AARNet - Australia's Academic and Research Network#

Peter Stamp — AARNet

• Why: A clean packet-optical convergence case study — coherent 400G ZR+ pluggables plugged straight into routers, eliminating transponder shelves — plus a well-explained model-driven automation stack. Core to the PM's optics and DC/WAN interconnect interests.
• What: AARNet5 redesign: at each ROADM site, a 1RU low-power router (2–4× 400G/100G ports) uses DWDM 400G QSFP-DD ZR+ coherent pluggables configured to a specific wavelength with high launch power, multiplexed directly by the ROADM — removing most transponders (each was 1RU and ~150W; ZR+ optics draw ~25W) and retiring end-of-life SDH. Every ROADM site becomes a regional PE offering 1/10/25/100G access with L2 e-line/e-LAN and L3VPN, eliminating city hairpins (a 30km regional circuit previously hauled 300km via the metro PE) and replacing manually provisioned optical protection with inherent IP fast-reroute. Automation: Cisco NSO with YANG service models ("order forms") and multi-vendor templates driving full service lifecycle — example backbone-link service encodes LAG members, micro-BFD, ISIS-SR/OSPF-LDP selection, delay measurement, SRLGs, MTU.
• How: YANG models abstract vendor CLI; templates expand to device config via RESTCONF; hierarchical service model (Internet service → logical access circuit → device/interface) means editing the access circuit migrates the BGP neighbor, filters, and service to the new device automatically.
• Where applicable: AARNet-specific topology and scale, but the techniques are broadly adoptable: ZR+-into-router requires close optical/router team coordination (wavelength, power, dispersion) and ROADM access; the NSO service-modeling pattern is generic. Steers usefully toward Steenbergen's NANOG optical tutorial for fundamentals.