The OTT (over-the-top) model is experiencing rapid growth as a complementary video distribution channel. Operators and programmers are facing the challenge of providing the same quality of experience for both traditional and OTT viewers, and doing this at a scale. Users are accustomed to robustness and quality of traditional video delivery ecosystems such as cable, IPTV, satellite and broadcast. A successful OTT deployment should be able to match, if not exceed, these. In this paper we are providing an overview DASH implementation of robust ad-supported live linear services and an OTT-centric transcoder/packager architecture to support it. We discuss DASH features that make such service a reality, as well as a range of issues unique to such deployments - from content conversion to timing to scalability and fault tolerance, as well as additional benefits coming from tighter integration between intermediate transcoder-packager format and DASH. Lastly this paper will discuss monitoring and verification of the end-to-end linear content delivery chain.