KR20090050458A - Network system based on ip multimedia subsystem and activity call connecting method according to each enterprise - Google Patents

Abstract

The present invention relates to an active call interworking method according to an IMS-based network system and a service provider, and has a service provider control network and another operator control network having different signaling profiles or policies. Among the plurality of interworking nodes, by selecting the interworking node (Node) in accordance with the signaling profile or policy of the other operator network to relay the call session control signaling message for routing (Signalling Profile) or different from each other Actively interworking calls between service provider control networks having a policy (policy), it is possible to flexibly interwork the call to match the signaling profile (Policy) or the characteristics of the policy (Policy) of the service provider.

IMS, call interworking, session, signaling profile, policy, routing

Description

IMS-based network system and active call interworking method according to service provider {Network system based on IP Multimedia Subsystem and Activity call connecting method according to each enterprise}

The present invention relates to an active call interworking method according to an IMS-based network system and a service provider, and more particularly to an active call interworking technology between service provider control networks having different signaling profiles or policies.

The present invention is derived from the research conducted as part of the IT new growth engine core technology development project of the Ministry of Information and Communication and the Ministry of Information and Communication Research and Development. / Service control technology development].

The 3rd Generation Partnership Project (3GPP) and the Interconnection Border Control Function (IBCF) of the Telecom & Internet converged Services & Protocols for Advanced Network (TISPAN) describe the functions required for the IP Multimedia Subsystem (IMS), but they are interoperable. It does not describe specific methods for system configuration.

Currently, when interworking between VoIP providers, a method using a call state control function (CSCF) server that performs call control and session handling functions based on Session Initiation Protocol (SIP) has been used.

However, in this case, there was a burden of directly modifying the call / session control node with respect to the interworking policy with the interworking providers. In other words, this means that it is difficult to have flexible call interworking between providers having different signaling profiles or policies.

On the other hand, some operators use a SIP relay node with a B2BUA (Back to Back User Agent) function as an interworking system. The conference bridge B2BUA is located between the IMS and the external network to handle all SIP signaling such as session attempts, subscriptions, and instant messaging.

However, in this case, it is advantageous to implement them in accordance with signaling profiles or policies of different operators, but the conference bridge (B2BUA) method exchanges data by negotiating between two terminals through an agent in the middle. In contrast, it is considerably more complicated than a proxy method, which simply routes hand signal data between two terminals.

Accordingly, the present inventors actively associate calls between service provider control networks having different signaling profiles or policies, but match the signaling profile or policy characteristics of the linked service providers. In order to make the call interworking flexible, the research was conducted.

The present invention has been invented under the above-described purpose, and actively interworking calls between operator control networks having different signaling profiles or policies, and signaling profiles or policies of interworking operators. It aims to provide active call interworking method according to IMS-based network system and service provider that can interwork call flexibly according to (Policy) characteristics.

According to an aspect of the present invention for achieving the above object, the IMS-based network system according to the present invention, the service provider control network having a different signaling profile (Signalling Profile) or policy (Policy) through the service interworking control device Between the and the other operator control network, the call session control signaling message for routing (Routing) is relayed by selecting the interworking node (Node) according to the signaling profile or policy of the other operator network among the plurality of interworking nodes. .

Meanwhile, according to another aspect of the present invention, an active call interworking method according to the present invention analyzes a Session Initiation Protocol (SIP) message received from an own operator control network, thereby proxies or proxy bridges (B2BUA). : Determine whether to operate in a Back to Back User Agent method, and if it is determined as a proxy method, select an interworking node corresponding to a signaling profile or policy of another provider network from the first routing group, and use a conference bridge ( B2BUA: When determined by the Back to Back User Agent (B2BUA) method, the interworking node matching the signaling profile or policy of another provider network is selected from the second routing group, and the interworking selected from the first routing group or the second routing group. The call session control signaling message for routing to a node may be relayed.

According to the present invention, a call can be actively interworked between service provider control networks having different signaling profiles or policies, and match the signaling profile or policy characteristics of the service providers. It is useful to secure interoperability by interlocking calls with flexibility.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily understand and reproduce the present invention.

1 is a schematic diagram of an IMS-based network system according to the present invention. As shown in the figure, the IMS-based network system includes a Resource Admission Control Subsystem (RACS) 100, an Own Operator Control Network 200, an IBG (Inter-connect Border Gateway) 300, and a service interworking control device. 400 is made.

