doROHN

doROHN is a conceptual framework in computer networking that seeks to unify dynamic routing decisions across optical and IP layers through a dedicated overlay control plane. The term is stylized as doROHN, with the do prefix signaling dynamic operation and ROHN standing for Routing Overlay for Heterogeneous Optical Networks. The concept emerged in scholarly discussions in the mid-2010s amid work on ROADM-based networks and software-defined networking, aiming to bridge traditional IP routing with optical layer control.

Architecturally, doROHN envisions a distributed controller cluster that interfaces with both IP routers and optical devices (such as ROADM and transponders). A northbound API accepts high-level service requests, which the overlay translates into actionable configurations on the optical layer while coordinating with the IP routing plane. The design emphasizes multi-domain scalability, rapid provisioning, and resiliency. It commonly employs standard information-exchange mechanisms such as BGP Link State (BGP-LS) for topology discovery and Path Computation Element Protocol (PCEP) for path computation, alongside open interfaces to optical control software.

Applications include large-scale data centers and service-provider backbones requiring fast reconfiguration and efficient bandwidth utilization. doROHN aims to enable near real-time restoration and dynamic bandwidth sharing across heterogeneous networks.

Critics note that the added control-plane complexity and potential vendor lock-in, along with energy overhead, can outweigh benefits in some deployments. As of today, doROHN remains primarily in academic and pilot-stage discussions, with limited real-world deployments.

See also: Software-defined networking, Optical networking, ROADM, PCEP, BGP-LS, SDN controllers.