Incoming Call Screening (ICS) service
P. Bleuse, Bernard Vilain · 1997
For new telephone companies to position themselves efficiently and cost effectively as long-distance network operators (LDNOs), they need a service to assist them in recognizing and screening local-loop subscribers placing a long-distance or international call. They must be able to: Check that a caller, identified by the calling line identity (CLI) and intending to use their network, is registered. Check that they have the information necessary to bill the call. Handle calls from unregistered callers and route them selectively towards attendants. Attendants work for operators or telephone companies and are in charge of new and existing subscribers. Attendants in a call center must be able to propose a new intelligent-network (IN) service subscription to these unregistered callers. Reroute a call meeting a busy or no-reply condition. Restrict calls based on the CLI and the dialed number. Generate a Call Detail Record (CDR) for billing purposes. Alcatel proposes the above capabilities to these long-distance network operators (LDNOs) with its new Incoming Call Screening (ICS) service. The ICS service will allow them to check if an incoming call request has been generated by a subscribed user or not, to validate such a request, and to process it accordingly. The service is invoked whenever a long-distance call attempt is received on incoming trunks, belonging to one or several predefined trunk categories, and when the caller has selected the LDNO as the carrier through equal-access mechanisms. Thus, the core of Alcatel’s ICS service is its ability to check incoming call requests and decide either on further routing or on rejection. Performing a check of this type inside the operator's network makes use of IN architecture, and both the checking and call-handling actions can be fairly sophisticated. This article contains information on these actions, including the concept of a caller profile, service logics, service triggering, service provision, service subscription, and statistics. The appendix contains a complete glossary and list of abbreviations.