Patent Publication Number: US-2012039452-A1

Title: Communication Connection Establishment Control for Preventing Unsolicited Communication

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a mechanism for controlling a communication connection establishment to a subscriber, and to a management system used to configure a corresponding communication connection establishment control. In particular, the present invention is related to a communication connection establishment control providing protection against unsolicited communications (UC), such as SPAM over Internet Telephony (SPIT), and to a management system for configuring a corresponding control. 
     2. Related Prior Art 
     In the last years, an increasing extension of communication networks, e.g. of wire based communication networks, such as the Integrated Services Digital Network (ISDN), and Digital Subscriber Line (DSL) access to the Internet, or wireless communication networks, such as the cdma2000 (code division multiple access) system, cellular 3rd generation (3G) communication networks like the Universal Mobile Telecommunications System (UMTS), cellular 2nd generation (2G) communication networks like the Global System for Mobile communications (GSM), the General Packet Radio System (GPRS), the Enhanced Data Rates for Global Evolutions (EDGE), or other wireless communication system, such as the Wireless Local Area Network (WLAN) or Worldwide Interoperability for Microwave Access (WiMax), took place all over the world. Various organizations, such as the 3 rd  Generation Partnership Project (3GPP), Telecoms &amp; Internet converged Services &amp; Protocols for Advanced Networks (TISPAN), the International Telecommunication Union (ITU), 3 rd  Generation Partnership Project 2 (3GPP2), Internet Engineering Task Force (IETF), the IEEE (Institute of Electrical and Electronics Engineers), the WiMax Forum and the like are working on standards for telecommunication network and access environments. 
     Generally, for properly establishing and handling a communication connection between network elements such as a user equipment (UE) and another communication equipment or user equipment, a database, a server, etc., one or more intermediate network elements such as control network elements, support nodes or service nodes are involved which may belong to different communication network. 
     For example, Voice over IP (VoIP) represents a new technology for delivery of voice communications over Internet Protocol (IP) networks such as the Internet or other packet-switched networks, including all the networks mentioned above, with the exception of ISDN. One embodiment of a VoIP network is an IMS network, as defined by 3GPP. VoIP networks in general, and IMS in particular, may be used in a mixed wireline-wireless environment, which is sometimes also called a Fixed-Mobile-convergence environment. VoIP offers a possibility for easy and also cheap access to speech communications. However, by such new transmission technologies like VoIP, there is also a problem that undesired features are taken over from the IP domain to the telecommunication domain. One of these features is the transmission of unsolicited communications to subscribers which is also known as “spamming”. 
     In case of VoIP, such transmission of unsolicited communications to users, especially VoIP users, is also known as SPAM over Internet Telephony (SPIT). SPIT/UC can be defined as a bulk unsolicited set of session initiation attempts, attempting to establish a voice, video, instant messaging or other type of communication session. If the user should answer, the calling side, also referred to as “spammer”, proceeds to relay the message. Usually SPIT/UC is perceived as nuisance by the users. 
     This problem is already well-known from Email SPAM which is seen as a huge plague today. The fear is that SPIT/UC will become a similar problem for communication connections concerning voice calls or the like, especially in the context of VoIP, since costs for VoIP are decreasing, the customer base for VoIP is growing significantly and Personal Computers (PCs) or the like can be used to generate large amounts of automated VoIP calls. These are the main pre-requisites for an increased SPIT/UC probability. 
     Therefore, there are several attempts to decrease this sort of threat for VoIP networks cumulating in a variety of standardization efforts that are currently ongoing in ETSI, IETF, ITU, 3GPP and the like. 
     In addition, it has to be considered that a consequence of increasing SPIT/UC may be that the acceptance of VoIP could be affected. Compared to Email SPAM, the impairment of SPIT/UC to the user is regarded to be even higher, because voice, video, etc. are real-time media that require immediate reaction of the user (in contrast to Email that is read at the time the user likes) and the nuisance has already taken place when the user reacts on the ringing tone and accepts the call (while Email offers the possibility to perform an offline content analysis with a subsequent filtering). Therefore VoIP vendors as well as VoIP operators show an increasing interest in SPIT/UC prevention techniques. 
     However, Voice SPAM or unsolicited communication is by its nature not restricted to VoIP networks. Due to the link of VoIP networks to other networks based on a different transmission technology, such as legacy networks like e.g. PSTN (Public Switched Telephony Network), SPIT/UC may also affect users of such other networks. Hence, although the SPIT/UC source may originate in a VoIP network, users of legacy networks can be affected, for example since VoIP-to-fixed-network flat rates diminish the cost for SPIT/UC calls significantly. 
     For handling annoying telephone calls, there have been proposed several service features of so-called supplementary services, which comprise, for example, SCR (selective call rejection, blacklisting), SCA (selective call acceptance, white listing), ACR (anonymous call rejection) or malicious call identification/tracing (MCID). In addition, also EACR (enhanced anonymous call rejection) is proposed which allows callers to decide between giving up their privacy, entering a PIN or speaking their name when calling a callee with ACR enabled. While malicious call tracing is intended for special purposes only, SCR or SCA can be used by subscribers to blacklist certain callers (SCR) or to allow connections only from white listed callers (SCA). In practice, however, these and further features are hard or impossible to combine and thus of little value to voice service subscribers. Furthermore, the setting and configuration of such services is complicated and the effects thereof on communication connections or the reachability of users are sometimes difficult to understand for a subscriber. 
     Regarding the handling of SPIT/UC, there are presently made basically two different approaches, i.e. a non-technical approach and by means of technical measures. 
     Usually, a combination of non-technical countermeasures on different levels is used against SPIT/UC:
         legislation (may be different per country),   measures of regulative authorities so as to block known SPIT/UC sources   measures based on operator&#39;s contract conditions (e.g. no commercial usage of flat rates) that allow short-term contract cancellation if users violate these contract conditions.       

     The disadvantage of the first two countermeasures (legislation, regulative authorities) is that the reaction is complicated and slow. The third countermeasure (operator&#39;s contract conditions) may be effective, but the difficulty for the operators is to prove the misuse of their contract conditions. 
     Regarding the technical approach to tackle the SPIT/UC problem, for example, VoIP networks may in future be equipped with servers that try to evaluate a SPIT/UC probability (SPIT/UC score) for each call by analyzing, for example, the SIP (Session Initiation Protocol) signaling traffic and user feedbacks. By means of this, the network or the user can possibly react according to the analysis. These SPIT/UC servers are currently on a research or prototype level. One example is the so-called SEAL system from NEC which proposes usage of a SPIT/UC server that provides a three-step approach: Identification of SPIT/UC—Marking of SPIT/UC—Reaction on SPIT/UC. Another example is the so-called SAVIT (SPAM Avoidance for Voice over Internet Telephony) system from Siemens, which pursues a similar concept as SEAL (a SPIT/UC server analyzes the SIP signaling traffic in parallel to the SIP server and builds up a SPIT/UC database, based on statistical analysis of signaling traffic and direct user feedback; the result is a SPIT/UC probability (SPIT/UC score) that can be either provided to the intended recipient of the call or it can be the input for a network-based decision unit that decides to either block the call or to put it through). 
     However, even though these technical approaches may provide countermeasures against SPIT/UC, there are some problems remaining. For example, these systems are related only to the SPIT/UC prevention in VoIP networks so that users of other networks such as the legacy networks impaired potentially as well by VoIP originated SPIT/UC can not be protected thereby. Furthermore, these approaches require changes in SIP signaling to transport SPIT/UC related signaling data and possibly changes in VoIP network interface definitions which makes the implementation thereof difficult. It has also to be considered that besides technical and architectural questions there are also legal aspects affected by these approaches, such as privacy protection (is the operator willing or allowed to indicate towards another operator that a specific user is deemed to be a SPIT/UC source) or liability problems (if an operator B blocks an important call, based on a false SPIT/UC decision of an operator A, legal implications may follow). 
     SUMMARY OF THE INVENTION 
     Thus, it is an object of the invention to provide an improved communication connection establishment control providing protection against unsolicited communications. In particular, it is an object of the invention to provide an apparatus, a method and a computer program product by means of which a communication connection establishment can be controlled such that unsolicited communications are prevented irrespective of the type of the communication network of a subscriber, such as a PSTN (Public Switched Telecommunications Network). In addition, it is an object of the invention to provide a subscriber or end user a possibility to create an own personalized, sophisticated communication connection establishment control profile (or SPIT/UC prevention profile) which is convenient to handle for users and does not negatively affect user experience. In addition, it is an object of the invention to provide a management system allowing an easy configuration of the communication connection establishment control profile (or SPIT/UC prevention profile) for the user and a flexible and sophisticated setting of communication connection establishment control profiles (or SPIT/UC prevention profiles) schemes for network operators. 