The RACS 100 is in charge of resource admission control of the IP transport network 500. The sub-business operator control network 200 performs a service (Service) and call session (Call Session) control. The IBG 300 is in charge of media interworking of the IP transmission network 500.

The service interworking control device 400 interworks with the S-CSCF 210, the P-CSCF 220, the I-CSCF 230 of the own operator control network 200 through the SIP, and the other operator control network 600. It is negotiated and controlled to connect media sessions such as voice and video between the terminals 810, 820, and 830 through interworking with the 700.

The Serving-Call State Control Function (S-CSCF) 210 performs main functions for call processing and is responsible for all functions related to providing a service. It performs control service while managing session state of user who is actually registered and provides information related to service resource to user. Obtain the address of the service interworking control device to link with the home domain of the called user through the dialed number of the user or the SIP URL.

The P-CSCF (Proxy-Call State Control Function) 220 is a point where a terminal first meets when accessing an IMS-based network system. In 3GPP, a terminal uses DHCP to find a P-CSCF 200 or a method of obtaining an address through a PDP context. The SIP registration request from the terminal is transmitted to the I-CSCF 230 of the terminal's home domain, and the address of the S-CSCF 210 is stored in this registration procedure and then the UE (User Equipment) is received from the terminal. When there is a SIP message destined for S-CSCF 210, it is forwarded to S-CSCF 210.

The Interrogating-Call State Control Function (I-CSCF) 230 determines the S-CSCF 210 by inquiring a Home Subscriber Server (HSS) (not shown in the drawing), and sends the S-CSCF to the UE during the registration process. CSCF 210 is allocated. In addition, it performs the role of forwarding the SIP request (Request) to the S-CSCF 210 and the generation of charging information.

On the other hand, the service interlocking control device 400 serves as a contact point for all incoming calls in order to connect to the subscriber in the network and a contact role with other network subscribers roaming in the network. Due to such a role, the service interworking control device 400 generally plays a role of a firewall and may have a hidden function of not exposing the configuration, topology, and capacity of an operator network to the outside.

In addition, the service interworking control unit 400 controls the IBG 300 in charge of media interworking of the IP transmission network 500 through the RACS 100, and in particular, the address and port information necessary for the media relay (Diameter) It acquires through the role of interworking with the multimedia session between the terminal. In addition, the transport layer control function is set as an operator's interworking policy, thereby giving flexibility to allow media interworking through the IBG 300 according to the operator's network configuration policy.

Specifically, the service interworking control device 400 of the IMS-based network system according to the present invention has a subsidiary operator control network 200 and another operator control network 600 having different signaling profiles or policies. Among the plurality of interworking nodes, among the plurality of interworking nodes, an interworking node corresponding to a signaling profile or policy of another provider network is selected to relay a call session control signaling message for routing.

2 is a block diagram showing a configuration according to an embodiment of a service interworking control apparatus of an IMS-based network system according to the present invention. As shown in the figure, the service interworking control apparatus 400 according to this embodiment includes a SIP stack processing unit 410, a proxy call control unit 420, and a conference bridge call control unit 430.

The SIP stack processor 410 analyzes a Session Initiation Protocol (SIP) message received from the own operator control network 200 to determine whether to operate in a proxy or a bridge to back user agent (B2BUA) method. do.

The proxy method simply routes the hand signal data for negotiation between the two terminals, and the conference bridge (B2BUA) method is a method of negotiating between two terminals through an agent to exchange data.

When the proxy call controller 420 is determined by the SIP stack processor 410 in a proxy manner, the proxy call controller 420 may select an interworking node matching the signaling profile or policy of another provider network from the first routing group 440a. Select to relay a call session control signaling message for routing to the selected interworking node (Node).

When the conference bridge call control unit 430 determines the conference bridge (B2BUA: Back to Back User Agent) method by the SIP stack processing unit 410, the conference bridge call control unit 430 selects an interworking node matching the signaling profile or policy of another provider network. It selects from the second routing group 440b and relays a call session control signaling message for routing to the selected interworking node.

In this case, the first routing group 440a or the second routing group 440b includes a domain routing processor 441, a static routing processor 442, and a number-based routing processor 443.

