There has been a lot of talk lately around white-box switching and the associated concept of network switching “disaggregation”. While understood by cloud service providers and/or operators of really large networks, the term “disaggregation” is not widely recognized in the mainstream.
What is it?
The easiest way to explain it is by example: In the server world, you buy a physical server and select the OS separately; organizations can use server hardware from HP, IBM, Dell, Cisco, etc. and run software/OS from Microsoft, Linux, etc. This is the way it has been for a while in the server world. However, in the networking world, if you buy a switch from Cisco, you run Cisco’s switching OS (IOS, NX-OS etc.), with HP you run Comware, and with Juniper you run JUNOS etc. The OS and hardware have been integrated (i.e., aggregated), unlike the server world in which they are separate (disaggregated). Another common misconception is that disaggregation (and white-box switching) is synonymous with SDN – it is not. While they can complement each other, they are different. Disaggregation decouples hardware/software on an individual network element. SDN decouples hardware/software for the network as a whole.
Who are the key players?
As of the last year or two, you can now buy physical switches from one vendor and then install a network switching OS from a separate vendor, which is a pretty dramatic paradigm shift in networking.
- From a software perspective, you can now get your network switching OS from companies like Cumulus Networks, Big Switch, and Pica8 (and is usually Linux-based).
- From a hardware perspective, you can buy switches from the ODM vendors (like Quanta, Accton, Foxconn, etc.) and even a few select Dell Top-of-Rack switches (see Dell and Cumulus Networks Aim to Take ‘BYO Switching’ Mainstream).
Given the opportunity to disrupt the market, I would anticipate other vendors considering this model, so where does it go from here? Does Dell sign on other switching OS vendors like Big Switch and Pica8? Or do other mainstream network vendors like Cisco, HP, Juniper, Extreme, Arista that utilize merchant silicon to some extent in their portfolio sign on Cumulus? Arista has even blogged about disaggregation here. Or maybe the mainstream network vendors decide to let customers run their software on top of merchant switches (NX-OS on Quanta anyone?) – I’ve had several clients specifically state a desire for this. It will be interesting to see where and how this pans out….
Just because we can doesn’t mean we should….
This often leads to the question of Why would I want to do this. In other words, what benefit is there given that I’ve now taken responsibility to glue together the hardware and software? Indeed, this is a radical change, breaks long-standing networking constants and upon a cursory glance would seemingly complicate support (do I call the hardware company or the software company when something breaks?). So, why would anyone do this, given it is such a radical change? Well, there are several benefits including:
- reduced vendor lockin (I can now make hardware/software decisions independently and change out one or the other)
- reduced software/maintenance costs
- simplified management (usage of Linux-tools)
- potential for improved availability (which we wrote about here: It’s Time to Rethink Your Data Center Network Software)
In closing, adoption is still very limited, mostly to cloud and network service providers but this approach is pretty darn “cool”…