mRSVP-TE based fast reroute in detour (1:1) protection mode

1. A method of detour protection by a merge point (MP) comprising:

sending a first multicast Resource Reservation Protocol-Traffic Engineering (mRSVP-TE) path request (PATH) message toward a multicast sender over a primary Label Switch Path (LSP);

checking whether a detour route is available for primary LSP protection; and

selecting a shortest detour route on a hop-by-hop basis and initiate a detour LSP setup when at least one detour route is found, wherein detour LSP setup comprises assigning a Point of Local Repair (PLR) as an end point of a detour LSP by:

sending a second PATH message toward the PLR along the shortest detour route; and

receiving a mRSVP-TE reserve (RESV) message from the PLR.

2. The method of claim 1 , wherein the detour LSP setup further comprises:

assigning a downstream label to the detour LSP; and

sending the assigned label via the second PATH message.

3. The method of claim 1 , wherein the RESV message comprises an upstream label assigned to the detour LSP by a node positioned on the shortest detour route.

4. The method of claim 1 , further comprising receiving traffic from the PLR along the detour LSP upon failure along the primary LSP.

5. The method of claim 1 , further comprising storing a one-to-one binding of the primary LSP and the detour LSP in a Forwarding Information Base (FIB).

6. The method of claim 1 , wherein upstream labels for traffic from the MP are not allocated by the PLR when the primary LSP is part of a Receiver Driven (RD) Point to Multipoint (P2MP) tree.

7. The method of claim 1 , further comprising:

receiving detour traffic from the detour LSP upon failure of the primary LSP;

merging the detour traffic with primary traffic from the primary LSP; and

forwarding the merged traffic downstream.

8. An apparatus comprising:

at least one receiver;

at least one transmitter configured to send a first multicast Resource Reservation Protocol-Traffic Engineering (mRSVP-TE) path request (PATH) message toward a multicast sender over a primary Label Switch Path (LSP); and

a non-transitory memory comprising instructions;

a processor coupled to the memory that reads and executes the instructions to:

cause the apparatus to act as a merge point (MP) for merging traffic between a detour LSP and a primary LSP;

check whether a detour route is available for protection of the primary LSP; and

select a shortest detour route on a hop-by-hop basis and initiate setup of the detour LSP when at least one detour route is found, wherein detour LSP setup comprises assigning a Point of Local Repair (PLR) as an end point of a detour LSP by:

sending, via the transmitter, a second PATH message toward the PLR along the shortest detour route; and

receiving, via the receiver, a mRSVP-TE reserve (RESV) message from the PLR.

9. The apparatus of claim 8 , wherein the detour LSP setup further comprises:

assigning a downstream label to the detour LSP; and

sending the assigned label via the second PATH message.

10. The apparatus of claim 8 , wherein the RESV message comprises an upstream label assigned to the detour LSP by a node positioned on the shortest detour route.

11. The apparatus of claim 8 , wherein the receiver is further configured to receive traffic from the PLR along the detour LSP upon failure along the primary LSP.

12. The apparatus of claim 8 , further comprising a memory coupled to the processor, the memory configured to store a one-to-one binding of the primary LSP and the detour LSP in a Forwarding Information Base (FIB).

13. The apparatus of claim 8 , wherein upstream labels for traffic from the MP are not allocated by the PLR when the primary LSP is part of a Receiver Driven (RD) Point to Multipoint (P2MP) tree.

14. The apparatus of claim 8 , wherein the receiver is further configured to receive detour traffic from the detour LSP upon failure of the primary LSP, wherein the processor is further configured to merge the detour traffic with primary traffic from the primary LSP, and wherein the transmitter is further configured to forward the merged traffic downstream.

15. A non-transitory computer readable medium comprising a computer program product comprising executable instructions, wherein the instructions when executed by a processor cause a network element (NE) to:

send a first multicast Resource Reservation Protocol-Traffic Engineering (mRSVP-TE) path request (PATH) message toward a multicast sender over a primary Label Switch Path (LSP);

check whether a detour route is available for protection of the primary LSP; and

select a shortest detour route on a hop-by-hop basis and initiate a detour LSP setup when at least one detour route is found, wherein detour LSP setup comprises assigning a Point of Local Repair (PLR) as an end point of a detour LSP by:

sending a second PATH message toward the PLR along the shortest detour route; and

receiving a mRSVP-TE reserve (RESV) message from the PLR.

16. The computer program product of claim 15 , wherein the detour LSP setup further comprises:

assigning a downstream label to the detour LSP; and

sending the assigned label via the second PATH message.

17. The computer program product of claim 15 , wherein the RESV message comprises an upstream label assigned to the detour LSP by a node positioned on the shortest detour route.

18. The computer program product of claim 17 , wherein the instructions further cause the NE to receive traffic from the PLR along the detour LSP upon failure along the primary LSP.

19. The computer program product of claim 15 , wherein the instructions further cause the NE to store a one-to-one binding of the primary LSP and the detour LSP in a Forwarding Information Base (FIB).

20. The computer program product of claim 15 , wherein upstream labels for traffic from the MP are not allocated by the PLR when the primary LSP is part of a Receiver Driven (RD) Point to Multipoint (P2MP) tree.