Transceiver to transceiver digital optical commands

1. A system comprising:

a first module;

an optical fiber coupled to the first module at a first end of the optical fiber;

a second module coupled to a second end of the optical fiber, the second module configured to generate and transmit instructions to the first module to control operation of the first module;

a third module at the first end of the optical fiber;

wherein the second module sends a first instruction to stop transmitting customer data from the second end of the optical fiber to the first module at the first end of the optical fiber and a second instruction to begin transmitting the customer data from the second end of the optical fiber to the third module at the first end of the optical fiber.

2. The system of claim 1 , wherein

the first module includes a first transmitter and the third module includes a second transmitter;

the first instruction directs the first transmitter to stop transmitting the customer data; and

the second instruction directs the second transmitter of the third module to begin transmitting the customer data.

3. The system of claim 1 , wherein the first and second instructions are generated in response to the second module detecting that an optical signal received from the first transmitter over the optical fiber is below a threshold.

4. The system of claim 1 , wherein the first and second instructions are generated in response to the first module transmitting diagnostic data to the second module.

5. The system of claim 4 , wherein the diagnostic data indicates one of a bias current or an optical output power is beyond a threshold.

6. The system of claim 1 , wherein the second module is configured to communicate with the first module at a physical layer.

7. The system of claim 1 , wherein the second module is configured to communicate with the first module using out-of-band communication.

8. The system of claim 1 , further comprising a forward error correction chip coupled to the second module.

9. The system of claim 8 , wherein

the instructions direct the first module to transmit back to the second module data received from the second module; and

the second module is further configured to:

measure a bit error rate (BER) based on the data transmitted back to the second module; and

transmit second instructions to the first module to adjust a receive decision threshold based on the BER.

10. The system of claim 9 , wherein the second module is further configured to transmit a third instruction to the first module to stop transmitting back data received from the second module based on the BER meeting the adjusted receive decision threshold.

11. The system of claim 9 , wherein the data received from the second module includes customer data.

12. The system of claim 1 , wherein the instructions request a security verification from the first module.

13. The system of claim 12 , wherein the security verification fails to establish a threshold level of security, and the second module performs one of disabling a transmitter of the second module based on the failure to establish the threshold level of security or generating a message to a near end host associated with the second module of the failure to establish the threshold level of security.

14. The system of claim 1 , wherein the instructions direct the first module to adjust wavelength tuning.

15. The system of claim 1 , wherein the instructions enable or disable clock and data recovery (CDR) at the first module.

16. The system of claim 1 , wherein the instructions update firmware of the first module.

17. The system of claim 1 , wherein the instructions reset a control module of the first module.

18. The system of claim 1 , wherein the instructions read or write from a memory page of the first module.

19. A method, comprising:

transmitting first instructions to a primary far end module to send diagnostic monitor data;

receiving diagnostic monitor data from the primary far end module;

determining whether the diagnostic monitor data is beyond a threshold;

sending, based on the diagnostic monitor data being beyond the threshold, second instructions to the primary far end module to turn off a transmitter of the primary far end module; and

sending, based on the diagnostic monitor data being beyond the threshold, third instructions to a secondary far end module to turn on a transmitter of the secondary far end module.

20. The method of claim 19 , wherein the diagnostic monitor data includes one of a transmitter output power and a bias current.

21. A method, comprising:

establishing a receive chain using a forward error correction (FEC) chip;

transmitting first instructions to a far end module to enable optical loop back of data received at the far end module;

making a determination as to whether a bit error ratio (BER) based on the looped back data is within a threshold;

sending second instructions to the far end module to adjust a receive decision threshold until the BER is within the threshold; and

communicating, based on the BER being within the threshold, third instructions to the far end module to disable the optical loop back.