The research note "Cat and Mouse with DDoS," written by Grant Lenahan, Partner and Principal Analyst at Appledore Research, examines the evolving landscape of Distributed Denial of Service (DDoS) attacks and the corresponding advancements in remediation strategies, focusing on the Nokia Deepfield DDoS security solution. The report emphasizes Nokia’s approach to DDoS security, which leverages advanced analytics (provided by Deepfield) and proprietary IP routing chips on Nokia service routers that monitor, identify, and mitigate these threats efficiently and at scale. The recent introduction of AI/ML capabilities and the Advanced Countermeasures Engine (ACE) on the 7750 Nokia Defender Mitigation System (DMS) enhances network operators’ ability to adapt to and counter evolving attacks swiftly. This ongoing cat-and-mouse game (between malicious actors acting as attacks and network owners defending their assets and customers) underscores the significant risks posed by DDoS attacks. The report concludes that Nokia’s integrated approach to DDoS security, combining advanced analytics with cutting-edge routing technologies, provides a comprehensive solution to the DDoS challenge. It also highlights a lucrative opportunity for communication service providers (CSPs) to offer DDoS protection as a managed (and chargeable) service. By adopting Nokia Deepfield's advanced, multi-faceted defense strategies, CSPs can improve network security while generating new revenue streams, turning a potential cost into a profitable business model.