Patent ID: 11876706
Assignee: JUNIPER NETWORKS, INC.
Field: Digital communication (Electrical engineering)
Classification: CPC H | IPC H

Claim 11:
12. A system, the system comprising:
a data forwarding device including:
a) at least one communications interface;
b) at least one processor; and
c) at least one storage device storing processor-executable instructions which, when executed by the at least one processor, cause the at least one processor to perform a method comprising:
1) receiving, by the data forwarding device on a label switched path (LSP), a data packet;
2) determining a next hop of the data packet received;
3) determining whether or not the next hop is reachable;
4) responsive to determining that the next hop is not reachable,
A) determining whether or not the data packet received includes a further label identifying that the data packet had made a backup detour, and
B) responsive to the determination that the data packet received includes the further label identifying that the data packet had made a backup detour,
 dropping the data packet, and

otherwise, responsive to a determination that the data packet received does not include a further label identifying that the data packet had made a backup detour,
 determining (i) a backup next hop and (ii) a forwarding label associated with the backup next hop, and
 adding to the data packet, (1) the forwarding label and (2) another label indicating that a backup detour is being made, to generate an updated data packet; and
 forwarding, by the data forwarding device, the updated data packet to the backup next hop, and

otherwise, responsive to determining that the next hop is reachable, forwarding the data packet using a forwarding label associated with the next hop; and

a second data forwarding device including:
a) at least one communications interface;
b) at least one processor; and
c) at least one storage device storing processor-executable instructions which, when executed by the at least one processor of the second data forwarding device, cause the at least one processor of the second data forwarding device to perform a method comprising:
1) receiving, by the second data forwarding device on the LSP, an instance of the data packet, wherein the instance of the data packet includes an incoming label;
2) determining, by the second data forwarding device, a further next hop of the instance of the data packet received using the incoming label;
3) determining, by the second data forwarding device, whether or not the further next hop is reachable; and
4) responsive to determining that the further next hop is not reachable,
determining, by the second data forwarding device, whether or not the instance of the data packet received includes the other label indicating that a backup detour was made, and
responsive to a determination that the instance of the data packet received includes the other label indicating that a backup detour was made, dropping the instance of the data packet, and

otherwise, responsive to determining that the further next hop is reachable,
popping the incoming label of the instance of the data packet,
removing the other label indicating that a backup detour was made if the other label indicating that a backup detour was made is at the top a label stack associated with the instance of the data packet,
adding an outgoing label if the next hop includes an outgoing label,
and
forwarding the instance of the data packet using the further next hop.