This is the end of the network as we know it, and we feel fine#

Aleksandr Kurbatov, Karel van Klink (GÉANT)

• Why: GÉANT has finished migrating its backbone packet layer to a new equipment vendor — and the interesting part is that the orchestration stack (the GÉANT Service Orchestrator, grown out of the Workflow Orchestrator programme) is what made a vendor swap of a pan-European backbone tractable. For anyone building network automation, the hard-won modeling decisions here transfer directly.
• What: A migration retrospective plus the orchestration model it enabled. The core of the presentation (per the slides) is how GÉANT models commercial peers: each peer is a single entity (ASN, prefix limit) that can hold multiple connections to different placement port types — IX port, private peering port, or transit port — explicitly avoiding a data-duplication anti-pattern. The same operator workflow produces different router configurations (communities, policies, BGP groups, prefix-limit handling) depending only on which port type the connection targets.
• How: A layered model in the orchestrator where connection Type is derived automatically from the target placement port; Ansible extracts the type, pulls the correct variables, and translates the orchestrator abstraction (one Peering Connection grouping IPv4+IPv6) into two independent BGP neighbor statements on the router. Per-connection Session States (Provisioning → Active → Disabled) act as predefined configuration shortcuts — e.g. Provisioning establishes BGP without route exchange, Disabled keeps all config in place but shuts down the neighbors. "One update, one workflow" propagates a peer change (e.g. prefix limit) across all of that peer's connections while leaving co-located peers untouched.
• Where applicable: GÉANT-specific backbone and orchestrator, but the patterns — model per organization not per port, port-type-derived config, session-state shortcuts, safe scoped deletion in multi-peer environments — are broadly applicable to any operator automating multi-site peering across IX, private, and transit contexts.