WAN and its components

For an enterprise, WAN is an enabler for them to run their business across multiple geographic locations. WAN (Wide Area Network) utilizes IP-based technology to connect two or more geographically dispersed corporate sites. It provides a reliable and secure way to interconnect multiple sites and enables centralization of IT resources that can be made available to any site. Typical enterprise WAN infrastructure is a conglomeration of the following components as given in the table:

Although not comprehensive, it certainly gives a general sense here that each of the components has a cost and effort attached to it. The TCO (Total Cost of Ownership) calculation for WAN infrastructure has different implications for enterprise, service provider, telco providers, data centers, public cloud provider and cloud brokerage. In this paper, we will focus on TCO calculation from an enterprise perspective.

WAN TCO parameters

The table below lists key factors that impact overall TCO:

Due to rising cost and high bandwidth requirement, enterprises have begun looking for Direct-Internet-Access (DIA) as an alternative option.

WAN technology trends and challenges

Let us compare the previous WAN deployment models:

MPLS VPN is a mature network product, and it is by far the most widely available international enterprise network service due to its capability to provide different CoS to match the application performance requirements. IPsec VPN remains a critical piece in the global WAN, as there is a growing number of enterprises who are rerouting some of their corporate traffic to the public Internet. However, due to rising cost and high bandwidth requirement, enterprises have begun looking for Direct-Internet-Access as an alternative option:

• Addressing the need for growing bandwidth requirements within the limited budget for the networks, enterprise network managers must be efficient in bargaining the contracts and optimizing the WAN design.
• Migrating the corporate traffic from VPN to public internet is complex because the application performance requirements must be mapped to the right connectivity, which can provide proper service levels and traffic flow.
• Security is inherent in the VPN connectivity, and it becomes a significant concern when moving corporate traffic over to Public Internet. However, this has reached a certain level of comfort and trust with the advent of alternate security solutions and assurances.
• WAN in Model-1 & Model-2, was complex to design, operate and troubleshoot. It had a high dependency on the skilled resources, had a repeat procurement cycle of the hardware devices. Also, the change was time-consuming and error-prone.

The graph below depicts how the WAN TCO changed due to evolving WAN technology trends.

In Model-3, CAPEX is zero, and the entire WAN service has only OPEX model. This was made possible by having the same requirement with the only Internet as the WAN technology whose performance was at par with the MPLS technology. This created total disruption in the WAN market, which impacted many of the service providers. Enterprise narrowed down their choices to:

• Basic MPLS
• Internet
• Hybrid (MPLS + Internet)

Enterprises are now not required to make decisions on CPEs, tools or even to hire skilled resources.

SD-WAN

Model-3, which is Software-Defined WAN, helped the enterprise network managers to address all the challenges mentioned above in Model 1 & 2, by leveraging the hybrid WAN solutions bringing positive impact to the overall TCO. The key concept in SD-WAN was on making WAN aware of application, which gave rise to following additional benefits:

• Agnostic to the underlying WAN technology
• Dynamically routes traffic across hybrid WAN in real-time based on SLA profile of the various applications
• Centralized configuration management
• 40% reduction in WAN transport spend with hybrid WANs layers & multi-service provider platform

Conclusion: WAN TCO disruption

As the Internet is getting more robust, more resilient and cheaper, in the coming years, we will see that WAN-as-a-Service is being looked upon as the most preferred among small, medium and large enterprises because of the attractive TCO and ROI it brings in.

Also, the rising adoption of the Cloud-1^st strategy by several enterprises is one of the critical reasons why WAN-as-a-Service model is gaining such traction. The Cloud-1^st adoption also raises the crucial need for secure interconnectivity with the various clouds to branch offices. Using the Internet for interconnectivity suffices for the low bandwidth requirements, but not for high bandwidth and business-critical applications, due to security concerns and the low reliability of the performance of the public Internet. These gaps are now being fulfilled by the cloud service brokers, acting as a hub to connect to all the public clouds.

Following agents are playing a catalytic role in bringing out the disruption in the overall WAN TCO:

• Application-awareness
• Automation
• Centralized management and operations
• Availability of cheaper bandwidth 

Reference

1. http://blog.telegeography.com/cloud-wan-trends-sdwan-mpls-ip-vpn
   

Ravindra K. Botkar

Principal Consultant, Global Infrastructure Services, Wipro Ltd

Infrastructure Services: Ravindra K. Botkar has 15+ years experience in N&S, encompassing several project deliveries. He is currently a part of GIS SDx team, as Principal Consultant. He has made key contributions to network automation of legacy and ACI via Python and Ansible, in addition to integration use cases around OpenStack, Cisco and L4-L7 devices. His recent execution of Cisco ACI solution using automation for a bank in APAC has been widely acknowledged by Cisco. His current interests are in DC technologies and Automation. He is currently architecting SDN solutions with specific focus on Open Networking.

To know more, reach out to marketing.gis@wipro.com