Multi-domain network path computation with minimal model and data sharing between domains

1. A non-transitory computer-readable medium having instructions stored thereon for programming an orchestration layer to perform steps of:

receiving a request for a path, wherein the path is requested from a source in a first domain to a destination in a second domain in a multi-domain network including a plurality of domains;

relaying the request to each domain in the multi-domain network;

obtaining matrix fragments from domains in the multi-domain network, wherein each domain is configured to compute a corresponding matrix fragment and the matrix fragments are used to find the path;

causing messaging between the source and the destination utilizing the matrix fragments to trace through and determine weights to select the path; and

providing a response with the path from the source in the first domain to the destination in the second domain.

2. The non-transitory computer-readable medium of claim 1 , wherein each matrix fragment includes one or more paths through a corresponding domain that have been computed by the corresponding domain with intradomain knowledge and where the intradomain knowledge is excluded from the matrix fragment.

3. The non-transitory computer-readable medium of claim 1 , wherein each matrix fragment is one of a 1×N matrix for a domain with the source having N Inter-Domain Handoff (IDH) points, an A×B matrix for an intermediate domain having A ingress IDH points and B egress IDH points, and an R×(S+T) matrix for a domain with the destination having R ingress IDH points, S egress IDH points, and T paths terminating at the destination.

4. The non-transitory computer-readable medium of claim 1 , wherein the matrix fragments are determined in a phase A path computation, and wherein the steps further include

performing a phase B path computation including finding paths from the source to the destination causing messaging through each internal domain paths in the matrix fragments for each domain of the plurality of domains.

5. The non-transitory computer-readable medium of claim 4 , wherein the steps further include performing the phase A path computation and a portion of the phase B computation concurrently as corresponding matrix fragments are determined.

6. The non-transitory computer-readable medium of claim 4 , wherein the messaging in the phase B path computation is a trace message that has a weight through the domain added thereto.

7. The non-transitory computer-readable medium of claim 4 , wherein the steps further include

exiting computation of any path in either the phase A path computation and the phase B path computation based on one or more early exit conditions.

8. The non-transitory computer-readable medium of claim 4 , wherein details of internal domain paths are maintained separate from each of the plurality of domains, and wherein the messaging includes quantitative details for path evaluation without exposing data privacy of the corresponding domain.

9. An orchestration layer comprising:

one or more processing devices communicatively coupled to a plurality of domains in a multi-domain network, wherein the one or more processing devices are configured to

receive a request for a path, wherein the path is requested from a source in a first domain to a destination in a second domain in a multi-domain network including a plurality of domains;

relay the request to each domain in the multi-domain network;

obtain matrix fragments from domains in the multi-domain network, wherein each domain is configured to compute a corresponding matrix fragment and the matrix fragments are used to find the path;

cause messaging between the source and the destination utilizing the matrix fragments to trace through and determine weights to select the path; and

provide a response with the path from the source in the first domain to the destination in the second domain.

10. The orchestration layer of claim 9 , wherein each matrix fragment includes one or more paths through a corresponding domain that have been computed by the corresponding domain with intradomain knowledge and where the intradomain knowledge is excluded from the matrix fragment.

11. The orchestration layer of claim 9 , wherein each matrix fragment is one of a 1×N matrix for a domain with the source having N Inter-Domain Handoff (IDH) points, an A×B matrix for an intermediate domain having A ingress IDH points and B egress IDH points, and an R×(S+T) matrix for a domain with the destination having R ingress IDH points, S egress IDH points, and T paths terminating at the destination.

12. The orchestration layer of claim 9 , wherein the matrix fragments are determined in a phase A path computation, and wherein the one or more processing devices are configured to

perform a phase B path computation including finding paths from the source to the destination causing messaging through each internal domain paths in the matrix fragments for each domain of the plurality of domains.

13. The orchestration layer of claim 12 , wherein the one or more processing devices are configured to

perform the phase A path computation and a portion of the phase B computation concurrently as corresponding matrix fragments are determined.

14. The orchestration layer of claim 12 , wherein the messaging in the phase B path computation is a trace message that has a weight through the domain added thereto.

15. The orchestration layer of claim 12 , wherein the one or more processing devices are configured to

exit computation of any path in either the phase A path computation and the phase B path computation based on one or more early exit conditions.

16. The orchestration layer of claim 12 , wherein details of internal domain paths are maintained separate from each of the plurality of domains, and wherein the messaging includes quantitative details for path evaluation without exposing data privacy of the corresponding domain.

17. A non-transitory computer-readable medium having instructions stored thereon for programming a processing device associated with a domain to perform steps of:

receiving a request from an orchestration layer, wherein the request is based on a path request for a path from a source in a first domain to a destination in a second domain in a multi-domain network including a plurality of domains;

computing one or more paths through the domain from any of entry and source to any of an exit and destination, with intradomain knowledge;

forming a matrix fragment based on the computing, wherein the matrix fragment includes details of the one or more paths computed with the intradomain knowledge and with the intradomain knowledge excluded from the matrix fragment;

causing messaging between the source and the destination utilizing the matrix fragments to trace through and determine weights to select the path; and

providing the matrix fragment for use in computing the path.

18. The non-transitory computer-readable medium of claim 17 , wherein each matrix fragment is one of a 1×N matrix when the domain includes the source having N Inter-Domain Handoff (IDH) points, an A×B matrix when the domain is an intermediate domain having A ingress IDH points and B egress IDH points, and an R×(S+T) matrix when the domain includes the destination having R ingress IDH points, S egress IDH points, and T paths terminating at the destination.

19. The non-transitory computer-readable medium of claim 17 , wherein the matrix fragments is determined in a phase A path computation, and wherein the steps further include

performing a phase B path computation including finding paths utilizing messaging through each internal domain paths in the matrix fragment.

20. The non-transitory computer-readable medium of claim 17 , wherein the messaging in the phase B path computation is a trace message that has a weight through the domain added thereto.