System and method for providing value-added services (VAS) in an integrated telecommunications network using session initiation protocol (SIP)

Abstract

A system and method for providing Value-Added Services (VAS) in an integrated telecommunications network having a packet-switched network portion (PSN) operable with Session Initiation Protocol (SIP). The integrated telecommunications network includes a SIPext SSP server, a trigger server, and a service node having a Service Logic Program (SLP) that is operable with Intelligent Network Application Protocol (INAP). The SIPext SSP and service nodes are provided with the capability to communicate using SIP-compliant messaging. New header fields are provided that specify operations to be performed by the service node with respect to a service. INAP service parametric data is also provided in the header fields in a sequential form. When a call is received in the SIPext SSP server for a user having a subscription for a VAS, it queries the user profile stored in the trigger server. If the user is subscribed for a service, a SIP request message is formulated based on the user profile, wherein appropriate headers are populated with relevant parametric information and call context data. The service node launches the SLP based on the information provided in the request message and sends a SIP response message to the SIPext SSP server with an instruction concerning the provisioning of the VAS. The SIPext SSP server, thereafter, takes an appropriate action based on the response message and any parametric information contained therein.

Claims

What is claimed is:

1. A method of providing a Value-Added Service (VAS) in a telecommunications network operable with Session Initiation Protocol (SIP), the telecommunications network including a SIPext SSP server, a trigger server, and a service node having at least one Service Logic Program (SLP) associated with the VAS, wherein the SLP is operable with Intelligent Network Application Protocol (INAP), the method comprising the steps of:

receiving a request message in the SIPext SSP server from a first user, the request message for initiating a call to a second user;

upon receiving the request message, consulting the trigger server by the SIPext SSP server to obtain a user profile associated with at least one of the first and second users;

formulating a SIP register request by the SIPext SSP server based on the user profile obtained from the trigger server, upon encountering an armed detection point during call processing, the register request including at least one header field, wherein the header field contains information specifying an operation that the service node is to perform, the header field further including call context data associated with the call initiated by the first user;

transmitting the register request by the SIPext SSP server to the service node;

upon receiving the register request, executing at least one SLP by the service node based on the operation specified in the header field and the call context data associated therewith;

sending a SIP response message from the service node to the SIPext SSP server, the response message including a header field and a return result obtained in response to the execution of at least one SLP by the service node; and

executing at least one action by the SIPext SSP server responsive to the header field and the return result in the response message received from the service node, the action being associated with the VAS.

2. The method of providing a VAS in a telecommunications network as set forth in claim 1, wherein the SIPext SSP server is addressable by two separate Internet Protocol (IP) addresses, a first IP address and a second IP address, and further wherein the request message is received in the SIPext SSP server from the first user using the first IP address.

3. The method of providing a VAS in a telecommunications network as set forth in claim 2, wherein the register request is sent from the SIPext SSP server to the service node using the second IP address.

4. The method of providing a VAS in a telecommunications network as set forth in claim 1, wherein the step of formulating the register request comprises the step of transforming INAP-compliant data structures associated with the VAS into linearly sequenced parametric data forming a portion of the header field of the register request.

5. The method of providing a VAS in a telecommunications network as set forth in claim 4, wherein the SIP-compliant response message from the service node comprises linearized INAP-compliant parametric information.

6. The method of providing a VAS in a telecommunications network as set forth in claim 4, wherein the header field in the SIP response message from the service node is organized in a Backus-Naur format.

7. The method of providing a VAS in a telecommunications network as set forth in claim 4, wherein the header field in the SIP register request from the SIPext SSP server is organized in a Backus-Naur form.

8. The method of providing a VAS in a telecommunications network as set forth in claim 1, wherein the return result comprises a destination routing number and the header field in the SIP response message from the service node includes a connect operation, responsive to which the SIPext SSP server forwards the call initiated by the first user to the destination routing number.

9. The method of providing a VAS in a telecommunications network as set forth in claim 1, wherein the return result comprises an error code, responsive to which the SIPext SSP server generates a SIP error message and forwards it to the first user.