The domain routing processor 441 finds and routes another provider network to be routed using domain information. If there is no domain information, the static routing processing unit 442 finds and routes the other provider network to be routed according to the operator's interworking policy. The number-based routing processor 443 finds and routes another provider network to be routed through number translation.

That is, the service interworking control apparatus 400 according to the present embodiment selects an appropriate one of a signaling profile constituting a double tree structure or a routing path according to a policy, thereby different signaling profiles or policies ( The call is actively linked between the operator control networks with the policy. This means that the call can be flexibly linked to match the signaling profile or policy characteristics of the interworking provider.

For example, it is assumed that an operator's network configuration and policy configuration are set by an operator operating the service interlocking control device 400 and stored in a database in advance. The network configuration and policy configuration setting for each service provider will be described in detail later.

When a SIP (Session Initiation Protocol) message is received from the subsidiary operator's control network 200, the service interworking control apparatus 400 analyzes the SIP message through the SIP stack processing unit 410, and applies the operator information included in the SIP message. The network configuration and policy configuration of the service provider are searched by referring to the network configuration and policy configuration of each service provider stored in the database, so that the call can be interworked by proxy or conference bridge (B2BUA). The primary decision is to interlock.

Next, the service interlocking control device 400 determines in what manner the routing is to be processed secondarily. In this manner, routing is handled by the proxy call controller 420 or the conference bridge call controller 430, respectively.

If it is determined that the call is interworked in a proxy manner, whether the proxy call control unit 420 performs domain routing or static routing according to the found network operator's network configuration and policy configuration, or The second decision is made by choosing whether to route based on number.

If it is first determined that the call is interworked by a conference bridge (B2BUA) method, the conference bridge call control unit 430 determines whether to route the domain or static according to the network configuration and the policy configuration of the retrieved service provider. The second decision is made by choosing whether to route or number-based routing.

When the routing method is determined by the proxy call controller 420 or the conference bridge call controller 430, the proxy call controller 420 or the conference bridge call controller 430 may be the first routing group 440a or the second, respectively. The domain routing processor 441 or the static routing processor 442 or the number-based routing processor 443 included in the routing group 440b may select one corresponding to the determined routing method to determine the interworking node. By relaying the call session control signaling message for routing to the determined interworking node, the call is actively interworked between service provider control networks having different signaling profiles or policies. Since the call is flexibly interlocked according to the signaling profile or policy characteristics of the operator, the above-described present invention You can achieve your purpose.

Meanwhile, according to an additional aspect of the present invention, the service interlocking control device 400 may further include a roaming control unit 450. The roaming controller 450 is in charge of processing a request for registration through a roaming terminal, and controls the roaming terminal to be routed through the number-based routing processor 443. do.

That is, this embodiment is an embodiment for performing call interworking with a roaming registered terminal. When there is a call session request from a roaming registered terminal, the corresponding operator control network allows roaming service. If the roaming is allowed, the number-based routing processing unit 443 performs the number translation, and finds and routes other network operators to route.

Meanwhile, according to an additional aspect of the present invention, the service interworking control device 400 may further include a session controller 460. The session controller 460 periodically checks the connection state of the session and deletes unnecessary call session information.

That is, this embodiment is an embodiment in which the session timer option (Option) is processed when the session timer function is set in the signaling profile or policy of the operator. Since the session timer option also includes session end time information, the session controller 460 periodically checks the connection state of the session and deletes call session information whose session end time has passed, thereby eliminating unnecessary call session connection. You can stop it.

On the other hand, according to an additional aspect of the present invention, the service interworking control device 400 may further include a Topology Hiding Inter-network Gateway (THIG) processing unit 470. The THIG processing unit 470 encrypts routing information in order to conceal its own network from other providers.

That is, this embodiment is an embodiment for reinforcing security by concealing its own network to other operators when the topology hiding function is set in a signaling profile or a policy of the operator. 470 encrypts the information routed by the domain routing processor 441, the static routing processor 442, or the number-based routing processor 443, and transmits another operator control network. The third party control network decrypts the encrypted routing information when it is received.

