Patent ID: 9516118
Filing Date: 2016-12-06
CPC Classification: H04L

Claim Text:
1. A method in a first network device that is communicatively coupled to a plurality of segment routing (SR) devices in a SR network, the method comprising: allocating a first set of local sub-blocks (LsBs) of segment identifiers (SIDs), each LsB associated with a start index and a range of SIDs, wherein the start index indicates a starting SID of a corresponding LsB and the range of SIDs indicates a total number of SIDs included in the corresponding LsB, wherein each LsB is identified by a sub-block number; mapping a plurality of segment routing global block (SRGB) indexes to a plurality of corresponding SIDs of the first set of LsBs, wherein the mapping is performed based on the SRGB indexes, start indexes of each LsB, and ranges of SIDs of each LsB; advertising the first set of LsBs to the plurality of SR devices by transmitting a first advertisement message that includes the start indexes, ranges of SIDs, and sub-block numbers of all LsBs of the first set of LsBs; determining whether an SRGB range exceeds a combined range of SIDs of all LsBs of the first set of LsBs; allocating a new LsB in response to a determination that the SRGB range exceeds the combined range of SIDs of all LsBs of the first set of LsBs; and advertising a second set of LsBs by transmitting a second advertisement message that includes start indexes, ranges of SIDs, and sub-block numbers of all LsBs of the first set of LsBs and the new LsB.