     These objects are achieved by the measures defined in the attached claims. 
     In particular, according to one example of the proposed solution, there is provided, for example, a method comprising setting a communication connection establishment control pro-file for a subscriber for handling unsolicited communication, receiving a setup request for a communication connection from a calling party, determining whether an identification element of the requesting calling party matches a stored identification of calling parties to be rejected, indicated in the communication connection establishment control profile, and determining whether the identification element of the requesting calling party matches a stored identification of calling parties allowed to be connected to the subscriber, indicated in the communication connection establishment control profile, sending, if the results of the determining are negative, a request to the calling party for returning a first authentication for allowing the establishment of the communication connection, said first authentication being indicated in the communication connection establishment control profile, and checking whether the first authentication is received. 
     Furthermore, according to one example of the proposed solution, there is provided, for example, an apparatus comprising a processor configured to set a communication connection establishment control profile for a subscriber for handling unsolicited communication, a receiver configured to receive a setup request for a communication connection from a calling party, a blacklist processor portion configured to determine whether an identification element of the requesting calling party matches a stored identification of calling parties to be rejected, indicated in the communication connection establishment control profile, a whitelist processor portion configured to determine whether the identification element of the requesting calling party matches a stored identification of calling parties allowed to be connected to the subscriber, indicated in the communication connection establishment control profile, a transmitter configured to send, if the determination results of the blacklist and whitelist processor portions are negative, a request to the calling party for returning a first authentication for allowing the establishment of the communication connection, said first authentication being indicated in the communication connection establishment control profile, and an authentication processor portion configured to check whether the first authentication is received. 
     According to further refinements, these examples may comprise one or more of the following features:
         in case the first authentication is not received, sending of an announcement may be initiated on the basis of information indicated in the communication connection establishment control profile to the calling party, said announcement indicating information usable for deriving a second authentication for allowing the establishment of the communication connection;   the communication connection to the calling party may be ended after sending the announcement;   at least one of rejecting the request for the establishment of the communication connection when the result of the determining of whether the identification element of the requesting calling party matches a stored identification of calling parties to be rejected is positive, and allowing the establishment of the communication connection to the subscriber when the result of the determining of whether the identification element of the requesting calling party matches a stored identification of calling parties allowed to be connected to the subscriber is positive, may be executed;   when sending the announcement, the calling party may be offered to store an identification information of the calling party and/or a message for the subscriber, and when the offer is accepted by the calling party, the identification information and/or the message may be stored for a retrieval by the subscriber;   the check whether the first authentication is received may comprise at least one of detecting whether the first authentication is received until a preset time is elapsed, and determining whether the received first authentication matches authentication data indicated by the communication connection establishment control profile, wherein the first authentication is defined to be not received when the preset time is elapsed without receiving the first authentication or when the received first authentication does not match the authentication data;   the first authentication and the second authentication may be character based authentication codes and the announcement may be a speech message;   the setting of the communication connection establishment control profile may comprise at least one of providing lists specifying one or more stored identifications of calling parties to be rejected and/or one or more identifications of calling parties allowed to be connected, providing data for specifying the first authentication and/or the second authentication, and providing data for generating the announcement;   further services may comprise at least one of detecting whether the calling party provides identification information usable for identifying the calling party, and, when the identification information is not detected, rejecting the request for the establishment of the communication connection, checking whether an instruction to block external communication connection establishment attempts is present, and if the instruction is present, rejecting the request for the establishment of the communication connection, and checking whether a specific communication connection forwarding instruction is present, and, when the specific communication connection forwarding instruction is present, handling the request for the establishment of the communication connection in accordance with the specific communication connection forwarding instruction, wherein the specific communication connection forwarding instruction may comprise at least one of a permission to establish a communication connection to the subscriber only at predetermined periods of time, an instruction to setup the communication connection to another destination, an instruction to setup the communication connection to another destination only at predetermined periods of time, and an instruction to send the announcement in case the result of the determining of whether the identification element of the requesting calling party matches a stored identification of calling parties allowed to be connected to the subscriber is positive; then, the setting of the communication connection establishment control profile may comprise at least one of providing lists specifying one or more stored identifications of calling parties to be rejected and/or one or more identifications of calling parties allowed to be connected, providing data for specifying the first authentication and/or the second authentication, providing data for generating the announcement, specifying the predetermined periods of time, and providing data for specifying the other destination;   the setting of the communication connection establishment control profile may further comprise receiving instructions and/or data by an interface comprising a graphical user interface part for assigning at least one of activation commands and parameters for the communication connection establishment control profile, and implementing the instructions and/or data in a communication connection establishment control scheme using one or more supplementary services of a communication network.       

     Moreover, according to another example of the proposed solution, there is provided, for example, a method comprising providing a plurality of services specified for a communication connection establishment control for handling unsolicited communication, establishing a preliminary communication connection establishment control scheme by defining and combining selected ones of the services, providing an interface for a subscriber comprising means for inputting instructions and/or data for generating a communication connection establishment control profile for the subscriber based on the preliminary communication connection establishment control scheme. 
     In addition, according to an example of the proposed solution, there is provided, for example, an apparatus comprising a first processor portion configured to provide a plurality of services specified for a communication connection establishment control for handling unsolicited communication, a second processor portion configured to establish a preliminary communication connection establishment control scheme by defining and combining selected ones of the services, a third processor portion configured to provide an interface for a subscriber comprising means for inputting instructions and/or data for generating a communication connection establishment control profile for the subscriber based on the preliminary communication connection establishment control scheme. 
     According to further refinements, these examples may comprise one or more of the following features:
         the establishing may further comprise combining the selected ones of the services in a specific order for execution;   there may be further comprised functions or portions for receiving instructions and/or data input in the interface by the subscriber, determining the communication connection establishment control profile for the subscriber on the basis of the input instructions and/or data, configuring a final communication connection establishment control scheme to be used for the subscriber on the basis of the communication connection establishment control profile, and implementing the final communication connection establishment control scheme for a request for establishing a communication connection to the subscriber;   the services may comprise supplementary services including at least one determining whether an identification element of a calling party requesting an establishment of a communication connection matches a stored identification of calling parties to be rejected, indicated in the communication connection establishment control profile, determining whether the identification element of the requesting calling party matches a stored identification of calling parties allowed to be connected to the subscriber, indicated in the communication connection establishment control profile, sending, if the results of the determining are negative, a request to the calling party for returning a first authentication for allowing the establishment of the communication connection, said first authentication being indicated in the communication connection establishment control profile, checking whether the first authentication is received, and in case the first authentication is not received, sending an announcement on the basis of information indicated in the communication connection establishment control profile to the calling party, said announcement indicating information usable for deriving a second authentication for allowing the establishment of the communication connection;—the supplementary services may be for at least one of GSM, ISDN, UMTS, and VoIP networks, such as IMS, and/or the supplementary services may comprise at least one of SCA, SCR, ACR, eACR, DND, CF.   the services may further comprise at least one of rejecting the request for the establishment of the communication connection when the result of the determining of whether the identification element of the requesting calling party matches a stored identification of calling parties to be rejected is positive, and allowing the establishment of the communication connection to the subscriber when the result of the determining of whether the identification element of the requesting calling party matches a stored identification of calling parties allowed to be connected to the subscriber is positive;   the services may further comprise offering, when sending the announcement, the calling party to store an identification information of the calling party and/or a message for the subscriber, and when the offer is accepted by the calling party, storing the identification information and/or the message for a retrieval by the subscriber;   the services may further comprise at least one of detecting whether the first authentication is received until a preset time is elapsed, and determining whether the received first authentication matches authentication data indicated by the communication connection establishment control profile, wherein the first authentication is defined to be not received when the preset time is elapsed without receiving the first authentication or when the received first authentication does not match the authentication data;   the first authentication and the second authentication may be character based authentication codes and the announcement may be a speech message;   the interface may comprise means for inputting instructions and/or data for generating the communication connection establishment control profile by specifying at least one of one or more identifications of calling parties to be rejected and/or one or more identifications of calling parties allowed to be connected, the first authentication and/or the second authentication, and a source and/or a content of the announcement;   the services may further comprise at least one of detecting whether the calling party provides identification information usable for identifying the calling party, and, when the identification information is not detected, rejecting the request for the establishment of the communication connection, checking whether an instruction to block external communication connection establishment attempts is present, and if the instruction is present, rejecting the request for the establishment of the communication connection, and checking whether a specific communication connection forwarding instruction is present, and, when the specific communication connection forwarding instruction is present, handling the request for the establishment of the communication connection in accordance with the specific communication connection forwarding instruction, wherein the specific communication connection forwarding instruction may comprise at least one of a permission to establish a communication connection to the subscriber only at predetermined periods of time, an instruction to setup the communication connection to another destination, an instruction to setup the communication connection to another destination only at predetermined periods of time, and an instruction to send the announcement in case the result of the determining of whether the identification element of the requesting calling party matches a stored identification of calling parties allowed to be connected to the subscriber is positive; then, the interface may comprise means for inputting instructions and/or data for generating the communication connection establishment control profile by specifying at least one of one or more identifications of calling parties to be rejected and/or one or more identifications of calling parties allowed to be connected, the first authentication and/or the second authentication, a source and/or a content of the announcement, the predetermined periods of time, and the other destination;   there may be further provided a function or portion for allocating price information to parts of the interface related to one or more of the selected ones of the services;   the interface may comprise a graphical user interface part for inputting the instructions and/or data for generating a communication connection establishment control profile and for assigning at least one of activation commands and parameters for parts of the communication connection establishment control profile.       

