by Trishan de Lanerolle, Linux Foundation

Retail reimagined: DENT open switch network platform paves the way for better experiences

Dec 17, 2020
Edge ComputingNetworkingRetail Industry

Combined with commercial off-the-shelf hardware, the open source NOS could drastically slash the cost of networks

mobile shopping personalization / personal data
Credit: ipopba / Getty Images

Retail is being reimagined on the fly to safeguard shoppers during Covid-19 and to keep pace with the convenience of shopping online. One of the most compelling new opportunities enables customers to simply pick up what they want and leave without having to wait in line or deal with the checkout process.

While seemingly the stuff of science fiction, the technology has already been rolled out in several cities. But a key component of enabling shoppers to grab and go is the network. Given the number of IP cameras and sensors and other IP components needed to determine what people leave with, the network needs to be scaled dramatically and the cost can pull the rug out from under the business case even before the idea gets off the drawing board.

That’s where DENT comes in. DENT is an open source NOS that can be used with commercial off-the-shelf hardware to drastically slash the cost of networks and pave the way for this next great shift in the retail user experience.

While initially targeted at the network edge in retail, where this technology is expected to rapidly expand from a nice to have to a competitive necessity, DENT will benefit any campus edge use case, especially those with vast WiFi requirements. And Phase II of the Linux Foundation project will see the project scope expand to address small enterprise data center needs.

The next frontier

The pandemic, of course, has been the mother of invention, with retailers scrambling to safeguard customers. Convenience store giant 7-Eleven, for example, recently rolled out online ordering and delivery and a mobile checkout feature that enables customers to use a mobile app to scan and pay for items and skip the checkout lane.

As it happens, Amazon was ahead of the curve with its Amazon Go convenience stores that use homegrown technology it calls Just Walk Out to let shoppers skip the scanning process. You badge in with an app on your phone and a network of cameras and sensors determine what you put in your basket and charges your account accordingly after you leave.

Although this nascent technology – now being pursued by a host of other retailers and technology players such as Grabango and AiFi – has obvious benefits during Covid-19, the appeal will outlast the virus.  After all, anything you can do to improve the customer experience will engender loyalty.

An executive at a major US retailer says of the emerging technology: “This capability is not going to be a competitive advantage. It is going to be a competitive necessity. If you’re a retailer that wants to be around in five years, you’re going to have to do something along these lines.”

While grab and go might be the straw that breaks the back of legacy networks, there are a host of other emerging retail technologies, such as electronic shelf labels, that are adding load.  Best Buy, for example, has deployed smart labels in a number of stores. The electronic labels enable Best Buy to synchronize pricing across online and brick and mortar locations, saves staff from having to do manual price changes, and makes it possible to dynamically price items based on supply and demand. The label system adds thousands of network endpoints to each store.

The big “but …”

Retailers that want to enable customers to just walk out will have to install some heavy-duty technology to figure out who is associated with what account, what they select (picking up items, returning them, selecting another, etc.), and distinguishing between like-sized items. A large retail store will require many cameras and many more different kinds of sensors, including weight, motion, trajectory, adjacency and other types.

The network needs to scale exponentially, and if you have to pay list price for network gear – say $5,000-$6,000 for a 48-port gigabit switch – the business case for grab-and-go evaporates.

DENT on white box hardware changes the cost calculus.

Because retailers can’t afford to add data centers in each location, the goal with DENT is this: lots of ports, low cost, low power consumption and low maintenance. All summed up, a 48-port gigabit switch powered by DENT on white box hardware can be had for $700 or less.

The DENT network edge switch profile distinguishes it from other open source switch efforts, most of which are designed for data centers or the cloud, including: the Linux Foundation’s Disaggregated Network Operating System (DANOS) project, SONiC in the Open Compute Project, Stratum in the Open Network Foundation, and the Facebook Open Switching System (FBOSS).

Because DENT is native Linux, it has better integration with the switching capabilities of the Linux kernel and uses the built-in switchdev Ethernet drivers so you don’t need to add additional software in the user space to accommodate different types of NICs. You can put your control management on top, and the I/O will be handled at the kernel level.

Unlike commercial switches that use proprietary hardware to make the switch ASIC function, DENT treats the ASIC in a white box like any other PCI-attached device, meaning you can get the performance of a proprietary switch without the cost and the vendor lock in.

Retail industry roots

DENT is a collaborative Linux Foundation network project based on contributions from premier members Amazon, Marvell, Nvidia’s Mellanox and Cumulus, Delta Electronics, and Winstron NeWeb. Other participants include Arcadyan, Innovium, Edgecore and Open Verification Lab.

In terms of momentum, DENT has an open technical steering committee that meets publicly, the source code released in December 2020, the effort is backed by a proper charter, has solid governance as part of the Linux Foundation, and is close to being demonstrated in production.

While the initial use case is the retail network edge, DENT infrastructure will be appropriate for any campus edge where the priority is a lightweight NOS for low cost infrastructure, not a feature rich NOS such as Sonic.  DENT will be iteratively built out by the community as its scope increases and, in Phase II, will be expanded to support simple data center use cases by enhancing support for capabilities such as VXLAN, IPv6, NAT, PPPOE, etc.

In all cases the value remains the same: DENT will provide enterprise shops a low cost, open, comparable performance alternative to proprietary switches that lock you into a limited ecosystem with painful upgrade cycles and strict license requirements.

Once you realize there are only about $300 worth of parts in a switch it gets hard to write those $5,000-$6,000 checks for a proprietary box that comes with a host of limitations. Linux helped the industry break the cycle with servers, and the time is now for the same revolution on the network side.

To learn more about DENT and engage with the Linux Foundation’s DENT community, visit  

Trishan de Lanerolle is Technical Program Manager & Community Architect, Networking at The Linux Foundation