10. An integrated telecommunications network for providing a Value-Added Service (VAS), comprising:

a SIPext SSP server including a proxy server and a service switching part, the proxy server for receiving a call initiation message from a first user with respect to a second user and the service switching part for determining if the second user has a subscription for the VAS;

a trigger server containing user profiles associated with the VAS, the trigger server being activatable in response to a determination by the service switching part that the second user has a subscription to the VAS;

means associated with the service switching part for formulating a register request based on user profile information for the second user, wherein the register request includes a header field containing an operation associated with the VAS; and

a service node including an Intelligent Network Application Protocol (INAP)-compliant Service Logic Program (SLP) associated with the VAS and a SIPext SSP interface server for receiving and interpreting the register request from the service switching part, wherein the service node executes the SLP based on the contents of the header field in the register request received from the service switching part.

11. The integrated telecommunications network for providing a VAS as set forth in claim 10, wherein the proxy server has a first Internet Protocol (IP) address and the service switching part has a second IP address.

12. The integrated telecommunications network for providing a VAS as set forth in claim 10, wherein the register request contains linearized INAP-compliant parametric data associated with the operation.

13. A system for providing a Value-Added Service (VAS) to a user in a telecommunications network operable with Session Initiation Protocol (SIP), the telecommunications network including a SIPext SSP server, a trigger server, and a service node having at least one Service Logic Program (SLP) associated with the VAS, wherein the SLP is operable with Intelligent Network Application Protocol (INAP), the system comprising:

means for receiving a call initiation request with respect to the user;

means for querying the trigger server, responsive to the determination that the user has a subscription for the VAS, to obtain a user profile associated with the user;

means for formulating a SIP register request based on the user profile obtained from the trigger server, responsive to encountering an armed detection point in call processing, the register request including at least one header field, wherein the header field contains information specifying an operation that the service node is to perform with respect to the VAS, the header field further including call context data associated with the call initiation request with respect to the user;

means for transmitting the register request to the service node;

means for launching the SLP in the service node based on the operation specified in the header field and the call context data associated therewith;

means for sending a SIP response message from the service node to the SIPext SSP server, the response message including a header field and a return result obtained in response to the launching of the SLP in the service node; and

means for executing an action by the SIPext SSP server responsive to the header field and the return result in the response message received from the service node, the action being associated with the VAS.

14. The system for providing a VAS to a user in a telecommunications network as set forth in claim 13, further comprising means for transforming INAP-compliant data structures associated with the VAS into linearly sequenced parametric data forming a portion of the header field of the register request.

15. The system for providing a VAS to a user in a telecommunications network as set forth in claim 14, wherein the return result comprises a destination routing number to which the call is to be forwarded.

Description

BACKGROUND OF THE INVENTION

1. Technical Field of the Invention

The present invention relates to integrated telecommunication systems and, more particularly, to a system and method for provisioning Intelligent Network (IN)-based Value-Added Services in an integrated telecommunications network which includes a packet-switched network (PSN) portion operable with Session Initiation Protocol.

2. Description of Related Art

Coupled with the phenomenal growth in popularity of the Internet, there has been a tremendous interest in using packet-switched network (PSN) infrastructures (e.g., those based on Internet Protocol (IP) addressing) as a replacement for, or as an adjunct to, the existing circuit-switched network (CSN) infrastructures used in today's telephony. From the network operators' perspective, the inherent traffic aggregation in packet-switched infrastructures allows for a reduction in the cost of transmission and the infrastructure cost per end-user. Ultimately, such cost reductions enable the network operators to pass on the concomitant cost savings to the end-users.

Some of the market drivers that impel the existing Voice-over-IP (VOIP) technology are: improvements in the quality of IP telephony; the Internet phenomenon; emergence of standards; cost-effective price-points for advanced services via media-rich call management, et cetera. One of the emerging standards in this area is the well-known Session Initiation Protocol (SIP), developed by the Internet Engineering Task Force (IETF) for multimedia communications over PSNs. Using SIP, devices such as personal computers can inter-operate seamlessly in a vast inter-network, sharing a mixture of audio, video, and data across all forms of PSNs which may interface with CSN portions.