     Furthermore, according to another example of the proposed solution, there is provided, for example, a graphical user interface comprising an indication portion configured to indicate a template of a preliminary communication connection establishment control scheme comprising a combination of a plurality of services specified for a communication connection establishment control for handling unsolicited communication, one or more input portions configured to input instructions and/or data for generating a communication connection establishment control profile of a subscriber based on the preliminary communication connection establishment control scheme, a receiver configured to receive instructions and/or data input in the one or more input portions by the subscriber, a determiner configured to determine the communication connection establishment control profile for the subscriber on the basis of the input instructions and/or data by assigning activation commands and/or parameters to the communication connection establishment control profile, and a transmitter configured to transmit the communication connection establishment control profile to a management system configuring a final communication connection establishment control scheme to be used for the subscriber on the basis of the transmitted communication connection establishment control profile. 
     Moreover, according to another example of the proposed solution, there is provided, for example, a computer program product for a computer, comprising software code portions for performing the steps of any of above defined methods, or for generating a graphical user interface as defined above, when said product is run on the computer. The computer program product may comprise a computer-readable medium on which said software code portions are stored. Furthermore, the computer program product may be directly loadable into the internal memory of the computer and/or transmittable via a network by means of at least one of upload, download and push procedures. 
     By virtue of the proposed solutions, it is possible to provide a communication connection establishment control or UC prevention by using supplementary services which are defined for legacy as well as for VoIP networks and can therefore be used in all networks to protect against SPIT/UC. These services are standardized and are running in the installed network base so that they can be used immediately and require no or only some small adaptations. Furthermore, protocol extensions are not necessary so that the proposed communication connection establishment control may be implemented also in existing network equipment or servers without extensive changes. For example, no changes in SIP or other signaling and in VoIP network interface definitions are required. 
     The proposed communication connection establishment control for UC prevention is in particular usable for preventing SPIT/UC from calling machines. However, also UC originating from natural persons can be limited due to additional effort required to be taken by the UC caller. 
     The proposed UC prevention measures apply both to traditional PSTN/ISDN networks as well as to modern VoIP/IP/NGN (Next Generation) networks, wherein in all network types basically the same mechanisms and procedures are used. Thus, the invention works advantageously not only in one network type environment but also in a mixed environment consisting of both PSTN/ISDN and VoIP/IP/NGN, thereby detecting/blocking UC/SPIT in either network. This yields direct value-add to users of arbitrary networks, e.g. either on the PSTN/ISDN or on the VoIP/IP/NGN network segment. 
     More generally, by means of the present invention, a reduced network usage from UC/SPIT is achieved, resulting in a reduced processing load in network nodes. Furthermore, subscribers can reduce SPIT/UC with little extra processing. Thus, the present invention offers a useful measure against SPIT/UC so that network operators/carriers providing this anti-SPIT/UC procedure as a network service feature can increase their ROI (Return Of Investment), either by charging corresponding services or by increasing the attraction of their offer. 
     In addition, the proposed communication connection establishment control (or UC prevention) avoids also possible implications of legal aspects for operators because the user configures and manages his personal UC prevention profile and is therefore responsible for the consequences. 
     By means of the proposed management system, it is possible to obtain a personally tailored SPIT/UC prevention profile for a subscriber enabling the user to create a SPIT/UC protection according to his personal needs and ideas. On the other hand, the proposed management system provides an operator the possibility to control which services are offered or to be used for the UC prevention profile, wherein also a consistency of the offered (and user selected) services can be ensured. Moreover, the management system provides a high flexibility for configuration and maintenance of the UC prevention. In addition, comprehensible input and setting options can be provided to the subscriber, in particular by the graphical user interface (also referred to as GUI), so that the communication connection establishment control (or UC prevention) can gain a high degree of acceptance. 
     The above and still further objects, features and advantages of the invention will become more apparent upon referring to the description and the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a diagram illustrating a communication connection establishment control scenario with UC prevention according to one example of an embodiment of the invention. 
         FIG. 2  shows a block circuit diagram of a network element comprising functions of the communication connection establishment control according to one example of an embodiment of the invention. 
         FIG. 3  shows a flowchart describing a process flow of a communication connection establishment control with UC prevention according to one example of an embodiment of the invention. 
         FIG. 4  shows a signaling diagram illustrating a first example of a call setup process based on the communication connection establishment control scenario with UC prevention according to  FIG. 1 . 
         FIG. 5  shows a signaling diagram illustrating a second example of a call setup process based on the communication connection establishment control scenario with UC prevention according to  FIG. 1 . 
         FIG. 6  shows a signaling diagram illustrating a third example of a call setup process based on the communication connection establishment control scenario with UC prevention according to  FIG. 1 . 
         FIG. 7  shows a signaling diagram illustrating a fourth example of a call setup process based on the communication connection establishment control scenario with UC prevention according to  FIG. 1 . 
         FIG. 8  shows a diagram illustrating a communication connection establishment control scenario with UC prevention according to a further example of an embodiment of the invention. 
         FIG. 9  shows a diagram illustrating a management system for configuring a communication connection establishment control with UC prevention according to an additional example of an embodiment of the invention. 
         FIG. 10  shows a block circuit diagram of a network element comprising functions of the management system according to the additional example of an embodiment of the invention. 
         FIG. 11  shows a diagram illustrating a graphical user interface used in the management system according to  FIG. 9 . 
         FIG. 12  shows a flowchart describing a process flow of setting communication connection establishment control scheme with UC prevention according to the additional example of an embodiment of the invention. 
     
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     In the following, examples and embodiments of the present invention are described with reference to the drawings. For illustrating the present invention, the examples and embodiments will be described in connection with a communication system which may be based on a 3GPP system where a voice based communication connection or session to a communication connection terminating node like a UE is tried to be established by a potential spammer. However, it is to be noted that the present invention is not limited to an application in such a system or environment but is also applicable in other network systems, connection types and the like. 
     A basic system architecture of a communication network may comprise a commonly known architecture of a wired or wireless access network subsystem. Such an architecture comprises one or more access network control units, radio access network elements, access service network gateways or base transceiver stations, with which a user equipment is capable to communicate via one or more channels for transmitting several types of data. The general functions and interconnections of these elements are known to those skilled in the art and described in corresponding specifications so that a detailed description thereof is omitted herein. However, it is to be noted that there are provided several additional network elements and signaling links used for a communication connection or a call between user terminals and/or servers than those described in detail herein below. 
     Furthermore, the network elements and their functions described herein may be implemented by software, e.g. by a computer program product for a computer, or by hardware. In any case, for executing their respective functions, correspondingly used devices, such as an application server or network control element, like a voice application server or a P-CSCF (Proxy Call State Control Function), comprise several means and components (not shown) which are required for control, processing and communication/signaling functionality. Such means may comprise, for example, a processor unit for executing instructions, programs and for processing data, memory means for storing instructions, programs and data, for serving as a work area of the processor and the like (e.g. ROM, RAM, EEPROM, and the like), input means for inputting data and instructions by software (e.g. floppy diskette, CD-ROM, EEPROM, and the like), user interface means for providing monitor and manipulation possibilities to a user (e.g. a screen, a keyboard and the like), interface means for establishing links and/or connections under the control of the processor unit (e.g. wired and wireless interface means, an antenna, etc.) and the like. 
