With Closed IPTV does the proprietary nature of the discovery lock you in, and why not just spend a few days writing scripts to achieve the same thing?
Again the base layer of Closed IPTV utilizes zeroconf as one of the more universal discovery schemes, supported by many devices, and likely to be the most popular solution under PSIA and ONVIF. It is the further deterministic solution of Closed IPTV that easily delivers the security advantages as well, which it is likely that while such scripts may enhance discovery, they do little for enhancing security. The basis of all open standards is that the fundamental lower layers should be non-proprietary to achieve common ground and interoperability. It is however the enhancements at the higher layers that deliver the unique benefits and strengths of a solution, otherwise no one would be able to deliver an enhanced, bespoke solution. Closed IPTV completely fulfills those goals and delivers them with a few key strokes, rather than days or weeks of writing custom scripts, assuming this knowledge is held.