Providing enterprise services in a service provisioning network

The invention relates to the provision of business services in a service delivery network, and in particular, but not necessarily, a method and system for providing business services in a service delivery network, a subscriber server and an edge control network node for use in such a system, and a computer program using such a method.

Background of the invention [0002] At present, many network operators are migrating to so-called next generation networks (NGNs), usually IP based communication systems such as the IP multimedia subsystem (IMS) developed by the third generation partner project (3GPP). IMS is designed to provide IP multimedia through mobile communication networks (standards

3GPP TS 22.228, TS 23.218, TS 23.228, TS 24.228, TS 24.229, TS 29.228, TS 29.229, TS 29.328 and TS 29.329). For fixed broadband services, such as voice transmission over an IP (VoIP) network, the ETSI TISPAN working group is further developing IMS (TS 24.229 standard: IP Multimedia Call Control Protocol based on SIP and SDP). Within the IMS architecture, the basic user subscription functions and IP session management are separate from the specific features of the VoIP service, e.g. number analysis, CLIP / R, call waiting, call exclusion, call waiting, etc. These services are supported by at least one trusted application server on the network.

[0003] Not only network operators, but also private organizations, e.g. enterprises, are beginning to migrate to IP-based communication systems. However, even the TISPAN architecture must still meet all the requirements associated with providing services to enterprises. In such an IP-based corporate network, usually called the next generation corporate network (NGCN), usually at least one private IP subscriber (IP-PBX) manages connections between enterprise communication devices (e.g., wired telephone, cordless telephone, software client) and interoperability with a network with circuit switching or with a network with packet switching. NGCN can be connected to a PSTN network or an IP-based network through a multi-link line, a single logical connection between two networks.

[0004] When connecting NGCN containing at least one IP-PBX to the IMS platform, the multiple link is the IP interface between the IP-PBX and the edge of the IMS platform, usually the session edge controller (SBC). Services offered by IP-PBX can be hosted locally. Currently, however, there is a visible trend of migrating these services to the network. In the IMS context, services associated with each IP-PBX, such as end-page connection services and / or start-up connection services and business multi-link services, host at least one application server connected to the IMS core.

[0005] Document WO 2007/103121 discloses a mobile application gateway for connecting devices in a cellular network with individual networks, such as company networks for

- 2 voice and data transmissions and / or networks in residential buildings. The method involves interconnecting the corporate network with the network providing the services by means of the edge control network node associated with the network providing the services, assigning the service request to the service network node and the application server implementing at least one business service based on the service request.

[0006] The ETSI TS 182 025 standard proposes two business multi-link schemes. The first scheme is associated with a subscription-based business multi-link scheme in which NGCN uses NGCN location registration in NGN, NGCN to NGN entry point location is P-CSCF. Registering a single NGCN location identifier results in hidden registration of a set of NGCN user identifiers. In this schema, the IMS Application Server (AS) can provide multi-link business services.

[0007] However, the business multi-link scheme has many disadvantages. One problem is that it requires that NGCN support IMS registration procedures (including associated authentication procedures). However, many existing NGCNs do not support IMS registration procedures, which severely limits the applicability of this schema.

[0008] IMS registration can be performed by "surrogate registration" using, for example, at least one session edge controller (SBC) between a non-IMS NGCN location and an IMS network. SBC - and in a broader context, many SBCs can do the registration on behalf of NGCN. For this reason, the SBC controller (s) should be provided with customer data (such as company identities and qualifications to register individual users on the network). In addition, client data would also be present in the IMS application server (AS), which would result in the client data being scattered across multiple entities. This situation is very undesirable, as it would significantly complicate the management of provided data and control of corporate data clients.

[0009] Another consequence of the registration procedure is that the identity of each NGCN user is uniquely associated with a single NGCN location. This excludes the possibility of having a variety of redundancy, load sharing and overfill prevention solutions where NGCN locations are connected through different routes (e.g. using different multiple links) with NGN.

