Advertising and programming preferred path routes using interior gateway protocols
A method implemented by a network element (NE) in a network, comprising receiving, by the NE, an advertisement comprising preferred path route (PPR) information representing a PPR from a source to a destination in the network, the PPR information comprising a PPR identifier (PPR-ID) and a plurality of PPR description elements (PPR-PDEs) each representing an element on the PPR, receiving, by the NE, a data packet comprising the PPR-ID, and forwarding, by the NE, the data packet having the PPR-ID to a next element on the PPR based on the plurality of PPR-PDEs.
1. A method implemented by a network element (NE) in a network, comprising:
receiving an advertisement comprising preferred path route (PPR) information representing a PPR from a source to a destination in the network,
the PPR being a path including a plurality of elements between the source and the destination in the network,
the PPR information comprising a PPR identifier (PPR-ID) identifying the PPR, a plurality of PPR description elements (PPR-PDEs), and a PPR-PDE type field,
each of the PPR-PDEs being an information element including an identifier representing an element of the plurality of elements on the PPR, and
the PPR-PDE type field including a value representing a type of the element being identified in a respective PPR-PDE, the type of element being either a topological element or a non-topological element;
when the NE is identified in one of the PPR-PDEs included in the advertisement:
determining a next PPR-PDE of the PPR-PDEs, the next PPR-PDE corresponding to a next element along the PPR identified by the PPR-ID to the destination; and
updating a forwarding database to include an entry for the PPR information carried in the advertisement, the entry indicating the PPR-ID and the next element along the PPR;
receiving, by the NE, a data packet comprising the PPR-ID; and
forwarding, by the NE, the data packet having the PPR-ID to the next element on the PPR.
2. The method of claim 1 , wherein the PPR-ID is at least one of a Multi-Protocol Label Switching (MPLS) label, a segment identifier (SID), an Internet Protocol (IP) version 4 (IPv4) address, or an IP version 6 (IPv6) address.
3. The method of claim 1 , wherein the PPR deviates from a predetermined shortest path between the source and the destination based on a network characteristic requested by a client.
4. The method of claim 1 , further comprising receiving, by the receiver, traffic engineering (TE) source routed path information relating to a plurality of sources attached to the NE, wherein the TE source routed path information comprises the PPR information for the source of the plurality of sources.
5. The method of claim 1 , wherein the topological element comprises at least one of a network element or a link, and wherein the non-topological element comprises at least one of a service, function, or context.
6. The method of claim 1 , wherein the advertisement comprises a flag set to indicate that the PPR-ID identifies a strict-PPR between the source and the destination, wherein the PPR-PDEs describes all topological NEs on the PPR.
7. The method of claim 1 , wherein the advertisement comprises a flag set to indicate that the PPR-ID identifies a loose-PPR between the source and the destination, wherein the PPR-PDEs describes a subset of topological NEs on the PPR.
8. The method of claim 7 , wherein the network implements Multi-Protocol Label Switching (MPLS), wherein the data packet comprises a bottom label and a top label, wherein the bottom label comprises the PPR-ID, and wherein the top label comprises a label identifying the next element on the PPR.
9. A network element (NE) implemented in a network, comprising:
a memory configured to store instructions; and
a processor coupled to the memory and configured to execute the instructions, which cause the processor to be configured to:
receive an advertisement comprising preferred path route (PPR) information representing a PPR from a source to a destination in the network,
the PPR being a path including a plurality of elements between the source and the destination in the network,
the PPR information comprising a PPR identifier (PPR-ID) identifying the PPR, a plurality of PPR description elements (PPR-PDEs), and a PPR-PDE type field,
each of the PPR-PDEs being an information element including an identifier representing an element of the plurality of elements on the PPR, and
the PPR-PDE type field including a value representing a type of the element being identified in a respective PPR-PDE, the type of element being either a topological element or a non-topological element;
when the NE is identified in one of the PPR-PDEs included in the advertisement:
determine a next PPR-PDE of the PPR-PDEs, the next PPR-PDE corresponding to a next element along the PPR identified by the PPR-ID to the destination; and
update a forwarding database to include an entry for the PPR information carried in the advertisement, the entry indicating the PPR-ID and the next element along the PPR;
receive a data packet comprising the PPR-ID; and
to forward the data packet having the PPR-ID to the next element on the PPR.
10. The NE of claim 9 , wherein the PPR-PDEs are carried in the advertisement according to an order of the elements on the PPR.
11. The NE of claim 9 , wherein each of the PPR-PDEs comprises an address of a respective element on the PPR and a path description element (PDE) identifier (PDE-ID) that defines a type of the address.
12. The NE of claim 9 , wherein the advertisement comprises a flag instructing the NE to maintain a count of a number of data packets comprising the PPR-ID transmitted along the PPR.
13. The NE of claim 9 , wherein the PPR information is received from a central entity of the network.
14. A non-transitory medium configured to store a computer program product comprising computer executable instructions that when executed by a processor of a network element (NE) cause the processor to:
receive an advertisement comprising preferred path route (PPR) information representing a PPR from a source to a destination in a network,
the PPR being a path including a plurality of elements between the source and the destination in the network,
the PPR information comprising a PPR identifier (PPR-ID) identifying the PPR, a plurality of PPR description elements (PPR-PDEs), and a PPR-PDE type field,
each of the PPR-PDEs being an information element including an identifier representing an element of the plurality of elements on the PPR, and
the PPR-PDE type field including a value representing a type of the element being identified in a respective PPR-PDE, the type of element being either a topological element or a non-topological element;
when the NE is identified in one of the PPR-PDEs included in the advertisement:
determine a next PPR-PDE of the PPR-PDEs, the next PPR-PDE corresponding to a next element along the PPR identified by the PPR-ID to the destination; and
update a forwarding database to include an entry for the PPR information carried in the advertisement, the entry indicating the PPR-ID and the next element along the PPR;
receive a data packet comprising the PPR-ID; and
forward the data packet having the PPR-ID to the next element on the PPR.
15. The non-transitory medium of claim 14 , wherein each of the PPR-PDEs comprises an address of a respective element on the PPR.
16. The non-transitory medium of claim 14 , wherein the topological element comprises at least one of a network element or a link, and wherein the non-topological element comprises at least one of a service, function, or context.
17. The non-transitory medium of claim 14 , wherein the PPR-ID is at least one of a Multi-Protocol Label Switching (MPLS) label, a segment identifier (SID), an Internet Protocol (IP) version 4 (IPv4) address, or an IP version 6 (IPv6) address.
18. The method of claim 1 , wherein at least one of the PPR-PDEs represents a physical NE.
19. The method of claim 1 , wherein the advertisement comprises a flag signaling the NE to maintain a counter indicating a quantity of times the NE forwards different data packets along the PPR.
20. The NE of claim 9 , wherein the advertisement comprises a flag signaling the NE to maintain a counter indicating a quantity of times the NE forwards different data packets along the PPR.
21. The non-transitory medium of claim 14 , wherein the advertisement comprises a flag signaling the NE to maintain a counter indicating a quantity of times the NE forwards different data packets along the PPR.