Cisco Nexus data-center switches promise 800Gb Ethernet but deliver 400GbE today

Cisco is prepping its high-end data-center Nexus switch family for high-speed Ethernet  that will better support high-bandwidth applications such as AI and cloud-native.  

The vendor rolled out five new Nexus data-center switches that include improved support for 100/400Gb Ethernet networks, but its flagship box—the 9800—now includes a migration path to support 800GbE requirements.

The new modular data-center switch product family with 14.4Tb/s fully encrypted bandwidth per slot. The Cisco Nexus 9800 Series features eight-slot and four-slot chassis that can scale from 57Tb/s to 115Tb/s with a combination of various first-generation line cards and fabric modules. Each line card slot can support 400GbE or 100GbE or 10/25/50GbE ports. The eight-slot option could support up to 288 400GbE ports, well above the current 9000’s 32-port capacity.

According to Cisco, the 9800 series features switch line cards and fabric modules built with a power-efficient, high-performance, and high-capacity ASIC that supports load balancing, fully shared packet buffer, and line-rate performance for small packets. It is optimized to support high-bandwidth applications across data centers regardless of size.

The chassis design lays the foundation to support higher capacity ASICs and higher power optics—such as 800GbE—in the future, Cisco said.

The need for increased data-center bandwidth is clear as “microservices architecture is clearly the preferred model for app development today, which has created a diversity of workload deployment models including on-prem, virtual machines, containers, bare metal, serverless, etc.,” wrote Thomas Scheibe, vice president of product management with Cisco’s Cloud Networking group in a blog about the new switches.

“In turn, this explosion of workloads has created more traffic within and among data centers and clouds than ever and, as always, it is the role of the network to serve as the ‘freeway’ and the backplane,”  Scheibe stated.

He said that this creates a bandwidth need that 400GbE helps to fill, and as a result there is an expected 224-fold increase in demand for it (from 2018) by 2026, while 800G technology will see an 84-fold uptick, Scheibe stated, citing the Dell’Oro Group, .

Recently, the Dell’Oro Group reported that 400GbE shipmants more than doubled, exceeding two million ports in 2021. And 400G deployments started to expand beyond just the hyperscalers, reaching smaller cloud service providers and large enterprises, acording to Dell’Oro.

Ethernet has evolved from 10Mb/s to 400Gb/s and will go to 800Gb/s or possibly 1Tb/s by about 2030, according to the Ethernet Alliance’s Ethernet roadmap.

New Nexus switches

The other new Cisco Nexus switches include the 9400 and the 9300 series. The 4U 9400 supports up to 64 ports of 400Gb/s line-rate performance or up to 128 ports of 100/200Gb/s performance. Use cases include compact spine designs and efficient multi-plane scale-out fabric designs enabling gradual transition from 100GbE to 200GbE to 400GbE links, Scheibe stated.

The 9300 series features three fixed-rate boxes. The Nexus 2U 9364D  supports 64 ports of  400GbE. The Nexus 9348D is a 2RU 48-port 400GbE switch supporting line rate 400Gb/s encryption on all ports. The 9332D is a 1U box capable of supporting 32 400GbE ports.

These switches support both leaf and spine roles in fabric designs, and their line-rate encryption supports a range of multi-layer security architectures, Scheibe stated. The idea is to give customers the ability to run data-intensive applications including AI/ML, storage over IP, rich media, and advanced analytics/telemetry processing, he stated.

The Nexus 9332D is shipping now. The Nexus 9348D and Nexus 9364D will be available this month. The Nexus 9800 will be available in July, and the Nexus 9400 in Q4 2022.