[0010] To provide services to individual users in NGCN, individual IP-PBX registrations and (through hidden registrations) of NGCN users to the IMS platform are necessary. This requires that all individual user profiles of each IPPBX connected to the IMS core be stored in UPSF / HSS. Hence, every change in the configuration of NGCN users (e.g. transferring the employee to another location) in different NGCN locations would require changing the hidden registration sets in UPSF / HSS combined with general re-registration by all NGCN locations covered by this. In addition, NGCN may contain multiple IP-PBXs that can share at least one number range.

[0011] The second business multi-link scheme suggested in TS 182 025 is associated with the equivalence-based business multi-link scheme, in which NGCN is assumed to behave as an NGN peer-to-peer network. Such a scheme implies that NGN is not able to provide advanced services, including services similar to those provided by IP-PBX, to NGCN as an application server.

[0012] In this scheme, NGN only provides routing functionality defined by entities such as a domain name server. In addition, due to the idea of ​​a peer-to-peer network, there is no idea that NGN provides start page services and end page services to NGCN through application servers, as in the subscription-based multi-link business schema. All complex services, such as number / identity consolidation (e.g. transformation of the national number format into the international number format, etc.), validation of the caller's identity, selective blocking of destination locations, call forwarding, complex redundancy, load sharing and anti-overflow solutions covering shared number ranges are not provided for in such architecture.

[0013] Hence, there is a need in the art for improved methods, systems and network components that can provide efficient, centralized control of advanced services, including IP-based communication services, associated with NGCN networks.

Summary of the invention [0014] The object of the invention is to limit or eliminate at least one of the disadvantages of known service delivery systems. According to claim 1, in a first aspect, the invention may be associated with a method of providing business services in a service providing network, the method may comprise the steps of: connecting a corporate network to a service providing network using a connecting edge control network node associated with the service providing network; receiving a request from the network business service associated with the corporate network; and performing by the application server associated with the network providing the services of at least one business service based on the service request.

[0015] The method may also be associated with a method of providing business services in a service providing network, preferably in an IMS based service delivery network, in which the service providing network is connected via at least one multiple link, preferably through a connecting edge control network node, associated with a delivery network to at least one company network. The method may comprise the steps of: providing a service request associated with the corporate network; assigning company identifier and multi-link information to the service request; route the service request to an application server containing at least one business service associated with the corporate network; and the application server performing at least one business service using the company identifier and their multi-link information.

[0016] Connecting the company network via the connecting edge control network node does not require registration of the company network in NGN. Therefore, unlike known multi-link business schemes, it does not require IMS registration (including appropriate authentication and security assignment procedures) and allows NGN to provide advanced start-up services and advanced end-up services, e.g. through a standard IMS application server. In addition, it enables centralized concentration of all company data (such as company user data and company routing data) in a trusted application, and thus enables simple updating (either by the NGN provider or the enterprise itself) throughout the lifetime of the enterprise service.

[0017] According to the invention, the service request is a start page service request, preferably a start page connection service request, and / or when the service delivery network acts as a start page service delivery network.

[0018] In another embodiment, the method may also comprise the steps of: sending a start page service request to the connecting edge control network node associated with the service providing network; where the connecting edge control network node assigns the request to the company identifier and multi-link information; generating a start page business service request by inserting a company ID and multi-link information into the start page service request header.

[0019] Alternatively, the P-Asserted-Identity header containing the company identifier is inserted into the request header of the start page service.

[0020] According to the invention, the method also comprises the step of assigning the start page business service request to the service network node associated with the start page company network.

[0021] In one embodiment, the method may also comprise the steps of: providing a company profile network service node, preferably the company profile is provided by a subscriber server associated with the service delivery network; performing a company profile, preferably based on filter criteria in that company profile, where the company profile is configured to route the company request to an application server containing at least one start page business service associated with the start page company network.

