While Cisco is certainly the first to implement SR in Nexus platform (who else should be it’s their own product), they are not the first in the DC industry. I think these guys came first with a working implementation: https://wiki.onosproject.org/display/ONOS/CORD%3A+Leaf-Spine+Fabric+with+Segment+Routing Anyways I’m pleased to see one of the major vendors encouraging this novel approach to DC architecture.