     According to one example of an embodiment of the invention, a communication connection establishment control comprising a SPIT/UC prevention is based on the use of services such as already existing supplementary services and suitable combinations thereof. The services may comprise, for example, SCR (also referred to as blacklisting or blacklist check), where it is determined whether an identification element or number of a calling party requesting a setup of a communication connection matches a stored identification of calling parties to be rejected. Another service may be SCA (also referred to as white listing or whitelist check), where it is determined whether the identification element of the requesting calling party matches a stored identification of calling parties allowed to be connected to the subscriber. Moreover, a corresponding service may comprise conditional call forwarding, e.g. based on a time of day or to another destination than that indicated in the request. Also other services or functions may be used, such as, for example, forwarding a request to the calling party for returning an authentication (like a character based authentication code or PIN) for allowing the establishment of the communication connection and checking the received authentication. This function, which is also referred to as PIN over-ruling of the whitelist, can be implemented either in form of a separate service portion or be combined with other services, in particular SCA or the like. Another service or function may be sending an announcement (like a speech message) to the calling party, the announcement may indicate information usable for deriving an authentication (like a character based authentication code or PIN) usable for getting allowance for the establishment of the communication connection. The authentication code or PIN on which this function or service is based may be checked in a similar manner as the authentication code or PIN related to the PIN over-ruling of the whitelist, i.e. it may be checked by the SCA service, for example, as another PIN over-ruling of the whitelist. Parameters used for the services may be set and/or configured in a communication connection establishment control profile for a subscriber. Resources to store and to execute the services for the UC or SPIT prevention may be provided by the communication network, such as a VoIP network or PSTN, while the configuration and the management of the UC prevention scheme (the communication connection establishment control profile) is performed by the user. It is to be noted that some of functions for the UC prevention, such as a CAPTCHA (Completely Automated Turing test to tell Computers and Humans Apart) module (described later) may be implemented in a user equipment. 
     As a first example of an embodiment of the invention, reference is made to  FIGS. 1 to 7 .  FIG. 1  shows a diagram illustrating a communication connection establishment control scenario with UC prevention giving an overview of a UC prevention scheme that is realized by using supplementary services provided by the voice network and a function (here, an audio CAPTCHA) in the user equipment.  FIG. 2  shows a block circuit diagram of a network element of  FIG. 1  (the Voice Application Server or VAS) comprising functions of the communication connection establishment control.  FIG. 3  shows a flowchart describing a process flow of the communication connection establishment control with UC prevention according to  FIG. 1 .  FIGS. 4 to 7  show signaling diagrams illustrating different situations, depending on the kind of the calling party, when a call setup process based on the communication connection establishment control scenario with UC prevention according to  FIG. 1  is executed. 
     In  FIG. 1 , reference sign  2  denotes a caller (UE A) which is requesting a communication connection establishment and may be a potential UC sender or “SPITter”. Reference sign  3  denotes a called subscriber of the network (UE B), i.e. the potential SPIT/UC victim. Reference sign  1  denotes a network element (or several network elements, depending on the corresponding network structure), like the VAS, where the communication connection establishment control with UC prevention is executed. In this network element  1 , a combination of several functions based, for example, on the above mentioned services is executed in a predetermined order (i.e. with a priority for the respective services). 
     In detail, according to this example of an embodiment of the invention, the communication connection establishment control comprises a blacklist check function  11 , a whitelist check function  12 , and an authentication code (or Personal Identification Number/PIN) check function  13  (the whitelist check function  12  and the authentication code check function  13  may be implemented by a same function set which is indicated by a dashed line). These functions may be located centralized in one network element, like the VAS  1 , or may be arranged in a distributed manner in several different network elements with the VAS  1  as a linking and controlling network node. 
     Furthermore, a consent mailbox (CMB)  4  is provided as a device useable to send an announcement to the calling UE A (described later) which may be part of the UE B or provided by another network element or be part of the VAS  1 . The announcement may be a voice message or another type of message, such as a Short Message Service (SMS) signaling or the like. 
     By means of the above described services and functions, the present example of an UC prevention or communication connection establishment control according to an embodiment of the invention is composed of a black list check, a white list check, elements of a grey list, a consent-based communication and Turing tests. It is to be noted that the order of corresponding services may be different to that of  FIG. 1  in other examples, for example, by conducting first a whitelist check, or the like. 
     In the following, the structure and function of a network element used in the communication connection establishment control scheme as illustrated in  FIG. 1  and corresponding to the VAS  1  is described in connection with  FIG. 2 . 
     In  FIG. 2 , a block circuit diagram of a network element like an application server implementing an UC prevention, for example the VAS  1  of  FIG. 1 , according to an example of an embodiment of the invention is shown. It is to be noted that the network element may comprise several further elements or functions besides those described in connection with  FIG. 2  which are omitted herein for the sake of simplicity as they are not essential for understanding the invention. 
     The network element  1  for performing the UC prevention (referred to as VAS hereinafter) according to  FIG. 2  comprises a processing function or processor  21 , such as a CPU or the like, which executes instructions given by programs or the like related to the processing shown in  FIG. 3  (described later). The processor  21  is in particular used for setting and executing the UC prevention scheme. Reference signs  22  and  23  denote input/output (I/O) units connected to the processor  21 . The I/O unit  22  may be used for communicating with the network (for example, network elements providing services used for the UC prevention, such as SCR, SCA etc.), and to the CMB  4  for initiating the transmission of the announcement. The I/O unit  23  may be used for communicating with the UE B (or an intermediate proxy leading to the UE B). The I/O units  22  and  23  may also be combined in one member, such as a transceiver unit or the like, or may comprise a distributed structure with a plurality of different interfaces. Reference sign  24  denotes a memory usable, for example, for storing data and programs to be executed by the processor  21  and/or as a working storage of the processor  21 . 
     Reference signs  25  to  30  denote portions or functions comprised in the processor  21 . It is to be noted that these portions  25  to  30  may represent either function blocks which provide the respective function by itself (e.g. in form of a program executed by the processor  21 ) or communication portions providing a link to another (external) server or the like which provides the respective function. Reference sign  25  denotes an anti UC profile setting portion by means of which the communication connection establishment control profile of the subscriber is setup. Reference sign  26  denotes a blacklist service portion (like SCR) which provides a blacklist check. Reference sign  27  denotes a whitelist service (like SCA) portion which provides a whitelist check. Reference sign  28  denotes a PIN service portion as an authentication check which provides a PIN request and determines whether the correct PIN is received, for example. The PIN service portion  28  may be a separate function or part of the whitelist (SCA) service portion  27 . Reference sign  29  denotes a Turing service portion which provides a Turing test (for example, CAPTCHA) via the CMB  4 , for example. It is to be noted that an authentication code or PIN which may be indicated by the Turing test is checked in a similar manner as the (first) authentication code, i.e. by the PIN service portion  28 . Reference sign  30  denotes a connection rejecting/forwarding portion which rejects or forwards the communication connection, depending on the results achieved by the services used for UC prevention. 
     Next, the process flow of the communication connection establishment control or UC prevention according to the example of an embodiment of the invention is described with reference to  FIGS. 1 and 3 .  FIG. 3  shows a flow chart of a method executed by an apparatus comprising the elements and functions of the VAS  1  and the CMB  4  according to  FIG. 1  for executing the communication connection establishment control according to the example of an embodiment of the invention. 
     As a first step, in S 10 , an anti UC profile for the communication connection establishment control is setup. For example, settings and parameters provided by a subscriber for a communication connection establishment control scheme with UC prevention in a communication connection establishment control profile are implemented in the network element  1 . Based on this profile, the services used for the UC prevention are set, as described below. 
     Next, in step S 20 , a caller (UE A) is trying to establish a communication connection like a voice call towards the subscriber (UE B) wherein a corresponding setup request (e.g. SIP INVITE or the like) is received at the VAS  1 . Due to the set anti UC profile, UC prevention processing as described below is executed. 
     In step S 30 , for example in the blacklist check function block  11 , a first check using a service (supplementary service) like ‘Selective Call Rejection’ (SCR) is executed. In this service, identification elements or numbers provided by the setup messaging for identifying the UE A are checked by using a black list (BL) that rejects all matching numbers, for example by means of a denial announcement or the like to the UE A. This functionality is used to ward off known ‘SPITters’ directly when they try to get access to subscriber B. Thus, if the first check is positive (i.e. there is a matching entry in the BL), then step S 80  is executed where the setup request is rejected. 