[0022] In another embodiment, the subscriber server may perform at least one start page service based on the company identifier and their multi-link information.

[0023] In a further embodiment, the multi-link may provide a connection between the connecting edge control network node associated with the service providing network and the company network controller, preferably with a private subscriber, to provide services associated with the initial nodes in the area of ​​the company network.

[0024] In one embodiment, the company identifier includes the global catalog number (GDN) of the company network controller associated with the company network.

[0025] In another embodiment, the service request may be routed based on the company profile stored on the subscriber's server, where the company profile is associated with at least one wildcard character of user identifier ranges, enabling the service providing network to provide services to a specific user identifier in the scope one of their ranges of identifiers.

[0026] In a further aspect, the invention may be associated with a system according to claim 15 for providing business services, wherein the system may comprise: a service delivery network, at least one company network; connecting the edge control network node associated with the service providing network to connect the company network to the service providing network; and an application server associated with the network providing services to perform at least one business service based on the service request associated with the corporate network. The invention may also be associated with a start page business service delivery system, where the system may include: a service delivery network, preferably an IMS based service delivery network, at least one company network connected to a service delivery network connected through at least one multiple link; an edge control network node associated with the service delivery network and connected to this multiple link m, where the connecting edge control network node is configured to assign company identifier and multi-link information to a service request from the corporate network; subscriber server containing at least one company profile; a service network node configured to route the start page service request based on the company profile to at least one application server containing at least one start page business service associated with the company network.

[0027] In another aspect, the invention may be associated with a connecting edge control network node for use in the systems described above, wherein the connecting edge control network node may be configured to connect via a multiple link to a corporate network controller, preferably a private subscriber, associated with the company network, and where the connecting edge control network node is configured to receive the end-party business service request containing the company identifier and multi-link information, and where the connecting edge control network node is configured to select based on the company identifier and the multi-link information in this request business services of the end page of a company network controller, preferably a private subscriber exchange, to provide end page services to the end node in the corporate network area identified in the end page business service request.

[0028] The invention may also be associated with a computer program according to claim 20, providing business services in a service delivery network, wherein the network preferably comprises an IP multimedia subsystem (IMS), the computer program comprising software code fragments configured to perform at least one method step according to described above when running on the appropriate nodes

- 6 networks in the network providing services. The invention will be further illustrated with reference to the accompanying drawings, which schematically show embodiments of the invention. It is understood that the invention is in no way limited to these specific embodiments.

Brief description of the drawings [0029]

Fig. 1 is a schematic diagram of a service delivery system according to one embodiment of the invention.

Fig. 2 is a schematic of the system for providing start page services to NGCN according to one embodiment of the invention.

Fig. 3 is a schematic of the system providing end page services to NGCN.

Fig. 4 shows a sequence of operations for a start page connection according to one embodiment of the invention.

Fig. 5 shows a sequence of end-page connection actions.

Fig. 6 is a diagram of a subscriber server data model according to one embodiment of the invention.

Fig. 7 shows a diagram of a session edge controller according to one embodiment of the invention.

Detailed Description [0030] Fig. 1 is a schematic of at least one part of an NGN service delivery system 100 in a particular IMS based service delivery system for providing a service to at least one corporate network according to one embodiment of the invention.

[0031] The system includes at least one NGCN, ie, an IP based company network 102, 104 connected to the IMS platform 106. The IP-PBX 108, 110 control panels associated with these company networks are responsible for controlling the endpoints within the enterprise as well as for managing the required services. Endpoints (i.e. terminals) 112a, 112b, 144a, 144b used in a company network may include wired and / or wireless telephones, SIP telephones, etc.

