Routing methods, systems, and computer program products
In various embodiments, a method and apparatus are configured to receive, at a node in a first access network, a data packet, wherein the first access network is connected, via a first area edge node, to a first area of a subdivided network; receive, from a centralized controller for the subdivided network, a segment identifier data structure, wherein the segment identifier data structure encodes a path extending from the first area edge node to a second access network; encapsulate the data packet; and forward the encapsulated data packet toward the first area edge node.
1. A method comprising:
receiving, at a node within a first segment routing enabled access network, a data packet, wherein
the first access network is connected, via a first area edge node, to a first area of a subdivided segment routing enabled network,
the first area comprises two or more nodes within the subdivided segment routing enabled network, and
a specified destination for the data packet is reachable via a second segment routing enabled access network connected to the subdivided segment routing enabled network;
receiving, from a centralized controller for the subdivided segment routing enabled network, a remote segment identifier stack, wherein
the remote segment identifier stack encodes a path extending from the first area edge node to the second segment routing enabled access network;
encapsulating the data packet with a full segment identifier stack comprising the remote segment identifier stack; and
forwarding the encapsulated data packet toward the first area edge node.
2. The method of claim 1 , further comprising:
sending, to the centralized controller, a request for the remote segment identifier stack.
3. The method of claim 2 , wherein the request comprises destination information for the data packet.
4. The method of claim 3 , wherein the destination information comprises a destination address carried by the data packet.
5. The method of claim 3 , wherein the destination information comprises a unique identifier for a segment routing enabled node within the second segment routing enabled access network.
6. The method of claim 3 , wherein the request further comprises an identification of the first area edge node.
7. The method of claim 1 , wherein the full segment identifier stack further comprises an area-segment identifier identifying the first area.
8. The method of claim 7 , wherein the full segment identifier stack further comprises a nodal segment identifier identifying the first area edge node.
9. A network device comprising:
one or more network interfaces adapted for connection of the network device within a first segment routing enabled access network, wherein
the first access network is connected, via a first area edge node, to a first area of a subdivided segment routing enabled network, and
the first area comprises two or more nodes within the subdivided segment routing enabled network; and
a processor adapted to
receive a data packet, wherein
a specified destination for the data packet is reachable via a second segment routing enabled access network connected to the subdivided segment routing enabled network,
receive, from a centralized controller for the subdivided segment routing enabled network, a remote segment identifier stack, wherein
the remote segment identifier stack encodes a path extending from the first area edge node to the second segment routing enabled access network,
encapsulate the data packet with a full segment identifier stack comprising the remote segment identifier stack, and
forward the encapsulated data packet toward the first area edge node.
10. The network device of claim 9 , wherein the processor is further adapted to send, to the centralized controller, a request for the remote segment identifier stack.
11. The network device of claim 10 , wherein the request comprises destination information for the data packet.
12. The network device of claim 11 , wherein the request further comprises an identification of the first area edge node.
13. The network device of claim 9 , wherein the full segment identifier stack further comprises an area-segment identifier identifying the first area.
14. The network device of claim 13 , wherein the full segment identifier stack further comprises a nodal segment identifier identifying the first area edge node.
15. A non-transitory computer readable medium comprising executable instructions, wherein a method is implemented in response to executing the instructions, the method comprising:
receiving, at a node within a first segment routing enabled access network, a data packet, wherein
the first access network is connected, via a first area edge node, to a first area of a subdivided segment routing enabled network,
the first area comprises two or more nodes within the subdivided segment routing enabled network, and
a specified destination for the data packet is reachable via a second segment routing enabled access network connected to the subdivided segment routing enabled network;
receiving, from a centralized controller for the subdivided segment routing enabled network, a remote segment identifier stack, wherein
the remote segment identifier stack encodes a path extending from the first area edge node to the second segment routing enabled access network;
encapsulating the data packet with a full segment identifier stack comprising the remote segment identifier stack; and
forwarding the encapsulated data packet toward the first area edge node.
16. The non-transitory computer readable medium of claim 15 , wherein the method further comprises:
sending, to the centralized controller, a request for the remote segment identifier stack.
17. The non-transitory computer readable medium of claim 16 , wherein the request comprises destination information for the data packet.
18. The non-transitory computer readable medium of claim 17 , wherein the request further comprises an identification of the first area edge node.
19. The non-transitory computer readable medium of claim 15 , wherein the full segment identifier stack further comprises an area-segment identifier identifying the first area.
20. The non-transitory computer readable medium of claim 19 , wherein the full segment identifier stack further comprises a nodal segment identifier identifying the first area edge node.