On the other hand, according to an additional aspect of the present invention, the service interlocking control device 400 may further include a diameter processor (480). The diameter processing unit 480 acquires the address and port information of the IBG for media interworking in the call session control signaling message relay process, and reconfigures the Session Description Protocol (SDP) based on this to proceed with the call. The diameter is an Internet protocol of an IP Multimedia Subsystem (IMS) network standardized by the Internet Engineering Task Force (IETF) along with a Session Initiation Protocol (SIP).

That is, in this embodiment, when a transport layer control function is set in a signaling profile or a policy of an operator, the SPDF of the RACS 100 is transmitted through the diameter processor 480. Create and send a Diameter message Authorization Authentication Request (AAR) requesting a binding address to Service-based Policy Decision Functions (11), and Authorization Authentication Accounting for AAR received from IBG 300 Message), if the response is successful, the call proceeds by reconfiguring the Session Description Protocol (SDP) of the call session request message (SIP message) using the address and port information in the AAA message.

The diameter processor 480 may include a diameter basic stack processor 481, a diameter Rx client controller 482, and a network address translation (NAT) controller 483. The diameter basic stack processor 481 manages a diameter connection and processes messages and parameters of the basic stack. The diameter Rx client controller 482 processes messages and parameters of an Rx interface that performs quality of service (QoS) resource control through a diameter. The NAT control unit 483 acquires the address and port information of the IBG for media interworking in the call session control signaling message relay process, and reconfigures the Session Description Protocol (SDP) to proceed with the call.

On the other hand, according to an additional aspect of the present invention, the service interworking control device 400 may further include an operation GUI (Graphic User Interface) 491 and the operation data processor 492. The operation GUI 491 provides a user interface for data input and output for network configuration and operator policy configuration for service provider interworking. The operation data processor 492 stores data for network configuration and operator policy configuration input through the operation GUI 491, and provides the stored data for interworking call processing.

That is, this embodiment is an embodiment for receiving and storing the network configuration and policy configuration for each operator from the operator operating the service interlocking control device 400, the service interlocking control device 400 through the operation GUI (491). The operator who manages) network configuration and operator policy configuration for each user interworking, for example, whether to interwork a call by proxy or conference bridge (B2BUA) or domain routing. Or, if you want to set up static routing, number-based routing, roaming service, session timer function, topology hiding function, transport layer control function, etc. The network configuration and service provider of each operator is inputted through the operation GUI 491 by the operation data processor 492. When setting data for book configuration is saved, and network configuration and provider policy configuration information for each provider is stored in the future, the call is actively linked between operator control networks having a different signaling profile or policy. Is used.

Referring to Figure 3, look at the active call interworking method according to the operator of the IMS-based network system according to the present invention having the above configuration. 3 is a flowchart illustrating an active call interworking procedure according to an operator of an IMS-based network system according to the present invention.

As described above, it is assumed that the network configuration and the policy configuration for each service provider are set and stored in the database in advance. When a call session request message, that is, a Session Initiation Protocol (SIP) message, is transmitted from the subsidiary operator control network 200 to the service interworking control apparatus 400, the service interworking control apparatus 400 is received from the subsidiary operator control network in step S110. Analyze a Session Initiation Protocol (SIP) message.

Subsequently, the service interworking control apparatus 400 performs a proxy method or a conference bridge (B2BUA) from the SIP message analysis result and the network configuration and policy configuration information for each service provider previously stored in the database in step S120. Decide if call interworking is done.

If it is determined by the proxy method by the step S120, the service interworking control device 400 selects an interworking node matching the signaling profile or policy of another provider network from the first routing group in step S200. .

If it is determined by the conference bridge (B2BUA: Back to Back User Agent) method by the step S120, the service interworking control device 400 in step S300 to match the interworking node (Node) in accordance with the signaling profile or policy of another provider network Select from the second routing group.

At this time, the first routing group or the second routing group and the domain routing processing unit to find and route to the other provider network to be routed using the domain (Domain) information, and if there is no domain information, routing according to the interworking policy of the operator It includes a static routing processing unit for finding and routing other provider networks, and a number-based routing processing unit for finding and routing other provider networks to be routed through number translation.

When the routing method is determined by the step S200 or S300, the service interlocking control device 400 relays a call session control signaling message for routing to the interworking node selected in step S410. Then, the companion node receiving the call session control signaling message transmits routing information to another operator control network in step S420.

