eans of network neutrality, SO there are no direct obligations on OTT service providers like those imposed on telecom operators for 6.9 Business and Regulatory Challenges for Services Over Ultra-Broadband telephony and TV over managed IP networks. OTT VoIP (Skype, Viber, WhatsApp, etc.) is offered by third parties (telecom operators and their customers are the first two par- ties) by using proprietary platforms and applications (i.e. they are not standardized and typically not open for further development by other parties than the owner of that appli- cation/service) in a deregulated manner. There are several regulatory challenges that may evolve or change regarding VoIP regulation. For example, QoS-enabled VoIP of tele- com operators should support all additional service features available in PSTN/ISDN, such as call line identification, call forwarding, call blocking probability, and SO on. Also, emergency calls and legal interception are mandatory for telecom operator grade VoIP (based on national legislation), but they are typically not required for OTT VoIP providers in most countries. Regarding the QoS aspects, the PSTNs were designed to meet strict QoS constraints such as end-to-end delay and bitrate, call success rate, which are followed by QoS-enabled VoIP [1]. That is not the case with OTT VoIP ser- vices which are provided over the existing Internet global network; however, customers can make their own choice (although such choice is directly dependent on other users with whom they communicate regularly, such as family, friends or colleagues, hence one or two OTT VoIP services are becoming dominant in a given country or region). Besides legacy services over IP networks, such as VoIP and IPTV, Internet access ser- vices are typically used by third parties for provision of OTT services, which are served in the broadband access network in a best-effort and network neutral manner. Network neutrality refers also to contents over public Internet access, SO this part is unregulated in most countries. (That mea