Supporting stateful explicit paths

1. An apparatus, comprising:

at least one processor; and

at least one memory storing instructions which, when executed by the at least one processor, cause the apparatus at least to:

support communication of a packet along a path in an Internet Protocol (IP) network from a first node to a second node, wherein the path includes a set of hops, wherein the packet includes a tuple configured to identify the path, wherein the tuple includes a first IP address of the first node, a second IP address of the second node, and a path identifier of the path, wherein the path identifier of the path is a unique identifier assigned to the path, wherein the communication of the packet along the path from the first node to the second node is supported based on state information configured to map the tuple to a next hop in the set of hops of the path; and

support communication of a second packet along a second path from the first node to the second node in the IP network, wherein the second path traverses the set of hops, wherein the second packet includes a second tuple configured to identify the second path, wherein the second tuple includes the first IP address of the first node, the second IP address of the second node, and a second path identifier of the second path, wherein the communication of the second packet is supported based on second state information of the second path configured to map the second tuple to a next hop in the set of hops.

2. The apparatus of claim 1 , wherein the set of hops of the path includes a set of network elements of which the path is composed, wherein the set of network elements includes at least one of a set of nodes or a set of links.

3. The apparatus of claim 1 , wherein at least one of the path identifier is unique to the first node or the path identifier is unique within the IP network.

4. The apparatus of claim 1 , wherein the path identifier is assigned to the path by the first node or by a controller.

5. The apparatus of claim 1 , wherein, to support communication of the packet, the instructions, when executed by the at least one processor, cause the apparatus at least to:

send, by a node, a path setup message including the tuple configured to identify the path and a hops list including hop identifiers of the respective hops of the path.

6. The apparatus of claim 1 , wherein, to support communication of the packet, the instructions, when executed by the at least one processor, cause the apparatus at least to:

receive, by a node, a path setup message including the tuple configured to identify the path and a hops list including hop identifiers of the respective hops of the path; and

determine, by the node from a local perspective of the node based on the hops list, the next hop in set of hops of the path.

7. The apparatus of claim 6 , wherein the path setup message includes at least one of:

a pointer configured to point to a current hop in the hops list, wherein the next hop in the set of hops of the path is determined based on the pointer; or

an indication of resources to be reserved on the next hop in the set of hops of the path.

8. The apparatus of claim 1 , wherein, to support communication of the packet, the instructions, when executed by the at least one processor, cause the apparatus at least to:

receive, based on a control protocol, the state information configured to map the tuple to the next hop in the set of hops of the path; and

store the state information configured to map the tuple to the next hop in the set of hops of the path.

9. The apparatus of claim 1 , wherein, to support communication of the packet, the instructions, when executed by the at least one processor, cause the apparatus at least to:

receive, by a node, the packet;

determine, by the node based on the tuple from the packet and based on the state information configured to map the tuple to the next hop in the set of hops of the path, the next hop in the set of hops of the path; and

send, by the node toward the next hop in the set of hops of the path, the packet.

10. The apparatus of claim 1 , wherein, to support communication of the packet, the instructions, when executed by the at least one processor, cause the apparatus at least to:

determine, by the node based on the tuple from the packet and based on the state information configured to map the tuple to the next hop in the set of hops of the path, that the node is the second node of the path; and

perform, by the node, processing for removing the packet from the path.

11. An apparatus, comprising:

at least one processor; and

at least one memory storing instructions which, when executed by the at least one processor, cause the apparatus at least to:

support communication of a packet along a path in an Internet Protocol (IP) network from a first node to a second node, wherein the path includes a set of hops, wherein the packet includes a tuple configured to identify the path, wherein the tuple includes a first IP address of the first node, a second IP address of the second node, and a path identifier of the path, wherein the path identifier of the path is a unique identifier assigned to the path, wherein the communication of the packet along the path from the first node to the second node is supported based on state information configured to map the tuple to a next hop in the set of hops of the path; and

support communication of a second packet along a second path from the first node to the second node in the IP network, wherein the second path traverses a second set of hops which is different than the first set of hops of the first path, wherein the second packet includes a second tuple configured to identify the second path, wherein the second tuple includes the first IP address of the first node, the second IP address of the second node, and a second path identifier of the second path, wherein the communication of the second packet is supported based on second state information of the second path configured to map the second tuple to a next hop in the second set of hops of the second path.