     Otherwise, if no matching entry is found, step S 40  is executed where a second check using another service like “Selective Call Acceptance” (SCA) is executed. In this service the identification elements or numbers provided by the setup messaging for identifying the UE A are checked by using a white list (WL), for example in the whitelist check function block  12 . Callers matching an entry on the WL may be directly put through to the subscriber UE B  3  (step S 90  in case the determination in step S 40  is positive). It is to be noted that, while it is not so difficult to circumvent a BL, e.g. by address spoofing, it is more difficult to guess the entries of a WL. 
     However, there may be a problem with WL check that no other callers than those matching the White List are able to reach the subscriber B. Consequently, not only ‘SPITters’, but also legitimate callers may be excluded when using this whitelist check. Thus, in order to solve a problem which could be summarized as “how do I get on the White List?”, also referred to as introduction problem, the communication connection establishment control according to the present example of an embodiment of the invention further comprises a consent-based communication. 
     Accordingly, in case the determination in step S 40  is negative, i.e. no matching WL entry is present for the identification of the caller, a service referred to as “Selective Call Acceptance” or the like is executed in step S 50 . Here, an authentication request is sent to the UE A indicating to the user of the UE A that an authentication code, like a PIN or the like, has to be returned before allowing the call to subscriber B. The PIN or the like allows overriding the WL. In other words, a user not matching the WL is asked by an announcement to enter a valid PIN. Then in step S 60 , it is checked whether a correct PIN or the like is received. This may be effected by the same function which checks whether a matching WL entry is present (like SCA). This checking may comprise, for example, a detection whether a (correct) PIN is returned within a predetermined time and whether the returned authentication code (PIN) corresponds to a stored master code (Master PIN) or the like, and may be executed by the function block  13  (or  12  if function block  13 &#39;s function is part thereof, as indicated above). 
     When the determination in step S 60  is positive, i.e. the correct PIN is received within a predetermined time period, the caller (UE A) is put through to the subscriber B (step S 90 ). 
     Otherwise, in case the determination in step S 60  is negative, step S 70  is executed. Here, a Turing test, such as a CAPTCHA test, is initialized. For this purpose, the caller may be forwarded to the Consent Mailbox (CMB)  4 . The CMB  4  can be either at user&#39;s site or it can be a network-based mailbox. The CMB performs now the Turing test where an announcement, like a speech message generated by the network or the subscriber, is sent to the UE A. This is in particular useful for preventing the subscriber B from being called by SPIT/UC automata, e.g. PCs or the like. For the Turing test, the CMB sends a message indicating, for example, a question or the like for asking the caller a riddle where the solution of the riddle is an authentication code allowing the forwarding to subscriber B, for example, by means of the function block  13 . The authentication code retrievable by the announcement may be different from the (first) authentication code asked in step S 50 , or may be the same code. Usually, the information provided by the announcement is only useful by a human so that the question leading to the (second) authentication code can not be solved by machines or the like being part of a SPIT/UC automata. As every subscriber is able to create his personal announcement, it is difficult to circumvent this Turing test, as the question has really to be understood and solved. If a human caller is able to solve the Turing test, he now possesses a correct PIN or the like and is able to call subscriber B again wherein the call can be established then in step S 60 , i.e. after entering a correct PIN. Since this second call causes additional cost plus additional time, this part of the UC prevention scheme is thus comparable to a grey list whose functionality is based on human behavior. Furthermore, since this procedure may lead to additional costs and time consumption, a human ‘SPITter’ with commercial interest is usually not willing to contact the subscriber B again. 
     It is to be noted that the Turing test in step S 70  and correspondingly the processing of the CMB  4  may comprise a further function in which the caller is given the possibility to leave a message for the subscriber B, e.g. the request to call him back, which can be retrieved by subscriber B. Also identification information of the UE A may be stored for later processing by the subscriber (e.g. entry in one of the BL and WL, or for a call-back function). The message and/or information may be stored in the CMB  4  or in another storage, depending on settings of the network operator and/or the subscriber (for example, an additional call forwarding to a personal mailbox of the UE B or the like may be set). 
     After the Turing test in step S 70 , i.e. the sending of the announcement to the UE A, the connection is ended, i.e. the setup request of UE A is rejected in step S 80  wherein a new call attempt, e.g. based on the retrieved (second) authentication code, can then be made by the caller UE A and correspondingly processed in the network. 
     It is to be noted that in case of a human ‘SPITter’ who has overcome all hurdles of the communication connection establishment control and nevertheless reaches subscriber B, this caller can be easily put on the BL (if not calling anonymously), so that he is blocked at the next call attempt. 
     Next, for illustrating the effects of an implementation of the communication connection establishment control according to the example of an embodiment as described above, in  FIGS. 4 to 7  different scenarios are explained by using schematic message sequences in a simplified network structure. It is to be noted that these signalling diagrams are not complete for any existing communication protocol (for example, connection release, timeouts or cancelled connections are excluded for simplicity). The diagrams are only for indicating the basic differences between the different scenarios. 
       FIG. 4  shows a case where a call setup between the UE A  2  and the UE B  3  is executed without a UC prevention scheme being implemented. 
     In step M 1 , an initial setup message (e.g. IAM or SIP INVITE) is sent to the network (e.g. the network element  1 ) and forwarded to the UE B so as to alert the subscriber (step M 2 ) and let the UE B ringing or the like. Corresponding return messages (steps M 3  and M 4 ) are returned to the UE A (e.g. ACM or SIP  180  ringing message). When the subscribed (UE B) answers the call (off-hook), this is again signaled towards UE A in steps M 5  and M 6  (e.g. ANM or SIP  200  OK message). Thus, the media connection is established between UE A and UE B. 
       FIG. 5  shows a case where a call setup between the UE A  2  and the UE B  3  is executed with the UC prevention scheme being implemented. In the scenario of  FIG. 5 , it is assumed that the identification element indicating the UE A, like the UE A&#39;s address information, is contained in the list of known ‘SPITters’ (blacklist for SCR). Thus, after the initial setup message (e.g. IAM or SIP INVITE) is sent to the network (e.g. the network element  1 ) in step M 11 , the network performs the communication connection establishment control with the blacklist check in step M 12  and determines that the call is to be rejected. Hence, in step M 13 , the setup request is rejected so as to block the call by the network while the UE B is not alerted. 
       FIG. 6  shows also a case where a call setup between the UE A  2  and the UE B  3  is executed with the UC prevention scheme being implemented. In the scenario of  FIG. 6 , it is assumed that the identification element indicating the UE A, like the UE A&#39;s address information, is neither contained in the list of known ‘SPITters’ (blacklist for SCR) nor part of the whitelist (SCA), but that the UE A knows the (first) authentication code or PIN. Thus, after the initial setup message (e.g. IAM or SIP INVITE) is sent to the network (e.g. the network element  1 ) in step M 21 , the network performs the communication connection establishment control with the blacklist check and the whitelist check in step M 22  and determines that there is not matching entry in the respective list. Hence, after being rejected by the SCA white list (i.e. the call is not forwarded to the UE B directly), UE A may enter a PIN or the like. For this purpose, in step M 23 , a request for an authentication code is sent back to the UE B. In step M 24 , the correct authentication code is returned from the UE A which is acknowledged by the network (e.g. network element  1 ). Therefore, like in  FIG. 4 , the setup is forwarded to the UE B so as to alert the subscriber (step M 25 ) and let the UE B ringing or the like. Corresponding return messages (steps M 26  and M 27 ) are returned to the UE A. When the subscribed (UE B) answers the call (off-hook), this is again signaled towards UE A in steps M 28  and M 29 . Thus, the media connection is established between UE A and UE B. 
