By Zeus Kerravala, founder and principal analyst of ZK Research
Network modernization, software-defined networking, and virtualization have had a profound impact on network infrastructure. However, the one network device that has managed to stand tall and buck that trend is the router. Switches operate locally, so taking a high-priced switch out of a branch and replacing it with something a little lower-cost is straightforward as the operations there do not impact anything else. Even in the data center, enterprise IT organizations can experiment with white boxes running a software operating system to keep the environment contained.
Unlike switches, routers operate as a fabric, with each router continuously communicating to every other router. Therefore, despite numerous attempts to get network engineers to consider replacing their routers, they have stood tall and strong in the face of evolution. SD-WANs have been game-changing on several fronts, most notably enabling enterprises to take advantage of low-cost broadband in favor of high-cost, private MPLS circuits. As companies get more comfortable with SD-WANs, it appears it’s having influence in another way and that’s finally getting network professionals to question whether the branch router is needed or not.
I have always remained skeptical of this because, despite the logic and the strong vendor marketing in this area, network engineers have resisted this and seem to have an enduring love affair with their routers. Over this past year though — more than at any other time in all my years as an industry analyst — I’ve had more inquiries from enterprises that are beginning to question their router dependence.
What network pros are finally starting to realize and appreciate is that elimination of the physical router doesn’t eliminate their ability to route application traffic across the WAN. Also, the rise of SD-WANs has introduced Ethernet, cable, and other network connectivity types that offer Ethernet handoffs for connectivity, thereby obviating the need for T1, E1, or other WAN specific connectivity types.
Another reason network engineers have explained to me for considering not refreshing the router is a simple one — cost. Despite technology evolution, routers have maintained a price premium. The cost of routers can range from a few thousand dollars to over ten thousand for high-end, multi-function routers. Finding a way to do this with low-cost network hardware can save large enterprises hundreds of thousands of dollars on an annualized basis.
An SD-WAN offers a compelling alternative to deploying physical, high-priced routers at every branch location. The benefits span:
- Routing on another platform. There are many network devices in a branch that could provide routing interoperability. These include WAN optimizers, firewalls or SD-WAN appliances, both physical and virtual. Modern appliances deliver enough processing capacity and memory to fully support basic routing capabilities.
- Routing in the cloud. Most SD-WAN solutions are backhauled to a cloud service. The routing decisions could be done in the cloud instead of at each local branch. If there is no need for complex routing schemes this is an excellent option.
- Routing as a virtual network function. Network Function Virtualization (NFV) has come a long way over the past few years. This enables router software to run in a virtual partition on a commodity server or other device. The difference between this and the first benefit above is that when routing is natively integrated on another device, it is typically a “light version” of the feature and supports basic functions. Software designed to run as a virtual function can often be fully-featured, making it indiscernible from a traditional physical device. This is typically the best option for distributed enterprises with advanced WAN requirements. It’s important to note that many other network services can also leverage NFV including VPNs, WAN optimization and other services.
I understand and appreciate that routers have been a staple in branch offices for decades now, but technology evolution means things change. If you’re in a position where your router needs refreshing, you owe it to yourself to seriously consider replacing the router with another form of routing.