[0032] The IMS core typically includes a set of connection session control functions (CSCF) including intermediate CSCF (P-CSCF) 116, interrogative CSCF (I-CSCF) 118 and service CSCF (S-CSCF) 120. Usually P-CSCF is the first contact within the IMS core, using routing information during registration to the IMS system, routes signaling messages (e.g. SIP INVITE invitation) to the S-CSCF associated with the user. I-CSCF is located at the edge of the edge of the domain and identifies the correct S-CSCF for each incoming SIP request and sends the request to this SCSCF. Her IP address is published in the DNS of the domain so that remote servers can find it. In addition, S-CSCF provides session control services and acts as a SIP recorder.

[0033] Registration with IMS requires the forwarding of the service profile associated with subscribers to IMS, which is stored in the home subscriber server database (HSS) 122 (sometimes also called user profile server function (UPSF)), to C-CSCF via Cx in standardized XML format. These service profiles contain routing information for routing signaling messages that either originate in or are addressed to a specific terminal or at least one trusted application server.

[0034] Application servers 128, 130 (AS) may include services, e.g. voice (VoIP) and / or multimedia services. The VoIP application server can provide a minimal set of functions to support call routing to and from NGCN, monitoring and invoicing requirements. In addition, at least one application server may include multi-link services, such as overflow services, in which specific multi-link sets are grouped in an ordered list to handle traffic in a certain way and / or overflow service, with the list multiple links that are part of the same set of multiple links will be used in a certain way to handle traffic.

[0035] If NGCN is based on a subscription based business multi-link scheme, IP-PBX registration to IMS may include SBC 132 registering on behalf of NGCN both IP-PBX and all individual terminals associated with IP-PBX via P-CSCF 116 to the IMS core. Such registration process may involve the transmission of a registration signaling message, e.g., SIP REGISTRATION registration message, by SBC and P-CSCF to the I-CSCF of the IMS core. I-CSCF selects the suitable S-CSCF based on information provided by the HSS. The registration message can then be sent to the serving S-CSCF for the UE to authenticate the user. After successful authentication and registration, the HSS may provide S-CSCF with service routing information that may be included in or associated with the service profile. Based on the service routing information, S-CSCF can register IP-PBX with at least one service to at least one application server by sending a registration message (such as the SIP REGISTER registration message) to the application servers identified in the service routing information. Services can be identified by a set of initial filter criteria (iFCs) in or associated with a user's service profile.

[0036] iFC can generally be regarded as service routing rules comprising a filter part and a decision part, the filter part comprising so-called call points that define at least one filter criterion applied to the incoming service message. The decision part defines the action (s) to be taken when the incoming message meets the filter criteria. In this way, the iFC contains information to determine whether or not a SIP message should be routed to a service located on a specific application server.

[0037] iFC are defined in the standard in paragraph B.2.2 of document TS 129 228, which is hereby incorporated by reference in this application. iFC may contain at least one trigger point, i.e. a Boolean algebra flag, as defined by the set

- 8 conditions to be met by the SIP request and at least one SIP URI of the application servers to which the request should be routed when the trigger point is the logical TRUE value. If the trigger point is the Boolean value, it will not be routed to the application server containing the service identified in iFC.

[0038] However, in the system of Fig. 1, NGCN networks are not necessarily connected to the IMS platform based on a subscription-based multiple business link scheme. Unlike conventional diagrams, the system of Fig. 1 also provides for at least one IP-PBX 112, 114 NGCN network that does not register in the IMS core but instead is directly connected via at least one multiple link to the interconnecting edge control function 124 (I-BCF) which can be connected to SBC 126, which usually deals with edge control for the SIP signaling interface, topology hiding, and connecting to non-IMS networks.

[0039] The multi-link provides an IP interface between the corporate network and the interconnecting edge control function (IBCF), the edge of the IMS platform, and includes the IP address and port number in the IMS core and the IP address and port (virtual) IP number of the enterprise PBX. A multiple link is assigned to a set of multiple links, which is a set of multiple links that NGCN can use to move to and from specific ranges of numbers (i.e. another range of phone numbers that can be used on the multi-link set by the company as the source / destination for SIP sessions).

