In this paper, we describe the validation of GNPy. GNPy is an open source application that approaches optical layer according to a disaggregated paradigm, and its core engine quality-of-transmission estimator for coherent wavelength division multiplexed networks. This software versatile. It can be used prepare request proposal/request quotation, as what-if analysis on physical layer, optimize network configuration maximize channel capacity, investigate capacity performance deployed network....

Dramatic increase in data traffic, future diffusion of bandwidth-hungry 5G connectivity and evolving services like virtual reality cloud will require the implementation open elastic network paradigm on backbone optical networks. To support such growth, operators are aiming at lowering costs by deploying multi-vendor disaggregated networks supporting white boxes while maintaining target performances. make this effort successful, a vendor-agnostic assessment performance is needed, vendors...

Reconfigurable optical add/drop multiplexers (ROADMs) based on 1 X N wavelength-selective switches (WSS) are evolving to support DWDM networks with higher capacity and increased flexibility in wavelength routing. Different WSS technologies can be employed provide colorless steerable functionality for ring, or meshed architectures. Improvements specifications of modules operating the 50 GHz grid have enabled 40 Gb/s transmission rates through extensive ROADM networks. The same ROADMs also...

In this paper we discuss the nature of and requirements for data center interconnects. We then demonstrate a switch-pluggable, 4.5 W, 100 Gbit/s, silicon-photonics-based, PAM4, QSFP-28 module to transport Ethernet directly over DWDM layer 2/3 connection between switches at centers up 120 km apart, thereby eliminating need separate optical layer. The module, based on direct detect modulation format, is much reduced complexity, power, cost compared coherent systems that are currently being...

To keep pace with the tremendous bandwidth growth in cloud networking, web-scale providers, such as Microsoft, have been quick to adopt elastic features of modern optical networks. In particular, colorless flexible-grid reconfigurable add-drop multiplexers, bandwidth-variable transceivers, and ability choose a variety source types are integral for network operators improve efficiency while supporting service types. We take an in-depth look at Microsoft's deployed infrastructure discuss...

Fiber optic cables connecting data centers are an expensive but important resource for large organizations. Their importance has driven a conservative deployment approach, with redundancy and reliability baked in at multiple layers. In this work, we take more aggressive approach argue adapting the capacity of fiber links based on their signal-to-noise ratio (SNR). We investigate idea by analyzing SNR over 8,000 optical backbone period three years. show that 64% 100 Gbps IP can be augmented...

Every day, customers across the globe connect to cloud service provider servers with requests for diverse types of data, requiring instantaneous response times and seamless availability. The physical infrastructure which underpins those services is based on optics optical networks, focus this paper being Microsoft’s approach network. Maintaining a global networking meets these customer needs means Microsoft must utilize solutions are highly tailored optimized application space they address,...

ROADM systems utilizing 4- and 9-degree broadcast-and-select or route-and-select architectures are studied experimentally with 120 Gb/s DP-QPSK transmission. Effects arising from passband narrowing crosstalk accumulation due to non-ideal WSS filtering considered concurrently.

We demonstrate a 4-Tb/s metro-DCI system with commercial QSFP28 modules (40×100G dual-wavelength 56-Gb/s PAM4). detail performance over 80km and quantify tolerance to chromatic dispersion nonlinearity wide range of fiber types.

The difficulty of building large data centers in dense metro areas is pushing big cloud providers towards a different approach to scaling: multiple smaller within tens kilometers each other, comprising "region". We show that networking this small number nearby sites with other surprisingly challenging and multi-faceted problem. draw out the operational goals constraints such networks, highlight design trade-offs involved using from Microsoft Azure's regions.

100G dense wavelength-division multiplexing networks with reconfigurable optical add-drop multiplexers (ROADMs) enable dynamically and are therefore part of the solution needed to meet increasing bandwidth routing flexibility requirements for transport networks. ROADMs, in particular cascaded also incur penalties including those induced by passband narrowing, frequency drift, imperfect isolation. As migrate toward denser wavelength assignments search higher capacity, these issues will become...

Optical line-side interoperability is a critical component for enabling cloud service providers to deploy capacity at scale with diverse supply chain. Historically, vendor-locked line systems and proprietary coherent digital signal processing (DSP) technologies have been barriers this goal. Advances in open platforms interfaces embedded directly layer-2/3 switches routers begun paving the way toward full end-to-end interoperation. In paper, we take partial step demonstrating interop by...

