etween layers and across domains. These gaps can be interpreted as opportunities for standardization. Middleware used for Parlay X includes an ESB. ESB solutions are not fully standardized as yet. Hence, we only incorporated standards-based technologies to hide distribution complexities. These technologies included basic protocols, such as SOAP [29] and HTTP [30]. As a result, the ESB did not provide additional functionality that benefited the Parlay X Web services. Service Delivery Platform for the Next-Generation Network Table 2.2 Summary of IPTV Implementation Results Parlay X Web Services Parlay SCF Functions Notes Payment Charging Provides a service billing and charging interface into the OSS/BSS Account Account Allows customer/provider management management account management by interfacing with account databases Short Delivers messages between message interaction customers Audio call Setup audio call between customers Third-party Setup conference calls between multiple customers Presence Presence and CSCF/HSS Enables customers to share, availability publish and notify others of their online presence Subscription Framework Allows customer service management subscription management Service Provides an interface to management customer service profiles Policy Manages and enforces policies management on customers, providers, services, and network Content Content Allows content providers to management management register content Content Data session Delivers content via a data delivery controlb stream to customers with negotiated quality of service CSCF/ Manages the conversion HSS/CCF between IMS-related protocols and Parlay API invocations Newly defined enabler and API. Modified enabler API to provide additional functions. Service Delivery Platforms Due to the lack of SCS specifications, we provide our own API and implemen- tation. Also, the interworking between the SCS and IMS functions are not fully standardized. For instance, no standard is defined to translate data session API invocations to SIP messages. W