[0040] In the embodiment shown in Fig. 1, I-BCF can be implemented in a session edge controller (SBC). Alternatively, in another embodiment, IBCF may be implemented at the IMS session layer. To establish a connection to I-BCF, IMS is either configured with the static IP address of the IP-PBX, or is configured with the domain name of the client's network, which is then used to obtain the IP-PBX IP via DNS.

[0041] The direct interconnection between NGCN and NGN via I-BCF provides the advantage that IP-IBX and individual users associated with NGCN do not need to register in the IMS core. Hence, problems with SBC "surrogate registration" can be avoided and NGN can be enabled to provide NGCN services, including multi-link services, through an application service. The advantages of using such a multi-link business scheme without registration will be apparent with reference to Fig. 2-7 as described below.

[0042] Fig. 2 is a schematic of a system 200 for providing home page services to NGCN according to one embodiment of the invention. In this configuration, NGCN 202 is interconnected via I-BCF 204 and I-CSCF 206 to S-CSCF 208 of the IMS platform. Therefore, for NGCN, the entry point to NGN is the I-BCF function (and not the P-CSCF function). In addition, neither NGCN nor its end users are explicitly or secretly registered to the IMS core. Instead, the HSS 210 IMS platform contains an unregistered position in the HSS to

- 9 uses for initial devices. Through an unregistered start page position in HSS (UPSF), NGN has the ability to provide start page business multiple-link services via the 212 IMS application server for connections leaving NGCN and entering NGN.

[0043] Similarly, Fig. 3 is a schematic of a system 300 providing an NGCN end-page service. Also in this case, the starting point of NGN to NGCN 310 is the IBCF 308 function (and not the P-CSCF function). In addition, neither NGCN nor its end users are explicitly or secretly registered to the IMS core. Through an unregistered end-page position in HSS (UPSF), NGN has the ability to provide end-to-end business multiple-link services via a 304 IMS application server for connections leaving NGN and entering NGCN. Diagram of a business multiple link without registration, described with reference to Fig. 2 and 3 provides the advantage that, with respect to known multi-link business schemes, it does not require IMS registration (including relevant related authentication and security procedures) and allows NGN to provide advanced start page services and advanced end page services, e.g. through an IMS application server . In addition, it enables centralized concentration of all company data (such as company user data and company routing data) in a trusted application, and thus enables simple updating (either by the NGN provider or the enterprise itself) throughout the lifetime of the enterprise service.

[0044] Fig. 4 shows the connection originating in the IP-PBX of NGCN towards NGN. SIP signaling must be routed to the application server (AS) assigned to provide initial device services to NGCN (corporate network). In this case, the starting page signaling path can be IP-PBX -> SBC -> I-CSCF -> S-CSCF -> AS.

[0045] The IP-PBX may be provided with the SBC host name or IP address and may send a connection attempt to this address. SBC can be provided with the IP address of the IP-PBX and based on this address SBC recognizes both the incoming multi-link set and the client, e.g. a user in a corporate network. This information can be used to fill the GDN P-Asserted-Identity header, i.e. the IPPBX global catalog number associated with the corporate network. The SBC may then send a request to the ICSCF provided.

[0046] I-CSCF can perform regular IMS start page support and uses the P-Asserted-Identity header to search for S-CSCF. S-CSCF also relies on the P-Asserted-Identity header when searching for AS. In addition, the AS may use the PAsserted-Identity header to search for another reserved network that contains user-specific settings.

[0047] IP-PBX can initiate connection with the IMS platform. In this case, IP-PBX can provide the desired destination and, optionally, a direct outgoing call (DDO) number that starts the connection. In no registration mode number

- 10 (DDO) and PBX are not registered in the IMS core. Instead, IMS services are delivered to DDO PBX numbers with unregistered start page service profiles provided in HSS. Start page multi-link services can be provided by an AS that includes multi-link services.