       FIG. 7  shows also a case where a call setup between the UE A  2  and the UE B  3  is executed with the UC prevention scheme being implemented. In the scenario of  FIG. 7 , it is assumed that the identification element indicating the UE A, like the UE A&#39;s address information, is neither contained in the list of known ‘SPITters’ (blacklist for SCR) nor part of the whitelist (SCA), and that the UE A does not know the (first) authentication code or PIN. Instead, the UE A&#39; user is receiving a hint by an announcement, e.g. from a CAPTCHA module, and can reach establishment of the call to subscriber B in a second call attempt. In detail, after the initial setup message is sent to the network (e.g. the network element  1 ) in step M 31 , the network performs the communication connection establishment control with the blacklist check and the whitelist check in step M 32  and determines that there is not matching entry in the respective list. Hence, after being rejected by the SCA white list, in step M 33 , a request for an authentication code is sent back to the UE B. In step M 34 , no correct authentication code is returned (in time) from the UE A. When this situation is determined by the network (network element  1 ), a further check in the form of a Turing test or the like is initiated by the network. Hence, in step M 35 , the call is forwarded to the CMB (or an audio CAPTCHA device) on a further connection line, e.g. a like assigned to the subscriber B (URI B 2 ) so as to initialize the Turing test. At the CMB, the user of UE A may get a possibility to leave a message and/or to listen to an announcement (step M 36 ) that will help the user of UE A to find out a (second) authentication code or PIN for a subsequent call attempt. After sending the announcement (or storing the message from the UE A&#39;s user, the communication connection to the UE A is ended in step M 37 . With the (second) authentication code, a second call attempt can be made by the UE A (steps M 38  to M 46 ) leading to a media connection between UE A and UE B, wherein in step M 41  the authentication code derived from the message in step M 36  is entered by UE A. Steps M 38  to M 46  correspond to steps MM 21  to M 29  of  FIG. 6  so that a description thereof is not repeated herein. 
     It is to be noted that in case of using the audio CAPTCHA/PIN scheme to solve the white list introduction problem in a more general fashion, a question like asking the birthday may not be suitable. Instead, a puzzle solvable by the intended audience may be chosen (e.g. “the PIN is nine thousand minus one hundred twenty-three”). 
     With reference to  FIG. 8 , a further example of an embodiment of the invention is described.  FIG. 8  shows a diagram illustrating a further communication connection establishment control scenario with UC prevention giving an overview of a UC prevention scheme that is realized by using supplementary services provided by the voice network and a function (here, an audio CAPTCHA) in the user equipment. 
     The communication connection establishment control scenario with UC prevention according to  FIG. 8  is based on the communication connection establishment control scenario with UC prevention according to  FIG. 1 . Thus, elements having the same functions are provided with the same reference signs. Hence, in  FIG. 1 , reference sign  2  denotes the caller (UE A) which is requesting a communication connection establishment and may be a potential UC sender or “SPITter”. Reference sign  3  denotes the called subscriber of the network (UE B). Reference sign  10  denotes a network element (or several network elements, depending on the corresponding network structure), like a VAS, where the communication connection establishment control with UC prevention according to this example is executed. In this network element  1 , a combination of several functions based on several services is executed in a predetermined order (i.e. with a priority for the respective services). 
     In detail, according to this example of an embodiment of the invention, the communication connection establishment control comprises a blacklist check function  11 , a whitelist check function  12 , and an authentication code (or Personal Identification Number/PIN) check function  13 . As in the example of an embodiment of the invention shown in  FIG. 1 , the whitelist check function  12  and the authentication code check function  13  may be implemented by a same function set which is indicated by a dashed line, i.e. the function, which is also referred to as PIN over-ruling of the whitelist, can be implemented either in form of a separate service portion or be combined with other services, in particular SCA or the like. These and further functions (like functions  14  to  16  described below) may be located centralized in one network element, like the VAS  1 , or may be arranged in a distributed manner in several different network elements with the VAS  1  as a linking and controlling network node. The portions  11  to  13  may operate in basically the same manner like the portions  11  to  13  of  FIG. 1 , i.e. according to steps S 30  to S 70  of  FIG. 3 , for example. 
     Also a consent mailbox (CMB)  4  is provided as a device useable to send an announcement to the calling UE A (described later) which may be part of the UE B or provided by another network element or be part of the VAS  10 . The announcement may be a voice message or another type of message, such as a Short Message Service (SMS) signaling or the like. 
     In addition to the portions  11  to  13 , the communication connection establishment control scenario with UC prevention in the network element  10  comprises also additional functions. These functions can be set optionally and combined with the other services in selected priority orders. The function include, for example, a service for checking whether an instruction to block external communication connection establishment attempts is present, and if the instruction is present, rejecting the request for the establishment of the communication connection, such as a DND (Do Not Disturb) function  14 . Another function may include, for example, a service checking whether a specific communication connection forwarding instruction is present, and, when the specific communication connection forwarding instruction (like a permission to establish a communication connection to the subscriber only at predetermined periods of time, an instruction to setup the communication connection to another destination, an instruction to setup the communication connection to another destination only at predetermined periods of time, and/or an instruction to send the announcement (of the CMB) in case the result of the determining of whether the identification element of the requesting calling party matches a stored identification of calling parties allowed to be connected to the subscriber is positive is present), and handling the request for the establishment of the communication connection in accordance with the specific communication connection forwarding instruction, such as a CF (Call Forwarding or in particular a Call Forwarding based on time of day) function  15 . Moreover, another function may include a service detecting whether the calling party provides identification information usable for identifying the calling party, and, when the identification information is not detected, rejecting the request for the establishment of the communication connection, such as an ACR (Anonymous Call Rejection) function  16 . It is to be noted that as a further alternative an EACR (enhanced anonymous call rejection) service may be implemented as a corresponding function. In this EACR function (not shown in  FIG. 8 ) the caller is allowed to decide between giving up their privacy (i.e. identifying themselves by sending a usable identification element or the like), entering a PIN or speaking their name when calling a callee with EACR enabled. An EACR function may be implemented in a system as shown in  FIG. 8  in a similar way as the ACR function  16 . 
     Anonymous Call Rejection (ACR) can be enabled if subscriber B generally wants to exclude anonymous callers. This can be an effective measure as commercial ‘SPITters’ often use the anonymity feature whether allowed by legislation or not. Do Not Disturb (DND) allows to occasionally block all external callers if subscriber B does not want to be interrupted. Call Forwarding or Call Forwarding Time-of-Day (CFToD) is service that provides Black- and White Lists (can be selected by user) that can be additionally combined with time tables. This service can be used to further restrict the whitelist (based on SCA) in a time dependent way, e.g. so as to further restrict the whitelist during night time, for example, to forward calls to another destination address (such as another terminal like a mobile phone  31 , or to an office terminal  32  during specific times, or to the CMB  4 ). 
     The processing and structure of the communication connection establishment control scenario with UC prevention according to the example shown in  FIG. 8  are similar to those the example described in connection with  FIGS. 1 to 3 , regarding the functions  11  to  13 . 
     However, different to the example according to  FIGS. 1 to 3 , in the communication connection establishment control scenario with UC prevention according to  FIG. 8 , when the whitelist check results in a matching entry in block  12  or a correct (first) authentication is detected to be returned from the UE A in block  13 , the call may not directly be forwarded to the subscriber but processed by the services in accordance with functions  14  and  15 . In other words, it is checked, whether a general call blocking is set by the DND function block  14 . If such an instruction is present, rejection of the call is performed and signaled to the UE A  2 . Otherwise, if no call blocking is set, a call forwarding instruction is checked in function block  15 . That is, depending on a setting for the call forwarding (e.g. considering the time of day of the call), the call is forwarded either to the subscriber (UE B  3 ) or to another destination like a mobile phone  31  or an office number  32  of the subscriber. In addition, it is also possible that the call is forwarded to a mailbox or the like, like the CMB  4 , where the caller may store a message or the like or receive an announcement. 
     Also in case the authentication check function in block  13  leads to a result that the PIN or the like is not correctly received, the processing of the communication connection establishment control scenario with UC prevention in the present example may differ by providing the function block  16  where it is checked whether the caller has sent a (usable) identification element at all, i.e. whether the call is made anonymous or not. If it is an anonymous call, it can be set in the function block  16  to reject the call and to end the connection which is indicated to the UE A  2 . Alternatively, if an EACR service is used instead, the caller at UE A  2  is allowed to give up privacy (i.e. identifying himself by sending a usable identification element or the like), to enter a PIN or to speak his name. Corresponding inputs may be processed by the function block (not shown) providing EACR (corresponding to ACR block  16 ). Otherwise, in case an identification element as such is detected, the call can be processed further by starting the Turing test and setting up the CMB  4  correspondingly. 
     It is to be noted that the order of services as indicated in 
       FIG. 8  may be different in other examples. For example, the ACR check in function block  16  may be located at a higher priority level, for example as the first check to be made. Furthermore, as indicated above, the setting of the communication connection establishment control profile may be such that one or more of these services are activated/deactivated. 
     Next, a management system according to a further example of an embodiment of the invention for configuring and setting a communication connection establishment control scheme and profile for UC prevention is described with reference to  FIGS. 9 to 12 . 