As is well-known in the telecommunications industry, services and service provisioning are the raison d'etre of a telecommunications network, including VoIP networks. Services are typically categorized into (i) "basic services" (i.e., services which allow basic call processes such as call establishment and termination) or (ii) "advanced services" which are also commonly referred to as Value-Added Services (VAS). Examples of advanced services include split charging, 800-services, credit card calls, call forwarding, hunt group, et cetera. It is also well-known that advanced services operate as factors for market differentiation and are crucial for network operators' (or service providers') success.

Value-Added Services in SIP-based VoIP networks are known as "standard telephony services" whose architecture draws quite heavily on the Internet's "end-to-end" paradigm and focuses on service creation. While service provisioning schemes based on SIP's service architecture offer certain strengths (e.g., flexibility in role mapping for realizing services with end-to-end connectivity and having intelligence distributed to the "edges" of the network), there exist several disadvantages and drawbacks. For instance, in SIP, service logic is provided to be co-located with the SIP-based IP telephony entities. Accordingly, in current implementations, SIP-based networks do not have the capability to effectively access remote service logic, e.g., Intelligent Network (IN)-based logic, that is already deployed in the market and geared to provide an array of customer-validated VAS. Moreover, if the IN-based service logic were to be used today in the context of SIP, SIP-based entities would need to support IN protocols (i.e., IN Application Protocol (INAP) over Signaling System 7 (SS7) or over IP) in order to remotely access the IN service node (e.g., Service Control Point or SCP) containing the service logic.

Those skilled in the art should readily appreciate that a significant part of the problem in providing remote service access capability to SIP-based entities stems from the fact that the two protocols, SIP and IN, follow different approaches and cannot be easily combined harmoniously. As is well-known, SIP is a lightweight, text-based protocol designed for Internet applications where space efficiency is of little concern. On the other hand, IN protocols are binary (i.e., coded in the Abstract Syntax Notation or ASN) and optimized for providing a large variety of VAS with parameters provided in rather complicated data structures. Using IN protocols to remotely access service logic in the context of SIP-based networks, accordingly, implies imposing additional functionality on IP telephony entities and introducing an extra category of "heavyweight" protocols in the network environment.

Based on the foregoing, it should be apparent that there has arisen an acute need for a service provisioning solution which advantageously provides remote service access capability within a SIP-based telecommunications network. The present invention provides such a solution.

SUMMARY OF THE INVENTION

In one aspect, the present invention is directed to a method of providing a Value-Added Service (VAS) in a telecommunications network operable with Session Initiation Protocol (SIP). The telecommunications network includes a SIPext SSP server, a trigger server, and a service node supporting VAS that is operable with Intelligent Network Application Protocol (INAP). Before processing a call (originating or terminating) between two users, which is effectuated by receiving a request message in the SIPext SSP server, the SIPext SSP server consults a user profile stored in the trigger server when a message for a user subscribed with a service provider arrives thereat. While processing the call, upon encountering an armed detection point for the subscribed service, a SIP register request is formulated by the SIPext SSP server based on the user profile obtained from the trigger server. The register request preferably includes at least one header field which contains information specifying an operation that the service node is to perform with respect to the VAS. The header field further includes call context data associated with the call initiated by the first user.

Subsequently, the register request is transmitted by the SIPext SSP server to the service node which launches the SLP based on the operation specified in the header field and the call context data associated therewith. The service node then formulates a SIP response message and transmits it to the SIPext SSP server, the response message including a header field and a return result obtained in response to the execution of the SLP by the service node. The SIPext SSP server executes an action responsive to the header field and the return result in the response message received from the service node, wherein the action corresponds to the provisioning of the VAS. In an exemplary embodiment, the return result comprises a destination routing number for a call forwarding service subscribed by the second user.

