Methods, systems, and computer readable media for emulating network devices with different clocks

1. A method for emulating network devices with different clocks, the method comprising:

in a network equipment test device:

generating or obtaining timing information to produce a first clock;

obtaining clock modification information, wherein the clock modification information includes at least one of frequency adjustment factors and phase offsets for generation of different emulated clocks that differ from each other in at least one of frequency and phase to simulate at least one of clock drift and clock jitter;

emulating the different clocks using the timing information and the clock modification information, wherein the different emulated clocks differ from each other in at least one of frequency and phase to simulate at least one of clock drift and clock jitter; and

emulating at least one network device that transmits test packets to a device under test using the different clocks, wherein different ones of the test packets include timestamps generated using the emulated clocks that differ from each other in at least one of frequency and phase.

2. The method of claim 1 wherein generating or obtaining timing information includes obtaining timing information from an IEEE 1588 grand master.

3. The method of claim 1 wherein emulating the different clocks includes utilizing the frequency adjustment factors to adjust frequencies of each emulated clock to be different from a frequency of the first clock.

4. The method of claim 1 wherein emulating the different clocks includes utilizing the phase offsets to vary phases of the emulated clocks to be different from a phase of the first clock.

5. The method of claim 1 wherein emulating the different clocks values includes, for packets in a first stream, varying over time at least one of a frequency adjustment factor and a phase offset.

6. The method of claim 1 wherein emulating at least one network device includes emulating an IEEE1588 grand master.

7. The method of claim 1 wherein emulating at least one network device includes varying a phase and/or frequency of at least one of the emulated clocks used to generate the timestamps in the packets transmitted to the device under test so that the timestamps advance non-uniformly with respect to time.

8. The method of claim 7 wherein varying the phase and/or frequency of the at least one of the emulated clocks includes varying the phase and/or frequency to simulate clock jitter.

9. The method of claim 7 comprising monitoring a response of the device under test to the changes in phase and/or frequency of the at least one of the emulated clocks.

10. A system for emulating network devices with different clocks, the system comprising;

a network equipment test device for generating or obtaining timing information and for obtaining clock modification information, wherein the clock modification information includes at least one of frequency adjustment factors and phase offsets for generation of different emulated clocks that differ from each other in at least one of frequency and phase to simulate clock at least one of clock drift and clock jitter;

a clock emulator located within the network equipment test device for emulating the different clocks using the timing information on the clock modification information, wherein the different emulated clocks include at least one of frequency adjustment factors and phase offsets for generation of different clocks that differ from each other in at least one of frequency and phase to simulate clock at least one of clock drift and clock jitter; and

a device emulator for emulating at least one network device that transmits test packets to device under test using the different clocks, wherein different ones of the test packets include timestamps generated using the emulated clocks that differ from each other in at least one of frequency and phase.

11. The system of claim 10 wherein the network equipment test device is configured to obtain timing information IEEE 1588 grand master.

12. The system of claim 10 wherein the clock emulator is configured to emulate the different clocks utilizing the frequency adjustment factors to adjust frequencies of the emulated clocks to be different from a frequency of the first clock.

13. The system of claim 10 wherein the clock emulator is configured to utilize the phase offsets to vary phases of the emulated clocks to be different from a phase of the first clock.

14. The system of claim 10 wherein the clock emulator is configured to vary over time at least one of a frequency adjustment factor and a phase offset used to generate the different emulated clocks.

15. The system of claim 10 wherein the device emulator is configured to emulate at least one network device includes emulating an IEEE 1588 grand master.

16. The system of claim 10 wherein the device emulator is configured to vary a phase and/or frequency of at least one of the emulated clocks used to generate the timestamps in the packets transmitted to the device under test so that the timestamps advance non-uniformly with respect to time.

17. The system of claim 16 wherein the clock emulator is configured to vary the phase and/or frequency of the at least one of the emulated clocks to simulate clock jitter.

18. The system of claim 16 wherein the network equipment test device is configured to monitor a response of the device under test to the changes in phase and/or frequency of the at least one of the emulated clocks.

19. A non-transitory computer readable medium having stored thereon executable instructions that when executed by the processor of a computer control the computer to perform steps comprising:

in a network equipment test device:

generating or obtaining timing information to produce a first clock;

obtaining clock modification information, wherein the clock modification information includes at least one of frequency adjustment factors and phase offsets for generation of different emulated clocks that differ from each other in at least one of frequency and phase to simulate clock at least one of clock drift and clock jitter;

emulating the different clocks using the timing information and the clock modification information, wherein the different emulated clocks differ from each other in at least one of frequency and phase to simulate at least one of clock drift and clock jitter; and

emulating at least one network device that transmits test packets to a device under test using the different clocks, wherein different ones of the test packets include timestamps generated using the emulated clocks that differ from each other in at least one of frequency and phase.