipment device terminates logging quality of service data after passing the test termination cell and in which the second service verification equipment device terminates logging quality of service data after receiving the test termination cell.

11. The system of claim 10 in which the data logged is a checksum of the payload of each data cell.

12. The system of claim 10 in which the data logged is a timestamp.

13. The system of claim 12 in which the timestamp is compressed by calculating elapsed time from the passing of an immediately previous data cell.

14. The system of claim 10 in which the first service verification equipment device transmits logged data to a test management workstation and the second service verification equipment device transmits logged data to the test management workstation.

15. A system for testing an in-service communications link between a first service customer located at a first service customer premise and a second service customer located at a second service customer premise, comprising:

a first service verification equipment device inserted between the first service customer and the in-service communications link passing data cells from the first service customer to the in-service communications link and passing to the in-service communications link a test termination cell having a header identical to the data cells of the first service customer and having an unique payload;

a second service verification equipment device inserted between the in-service communications link and the second service customer passing data cells from the in-service communications link to the second service customer and recognizing the unique payload in the test termination cell and not passing the test initiation cell on to the second service customer.

16. A method of testing QoS in an in-service communications link comprising the steps of:

inserting, by a transmitting service verification equipment device located at a transmitting customer premise, a test initiation cell having a standard header and a specific payload into a data stream from said transmitting customer premise indicating to a receiving service verification equipment device located at a receiving customer premise that a test is being initiated;

continuing to transmit by the transmitting service verification equipment device a number of cells of the customer'"'"'s data stream;

receiving by said receiving service verification equipment device said number of cells of customer'"'"'s data stream;

collecting by said receiving service verification equipment device statistical data regarding the QoS of the communications link, said statistical data comprising a checksum of each of the number of cells of the customer'"'"'s data stream;

inserting, by said transmitting service verification equipment device located at a transmitting customer premise, a test termination cell having a standard header and a specific payload into a data stream of said customer indicating to said receiving service verification equipment device located at said receiving customer premise that said test is being terminated; and

analyzing said data collected by said receiving service verification equipment device to determine QoS.

17. The method of claim 16 further comprising the step of determining, by the receiving service verification device, that a cell is a test initiation cell by reading the payload of the cell.

18. The method of claim 16 further comprising the step of determining, by the receiving service verification device, that a cell is a test termination cell by reading the payload of the cell.

19. The method of claim 16 further comprising the step of transmitting the statistical data collected to a test management workstation.