The concept of the “intelligent network” (IN) was developed for efficient deployment of resources when using digital communication networks. This is a structural concept for flexible service control and service development through the use of software and functionality implemented therewith. Internationally IN is defined in the Q.1200 series recommendations, for which the ITU (International Telecommunications Union) is responsible. The basic thinking behind IN is the separation of switching functions and service functions, i.e. resources for connection set-up are no longer located wholly in the individual switching point but are centralized. The advantage of this concept is simpler management and adaptation of these centralized resources. For example, when new services are introduced, not all switching points have to be adapted individually.
There are three hierarchical levels in the IN architecture, management level, service control level, and switching and transport level. The switching points—generally referred to as SSP (service switching point)—of the lowest level, i.e. the switching and transport level, are controlled by control points—generally referred to as SCP (service control point)—at service control level for the implementation of services and where appropriate are supplied with data from centralized databases. SSP and SCP are defined as physical entities for the IN concept in Q.1205.
General aspects of an INAP (intelligent network application protocol) protocol are described in Q.1208 for IN applications. At present INAP protocols with CS2 (capability set 2) and CS3 (capability set 3) operational features in accordance with the ITU recommendations numbered Q.122x and Q.123x are frequently used for IN applications.
Further specifications are required to provide telecommunication services and service features in the context of the IN concept. For example, for ISDN (integrated services digital network) applications signaling functions are standardized in the context of the ISUP (ISDN user part) in ITU documents Q.761-Q.764 and Q.766, with the ISUP representing a protocol based on signaling system no. 7 (SS#7), which allows separation of the transfer of user data and control data and which is standardized by the ITU in the Q.700 series. For ISDN applications in the context of the IN concept the ITU has produced standards Q.1600 and Q.1601 which govern the interaction of ISUP and INAP CS1 or INAP CS2.
Given the increasing importance of the transfer of user data and any signaling data via different networks or carriers, as is frequently the case, for example, with IP based applications, signaling protocols are being developed, which allow a specific set of services and service features, regardless of the carrier. An important example of such a service is internet telephony (VoIP), in which connection-based voice transfer is to be achieved via different physical networks. The ITU draft of Q.1901 describes a signaling protocol, the BICC (bearer independent call control) protocol, with which the services and service features defined for the ISDN network—hereafter referred to as ISDN services or service features—are to be implemented, regardless of the carrier. The BICC protocol is based on the ISUP protocol. As described in the draft of Q.765.5, the transport mechanism (application transport mechanism) set out in Q.765 can be used for the transport of carrier-related data using the BICC protocol.
When implementing ISDN services and service features in the context of the IN concept with user data transfer via a packet network using a carrier-independent signaling protocol, such as, for example, BICC CS2, there is the problem that the parameter changes necessary or desirable for this are not supported.