In this interview, Avik Bhattacharya, Ixia technical product manager, discusses the business benefits of software-defined WAN (SD-WAN) and the products Ixia provides to assist adopters in internal Proof of Concepts (PoC) validation. Ixia, who is a Tolly lab partner provides testing, visibility, and security solutions, strengthening applications across physical and virtual networks for enterprises, service providers, and network equipment manufacturers. Ixia offers companies trusted environments in which to develop, deploy, and operate.
Tolly: Software-defined WAN (SD-WAN) is one of the most popular SDN applications over the last few years. Can you shed some light on the application and its benefits?
Bhattacharya: The business benefit for the enterprises that comes from SD-WAN is the ability to use Internet bandwidth in place of dedicated MPLS links to bring down cost. In addition to this SD-WAN allows programmable networks to adapt to the dynamically changing business needs. The enterprises benefit from quick application prioritization, load balancing and security policy enforcements.
On the other hand, SDN enabled WANs make it easy for the service providers to monetize their networks through value added services. With programmable service chaining introduced by SDN, customers can even configure their services through a self-service portal.
Virtual customer premises equipment (vCPE) is another aspect SD-WAN. Replacing traditional specialized gear with virtual network functions on COTS hardware brings flexibility for deployment and maintenance for the service providers.
Tolly: When adopting SD-WAN what elements should an end-user consider?
Bhattacharya: A hybrid WAN solution needs to dynamically steer application traffic over MPLS or Internet links—on a per‐packet basis. Performing this at line rate based on the policy inserted by the WAN Controller is an important task of the WAN gateway.
To provide five-nine reliability for enterprise applications, the solutions also have redundancy built into the system and super-fast failure protection switching. The SD-WAN gateways need to be validated from this perspective.
On the other hand, the end to end solution transports data traffic through an overlay network on top of the hybrid infrastructure. Overlay processing, public network and compatibility with existing network contributes to the overall latency of the system. Keeping the latency within the permissible limit of applications is another aspect of validation.
Generally, the enterprises prefer to do a step by step migration from a traditional WAN to an SD-WAN. During the process, the SD-WAN solution needs to maintain interoperability with existing WAN elements.
Finally, validating end to end user experience in real world application mix and characterizing performances of WAN optimization elements are key to successful qualification of a system.
Tolly: We’re seeing a significant increase in demand from IT vendors in validating the benefits of their SD-WAN solutions. What products does Ixia offer to test SD-WAN?
Bhattacharya: Ixia test solutions can be used to validate an SD-WAN implementation at different levels –
Ixia’s Applications and Security test tools help end-to-end validation of the design and the deployment of SD-WAN solutions. IxLoad can assess the quality of experience of applications delivery or determine the data reduction performance of WAN optimization in the network. BreakingPoint can measure and harden the performance of network and security devices.
At a network infrastructure level, IxNetwork can be used to measure failure switch-over time or traffic characteristics like latency and QoS between two branches. IxNetwork’s protocol emulation can validate the implementation at layer 2-3 for checking the interoperability with traditional system.
Testing a virtual CPE requires different techniques than a hardware CPE. In service chained environment, the workloads can flow in between the VNFs inside a hypervisor or between two hypervisor systems. To efficiently emulate and analyze this type of traffic-flow-pattern in the lab, the tester node also needs to be virtualized and sit inside the hypervisor along with the other VNFs. All testing capabilities of IxNetwork, IxLoad and Breaking Point are also available in virtualized form.
IxChariot is a lightweight option for instant performance assessment for an SD-WAN deployment. This document shared few examples on how IxChariot can be used for top SD-WAN validation requirements as per ONUG- https://opennetworkingusergroup.com/wp-content/uploads/2015/05/ONUG_Ixia-SD-WAN-Test-Plan-Final.pdf