12. The apparatus of claim 11 , wherein the set of hops of the path includes a set of network elements of which the path is composed, wherein the set of network elements includes at least one of a set of nodes or a set of links.

13. The apparatus of claim 11 , wherein at least one of the path identifier is unique to the first node or the path identifier is unique within the IP network.

14. The apparatus of claim 11 , wherein the path identifier is assigned to the path by the first node or by a controller.

15. The apparatus of claim 11 , wherein, to support communication of the packet, the instructions, when executed by the at least one processor, cause the apparatus at least to:

send, by a node, a path setup message including the tuple configured to identify the path and a hops list including hop identifiers of the respective hops of the path.

16. The apparatus of claim 11 , wherein, to support communication of the packet, the instructions, when executed by the at least one processor, cause the apparatus at least to:

receive, by a node, a path setup message including the tuple configured to identify the path and a hops list including hop identifiers of the respective hops of the path; and

determine, by the node from a local perspective of the node based on the hops list, the next hop in set of hops of the path.

17. The apparatus of claim 16 , wherein the path setup message includes at least one of:

a pointer configured to point to a current hop in the hops list, wherein the next hop in the set of hops of the path is determined based on the pointer; or

an indication of resources to be reserved on the next hop in the set of hops of the path.

18. The apparatus of claim 11 , wherein, to support communication of the packet, the instructions, when executed by the at least one processor, cause the apparatus at least to:

receive, based on a control protocol, the state information configured to map the tuple to the next hop in the set of hops of the path; and

store the state information configured to map the tuple to the next hop in the set of hops of the path.

19. The apparatus of claim 11 , wherein, to support communication of the packet, the instructions, when executed by the at least one processor, cause the apparatus at least to:

receive, by a node, the packet;

determine, by the node based on the tuple from the packet and based on the state information configured to map the tuple to the next hop in the set of hops of the path, the next hop in the set of hops of the path; and

send, by the node toward the next hop in the set of hops of the path, the packet.

20. The apparatus of claim 11 , wherein, to support communication of the packet, the instructions, when executed by the at least one processor, cause the apparatus at least to:

determine, by the node based on the tuple from the packet and based on the state information configured to map the tuple to the next hop in the set of hops of the path, that the node is the second node of the path; and

perform, by the node, processing for removing the packet from the path.

21. A method, comprising:

supporting communication of a packet along a path in an Internet Protocol (IP) network from a first node to a second node, wherein the path includes a set of hops, wherein the packet includes a tuple configured to identify the path, wherein the tuple includes a first IP address of the first node, a second IP address of the second node, and a path identifier of the path, wherein the path identifier of the path is a unique identifier assigned to the path, wherein the communication of the packet along the path from the first node to the second node is supported based on state information configured to map the tuple to a next hop in the set of hops of the path; and

supporting communication of a second packet along a second path from the first node to the second node in the IP network, wherein the second path traverses the set of hops, wherein the second packet includes a second tuple configured to identify the second path, wherein the second tuple includes the first IP address of the first node, the second IP address of the second node, and a second path identifier of the second path, wherein the communication of the second packet is supported based on second state information of the second path configured to map the second tuple to a next hop in the set of hops.

22. A method, comprising:

supporting communication of a packet along a path in an Internet Protocol (IP) network from a first node to a second node, wherein the path includes a set of hops, wherein the packet includes a tuple configured to identify the path, wherein the tuple includes a first IP address of the first node, a second IP address of the second node, and a path identifier of the path, wherein the path identifier of the path is a unique identifier assigned to the path, wherein the communication of the packet along the path from the first node to the second node is supported based on state information configured to map the tuple to a next hop in the set of hops of the path; and

supporting communication of a second packet along a second path from the first node to the second node in the IP network, wherein the second path traverses a second set of hops which is different than the first set of hops of the first path, wherein the second packet includes a second tuple configured to identify the second path, wherein the second tuple includes the first IP address of the first node, the second IP address of the second node, and a second path identifier of the second path, wherein the communication of the second packet is supported based on second state information of the second path configured to map the second tuple to a next hop in the second set of hops of the second path.