By Lisa Crewe | Posted on April 5, 2021
Increased bandwidth demands are requiring carriers to build more flexible networks that can adapt and grow as needed. They also need standardization to ensure multiple sources of supply and provide options for higher performance implementations. 400G coherent pluggable modules enable them to meet those requirements, while also being scalable and easy to maintain for the long term.
At a fraction of the size of comparable network electronics currently in use, these multi-MSA (Multi-Source Agreement) compliant pluggables allow for deployment models and cost savings that were not feasible with previous generations of long-reach optics.
According to ACG Research paper, The Economic Benefits of IP Transport at 400G, 400G IP transport networks will be more operationally cost effective than typical router bypass networks. In addition, IP transport networks have 46% TCO savings, 57% OPEX savings, and 35% CAPEX savings over router bypass networks because of increased router capacity, lower price per Gbps and significant reductions in OPEX by simplifying the optical layer.
400G Pluggables – Not Just for DCI Anymore
While the first 400G pluggable application was 400ZR targeting point-to-point data center interconnect (DCI) primarily for hyperscalers, carriers are now seeing the benefits in other applications including metro/regional and long-haul. For example, some carriers might have data centers to offer as a service to enterprise customers or to host their own content (e.g., entertainment). Others may want to build an infrastructure to offer wholesale pipes as a service to large bandwidth customers such as hyperscalers.
Windstream Wholesale Sets Two Industry Records
Windstream Wholesale announced last month that it had completed a live network trial that successfully deployed 400G single-wavelength transmission over 1,027 kilometers. The trial, which was deployed on Windstream’s long-haul network between Phoenix and Los Angeles, set an industry-leading real-world benchmark of 400G using Acacia Communications’ digital coherent optics technology. Also, during these trials, Windstream set another industry record by looping back the signal to achieve 300G transmission over 2,054 kilometers.
The optical performance results of the Windstream trial marked a milestone in optical networking by demonstrating that pluggable modules can be used for regional and long-haul reaches.
Windstream Wholesale said that it expects to begin deploying ZR+ coherent pluggable modules in the second half of 2021, and claims the technology has applicability in as many as 80% of its existing links.
Telia Carrier Simplifies its Network with 400G Pluggables
In December 2020, Telia Carrier announced that it was preparing to converge their IP and optical networking layers to simplify their networks. In preparation for this new solution, Telia Carrier claimed it had already deployed open line systems and terminal equipment that could support new 400G pluggable technology.
As an early adopter of this new architecture, Telia Carrier is one of the first network operators to perform full end-to-end validation of the solution. The testing leveraged Acacia’s 400G QSFP-DD coherent modules with OIF 400ZR and OpenZR+ operating modes, enabling Telia to support data rates from 100G to 400G depending on the desired reach. The modules also support client n x 100GbE multiplexing functionality as well as 400GbE transport.
Moving to 400G coherent optical transceiver modules enables Telia Carrier to migrate to a more converged network architecture capable of enabling OpEx and CapEx savings, as well as a pay as you grow business model.
Interoperability with Multi-MSA Compliance
Standardization of optical networking technology helps carriers by providing simplicity, interoperability and volume-driven cost. In the 400G pluggable market, standardization started with 400ZR and quickly evolved as carriers demanded higher performance. This led to the creation of both the Open ROADM and OpenZR+ MSAs.
Open ROADM MSA – The Open ROADM MSA defines interoperability specifications for Reconfigurable Optical Add/Drop Multiplexers (ROADM) networks. Included are the ROADM switch as well as transponders and pluggable optics. Specifications consist of both Optical interoperability as well as YANG data models. The Open ROADM MSA defines a framing approach that supports line rates of 200G, 300G or 400G, greater host interface flexibility and supports a high performance soft-decision FEC, called openFEC, which offers higher coding gain more comparable to proprietary implementations typically used in long-haul applications.
OpenZR+ MSA – OpenZR+ modules maintain the simpler ethernet-only host interface of 400ZR, and add support for multi-rate Ethernet and multiplexing capabilities at 100G, 200G, 300G or 400G line interfaces. OpenZR+ modules enable reaches beyond 400ZR with higher dispersion tolerance and higher coding gain using openFEC, which has been selected for standardization by the OpenROADM MSA and CableLabs. These enhanced modes allow an OpenZR+ module in a QSFP-DD or OSFP form factor to support a wide range of ethernet applications.
Higher Performance and Longer Distances
It’s exciting to see Windstream and Telia investing in plans to deploy 400G for metro/regional and long-haul applications to leverage the pay as you grow and operational benefits that 400G pluggable coherent optics has to offer.
Watch this video to learn more about Acacia’s 400G pluggable portfolio supporting 400ZR, OpenZR+ MSA, and Open ROADM MSA in QSFP-DD, OSFP and CFP2-DCO pluggable form factors. Please contact us if you’d like to discuss 400G solutions for your network.