     The management system according to the further example of an embodiment of the invention provides measures for generating and setting a communication connection establishment profile for a subscriber. For this purpose, for example, the operator of the network may generate or establish a preliminary communication connection establishment control scheme by defining and combining one or more services specified for the communication connection establishment control with UC prevention, such as the services described in connection with  FIGS. 1 and 8 . When the preliminary communication connection establishment control scheme is established, an interface for a subscriber, such as a graphical user interface (GUI) is provided comprising means for inputting instructions and/or data for generating a communication connection establishment control profile for the subscriber, wherein the subscriber uses the preliminary communication connection establishment control scheme as a template for tailoring his own profile. 
     The selected services may be provided by the operator in a specific order for execution, i.e. with a priority of processing. This order may be also set or changed by the subscriber when configuring the communication connection establishment control profile. 
     Basically, instructions and/or data input in the interface by the subscriber are processed by the management system so as to determine in which way the subscriber has configured his communication connection establishment control profile. On this basis, a final communication connection establishment control scheme is set which is used for processing a request for establishing a communication connection to the subscriber. 
     In the management system indicated in  FIG. 9 , reference sign  51  denotes a terminal (like a PC or the like) or the UE B of the subscribed by means of which the interface is displayed or the like to the user and instructions and/or data for the communication connection establishment control profile are entered. Reference sign  52  denotes the interface like the GUI provided by means of a web portal, like an Internet page based on HTML (Hyper Text Markup Language or the like) which is accessible by the subscriber  51 . Reference sign  53  denotes a management server which is connected or linked to the interface  52 . The management server provides the preliminary communication connection establishment control scheme, templates and data for generating the GUI, and retrieves the anti UC profile (the communication connection establishment control profile of the subscriber) based on the input instructions/data for configuring the final communication connection establishment control scheme. The management server is also connected to plural network elements  54 ,  55 ,  56  which may provide the services used in the communication connection establishment control. The management server may be part of the network element  1  or  10  according to  FIGS. 1 and 8 , or connected thereto as an external element. 
     According to the management system shown in  FIG. 9 , services such as supplementary service for UC prevention are selected combined in a specific order of priority for providing a comprehensive SPIT/UC prevention scenario. 
     In particular, the management system is used for the configuration and the management of the services by the user in the form of a coordinated SPIT/UC prevention scenario, and for offering the operator to prepare or establish preliminary communication connection establishment control schemes as a kind of template for the user setting. The setting of the subscriber may be done either by means of DTMF (Dual Tone Multi Frequency) setting or preferably by a Web interface provided by the operator. Moreover, additional means, such as an additional software layer, may be provided that gives the user the feeling to configure an interrelated and complete SPIT/UC prevention scenario, for example, wherein the management system is preferably also able to check whether the entries of the subscriber, such as entries into different lists (described later) are consistent, and whether the combination of services selected for the UC prevention is consistent. 
     Next, the structure and function of the management server  53  used in the management system for the communication connection establishment control as illustrated in  FIG. 9  is described in connection with  FIG. 10 . 
     In  FIG. 10 , a block circuit diagram of a network element  53  like a server implementing a management for an UC prevention, according to the further example of an embodiment of the invention is shown. It is to be noted that the network element  53  may comprise several further elements or functions besides those described in connection with  FIG. 10  which are omitted herein for the sake of simplicity as they are not essential for understanding the invention. 
     The management server  53  according to  FIG. 10  comprises a processing function or processor  531 , such as a CPU or the like, which executes instructions given by programs or the like related to the management of the communication connection establishment control described above. The processor  531  is in particular used for generating, setting and configuring the preliminary and final communication connection establishment control schemes and for processing the communication connection establishment control profile configured by the subscriber  51 . Reference signs  532  and  533  denote input/output (I/O) units connected to the processor  531 . The I/O unit  533  may be used for communicating with the subscriber, i.e. the web portal for the GUI  52 . The I/O unit  532  may be used for communicating with the network elements  54  to  56  providing different services for the UC prevention, such as SCR, SCA etc. The I/O units  532  and  533  may also be combined in one member, such as a transceiver unit or the like, or may comprise a distributed structure with a plurality of different units. Reference sign  534  denotes a memory usable, for example, for storing data and programs to be executed by the processor  531  and/or as a working storage of the processor  531 . 
     Reference signs  535  to  540  denote portions or functions comprised in the processor  531 . It is to be noted that these portions  535  to  540  may represent either function blocks which provide the respective function by itself (e.g. in form of a program executed by the processor  21 ) or communication portions providing a link to another (external) server or the like which provides the respective function. Reference sign  535  denotes service providing portion by means of which services to be used for the UC prevention can be designated and corresponding data necessary for setting the service can be retrieved. Reference sign  536  denotes a preliminary control scheme portion by means of which the (selected) services can be arranged in a preliminary communication connection establishment control scheme on which basis the further configuration of the UC prevention is executed. Reference sign  537  denotes a GUI generation portion by means of which the GUI for the subscriber&#39;s input can be generated on the basis of the preliminary communication connection establishment control scheme. Reference sign  538  denotes an input processing portion which processes the input instructions and/or data from the GUI, i.e. the communication connection establishment control profile, for the generation of the communication connection establishment control scheme. Reference sign  539  denotes a final control portion for establishing the final communication connection establishment control scheme. Reference sign  540  denotes an implementation control scheme for implementing the final communication connection establishment control scheme in a communication connection establishment control. 
     Assuming a case where the communication connection establishment control scheme has a structure corresponding to  FIG. 8 . Then, the management system generates a preliminary communication connection establishment control scheme comprising the functions indicated by blocks  11  to  16  of  FIG. 8 . Based on the architecture of  FIG. 10 , the subscriber  51  gets the information about the communication connection establishment control scheme by means of the GUI in the web portal  52  and configures the communication connection establishment control profile. This communication connection establishment control profile is then converted by the management server  53  into the final communication connection establishment control scheme wherein the services to be used for the UC prevention are set in accordance with the input instructions/data. 
     In  FIG. 11 , an example of the GUI according to an example of an embodiment of the invention is illustrated which is based on the communication connection establishment control scheme according to  FIG. 8 . The GUI represents a template for the preliminary communication connection establishment control scheme established by the operator. In the example according to  FIG. 11 , the services used for the UC prevention are arranged side by side on one layer or sheet. Alternatively, the services may be arranged on respective separate layers or sheets ordered one after the other, for example according to the priority of the respective service in the communication connection establishment control scheme. 
     In detail, the GUI comprises means for inputting instructions and/or data for assigning, for example, activation commands and parameters for parts of the communication connection establishment control profile. In the example of  FIG. 11 , there is provided, for example, activation means SW 1  for activating/deactivating the whole anti-UC feature (on/off). 
     In addition, there are provided an activation means SW 2  and data input means L 1  for a blacklist service comprising a selection to use blacklisting (on/off), and a list for specifying identifications of callers to be used as a part of the blacklist. Furthermore, an activation means SW 7  is provided which activates/deactivates a service allowing a later entry of numbers in the list L 1  on the basis of identification elements received from calling users when entering a specific blacklist entry code L 6  (to be entered prior to accepting the call/during the call/after terminating a call). 
     Furthermore, there are provided an activation means SW 3  and data input means L 2  for a whitelist service comprising a selection to use whitelisting (on/off), and a list for specifying identifications of callers to be used as a part of the whitelist. Moreover, there may be provided a service allowing an automatic entry of dialed numbers into whitelist wherein a corresponding activation means (on/off) may be also part of the GUI. 
     In addition, there is provided a set of services used as a whitelist bypass. 
     For using these services, there are provided activation means SW 4  for activating/deactivating a PIN service for using an authentication code or PIN (on/off), and input means for selecting (SW 5 ) a sort of PIN and for configuring (L 3 , L 4 ) the PIN (for example, a fixed number L 3  to be used as the PIN, or a specification of an algorithm or the like for dynamically setting an authentication, e.g. in the form of a date in mmdd (month-day) format+a predetermined number L 4  (here  5 )). As an alternative to the subscriber setting, a PIN or the like may be also preset by the network operator and communicated to the subscriber. 
     Moreover, there are provided activation means SW 6  for activating/deactivating a Turing test service using a CMB and CAPTCHA device (on/off), and input means L 5  for specifying a destination address where the call is to be forwarded, i.e. the address of the CMB, for example. The entry in L 5  may also be auto-configured by the network operator. 
