SDN Switches - Black, White and the Gray

Marcus Luttrell, a former US Navy SEAL once said "War is not black and white; it's gray. If you don't fight in the gray area, you're going to lose". Well, the hardware equipment vendors have realized, that in the era of SDN, if they don't fight in the gray area, they are going to lose. Several small startups and open source communities waged the SDN war on traditional equipment vendors, by fighting their proprietary black box switches with the white box switch. The equipment vendors retaliated back, by introducing gray box switches. 

(Also read: SDN white box switch vendors in the market)

If you are confused about the differences between the black and the white and the gray box switches, this article will rescue you. Equipment vendors are inventing new terminologies to keep them afloat - so that, they can continue to sell hardware equipment to enterprises, data centers and service providers. You can't blame them, as hardware is where they make money. 

Now, let us cut to the chase.

Black Box Switches

Black Box switches are the legacy network switches. Both the hardware and software running on those switches were developed by the same vendor. Black Box switches are typically propriety network equipment, using proprietary hardware and proprietary software. Customers using the Black Box switches cannot write their own applications. They've to go to the device vendor to get any customizations - involving long lead time and huge costs. You can compare this to the good old days where HP, IBM and Sun sold their Unix operating systems bundled with their proprietary hardware. Today, almost every network equipment vendor claims support for open APIs and SDN protocols in their black box switches. Black box switches are costly and customers get locked-into proprietary hardware and software. 

White Box Switches

One of the goals of SDN is to challenge the proprietary Black Box switches in the market. Thus came the White Box switches. White Box switches are typically SDN enabled switches. One of the major differences between the white box and black box switches is the decoupling of the software from the hardware. Customers would have an option of picking the software (network operating system / applications) of their choice and run it on a hardware of their choice. On top of it, White Box switches can be managed using open APIs or SDN protocols such as OpenFlow or OpenConfig. You can compare this to Microsoft Windows operating system running in Dell, HP or IBM hardware. There is no tight coupling between the hardware and software - however, they interoperate with each other. White Box switches are ideal for data center deployments, where reliability is achieved by flexibly moving the workload to a different server, rack or even datacenter. White Box switches are typically low cost and do not meet the service providers' "carrier grade" requirements. 

(Also read: SDN white box switch vendors in the market)

Gray Box Switches

In most cases, the white box switches came from vendors such as Advantech, Accton, Dell and HP. This posed a huge threat to the traditional network equipment vendors such as Juniper and Cisco. So, they started re-incarnating their traditional offerings and branded them as "open solutions". For example, they decoupled their network software from hardware and started licensing them to customers. They also invented a new breed of offering called the gray box switch. The gray box switch allows you to not only run the proprietary vendor software, but also allows you to run other vendors' software. Juniper's NFX250 Network Services Platform is a good example of the gray box. NFX250 is a Universal Customer Premise Equipment (CPE) platform that allows customers to run  other vendors' Virtual Network Functions (VNFs) in addition to supporting Juniper's VNFs. SD-WAN like use-cases require enterprise customers to run multiple VNFs on the edge to support services such as routing, firewall and WAN optimization.  Gray box switches serve as an ideal platform for running such applications. Gray box switches are "carrier grade" and they meet the service provider's reliability requirements. Hence, they are costlier than the whitebox switches.

So, which one of these network equipment is the best for your use? Actually, that depends on your use case, budget and reliability requirements.