[0048] The sequence of start page connection actions of Fig. 4 starts with IP-PBX sending the INVITE invitation message to the IMS platform (step 402). The INVITE message complies with the basic RFCs for SIP in the scope of the initiating INVITE message. The entry point for the IMS platform is I-BCF / SBC. I-BCF / SBC adapts the INVITE message and makes the following modifications of the INVITE message (modified and / or added fields are shown in bold): modification of the INVITE message to support the specific SIP communication method of the IP-PBX exchange to the IMS form; modification of the SIP URI domain names for the external IMS domain [HomeDomain] to form the internal IMS domain [HomeDomain]; adding the P-Asserted-Identity header with the company's global catalog number (GDN) (i.e. the enterprise’s default default number); adding a routing header that points to I-CSCF and includes the "orig" parameter (initial device); and adding a contact header containing contact information for contacting the IPPBX of the start page including the address and port associated with IP-PBX in the "trunkcontext" parameter and the multi-link group in the "tgrp" parameter.

[0049] Hence, the "tgrp" (multiple link group) and "trunk-context" parameters are used to identify the appropriate multiple link between IP-PBX and SBC. In particular, the "tgrp" parameter can identify the VLAN associated with the IP address on the SBC (see also Fig. 7), and the "trunk context" parameter (i.e. domain name or company identifier) ​​can identify the enterprise using a multi-link connection identified by the " tgrp. " In this way, corporate multi-link connections can be uniquely identified using these parameters. Other header parameters, such as SbcIP and IpPort, identify the IP address and IP port of the SBC controller, respectively.

[0050] Furthermore, the P-Asserted-Identity header (representing NGCN) created by SBC is then used by S-CSCF to locate the corresponding initial filtering criterion. The P-Asserted-Identity header uses the enterprise's global catalog number (GDN) as part of the user.

[0051] Then, the SBC sends the adapted INVITE message to I-CSCF (step 404). Based on the "orig" parameter in the routing header and the global catalog number (GDN) of the IP-PBX in the P-Asserted-Identity header, I-CSCF queries the HSS to assign the S-CSCF assigned to IP-PBX (step 406) . HSS returns the S-CSCF assigned for IP-PBX support. Then, the I-CSCF sends a start page processing request to this S-CSCF (step 408). I-CSCF and S-CSCF may treat INVITE messages as start page messages due to the use of the "orig" parameter in the routing headers.

[0052] If this has not yet been done, the S-CSCF receives the user profile from the HSS (step

410) and performs filtering criteria for the unregistered initial SIP request associated with IP-PBX, which results in the request being sent to the AS. After receiving the start page INVITE message (step 412), the AS may perform certain actions. Maybe for example:

- carry out post-connect call control and reject after start page linking if the incoming call control limitations are exceeded; carry out the validation of the A number and the standard A number;

- perform the initial page functions associated with the initial page user and initial user enterprise;

- replace the P-Asserted-Identity header with a validated and normalized number A;

- complete the heading 'From' with the validated and normalized number A;

in the event that the From: number does not match the range for the enterprise, the global enterprise dn will be used in the From: header;

- normalize the destination number in the Request URI message and the "To" header;

- return the INVITE message to the S-CSCF start page for further routing of the request.

[0053] Validation of the number A comprises the steps of matching the number of the calling party taken from the "From" header with respect to the number ranges assigned to the multiple links associated with IP-PBX. These number ranges are stored in HSS in the user profile associated with HSS. If the number matches the search, the calling party is considered validated. In case the "From" number does not match the range of numbers assigned to IP-PBX, then the global catalog number (GDN) will be used in the From: header. In addition, the DisplayName value is overwritten here by the display name defined in AS.

[0054] In particular, the application server can be used to implement various number normalization. For example, it can convert [No.No.] (E.g., number in national format) to [No.Loc.Doc.] (In international format beginning with the + sign) and can convert [No.No.] (E.g. in national format) to [Normalized From] (in international format starting with the + sign).

