Reconfigurable mesh interconnect for hybrid electrical-optical connectivity between regional data centers

1 . An optical bypass system for interconnecting a plurality of data centers with a regional hub networking node, the optical bypass system comprising:

an optical switching layer configured to receive a plurality of channels from each of the plurality of data centers, and to switch the plurality of channels from each of the plurality of data centers (1) between one another for optical bypass and (2) to an electrical switching fabric at the regional hub networking node; and

a controller configured to (1) configure wavelengths on corresponding optical transceivers for each of the plurality of channels from each of the plurality of data centers, wherein the corresponding optical transceivers comprise pluggable coherent optical transceivers housed in electrical switches at the plurality of data centers, (2) configure wavelength switching in the optical switching layer, and (3) determine packet forwarding between the corresponding optical transceivers,

wherein configuring the wavelengths includes computing a wavelength assignment that avoids wavelength collisions through the optical switching layer and assigns wavelengths to prevent blocking on links between the plurality of data centers and on ports of the optical switching layer, and

wherein the packet forwarding between the corresponding optical transceivers is configured in an Equal Cost Multi-Path (ECMP) group, and wherein the controller configures the ECMP group to distribute inter-data-center traffic on a per-flow basis across multiple equal-cost paths including at least one optically bypassed path and at least one path through the electrical switching fabric at the regional hub networking node, such that individual flows are restricted to a single selected path to prevent packet reordering.

2 . The optical bypass system of claim 1 , wherein the corresponding optical transceivers are each a coherent optical transceiver in an electrical switch at a data center of the plurality of data centers.

3 . The optical bypass system of claim 1 , wherein the optical switching layer is located at the regional hub networking node, and the optical switching layer includes a Wavelength Selective Switch (WSS) for each of the plurality of data centers.

4 . The optical bypass system of claim 3 , wherein the WSS for each of the plurality of data centers is an N×M WSS, N and M are integers and represent ports thereon, wherein the N ports are connected to a corresponding data center of the plurality of data centers, and wherein the M ports are connected to other data centers of the plurality of data centers and the electrical switching fabric at the regional hub networking node.

5 . The optical bypass system of claim 4 , wherein M is greater than N.

6 . The optical bypass system of claim 3 , wherein the optical switching layer further includes an optical circuit switch connected to the WSS for each of the plurality of data centers.

7 . The optical bypass system of claim 3 , wherein the optical switching layer further includes a WSS located at each of the plurality of data centers configured to either connect to the WSS located at the regional hub networking node or a WSS located at another data center of the plurality of data centers.

8 . The optical bypass system of claim 1 , wherein the ECMP group includes a first set of paths assigned to corresponding optical transceivers that are optically bypassed between data centers and a second set of paths assigned to corresponding optical transceivers that connect to the electrical switching fabric at the regional hub networking node.

9 . The optical bypass system of claim 1 , wherein the wavelengths are assigned to prevent blocking in the optical switching layer.

10 . A method comprising steps of:

interconnecting a plurality of data centers with a regional hub networking node via an optical bypass system;

configuring an optical switching layer in the optical bypass system, wherein the optical switching layer is configured to receive a plurality of channels from each of the plurality of data centers, and to switch the plurality of channels from each of the plurality of data centers (1) between one another for optical bypass and (2) to an electrical switching fabric at the regional hub networking node;

configuring wavelengths on corresponding optical transceivers for each of the plurality of channels from each of the plurality of data centers, wherein the corresponding optical transceivers comprise pluggable coherent optical transceivers housed in electrical switches at the plurality of data centers;

configuring wavelength switching in the optical switching layer; and determining packet forwarding between the corresponding optical transceivers,

wherein configuring the wavelengths includes computing a wavelength assignment that avoids wavelength collisions through the optical switching layer and assigns wavelengths to prevent blocking on links between the plurality of data centers and on ports of the optical switching layer, and

wherein the packet forwarding between the corresponding optical transceivers is configured in an Equal Cost Multi-Path (ECMP) group, and wherein the controller configures the ECMP group to distribute inter-data-center traffic on a per-flow basis across multiple equal-cost paths including at least one optically bypassed path and at least one path through the electrical switching fabric at the regional hub networking node, such that individual flows are restricted to a single selected path to prevent packet reordering.

11 . The method of claim 10 , wherein the corresponding optical transceivers are each a pluggable coherent optical transceiver in an electrical switch at a data center of the plurality of data centers.

12 . The method of claim 10 , wherein the optical switching layer is located at the regional hub networking node, and the optical switching layer includes a Wavelength Selective Switch (WSS) for each of the plurality of data centers.

13 . The method of claim 12 , wherein the WSS for each of the plurality of data centers is an N×M WSS, N and M are integers and represent ports thereon, wherein the N ports are connected to a corresponding data center of the plurality of data centers, and wherein the M ports are connected to other data centers of the plurality of data centers and the electrical switching fabric at the regional hub networking node.

14 . The method of claim 13 , wherein the optical switching layer further includes an optical circuit switch connected to the WSS for each of the plurality of data centers.

15 . The method of claim 13 , wherein M is greater than N.

16 . The method of claim 12 , wherein the optical switching layer further includes a WSS located at each of the plurality of data centers configured to either connect to the WSS located at the regional hub networking node or a WSS located at another data center of the plurality of data centers.

17 . The method of claim 10 , wherein the ECMP group includes a first set of paths assigned to corresponding optical transceivers that are optically bypassed between data centers and a second set of paths assigned to corresponding optical transceivers that connect to the electrical switching fabric at the regional hub networking node.

18 . The method of claim 10 , wherein the wavelengths are assigned to prevent blocking in the optical switching layer.