Segment Routing policies are constrained by the Maximum SID Depth (MSD) that a router can impose on an outgoing packet. In large or multi-domain networks, the number of SIDs required to express an end-to-end path can exceed the MSD capability of the headend, making it impossible to impose the full Segment List without assistance. Binding SIDs (BSIDs) address this by allowing an intermediate anchor node to impose the remaining segment stack, effectively hiding path complexity beyond the anchor from the headend. To demonstrate automatic MSD handling, we configured an MSD of two across several runs, a value well below typical production deployments. The Nokia Network Services Platform (NSP) controller learned the per-node MSDs via BGP-LS Node MSD TLV, computed candidate paths, and, where the computed SID list exceeded the MSD limit, inserted a BSID at an intermediate anchor node. The anchor node imposed the remaining segment stack toward the destination, allowing the headend to impose only two SIDs.
Nokia Network Services Platform (NSP) acted as the controller in all test runs. The headend and anchor roles varied across runs:

• Cisco 8201-24H8FH as headend, Arista 7280R3 as BSID anchor
• Nokia 7750 SR-1 as headend, Arista 7280R3 as BSID anchor
• HPE MX204 as headend, Nokia 7750 SR-1 as BSID anchor

Other Nokia, Cisco, HPE, and Arista routers appeared as transit nodes, depending on the scenario.
After each simulated link failure, the controller detected the change, recomputed an MSD-compliant path, generated a new BSID at the current anchor, re-advertised the updated SR Policy, and headends installed the new segment list. This automatic re-optimization and BSID-based stack reduction is especially useful at domain borders, where gateway routers act as BSID anchors.