[0055] Next, the session request is sent to the S-CSCF and continues as a standard start page session request (steps 414 and 416) to the destination. S-CSCF (early) may ask ENUM for the calling party's number. The connection is then routed based on the information returned to ENUM.

[0056] Fig. 5 shows a sequence of operations of the end page connection. The sequence of actions of the end page connection shows the sequence of actions of the SIP message for the connection

End page PBX. Signaling for connection to IP-PBX is routed through the AS via the IMS core to IP-PBX. The signaling route is I-CSCF -> S-CSCF-> AS -> SCSCF -> SBC -> IP-PBX.

[0057] Under this scheme, the direct dial-in (DDI) numbers of the PBX, ie the numbers associated with users in NGCN and the PBX itself are not recorded in the IMS core. Routing to the DDI number is based on static data, and IMS services are delivered to PBX numbers with end-site service profiles not registered in the HSS. AS is used for end-page services, including end-page multi-link services, which results in the selection of a multi-link connection to IP-PBX.

[0058] For end page routing, the I-CSCF may perform a HSS lookup of the called page number, which returns the assigned S-CSCF. In addition, the S-CSCF may use the called page number to receive a service profile that includes a filter criterion, resulting in AS involvement. AS uses the called page number to determine which NGCN the user belongs to, and then performs the business multi-link functions. Then, the AS may return a request with the output multi-link group ID (trkgID) selected in the URI request message to S-CSCF. The trkgID domain name can be an external domain name, and on this basis, S-CSCF can search for that external domain name and send a request to the found host. This host can be I-BCF / SBC, which, based on trkgID and the "tgrp" parameter in the URI request message, specifies the IP-PBX company address and sends an INVITE message to this address.

[0059] The sequence of operations of the end-page connection of Fig. 5 comprises the following steps. After the AS finishes the start page of the start page services, the request for routing the end location can be returned to the S-CSCF of the start page. Then the start page S-CSCF queries ENUM, whereby the result indicating the destination number is part of the IMS. Then S-CSCF sends a request to I-CSCF (step 502 in Fig. 5). Later, the I-CSCF polls the HSS with the page number called from the RequestURI message to locate the end-page S-CSCF (step 504) and sends the INVITE message to the end-page S-CSCF (step 506).

[0060] If this has not yet been done, the S-CSCF of the end page downloads the HSS service profile and assesses the filter criterion for the unregistered end page service. The end page S-CSCF sends a request to the AS for the end page services (step 508). Then, after receiving the INVITE, AS end page message can:

- provide end-user services such as call forwarding;

- perform end-page multi-link services, such as load balancing, overflow, and backup, resulting in an outbound multi-link selection;

- complete the ongoing INVITE message with the "tgrp" and "trunk-context" parameters to describe routing to the appropriate SBC and appropriate multiple link between the SBC and IP-PBX of the NGCN network;

- put the normalized destination number (DDI) in the heading 'To'; and / or

- send an INVITE message to S-CSCF as a new unexpected (OOTB) end page session request. This request does not contain odi generated by S-CSCF.

[0061] The end page application server may use the pilot catalog number [PilotowyNrKat] (ie the general default number of the specified IP-PBX), the edge gateway [Edge Gateway] and the routing domain [Routing Domain] to route the session to the appropriate SBC. In addition, the INVITE message sent from the server to the S-CSCF is considered a new session so that it can be routed to I-BCF instead of to P-CSCF. This is achieved by omitting any original dialogue identifiers in this INVITE message.

[0062] After the end page services have been performed, the modified request message is sent to the S-CSCF (step 510). After receiving the INVITE message with the external domain name, S-CSCF can perform the next hop network element lookup that connects to the external domain name and sends a request to it. The next leap can be solved by S-CSCF-based table search or, alternatively, by DNS query. The resulting host name is SBC used for the VoIP connection. In further embodiments, the embedded IBCF could be returned and the IBCF specifies the SBC to be used.

