When Operations Drive Architecture-- A Missive on EVPN
Apr 30, 2019
Despite all of the recent talk of automation, it’s hard to argue that operations is little more than an afterthought for most enterprise networks. It’s not that operations aren’t important. It’s just something that needs to be figured out after the architecture has been determined.
At least, that’s the way it used to be. But that’s changing, and in a huge way. Why?
Enterprise IT as a Provider of Services
There is far too much baggage with the term “service provider”, so for the purposes of this blog, I will use the more difficult term “provider of services.” Enterprise IT has been on a steady march from largely an enabler of the business to a provider of services. As technology moves from a supporting function to an integral part of the offering, IT moves from an entity that people complain about to part of the product supply chain. And enterprises treat their supply chains differently.
The supply chain has to be efficient; when it’s not, costs soar, margins shrink and profits dwindle. The supply chain also has to be reliable; when it fails, the production line grinds to a halt. And the supply chain has to be repeatable; it’s not about building one product for one customer—it’s about building a pipeline of products for a market.
Manufacturing operations are a science. And as IT joins the mainstream and becomes a more traditional manufacturing process, it should come as no surprise that operations are following a similar track. And the end result is to make IT a more efficient provider of the very services needed to develop and ship technology products.
Learning from Traditional Service Providers
As enterprises become providers of services, they can learn from service providers who preceded them and have been operating this way for decades.
Service providers elevated operations long ago. Operational expenses, not capital outlay for equipment, dominates service provider economics. When your customer base is expansive and has a myriad of needs, the underlying infrastructure naturally becomes more diverse. The key to service provider economics is managing this diverse infrastructure with a uniform operating model.
Building blocks that abstract the lower layers of the service deliver the common operational platforms on top of which the business can be built. They are critical components of any would-be solution.
Operational Uniformity in the Data Center
In many ways, enterprises have it worse than service providers. At least service providers have control over the product they offer, whereas enterprises must answer to lines of business that have traditionally been the power brokers in enterprise IT. This makes it virtually impossible to remove things, forcing enterprises to drive toward the “new” while simultaneously supporting the old.
How do you create operational uniformity when you are forced to keep decades-old technology alive? For these cases, there needs to be a bridging technology capable of supporting the old while enabling the new. In the language of enterprise data center networking, it’s about providing secure connectivity for Layer 2 applications while building an infrastructure that can efficiently handle Layer 3 applications.
EVPN as a Bridge
EVPN is that bridge between the old and the new.
Originally developed for service providers, EVPN was about providing secure connectivity to virtualized compute resources that connect at the edge of the network. The key to efficient operations was that regardless of whether an application required Layer 2 or Layer 3, operators could leverage a single protocol with a common interface.
EVPN abstracts the underlying transport, which is exactly why it is so well suited to provide a bridge from old to new. Even moderately sophisticated enterprises have scores of applications. As they upgrade, rewrite and replace these applications, enterprise IT is forced to operate in a hybrid environment. Without a common protocol to unify the operating model, there is simply no path to becoming an efficient part of the technology supply chain.
What Does EVPN Do?
EVPN basically gives enterprises the ability to run an overlay across an enterprise-wide L3 network. It provides the control plane required to route between virtual segments while maintaining independence from the physical underlay network. Within that virtual network, applications can be separated, effectively creating a multi-tenant domain managed through the administration of distributed network policy.
If that’s what EVPN does, what does it enable?
Highly scalable support for both L2 and L3 services, allowing it to be used in the data center, data center interconnect (DCI), WAN, campus and metro. EVPN reduces the number of protocols the enterprise needs to operate the network, making it simpler and more reliable, lowering operating costs and improving service availability.
EVPN removes the need to flood broadcast, unknown unicast and multicast (BUM) traffic through stretched ethernet segments. This suppresses ARP, eliminating unnecessary traffic replication, improving scalability and reducing traffic noise for more efficient monitoring and troubleshooting, leading to higher service availability.
EVPN provides first-class support for multi-homed attachment at both L2 and L3 with fast-failure recovery, allowing more efficient use of resources by eliminating standby links. It also removes the need for multi-chassis LAG protocols, leading to better ROI and higher service availability.
The original problem statement and early design considerations for EVPN are well documented in the following standards drafts:
The rise of EVPN is consistent with Juniper’s belief that simplicity will ultimately be on the right side of change. The key to scaling operations for enterprises is converging on a narrower set of protocols that provide a common operating model despite the diversity with which enterprises must grapple.
EVPN has been developed in the public eye with the explicit objective of remaining open, which is also consistent with the principles upon which Juniper was founded and continues to operate. The future of enterprise IT cannot be a fractured mess of vendor-specific solutions to industry-wide problems.
If the key to progress is simplification, it makes perfect sense to leverage a common operating system—Juniper Networks’ Junos® software—to deliver EVPN across the entire portfolio. The future of the data center has been under development for years, both within standards bodies and within Juniper’s development teams. As enterprise IT shifts from an enabler to a provider of services, it will be built on a foundation that is purpose-built exactly for this type of transition.
Today, Juniper kicks off the second video in a series of content designed not to sell, but rather to illuminate. With our GetSmart series on SDxCentral, Juniper will look at why EVPN matters, providing an industry view of what EVPN can do as the de facto architectural foundation for the modern data center. For additional information please download the E-Book on EVPN-VXLAN.