Migrating the GÉANT Network to a new vendor#

Simone Spinelli · GÉANT (per talk content)

• Why: A two-year, zero-major-disruption Juniper → Nokia migration of a pan-European IP/MPLS WAN at 800G — physical backbone and interconnection work at continental scale, exactly this PM's core.
• What: GÉANT (31 PoPs, 44 nodes, >1,000 services: BGP-based L3, L2 circuits, directly attached servers) migrated to Nokia 7750-SR (SR-OS, not SR-Linux) between June 2024 and February 2026, while simultaneously building the in-house GÉANT Automation Platform (GAP) on open-source Workflow Orchestrator and Ansible.
• How: Top-down modeling: every config line exists because it belongs to the node or to a service; one network construct = one Ansible role, with lifecycle management embedded. Peering is modeled org-centrically with lifecycle states (provisioned/active/disabled), covering IX peering, private peering, and upstreams. Concrete migration example: moving an IX port where GAP finds all peers, Moodi starts monitoring, Ansible generates config, operator confirms — AMS-IX with ~120 peers took 30 minutes.
• Where applicable: GÉANT/NREN scale, but WFO is a genuinely open, joinable community (SURF, ESnet as partners; public money, public code). The "design as the primary source of truth" and per-construct role patterns transfer to any multi-vendor WAN.