US 10,892,981 B2
Method and apparatus for segment routing and RSVP-TE routing in transport SDN networks
Daniele Ceccarelli, Sollentuna (SE); Massimiliano Maggiari, Pleasanton, CA (US); and Paolo Rebella, Bergeggi (IT)
Assigned to Telefonaktiebolaget LM Ericsson (publ), Stockholm (SE)
Appl. No. 16/302,738
Filed by Telefonaktiebolaget LM Ericsson (publ), Stockholm (SE)
PCT Filed May 20, 2016, PCT No. PCT/EP2016/061497
§ 371(c)(1), (2) Date Nov. 19, 2018,
PCT Pub. No. WO2017/198319, PCT Pub. Date Nov. 23, 2017.
Prior Publication US 2019/0280960 A1, Sep. 12, 2019
Int. Cl. H04L 12/721 (2013.01); H04L 12/717 (2013.01)
CPC H04L 45/123 (2013.01) [H04L 45/124 (2013.01); H04L 45/34 (2013.01); H04L 45/42 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A method for routing packet traffic through a network comprising a plurality of network nodes, the nodes supporting Resource Reservation Protocol—Traffic Engineering (RSVP-TE) protocol and Segment Routing protocol, wherein each of the two protocols is associated with a separate set of labels, the method comprising:
calculating a path through the network;
checking support for both protocols at nodes along the calculated path;
encoding the calculated path as a set of Adjacency Segment Identifiers;
optimizing a label stack of the calculated path by substituting more than one adjacency Segment Identifier (SIDs) with a node SID if a partial path identified by the substituted adjacency SIDs equals a shortest path; and
if all nodes along the calculated path support label stack depth equal to or deeper than the depth of the optimized label stack, then the calculated path is set up using segment routing and the optimized label stack; and
if a node along the calculated path does not support a label stack depth equal to or deeper than the depth of the optimized label stack, then an Explicit Route Object is used for signaling the calculated path using RSVP-TE.