Synchronization of an instrument's time-base clock and notable events utilizing unused signal pairs on a daisy-chained ethernet communication link

• US 20040225739A1
• Filed: 05/21/2002
• Published: 11/11/2004
• Est. Priority Date: 05/21/2002
• Status: Active Grant

• Current Assignee: Viavi Solutions, Inc. (Lumentum Holdings Inc.)
• Original Assignee: Agilent Technologies, Inc.
• Inventors: Ruhnow, Roger William
• Granted Patent: US 7,092,407 B2
• Time in Patent Office: Days
• US Class Current: 709/227
• CPC Class Codes: H04L 43/00 Arrangements for monitoring or testing data switching networks

Abstract

An apparatus including two distributed network analyzers (each, a “DNA”) and Ethernet cabling to connect the DNAs. Each DNA performs time correlation with the other through the Ethernet cabling.

Claims

1. An apparatus comprising:

first and second distributed network analyzers; and

Ethernet cabling connecting the first and second distributed network analyzers together, wherein the first and second distributed network analyzers perform time correlation with each other through the Ethernet cabling.

2. The apparatus of claim 1, wherein the first and second distributed network analyzers perform sample interval correlation with each other through the Ethernet cabling.

3. The apparatus of claim 1, wherein the first and second distributed network analyzers perform event broadcasting with each other through the Ethernet cabling.

4. The apparatus of claim 1, further comprising a host controller coupled with the first distributed network analyzer via the Ethernet cabling, the host controller and first and second DNAs to exchange Ethernet data via the Ethernet cabling.

5. The apparatus of claim 1, further comprising a network analyzer coupled with the first distributed network analyzer via the Ethernet cabling, the network analyzer and first and second DNAs to exchange Ethernet data via the Ethernet cabling.

6. An apparatus comprising:

a plurality of distributed network analyzers; and

Ethernet cabling, comprising four twisted pairs of wires, to daisy-chain connect the distributed network analyzers, wherein the plurality of distributed network analyzers perform time correlation, sample interval correlation, and event broadcasting with one another through the Ethernet cabling.

7. The apparatus of claim 6, wherein each distributed network analyzer comprises:

an input connector to receive a first time correlation, a first sample interval correlation, and a first event broadcast;

a correlation handler to;

extract a first clock from the first time correlation and a first heartbeat from the first sample interval correlation if the first time correlation and the first sample interval correlation are received, and

generate and encode a second clock into a second time correlation and a second heartbeat into a second sample interval correlation if the first time correlation and the first sample interval correlation are not received;

an event handler to;

extract a first event from the first event broadcast if the first event broadcast is received, and

generate and encode a second event into a second event broadcast if a second event is to be broadcast to the other distributed network analyzers that are downstream and if the second event is not extracted from the first event signal;

an Ethernet data handler to transmit and receive Ethernet data; and

an output connector to transmit the first or second time correlation, the first or second sample interval correlation, and the first or second event broadcast.

8. The apparatus of claim 6, further comprising a host controller or network analyzer coupled to the first of the plurality of distributed network analyzers via the Ethernet cabling, the host controller or network analyzer and the plurality of DNAs to exchange the Ethernet data via the Ethernet cabling.

9. The apparatus of claim 8, wherein the first and second correlations are transmitted on the first of the four pairs of twisted wires of the Ethernet cabling, the first and second event broadcasts are transmitted the second of the four pairs of twisted wires of the Ethernet cabling, and the Ethernet data is transmitted on the third and fourth of the four pairs of twisted wires of the Ethernet cabling.

10. The apparatus of claim 8, wherein the network analyzer comprises a host controller and a distributed network analyzer.

11. The apparatus of claim 7, wherein the output connector includes a crossover wiring function.

12. An apparatus comprising:

a plurality of distributed network analyzers; and

Ethernet connecting means for daisy-chain connecting the distributed network analyzers, comprising four twisted pairs of wires, wherein the plurality of distributed network analyzers perform time correlation, sample interval correlation, and event broadcasting with one another through the Ethernet connecting means.,

13. The apparatus of claim 12, wherein each distributed network analyzer comprises:

an input connector to receive a first time correlation, a first sample interval correlation, and a first event broadcast;

a correlation handler to;

extract a first clock from the first time correlation and a first heartbeat from the first sample interval correlation if the first time correlation and the first sample interval correlation are received, and

generate and encode a second clock into a second time correlation and a second heartbeat into a second sample interval correlation if the first time correlation and the first sample interval correlation are not received;

an event handler to;

extract a first event from the first event broadcast if the first event broadcast is received, and

generate and encode a second event into a second event broadcast if a second event is to be broadcast to the other distributed network analyzers that are downstream and if the second event is not extracted from the first event signal; and

an Ethernet data handler to transmit and receive Ethernet data; and

an output connector to transmit the first or second time correlation, the first or second sample interval correlation, and the first or second event broadcast.

14. The apparatus of claim 12, further comprising a host controller or network analyzer coupled to the first of the plurality of distributed network analyzers via the Ethernet connecting means, the host controller or network analyzer and the plurality of DNAs to exchange the Ethernet data via the Ethernet cabling.

15. The apparatus of claim 14, wherein the first and second correlations are transmitted on the first of the four pairs of twisted wires of the Ethernet connecting means, the first and second event broadcasts are transmitted the second of the four pairs of twisted wires of the Ethernet connecting means, and the data is transmitted on the third and fourth of the four pairs of twisted wires of the Ethernet connecting means.

16. The apparatus of claim 14, wherein the network analyzer comprises a host controller and a distributed network analyzer.

17. The apparatus of claim 13, wherein the output connector includes a crossover wiring function.