Optical networking with support for unidirectional optical links

1. An apparatus comprising:

bidirectional communications equipment configured to communicate information along optical fibers;

wherein the bidirectional communications equipment is configured to provide a first unidirectional communication link along the optical fibers from the bidirectional communications equipment to a first location and a second unidirectional communication link along the optical fibers to the bidirectional communications equipment from a second location that is different from the first location;

wherein the bidirectional communications equipment comprises a transmitter and receiver of a bidirectional interface card; and

wherein the transmitter and receiver are configured to:

provide a bidirectional communication link over an optical fiber pair with a transmitter and receiver of a second bidirectional communications equipment; and

alternatively provide the first unidirectional communication link between the transmitter of the bidirectional communications equipment and the receiver of the second bidirectional communications equipment and the second unidirectional communication link between the receiver of the bidirectional communications equipment and a transmitter of a third bidirectional communications equipment.

2. The apparatus of claim 1 , wherein the bidirectional communications equipment is configured to provide the first unidirectional communication link with a different capacity than the second unidirectional communication link.

3. The apparatus of claim 1 , wherein the bidirectional communications equipment is configured to use different wavelengths for the first and second unidirectional communication links.

4. The apparatus of claim 1 , wherein each of the first and second unidirectional communication links is direct.

5. The apparatus of claim 1 , wherein the bidirectional communications equipment is further configured to increase a capacity of an optical network that includes the optical fibers.

6. The apparatus of claim 5 , wherein, to increase the capacity of the optical network, the bidirectional communications equipment is configured to:

change software that controls provisioning of communication links to and from the bidirectional communications equipment to enable the unidirectional communication links to be provisioned.

7. An optical network comprising:

first, second, and third bidirectional communications equipment, each of the first, second, and third bidirectional communications equipment comprising a transmitter and receiver of a bidirectional interface card;

a first optical fiber link connecting the transmitter of the first bidirectional communications equipment and the receiver of the second bidirectional communications equipment;

a second optical fiber link connecting the receiver of the first bidirectional communications equipment and the transmitter of the third bidirectional communications equipment; and

a third optical fiber link connecting the transmitter of the second bidirectional communications equipment and the receiver of the third bidirectional communications equipment;

wherein the optical network is configured with a first unidirectional communication link along the first optical fiber link, a second unidirectional communication link along the second optical fiber link, and a third unidirectional communication link along the third optical fiber link; and

wherein the second unidirectional communication link differs from at least one of the first unidirectional communication link and the third unidirectional communication link in at least one of: wavelength, bandwidth, modulation scheme, forward error correction, and distance.

8. The optical network of claim 7 , wherein each of the first and second optical fiber links is direct.

9. A method of configuring an optical network, the optical network comprising bidirectional communications equipment configured to provide one or more bidirectional communication links over one or more optical fiber pairs, the method comprising:

configuring optical fiber connections of the optical network between the bidirectional communications equipment; and

provisioning unidirectional communication links between the bidirectional communications equipment over the optical fiber connections of the optical network using the bidirectional communications equipment;

wherein configuring the optical fiber connections comprises providing (i) a first optical fiber connecting a transmitter of a first selected bidirectional communications equipment and a receiver of a second selected bidirectional communications equipment and (ii) a second optical fiber connecting a receiver of the first selected bidirectional communications equipment and a transmitter of a third selected bidirectional communications equipment; and

wherein provisioning the unidirectional communication links comprises provisioning a first unidirectional communication link along the first optical fiber and a second unidirectional communication link along the second optical fiber.

10. The method of claim 9 , further comprising:

increasing a capacity of the optical network by re-configuring the bidirectional communications equipment.

11. The method of claim 10 , wherein re-configuring the bidirectional communications equipment comprises changing software that controls provisioning of communication links to and from the bidirectional communications equipment to enable the unidirectional communication links to be provisioned.

12. The method of Claim 9 , wherein the first unidirectional communication link has a different capacity than the second unidirectional communication link.

13. The method of claim 9 , wherein the first and second unidirectional communication links are used to provision a specified one of the one or more bidirectional communication links between a first location and a second location, the first unidirectional communication link having a different optical path than the second unidirectional communication link.

14. A non-transient computer readable medium comprising instructions that, when executed on a first bidirectional communications equipment, are configured to cause the first bidirectional communications equipment to:

provision unidirectional communication links over an optical network comprising optical fiber connections that include (i) a first optical fiber connecting a transmitter of the first bidirectional communications equipment and a receiver of a second bidirectional communications equipment and (ii) a second optical fiber connecting a receiver of the first bidirectional communications equipment and a transmitter of a third bidirectional communications equipment;

wherein the instructions that, when executed, cause the first bidirectional communications equipment to provision the unidirectional communication links comprise:

instructions that, when executed, cause the first bidirectional communications equipment to provision a first unidirectional communication link along the first optical fiber and a second unidirectional communication link along the second optical fiber.

15. The non-transient computer readable medium of claim 14 , wherein the unidirectional communication links are direct to the second bidirectional communications equipment and to the third bidirectional communications equipment.

16. The non-transient computer readable medium of claim 14 , wherein the instructions when executed further cause the first bidirectional communications equipment to provision the first unidirectional communication link with a different capacity than the second unidirectional communication link.

17. The non-transient computer readable medium of claim 14 , wherein the instructions when executed further cause the first bidirectional communications equipment to use different wavelengths for the first and second unidirectional communication links.

18. The non-transient computer readable medium of claim 14 , wherein the instructions when executed further cause the first bidirectional communications equipment to increase a capacity of the optical network by re-configuring the first bidirectional communications equipment.

19. The non-transient computer readable medium of claim 18 , wherein the instructions that when executed cause the first bidirectional communications equipment to increase the capacity of the optical network comprise:

instructions that when executed cause the first bidirectional communications equipment to change software that controls provisioning of communication links to and from the first bidirectional communications equipment to enable the unidirectional communication links to be provisioned.

20. The non-transient computer readable medium of claim 14 , wherein the instructions when executed further cause the first bidirectional communications equipment to:

use the first and second unidirectional communication links to provision a bidirectional communication link between a first location and a second location, the first unidirectional communication link having a different optical path than the second unidirectional communication link.