     Furthermore, there are provided activation means SW 8  for activating/deactivating an ACR service for excluding anonymous calls without an identification element. A corresponding activation means may be provided also for an EACR service (not shown). 
     As also indicated in  FIG. 11 , there are provided means for instructing an edit function key or the like for the respective lists, i.e. for a manual introduction of additional numbers or for changing existing entries. Moreover, storing instruction means or keys are provided for storing the input instructions/data as a communication connection establishment control profile for the subscriber. In addition, the GUI may indicate costs for the activating the services, for example by allocating price information to parts of the interface related to one or more of the services. 
     In  FIG. 12 , a flow chart illustrating a process flow of setting a communication connection establishment control scheme with UC prevention according to the present example of an embodiment of the invention is shown. In  FIG. 1 , there are defined several functions F 1  to F 7  which may correspond to services described above. For example, F 1  may correspond to the SCR service, F 2  may correspond to the SCA service, F 3  may correspond to the PIN service, F 4  may correspond to the PIN Update service, F 5  may correspond to the Turing service using the CMB, F 6  may correspond to the post call service for adding to the BL, and F 7  may correspond to the ACR service. In addition, indications “0” and “1” are used for defining whether an activation means or switch SW 1  to SW 8  according to  FIG. 11  in the GUI is turned on (“1”) or off (“0”). 
     When in step S 100  the settings of the subscriber B in the communication connection establishment control profile are stored, the communication connection establishment control scheme is set in accordance with the input parameters. Therefore, in step S 110 , it is checked whether the UC prevention is activated at all by SW 1 . If it is not activated, then the functions F 1  to F 7  are deactivated in S 120  for the further processing of a communication connection establishment control and the processing is ended. 
     Otherwise, in case SW 1  is turned on, it is checked whether SW 2  is activated or deactivated. If it is activated, the SCR service (function F 1 ) is activated and the list entries L 1  are setup in the service (step S 140 ). Thereafter, the process proceeds to step S 150 . Otherwise, if it is determined in step S 130  that SW 2  is turned off, the process proceeds directly to  5150 . 
     In S 150 , it is checked whether SW 3  is activated or deactivated. If it is activated, the SCA service (function F 2 ) is activated and the list entries L 2  are setup in the service (step S 160 ). Thereafter, the process proceeds to step S 170 . 
     Otherwise, if it is determined in step S 150  that SW 3  is turned off, the processing is ended. 
     In S 170 , it is checked whether SW 4  is activated or deactivated. If it is not activated, the PIN service (function F 3 ) is deactivated in S 180 . If it is activated, the PIN service (function F 3 ) is activated in S 190 . Furthermore, in order to determine the type of PIN to be used, it is checked in S 200  whether a setting for a fixed PIN or a dynamic PIN on a per day basis, for example, is selected by the setting of SW 5 . If in step S 200  a fixed PIN is determined, step S 210  is executed for setting the PIN to the L 3  entry. Otherwise, if in step S 200  a selection of a PIN on a per day basis is determined, step S 220  is executed for activating the PIN Update service (function F 4 ) and setting the PIN according to the specified scheme based on the L 4  entry. 
     Then, step S 230  is executed for determining whether SW 6  is activated and a target destination for call forwarding (to CMB) is known (either a preset number from the operator or an entry in L 5 ). If the determination in S 230  is negative (no activation of SW 6  and/or no target destination being known), S 240  is executed where the Turing test service (function F 5 ) is deactivated. Otherwise, if the determination in S 230  is positive (activation of SW 6  and target destination being known), step S 250  is executed for activating the Turing test service and for setting a call forwarding destination to the number of the CMB, for example. 
     Next, step S 260  is executed where it is checked whether SW 7  is activated or deactivated. If it is not activated, the post call service (function F 6 ) is deactivated in S 270 . If it is activated, the post call service (function F 6 ) is activated in S 280  and the specified code to be used to introduce the caller identification in the blacklist is set. 
     Then, step S 290  is executed where it is checked whether SW 8  is activated or deactivated. If it is not activated, the ACR service (function F 7 ) is deactivated in S 300 . If it is activated, the ACR service (function F 7 ) is activated in S 310 . 
     Thereafter, the processing is ended. 
     By means of the management system defined in connection with  FIGS. 9 to 12 , it is possible to provide a flexible and comprehensible mechanism to configure and define a communication connection establishment control profile for UC prevention. The resulting communication connection establishment control scheme may comprise one or more services which are selected by the operator as useful tools against the UC and which are individually setup by the subscriber. 
     It is to be noted that the management system may also include tools and/or a corresponding GUI which are used by the network operator to configure what supplementary services are offered to subscribers under the anti-UC heading, i.e. to select which types of services are part of the preliminary communication connection establishment control scheme. Furthermore, these tools may be also useful to determine how the supplementary services are combined into anti-UC scheme, i.e. with which priority they are ordered. Moreover, it is also possible to provide tools allowing further pricing settings indicating to users for example extra price tags for blacklists or white lists above a certain size. 
     The above described communication connection establishment control with UC prevention can be implemented, for example, a P-CSCF (a SIP server), a Voice Application Server (VAS) and the like. 
     For the purpose of the present invention as described herein above, it should be noted that
         an access technology via which signaling is transferred to and from a UE may be any technology by means of which a user equipment can access an access network (e.g. via a base station or generally an access node). Any present or future technology, such as WLAN (Wireless Local Access Network), WiMAX (Worldwide Interoperability for Microwave Access), BlueTooth, Infrared, and the like may be used; although the above technologies are mostly wireless access technologies, e.g. in different radio spectra, access technology in the sense of the present invention implies also wirebound technologies, e.g. IP based access technologies like cable networks or fixed lines but also circuit switched access technologies; access technologies may be distinguishable in at least two categories or access domains such as packet switched and circuit switched, but the existence of more than two access domains does not impede the invention being applied thereto,   usable access networks may be any device, apparatus, unit or means by which a station, entity or other user equipment may connect to and/or utilize services offered by the access network; such services include, among others, data and/or (audio-) visual communication, data download etc.;   a user equipment may be any device, apparatus, unit or means by which a system user or subscriber may experience services from an access network, such as a mobile phone, personal digital assistant PDA, or computer;   method steps likely to be implemented as software code portions and being run using a processor at a network element or terminal (as examples of devices, apparatuses and/or modules thereof, or as examples of entities including apparatuses and/or modules therefor), are software code independent and can be specified using any known or future developed programming language as long as the functionality defined by the method steps is preserved;   generally, any method step is suitable to be implemented as software or by hardware without changing the idea of the invention in terms of the functionality implemented;   method steps and/or devices, apparatuses, units or means likely to be implemented as hardware components at a terminal or network element, or any module(s) thereof, are hardware independent and can be implemented using any known or future developed hardware technology or any hybrids of these, such as MOS (Metal Oxide Semiconductor), CMOS (Complementary MOS), BiMOS (Bipolar MOS), BiCMOS (Bipolar CMOS), ECL (Emitter Coupled Logic), TTL (Transistor-Transistor Logic), etc., using for example ASIC (Application Specific IC (Integrated Circuit)) components, FPGA (Field-programmable Gate Arrays) components, CPLD (Complex Programmable Logic Device) components or DSP (Digital Signal Processor) components; in addition, any method steps and/or devices, units or means likely to be implemented as software components may for example be based on any security architecture capable e.g. of authentication, authorization, keying and/or traffic protection;   devices, apparatuses, units or means can be implemented as individual devices, apparatuses, units or means, but this does not exclude that they are implemented in a distributed fashion throughout the system, as long as the functionality of the device, apparatus, unit or means is preserved,   an apparatus may be represented by a semiconductor chip, a chipset, or a (hardware) module comprising such chip or chipset; this, however, does not exclude the possibility that a functionality of an apparatus or module, instead of being hardware implemented, be implemented as software in a (software) module such as a computer program or a computer program product comprising executable software code portions for execution/being run on a processor;   a device may be regarded as an apparatus or as an assembly of more than one apparatus, whether functionally in cooperation with each other or functionally independently of each other but in a same device housing, for example.       

     As described above, there is proposed a mechanism for controlling a communication connection establishment to a subscriber using service comprising blacklisting, whitelisting, authentication request and/or Turing test for unsolicited communications prevention. Furthermore, there is proposed a management system used to configure a corresponding communication connection establishment control on the basis of an interface for the subscriber for defining a personalized communication connection establishment control profile. 
     Although the present invention has been described herein before with reference to particular embodiments thereof, the present invention is not limited thereto and various modifications can be made thereto.