[0063] The S-CSCF may then send an INVITE message to the SBC (step 512), which may select IP-PBX based on the URI request domain name and the "tgrp" parameter. In particular, SBC may convert the internal domain [Home Domain] to the external domain [EndCompany Domain]. The [EndCompanyName] value is taken from [Company ID]. The SBC may change the SIP type specific SIP header of the PBX and send the request to IP-PBX (step 514). After receiving the INVITE message, the IP-PBX exchange provides the called party with the end page service.

[0064] In the sequence of operations described with reference to Figs. 4 and 5, multi-link services in the AS may use the multi-link URI parameters specified in RFC 4904 to identify the inbound multi-link from IP-PBX and outbound multi-link in the IP-PBX direction. The RFC document defines two parameters: the "tgrp" parameter and the "trunk-context" parameter.

[0065] Fig. 6 is a schematic layout 600 of an HSS data model according to one embodiment of the invention.

[0066] The HSS may include the enterprise's private identity 602. This private identity can be associated with a hidden registration set containing the SIP wildcard and a TEL entry for a range of 604, 606 customer numbers. The registration set is connected to the subscriber service profile 608 to IMS.

[0067] Hence, HSS may support a wildcard character mechanism that can be used to represent a range of numbers in HSS. For example, a single HSS registration set can contain up to 10 items. Each number or range of numbers must be defined as tel and sip uri, so it requires 2 items. This results in the fact that one registration set in the HSS can store up to five numbers / number ranges. In case the enterprise requires more than 5 ranges of HSS numbers it can be equipped with many HSS positions, all of which lead to the same profile

- 14 services. At least one wildcard character for user identifier ranges allows IMS to provide services to at least one specific user identifier in at least one user identifier range.

[0068] Fig. 7 is a high level SBC diagram that is used to connect company networks to the IMS platform. In addition, SBC can implement a SIP change for a specific type of PBX. The SBC domain idea represents the client associated with the services, and the SBC session agent is an IP-PBX representation.

[0069] For a new connection from IP-PBX to IMS platforms, the realm may be determined by the VLAN in which the message was received at the SBC. In the VLAN area, the IP address of the IP-PBX can be used to identify the session agent.

[0070] For a connection from a VoIP call platform to an IP-PBX, the SBC domain may be determined by the highest element of the Request URI domain name, and the session agent may be determined based on the "tgrp" parameter of the Request URI. The "tgrp" parameter uniquely identifies IP-PBX in the domain area. PBX-specific SIP modification is associated with the session agent.

[0071] It should be understood that any function described in relation to any embodiment may be used alone or in combination with the other functions described, and may also be used in combination with at least one function of any other embodiment or combination of any other embodiment. One embodiment can be implemented as a computer program for use with a computer system. The program (s) define the functions of the embodiments (including the methods described in this document) and may be contained on various data carriers that can be read by a computer. Illustrative storage media readable by a computer include, but are not limited to: (i) a non-writable storage medium (e.g. read-only memories inside the computer, such as CD-ROMs read by a CD-ROM drive, flash memories, ROM memory chips and any type of solid state memory) on which data is permanently stored; and (ii) a recordable storage medium (e.g., floppy disks or hard disks or any type of random access semiconductor memory) on which the information that can be modified is stored.

[0072] Furthermore, the invention is not limited to IMS, but may also be implemented in 3GPP networks for long-term network evolution (LTE) or 3GPP networks for service architecture evolution (SAE). In addition, although the embodiments are described with reference to the SIP signaling protocol (session initiation protocol), other signaling protocols such as H.323, H.248 and MGCP (media gateway control protocol) can also be used. In addition, the invention is not limited by the embodiments described above, but may vary within the scope of the accompanying claims.

Dorota Rz ążewska

Attorney Patent