“Over the top” (OTT) is one of the most overused and ambiguous buzzwords in our industry.
In order to understand linear video delivery in OTT models, first, you have to look at what OTT means outside of video. To mobile operators, OTT is a scary proposition. Calls, text messaging, and image messaging had been entirely within operators’ control until now, and therefore presented an opportunity for revenue. For those operators, OTT services are an almost unavoidable symptom of smartphones requiring open internet access, and bring with them many services that compete with operators’ traditional revenue models. King of all these is Skype, and it provides a clear example of what “top” the service comes “over” to earn the moniker OTT: Namely the pay wall that is the per-minute billing system of the mobile operator.
In exactly the same way I often dogmatically emphasize that “cloud” is an economic term defining the move of CAPEX to OPEX when building IT infrastructure, OTT is also an economic term first and foremost. At best, it means that the operators are able to derive data transit and bandwidth-oriented revenues for the delivery of network service on behalf of providers who otherwise charge much higher premiums to end users or sponsors. At worst, operators are loss-leading that data transit to encourage subscribers to stay with them rather than take their business to other operators. All the while, OTT services are taking revenue from network operators’ subscribers and not (necessarily) sharing any of that revenue with the network operator.
However, with this economic common denominator noted, in any specific technical context the term OTT has a range of implementation models that ensure that the cost of this data transit and bandwidth delivery itself is as profitable as possible for the network operator, whether profit is measured in operator CDN revenues or in terms of subscriber retention.