Data connection quality analysis apparatus and methods

• US 20060250967A1
• Filed: 04/25/2005
• Published: 11/09/2006
• Est. Priority Date: 04/25/2005
• Status: Active Grant

• Current Assignee: Viavi Solutions, Inc. (Lumentum Holdings Inc.)
• Original Assignee: Acterna LLC (Lumentum Holdings Inc.)
• Inventors: Miller, Walter, Gotwals, Michael, Massey, Gregory
• Granted Patent: US 7,489,641 B2
• Time in Patent Office: Days
• US Class Current: 370/241
• CPC Class Codes: H04L 12/2801 Broadband local area networks
• CPC Class Codes: H04L 43/50 Testing arrangements

Abstract

A test device enables DOCSIS link testing in a HFC network without requiring the CMTS or other router at the headend of the HFC network to respond to ICMP messages. The test device includes a test packet generator for generating test packets having a destination Internet protocol (IP) address associated with a test device, a memory for storing transmission parameters of the test packets, and a test packet evaluator associated with the IP address in the generated test packets. The test packet evaluator receives the generated test packets after the test packets have been routed through a router at a head end of a HFC network and compares reception parameters for the received test packets to the transmission parameters stored in the memory.

Claims

1. A test device for evaluating data communication paths over a hybrid fiber cable (HFC) network comprising:

a test packet generator for generating test packets having a destination Internet protocol (IP) address associated with a test device;

a memory for storing transmission parameters of the test packets; and

a test packet evaluator associated with the IP address in the generated test packets, the test packet evaluator for receiving the generated test packets after the test packets have been routed through a router at a head end of a HFC network and for comparing reception parameters for the received test packets to the transmission parameters stored in the memory.

2. The device of claim 1, the test packet generator being a cable modem that is external to the test device and the test device further comprising:

a cable modem interface for communicating commands and data with the test packet generator.

3. The device of claim 1, the test packet generator being a cable modem circuit that is internal to the test device and coupled to the HFC network.

4. The device of claim 1, the test packet evaluator being a cable modem that is external to the test device and the test device further comprising:

a cable modem interface for communicating commands and data with the test packet evaluator.

5. The device of claim 1, the test packet evaluator being a cable modem circuit that is internal to the test device and coupled to the HFC network.

6. The device of claim 2, the test packet evaluator being a second cable modem that is external to the test device and the test device further comprising:

a second cable modem interface for communicating commands and data with the test packet evaluator.

7. The device of claim 3, the cable modem circuit internal to the test device includes the test packet evaluator.

8. The device of claim 1, wherein the test packets generated by the test packet generator have a source address that is a public IP address associated with the test packet generator.

9. The device of claim 1 further comprising:

a snoop coupled between the test packet generator and the HFC network; and

the test packet generator generates test packets having an IP source address and a dummy IP destination address, and the snoop substitutes the IP address that is used for the IP source address for the dummy IP destination address before the test packets are transmitted to a router at the headend of the HFC network.

10. The device of claim 1 further comprising:

a test router coupled to a managed IP backbone that is coupled to the headend of the HFC network; and

the test packet generator generates a first and a second set of test packets, the first set of test packets having a destination address associated with the test evaluator and the second set of test packets having a destination address associated with the test router;

the memory storing transmission parameters for the first and the second set of test packets; and

the test evaluator for receiving the first set of test packets after the first set of test packets have been routed through the headend of the HFC network and for receiving the second set of test packets after the second set of test packets have been routed through the test router and for comparing reception parameters for the first and the second set of test packets with the transmission parameters stored in the memory.

11. A method for evaluating data communication paths over a hybrid fiber cable (HFC) network comprising:

generating test packets having a destination Internet protocol (IP) address associated with a test device;

storing transmission parameters for the test packets;

receiving the generated test packets at the IP address associated with the test device after the test packets have been routed through a router at a head end of a HFC network; and

comparing reception parameters for the received test packets to the stored transmission parameters.

12. The method of claim 11, the method further comprising:

communicating commands and data with an external cable modem for generation of the test packets by the test packet generator.

13. The method of claim 11, the method further comprising:

communicating commands and data with an internal cable modem circuit for generation of the test packets by the test packet generator.

14. The method of claim 11, the method further comprising:

communicating commands and data with an external cable modem for reception and comparison of the test packets by the test packet evaluator.

15. The method of claim 11, the method further comprising:

communicating commands and data with an internal cable modem for reception and comparison of the test packets by the test packet evaluator.

16. The method of claim 12, the method further comprising:

communicating commands and data with a second external cable modem for reception and comparison of the test packets by the test packet evaluator.

17. The method of claim 13, the method further comprising:

communicating commands and data with the internal cable modem circuit for reception and comparison of the test packets by the test packet evaluator.

18. The method of claim 11, wherein the test packet generation includes:

generating the test packets with a source address that is a public IP address.

19. The method of claim 11 further comprising:

generating test packets having an IP source address and a dummy IP destination address; and

substituting the IP address that is used for the IP source address for the dummy IP destination address before the test packets are transmitted to a router at the headend of the HFC network.

20. The method of claim 11 further comprising:

generating a first set of test packets having a destination address associated with a test evaluator;

generating a second set of test packets having a destination address associated with a test router coupled to the headend of the HFC network through a managed IP backbone;

storing transmission parameters for the first and the second set of test packets;

receiving the first set of test packets after the first set of test packets have been routed through the headend of the HFC network;

receiving the second set of test packets after the second set of test packets have been routed through the test router; and

comparing reception parameters for the first and the second set of test packets with the transmission parameters stored in the memory.