A generalized method for estimating transmission penalties from spectrally-shaped crosstalk in cascaded multi-port WSS networks is derived, including effects of ASE, signal filtering, and filtering. The weighted value computed by multiplying the shaped interfering power spectral density primary signal. This used to predict OSNR with WSSs arbitrary port count. Theoretical treatment supported extensive numerical simulations experiments a variety network configurations. Examples are presented...

We demonstrate that the transmission BER, OSNR penalty, and system margin can be accurately predicted for multiple fiber types using back-to-back response together with Gaussian Noise model of nonlinear penalties. first experimentally quantify 1600 km link performance SMF, MDF, LAF in a coherent, WDM PDM-QPSK at both 28 32 GBaud employing all-EDFA amplification nearly identical span lengths to isolate effects. versus per-channel launch power linear regimes. total directly parameters α, D, γ,...

Fiber optic cables are the workhorses of today's Internet services. Operators spend millions dollars to purchase, lease and maintain their optical backbone, making efficiency fiber essential business. In this work, we make a case for adapting capacity links based on signal-to-noise ratio (SNR). We show two immediate benefits by analyzing SNR over 2000 in an backbone period 2.5 years. First, 80% IP can be augmented 75% or more, leading overall gain 145 Tbps large North America. Second, at...

We test the QoT-E of GNPy library fed by data from network controller against experimental measurements on mixed-fiber, Raman-amplified, multi-vendor scenarios full C-band: an excellent accuracy within 1 dB is shown.

Reliable and conservative computation of the quality transmission (QoT) transparent lightpaths (LPs) is a crucial need for software-defined control management wavelength division multiplexing optical transport. The LP QoT summarized by generalized SNR (GSNR) that can be computed estimator (QoT-E). Within context network automation, QoT-E must rely only on data from controller or provided elements through common protocols structures. Therefore, given theoretical accuracy QoT-E, in-field in...

We present GNPy: an open source software abstracting the physical layer of optical network. GNPy has been developed by simulation environment (PSE) team in telecom infra project (TIP) consortium. experimentally demonstrate accuracy tool predicting quality transmission (QoT) a network, and then we how can be used to address upgrades this lead large benefits

DWDM transmission with flexible-bandwidth ROADM supporting 25GHz-spaced 10G channels and co-propagating 50GHz-spaced 40G is studied experimentally. Nonlinear ROADM-induced OSNR penalties are measured, XPM mitigation demonstrated.

We demonstrate a method of quantifying the penalty in-band crosstalk that accounts for varying spectral content. Experimentally evaluated penalties widely content are shown to be readily predetermined based on and power within single 112 Gb/s polarization-division multiplexing quadrature phase-shift keying (PDM-QPSK) link. Optical signal-to-noise ratio (OSNR) predicted using weighted correlated with experimental results 1 dB 8 spans AllWave [standard single-mode fiber (SSMF)] or TrueWave...

Recent developments in WSS technologies enable ROADM architectures with increased wavelength routing flexibility and efficient bandwidth allocation for future capacity growth. ROADM-induced transmission impairments, mitigation strategies, benefits of next-generation ROADMs are presented.

Tolerance to cascaded WSS filtering is studied for QPSK, 8QAM, and 16QAM formats operating at 32 GBaud. Channel spacing, filter shape, DSP parameters are considered, recommendations made performance optimization using methods which practically implementable in modern hardware.

We discuss the key metrics of analog coherent interfaces for today's 200G 16QAM and future 400-600G 64QAM pluggable systems. A cloud service provider perspective on next generation DCI requirements is also discussed.

Transmission penalties of ROADM isolation functions in high capacity systems are quantified using a weighted crosstalk. Excellent correlation between the crosstalk and OSNR penalty 40G DPSK is found diverse scenarios.

Data center interconnect (DCI) links with high data-rate direct-detection require strict chromatic dispersion compensation. One such solution which has been widely deployed is based on four-level pulse amplitude modulation (PAM4). With this application in mind, we describe detail a 50-GHz channelized fiber Bragg grating (FBG) tunable compensation module (TDCM) can compensate slope over the full C-band (4.8 THz) and thus suitable for dense wavelength division multiplexing (DWDM) PAM4 DCI...