---
title: "IP-Optical Integration and Disaggregation: What's Real in 2026"
slug: "ip-optical-integration-disaggregation"
type: opinion
category: "Network Architecture"
tags: [disaggregation, open-line-system, ROADM, OpenConfig, ONOS, IP-optical, coherent]
seo_focus_keyword: "IP optical disaggregation open line system"
---

The disaggregation narrative in optical networking has been running for about a decade. The pitch is straightforward: separate the ROADM hardware from the amplifiers, separate the amplifiers from the coherent transponders, use open APIs to control everything, and stop being locked into single-vendor end-to-end optical systems. The reality in 2026 is more nuanced than either the enthusiasts or the skeptics claim.

## What Disaggregation Actually Means

Traditional optical networking sells you a complete system: ROADM nodes from one vendor, with that vendor's coherent transponder cards inside, managed by that vendor's NMS, with amplifier modules designed specifically for that chassis. Ciena's WaveLogic, Nokia's PSI, Infinera's ICE — all traditionally vertically integrated stacks.

Disaggregation separates these components. An "open line system" (OLS) provides the ROADM function — wavelength switching, amplification, and optical performance monitoring — from one vendor (or a white-box OLS vendor), while the coherent transponders come from a different vendor or sit in an IP router as pluggable ZR/ZR+ modules. The control plane — allocating wavelengths, configuring gain, monitoring OSNR — runs on a separate controller using open APIs.

The practical driver for operators: coherent transceiver technology has advanced to where pluggable modules like 400G ZR (OpenZR+ standard) deliver acceptable performance for many use cases, particularly metro and regional DCI. Operators can buy QSFP-DD 400ZR modules from multiple vendors (Acacia/Cisco, Lumentum, Viavi, Flexoptix) and insert them into routers, eliminating the separate transponder shelf. The "open line system" then becomes the common infrastructure that all those pluggables share.

## Where OpenConfig Actually Runs

OpenConfig has become the primary data model for IP-optical control. The OpenConfig optical transport model covers the channel (OCH), optical media channel, and amplifier configuration. Vendors including Ciena, Nokia, Infinera, Fujitsu, and Lumentum all publish OpenConfig YANG model support for their optical equipment, which theoretically means a controller can configure any of them using the same data model.

"Theoretically" carries significant weight here. OpenConfig model coverage is vendor-specific. One vendor may implement 80% of the optical amplifier model and leave gain tilt configuration as a proprietary extension. Another may implement the full model but with subtly different semantics for target power versus actual power reporting. The test of real interoperability is not whether the YANG is there but whether you can actually manage a multi-vendor optical layer from a single controller without platform-specific workarounds.

ONOS (Open Network Operating System) from the Open Networking Foundation has an optical south-bound layer that supports OpenConfig and NETCONF. Organizations like AT&T, NTT, and several European operators have deployed ONOS-controlled optical networks in production, with the important caveat that those deployments typically involve one or two vendor platforms, not arbitrary multi-vendor mixing.

The IETF Transport API (TAPI) provides a higher-level abstraction for topology and service provisioning on top of the device-level OpenConfig models. TAPI is where real multi-vendor automation lives, and it's where the most active standards development is happening. Operatr and similar open-source tooling has made TAPI more accessible for operators building northbound OSS integration.

## The Proprietary Wall That Still Holds

Despite a decade of disaggregation progress, several areas remain proprietary or de-facto single-vendor in 2026.

Optical performance monitoring at the level needed for margin prediction is still mostly proprietary. Measuring OSNR, CD (chromatic dispersion), PMD (polarization mode dispersion), and Q-factor across a multi-span optical link requires access to DSP internals of the coherent transceiver. OpenZR+ defines a management interface but the actual impairment measurement detail varies by vendor DSP implementation. If you're building an automated margin-based routing system, you're relying on vendor-specific telemetry in most cases.

FEC performance monitoring data is partially standardized (the G.709 OTN management model covers some of it) but the per-vendor FEC algorithm performance curves are not public. A link that's "above threshold" per the open API may have 3 dB of actual margin or 0.1 dB, depending on which vendor's DSP is in the transponder. This makes cross-vendor OSNR margin comparisons difficult in automated systems.

Amplifier gain tilt optimization — adjusting gain profiles across the C-band to equalize power across WDM channels — is handled differently by every amplifier vendor. OpenConfig has models for this, but the closed-loop algorithms that actually flatten the spectrum are proprietary and vendor-specific. You can read and set target values via OpenConfig, but the adaptive behavior that achieves those targets is in proprietary firmware.

## The Case for Open Line Systems

Despite the limitations, open line systems make genuine economic sense in specific deployment patterns.

For metro and regional DCI (distances under 400 km), the 400G ZR pluggable in a router eliminates the transponder shelf entirely. The "open line system" provides the optical amplification and switching that the ZR module needs, but the ZR module itself is now a commodity item available from multiple vendors. The economics are compelling: a QSFP-DD 400ZR module from a compatible vendor costs roughly $3,000–5,000; a comparable proprietary transponder card is $15,000–25,000. The OLS amplifier cost is similar either way. Multiplied across a 40-wavelength metro network, the savings justify the integration effort.

For operators with multi-vendor transport networks — which includes most tier-1 operators running networks acquired through mergers — a common control plane via OpenConfig/TAPI provides operational benefits even if it doesn't achieve full technical interoperability. Being able to view all optical network elements in one NMS topology regardless of vendor reduces MTTR significantly.

For research and education networks (R&E networks), where operational complexity tolerance is higher and wavelength counts are modest, full disaggregation has been successfully implemented. GÉANT, Internet2, and several national R&E networks run disaggregated optical with multi-vendor hardware. These deployments are valid proof points, but they also have teams that tolerate a level of platform-specific tuning that most commercial operators don't.

## The Honest Summary

Open line systems are real, deployed at scale by tier-1 operators, and continue to grow as a percentage of new optical deployments. The economics of 400G ZR pluggables versus proprietary transponders are compelling enough that the adoption curve has accelerated past the "early adopter" phase.

The proprietary wall hasn't fallen — it's moved. Vertical integration still exists at the amplifier and monitoring level. OpenConfig gets you to 70–80% of what you need for automated optical control. The last 20–30% — adaptive margin management, optimal gain tilt, per-channel impairment prediction — still requires either vendor-specific tools or a team willing to build the integration layer themselves.

The honest recommendation for operators evaluating disaggregation in 2026: build your business case around the ZR/ZR+ pluggable economics, which are solidly favorable. Plan for proprietary integration requirements at the amplifier management level, and evaluate whether your operational team has the capacity to manage multi-vendor optical layer complexity versus the cost savings from avoiding vertical integration lock-in.
