egacy and current server technologies can be fitted into the proposed architecture. For example, CAMEL [22], Weblogic in [24] and Parlay services in [25] are modules between the mod- ule of WS bus as well as the linked modules of the SIP-based microservice orches- tration layer. Similarly, both policy manager and home subscriber server have interface (indicated as dotted lines) to the WS service bus as shown in Figure 9.6. The end goal for the proposed solution is to achieve effective blending of both WS service bus IP-multimedia BEA Web services IBM parlay Location Presence logic (PTT, VoIP, etc.) service service service SIP-based microservice orchestration subscriber Policy Network QoS Mobility server resource manager management (user/app. manager profiles) IMS core session control functions (S-CSCF, I-CSCF, BGCF) and gateway control functions Figure 9.6 Inter-working between IMS and WS components via SIP-based micro- service orchestration module. Service Delivery Platforms WS- and IMS-based services. The relevant WS and IMS inter-working compo- nents of Figure 9.6 are briefly explained below, and the sequence of execution involving the proposed SIP-based microservice orchestration is illustrated in the next subsection. Interface with WS-Based Servers: Building of SIP-aware applications using the API available in programming environments such as JAIN and JSLEE does not represent a general-purpose solution to interconnecting ASs to IMS. This is because such an approach will generally make ASs network aware. In addi- tion, such an approach will not be viable to inter-work IMS with legacy sys- items implemented based on CAMEL or OSA definitions. A preferred solution is to define a set of basic interface functions (AKA IMS's service capabilities interface manager-which is not completely defined in the current IMS stan- dard) between the WS-based ASs and SIP-based Micro Service Orchestration layer. SIP-Based Micro Service Orchestration Module: The main objective of this module is to enhance the basic function provid