This case study details a major service provider's post-merger efforts to expand its Enterprise services business and implement SD-WAN. Focused on quicker and more cost-effective activation of services for new Enterprise customers, the provider grappled with integrating legacy systems from multiple pre-merger companies. They faced the challenge of selecting suitable assurance systems for layer 2 and layer 3 services, ultimately opting for a proactive active assurance approach for layer 3 to ensure continuous monitoring and early detection of potential performance issues. Integration with back-office and network management systems was deemed necessary for streamlined workflows, and the study also highlights the critical need to enhance the efficiency of topology updates to meet troubleshooting and urgent requirements.