In another aspect, the present invention is directed to an integrated telecommunications network for providing a Value-Added Service (VAS). The integrated telecommunications network comprises a SIPext SSP server which includes a proxy server and a service switching part. In one exemplary embodiment, the proxy server and the service switching part are addressable by two separate Internet Protocol (IP) addresses. The proxy server is provided for receiving a call initiation message from a first user with respect to a second user. The service switching part is included for determining if the second user has a subscription for the VAS. A trigger server containing user profiles associated with the VAS is also included in the telecommunications network. Also, the service switching part is provided with the capability for formulating a register request based on user profile information for the second user retrieved from the trigger server, wherein the register request includes a header field containing an operation associated with the VAS. The telecommunications network further includes a service node which contains an Intelligent Network Application Protocol (INAP)-compliant Service Logic Program (SLP) associated with the VAS and a SIPext SSP interface server for receiving and interpreting the register request from the service switching part. Preferably, the service node executes the SLP based on the contents of the header field in the register request received from the service switching part.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present invention may be had by reference to the following Detailed Description when taken in conjunction with the accompanying drawings wherein:

FIG. 1 (Prior Art) depicts a simplified message flow diagram for an exemplary call setup scenario in a conventional SIP-based network;

FIG. 2 depicts a functional block diagram of the architecture of an exemplary integrated communications network wherein IN-based service logic (i.e., SCP) is advantageously accessed from a SIP-based network portion by utilizing Extended SIP (ESIP or SIPExt) structures provided in accordance with the teachings of the present invention;

FIG. 3A depicts a functional message flow diagram which illustrates the basic operation of an integrated telecommunications network provided in accordance with the teachings of the present invention;

FIGS. 3B and 3C depict a flow chart illustrating the steps involved in the basic operation of Extended SIP messaging used in an integrated telecommunications network;

FIGS. 4A and 4B depict exemplary INAP tree data structures for providing parametric data;

FIG. 5 depicts a functional message flow diagram illustrating the functionality of a SIPExt SCP node as a client;

FIG. 6 depicts a functional message flow diagram illustrating the functionality of a SIPExt SSP component as a client, wherein an Extended SIP REGISTER message is forwarded to a SIPExt SCP node as result of event detection;

FIG. 7 depicts a functional message flow diagram illustrating the functionality of a SIPExt SSP component as a client, with its request to a SIPExt SCP node being unsuccessful;

FIGS. 8A-8D depict various message flow diagrams for providing an exemplary Value-Added Service in an integrated communications network in accordance with the teachings of the present invention; and

FIGS. 9A-9E depict various message flow diagrams for providing another exemplary VAS in an integrated communications network in accordance with the teachings of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

In the drawings, like or similar elements are designated with identical reference numerals throughout the several views, and the various elements depicted are not necessarily drawn to scale. Because the teachings of the present invention are particularly exemplified in the context of SIP-based messaging, a brief description thereof is set forth hereinbelow.

SIP is an application-layer control protocol that can establish, modify, and terminate multimedia sessions or calls with one or more participants. These multimedia sessions include, for example, multimedia conferences, multimedia distribution, distance learning, Internet Telephony, and similar applications. Members in a session, typically denoted as users, can communicate via multicast or via a mesh of unicast relations, or a combination of both.

SIP can invite both persons and "robots," such as a media storage service to a session. Typically, SIP invitations used to create sessions carry session descriptions which allow participants to agree on a set of compatible media types. Also, SIP can be used to initiate sessions as well as invite members to sessions that have been advertised and established by other means. For example, SIP sessions can be advertised using multicast protocols such as Service Advertising Protocol (SAP), electronic mail, news groups, World-Wide Web (WWW) pages, directory access protocols such as Lightweight Directory Access Protocol (LDAP), among others.

SIP makes minimal assumptions about the underlying transport and network-layer protocols. The lower layers can provide either a packet or a byte-stream service, with reliable or unreliable service. In the Internet context, SIP is able to use both User Datagram Protocol (UDP) and Transport Control Protocol (TCP) as transport protocols, among others.

