Enterprise Network Architecture
The use of cloud infrastructure and SaaS applications has been a key element in helping companies improve business processes. One missing ingredient to a better performance is still a truly agile network. CEOs don’t have to start worrying about increasing CAPEX with a wholesale replacement of the gear underpinning the corporate MPLS network. However, SD-WAN technology can help transition the enterprise to a more agile network, and provide an opportunity to leverage (different/new/fresh) network architecture concepts that can help put executives in a better position to re-engineer their business for new digital opportunities.
Moving to the cloud-can your network get you there?
Numerous market research firms have pointed out that a hybrid cloud model (the delivery of a business function across different cloud environments) is increasingly used by enterprises today. An example of a hybrid cloud deployment is running an application on a private cloud in the enterprise datacenter and using an off-premises cloud for extra processing capacity as needed. Furthermore, research shows that organizations are still running an increasingly diverse array of applications on cloud infrastructure, including analytics and enterprise applications.
Let’s summarize what’s happening: more core business applications are going to run “in-cloud”, and applications are over time going to be working in a hybrid cloud configuration where data is moving between on- and off-premise compute infrastructure. This means that network performance and reliability is going to be a critical factor in keeping the business running.
A Next-generation WAN architecture – software defined
The traditional hub and spoke network architecture for corporate WANs has shortcomings that are limiting digital transformation efforts, as noted in our previous article. SD-WAN enables a new architecture that can help solve some of the performance, security and operational challenges encountered with digital transformation efforts.
What does a next-generation WAN architecture that’s software-defined look like? First, traffic from regional branches of the enterprise or partners and suppliers can be aggregated into regional hubs. These hubs are located in carrier neutral multi-tenant datacenters. The hubs are connected together with networks, of course. But here’s the key: SD-WAN can act as the glue that binds the architecture together while allowing for easier configuration and adjustment of routes and application-level optimization.
The architecture can now also accommodate moving traffic over ‘vanilla’ broadband connections, cellular networks as well as those MPLS links your enterprise already has contracts for. One use case: bond together broadband connections for more resiliency, while still getting the needed bandwidth provisioned faster and at a lower cost than a new MPLS link.
Next steps in developing an SD-WAN strategy
The next step, then, is to evaluate whether to get the SD-WAN component of the network running through internal development or with the aid of an external service provider or integrator. Some large firms certainly have the expertise and wherewithal to deploy a SD-WAN solution (sometimes referred to as a premises-based implementation). Between managing contracts, provisioning services, and ongoing network engineering and administration, these companies essentially have built a network service provider function within the enterprise. Other companies need to ask: Is being a network service provider going to help the company differentiate itself in the market?
Most enterprises will find that using a SD-WAN as a managed service to be an appealing alternative to the DIY approach in terms of initial cost outlay and ongoing operating costs. In terms of evaluating service provider options, the enterprise has two main options: an ‘on-network’ SD-WAN service which is provided by an asset-based NSP like a Level 3 or Verizon, or an overlay SD-WAN service provider, which does the work of sourcing and maintaining links to points of presence (POPs) around the globe.
On-network SD-WAN service providers
- 24/7 Operations/monitoring on a global basis
- Often there’s an existing vendor relationship – ‘trusted source’
- A variety of competitors, many of whom are big, stable companies
Overlay SD-WAN service providers
- 24/7 Operations/monitoring on a global basis
- Network – sourcing and provisioning on a global basis
- Can aggregate of multiple access types (broadband, Wi-Fi, 4G, LTE, etc.)
- Tend to be smaller companies that are more responsive to customer requests
SD-WAN is a double-edged sword for NSPs. On the one hand, it’s enabling competitors to come in and take business by going over the top of a standard internet service; by the same measure, they can offer services in new territories, too. Some NSPs have been evolving their portfolios to include what’s being referred to as a hybrid WAN option. This uses SDN technology to aggregate wireless and wirelines access technologies while acting as a system integrator and managing provisioning and contracts from other service providers. Some vendors say they are planning to extend these services into Europe and Asia-Pacific markets, but few (if any) among the traditional telecoms providers have built an extensive network of POPs to enable both SD-WAN network as well as additional services such as WAN acceleration and network firewall services.
Providers of SD-WAN as a service using the overlay model are another option. These companies don’t own networks — instead, they lease fiber and buy bandwidth from suppliers around the globe and link networks at POPs located in third-party datacenters. Depending on the vendor, customers may have an option of installing an appliance for full end-to-end WAN acceleration, for example, but in some cases simply leveraging dual internet links to a nearby POP still provides the bulk of the performance and management gains of SD-WAN, while not going down the path of paying for a hardware-based solution.
SD-WAN as a service is generally sold on a bandwidth-consumed basis, making it an affordable option as compared to MPLS services. In terms of deployment, enterprises that are moving down the SD-WAN path with over-the-top service providers are able to add new locations on an as-needed basis, meaning that as other service contracts come due, MPLS services can be augmented or replaced by internet access services without the upfront investment required by a DIY premises-based SD-WAN solution.
What executives will find is that SD-WAN is a key ingredient to enabling a more agile, cloud-ready WAN. At the same time, they can move forward with network transformation at their own pace-no ‘big-bang’ replacement of MPLS links and the associated networking gear is required. Before making a decision on which SD-WAN service and deployment model is right for your organization, do also consider whether services such as WAN acceleration/optimization and security are an integrated part of the networking service. Improving the performance of the network while also adding an easy-to-manage layer of security can provide significant additional financial and operational benefits. Indeed, programmability and the enablement of a more flexible network architecture will help fulfill the promise of digital enterprise transformation efforts.
By Mark Casey