Path computation systems and methods for heterogeneous multi-domain networks
The present disclosure provides path computation systems and methods operating over heterogeneous multi-domain networks. Specifically, path computation systems and methods utilize PCE mechanisms with additional functionality enabling heterogeneous domain characteristics. In an exemplary embodiment, a network includes a plurality of domains with each domain having a PCE implemented either as a separate server-based application or resident application in a network node. Different methods may be utilized for determining what PCE to access for information. Instead of a list of nodes and links given in a common format, each PCE can compute a path within its domain using a node and link address/identification format of its own, without having to ensure that it can be interpreted by nodes in other domains. This path segment can be further distinguished by a path identifier that verifies that it is created for a particular domain, and avoiding misinterpretation.
1. A path computation method across a multi-domain network, comprising:
requesting a path setup from a node A in a domain A to a node Z in a domain Z;
receiving an Explicit Route Object comprising a path from the node A to the node Z, wherein the Explicit Route Object comprises an unparsed domain-specific path segment for domain Z or any intermediate domains between the domain A and the domain Z, and wherein the unparsed domain-specific path segment is not understood by the domain A; and
using the Explicit Route Object to set up a path from the node A to the node Z.
2. The path computation method of claim 1 , wherein the unparsed domain-specific path segment is treated as a single, non-parsed object in the domain A.
3. The path computation method of claim 1 , wherein the unparsed domain-specific path segment is utilized because the domain A uses a different addressing scheme and is not configured to parse the unparsed domain-specific path.
4. The path computation method of claim 1 , wherein the requesting and receiving steps are performed by a Path Computation Element (PCE) in the domain A.
5. The path computation method of claim 4 , wherein the unparsed domain-specific path segment is determined by a Path Computation Element (PCE) in the domain Z or any intermediate domains.
6. The path computation method of claim 5 , wherein a PCE in the domain Z or any intermediate domains is configured to parse the unparsed domain-specific path segment during path setup.
7. The path computation method of claim 5 , further comprising:
with each PCE in each domain, temporarily reserving resources on a computed path segment in the Explicit Route Object;
using the reserved resources in path setup; and
if no setup message received for a predetermined time, releasing the temporarily reserved resources.
8. A multi-domain network, comprising:
two or more domains;
a plurality of nodes in each of the two or more domains;
a first addressing scheme for the plurality of nodes in a first domain of the two or more domains;
a second addressing scheme for the plurality of nodes in a second domain of the two or more domains;
wherein a first node in the first domain is configured to receive an Explicit Route Object comprising a path from the first node to a second node in the second domain, wherein the Explicit Route Object comprises an unparsed domain-specific path segment for the second domain.
9. The multi-domain network of claim 8 , wherein the unparsed domain-specific path segment is treated as a single, non-parsed object in the first domain.
10. The multi-domain network of claim 8 , further comprising:
a first Path Computation Element (PCE) in the first domain; and
a second PCE in the second domain.
11. The multi-domain network of claim 10 , wherein the unparsed domain-specific path segment is determined by the second PCE.
12. The multi-domain network of claim 11 , wherein the second PCE or node in the second domain is configured to parse the unparsed domain-specific path segment during path setup.
13. The multi-domain network of claim 11 , wherein the second PCE is configured to:
temporarily reserve resources on a computed path segment in the second domain in the Explicit Route Object;
use the reserved resources in path setup; and
if no setup message received for a predetermined time, release the temporarily reserved resources.
14. A Path Computation Element (PCE), comprising:
an interface communicatively coupling the PCE to a plurality of nodes forming a first domain;
algorithms for path computation and setup;
a processor communicatively coupled to the interface and configured to execute the algorithms for path computation and setup; and
an algorithm to set up a path over heterogeneous domains outside the first domain;
wherein the algorithm to set up a path over heterogeneous domains outside the first domain comprises:
requesting a path setup from a first node in the first domain to a second node in an external domain;
receiving an Explicit Route Object comprising a path from the first node to the second node, wherein the Explicit Route Object comprises an unparsed domain-specific path segment for the external domain or any intermediate domains between the first domain and the external domain, and wherein the unparsed domain-specific path segment is not understood by the PCE; and
using the Explicit Route Object to set up a path from the first node to the second node.
15. The PCE of claim 14 , wherein the unparsed domain-specific path segment is treated as a single, non-parsed object in the first domain by the PCE.
16. The PCE of claim 14 , wherein the unparsed domain-specific path segment is determined by a second PCE in the external domain or any intermediate domains.
17. The PCE of claim 16 , wherein the second PCE or node in the second domain is configured to parse the unparsed domain-specific path segment during path setup.
18. The PCE of claim 16 , wherein the second PCE is configured to:
temporarily reserve resources on a computed path segment in the Explicit Route Object;
use the reserved resources in path setup; and
if no setup message received for a predetermined time, release the temporarily reserved resources.