In a SIP-based telephony network, users place calls via entities known as user agent clients (UACs) and receive calls via user agent servers (UASs). Accordingly, a SIP "user" is identified by a particular combination of a UAC and its associated UAS. Also, usually, there may be intermediate servers between a calling party UAC and the called party UAS. Some of the relevant SIP entities are briefly defined hereinbelow:

User Agent Client: Also known as a calling user agent. It is an application which initiates a SIP request.

User Agent Server: Also known as a called user agent. It is an application which contacts the end-user when a SIP request is received. Also, it returns a response on behalf of the user since the user may select to accept, reject, or redirect the request.

Proxy or Proxy Server: It is an intermediary application which acts as a client as well as a server for the purpose of making requests on behalf of other clients. As a server, it receives SIP requests from other SIP entities. It either services the requests internally or acts as a client towards other servers in order to get the requests serviced. A proxy interprets and, if necessary, rewrites a request message before forwarding it.

Redirect Server: It is an application which accepts a SIP request, maps the address into one or more new addresses and returns these addresses to the client. Unlike a proxy server, it does not initiate its own SIP request. Also, unlike a UAS, it does not accept calls.

Registrar: A registrar is a server that accepts REGISTER requests. It may typically be co-located with a proxy or redirect server. Essentially, it operates as an application which allows end-users to register their current location.

The basic protocol functionality and its operation is summarized in the following. Calling parties (also referred to as "callers") and called parties (also referred to as "callees") are identified by SIP addresses which point to "objects" on a network. The objects are "users at hosts," having appropriate SIP Universal Resource Locators (URLs) as addresses. The SIP URL typically takes a form similar to a mailto or telnet URL, i.e., user@host. The user part is generally provided as a user name or a telephone number. The host part typically comprises a domain name having a Domain Name System (DNS) Server Name, CNAME, or a numeric network address, among others.

The client-server approach of the SIP methodology employs a text-based messaging scheme. A SIP message is either a request from a client to a server, or a response from a server to a client. Both types of messages typically comprise a start-line, one or more header fields (also known as "headers"), an empty-line (i.e., a line with no text before a carriage-return line-feed (CRLF)) indicating the end of the header fields, and an optional message body.

            A SIP Request message format is usually as follows:
            Request = Request-Line
                      * (general header
                      .vertline. request-header
                      .vertline. entity-header)
                      CRLF
                      [message-body]

                     Response = Status-Line
                                * (general header
                                .vertline. response-header
                                .vertline. entity-header)
                                CRLF

    message-header = field-name ":" [field-value] CRLF
       field-name = token
      field-value = * (field-content .vertline. Leading White Space)
    field-content = < the OCTETS making up the field-value and others >

        TABLE I
                                       SIP ERROR
        INAP ERRORS                    RESPONSES
        MissingParameter               400 Bad Request
        ParameterOutOfRange            400
        SystemFailure                  500 Server Internal Error
        MissingCustomerRecord          500
        TaskRefused                    400
        UnexpectedComponentSequence    400
        UnexptectDataValue             400
        UnexpectedParameter            400
        RequestedInfoError             400

• Inventors
  Glitho, Roch; Gourraud, Christophe; Evloguieva, Evelina;
• Assignee
  Telefonaktiebolaget L M Ericsson (publ) (Stockholm, SE)
• Published
  Sep-23-2003
• Current US Classes:
  370/352
  370/493
  707/10
  707/4
  709/203
  709/227
• Application #
  537592
• International Classes
  H04L 012/66
• Field of Search
  370/352 370/353 370/354 370/355 370/356 370/493 370/494 370/495 370/465 707/1 707/3 707/4 707/5 707/10 709/10 709/201 709/203 709/224 709/227
• Examiner
  Hsu; Alpus H.
• Agent
  Smith & Danamraj, PC
• US Patent References:
  6363424
  6421674
  6430176
  6446127
  6519242