Accordingly, the present invention is active between operator control networks having different signaling profiles or policies by selecting an appropriate one of a signaling profile or a policy-based routing path forming a double tree structure. Since the call can be linked to, it is possible to achieve the object of the present invention presented above.

On the other hand, according to an additional aspect of the present invention, if the operator network configuration and policy configuration set the Session Timer (Session Timer) function, the service interlocking control device 400 performs the session timer option processing after the step S120 Step S500 may be further included. Since this has been described above, duplicate description will be omitted.

On the other hand, according to an additional aspect of the present invention, if the operator network configuration and policy configuration set the topology hiding function, the service interlocking control device 400 further comprises a step S600 to encrypt the routing information after the step S400 It may be. Since this has been described above, duplicate description will be omitted.

On the other hand, according to an additional aspect of the present invention, if the carrier network configuration and policy configuration set the transport layer control function, the service interworking control device 400 after the step S120 (Service-based SPDF (RA) of the RACS 100) Create and send a Diameter message Authorization Authentication Request (AAR) requesting a binding address to Policy Decision Functions (11), and process the Authentication Authentication Accounting (AAA) message for the AAR received from the IBG 300. If the response is successful, the method may further include a step S700 of reconfiguring the Session Description Protocol (SDP) of the call session request message (SIP message) using the address in the AAA message and the session timer port information. . Since this has been described above, duplicate description will be omitted.

Accordingly, by the above, the present invention actively associates calls between operator control networks having different signaling profiles or policies from each other, but has a signaling profile or policy of the interworking operators. Since the call can be flexibly interlocked according to the characteristics, it is possible to achieve the above object of the present invention.

While the invention has been described with reference to the preferred embodiments, which are referred to by the accompanying drawings, it is apparent that various modifications are possible without departing from the scope of the invention within the scope covered by the following claims from this description. .

The present invention can be industrially used in the field of call interworking technology between operator control networks having different signaling profiles or policies.

1 is a schematic diagram of an IMS-based network system according to the present invention;

2 is a block diagram showing a configuration according to an embodiment of a service interworking control apparatus of an IMS-based network system according to the present invention;

3 is a flowchart illustrating an active call interworking procedure according to an operator of an IMS-based network system according to the present invention.

<Explanation of symbols for the main parts of the drawings>

100: RACS 110: SPDF

200: sub operator control network 210: S-CSCF

220: P-CSCF 230: I-CSCF

300: IBG 400: service interlocking control device

410: SIP stack processing unit 420: proxy call control

430: conference bridge call control unit 440a: first routing group

440b: second routing group 441: domain routing processing unit

442: static routing processing unit 443: number-based routing processing unit

450: roaming control unit 460: session control unit

470: THIG processing unit 480: diameter processing unit

491: operation GUI 492: operation data processing unit

500: IP transmission network 600, 700: other operator control network

810, 820, 830: terminal

Claims (10)

Resource Admission Control Subsystem (RACS) for resource admission control of IP transport network; A sub-business operator control network for performing service and call session control; An IBG (Inter-connect Border Gateway) in charge of media interworking of an IP transport network through the RACS; In the IMS (IP Multimedia Subsystem) -based network system comprising, Selecting an interworking node that matches the signaling profile or policy of another operator network among the interworking nodes between the sub-operator control network and the other operator control network having different signaling profiles or policies. A service interworking control device for relaying a call session control signaling message for routing; IMS-based network system comprising a. The method of claim 1, The service interworking control device: A SIP stack processor configured to analyze a Session Initiation Protocol (SIP) message received from an own operator's control network and determine whether to operate in a proxy method or a back-to-back user agent (B2BUA) method; If the SIP stack processor determines the proxy method, a call session for routing to the selected interworking node by selecting an interworking node corresponding to a signaling profile or policy of another provider network from the first routing group. A proxy call controller for relaying a control signaling message; When determined by the SIP stack processor in a conference bridge (B2BUA) method, an interworking node selected by selecting an interworking node corresponding to a signaling profile or policy of another provider network from a second routing group. A conference bridge call control relaying a call session control signaling message for routing; IMS-based network system comprising a. The method of claim 2, The first routing group or the second routing group: A domain routing processor configured to find and route other provider networks to be routed using domain information; A static routing processing unit for finding and routing other provider networks to be routed according to a provider's interworking policy when there is no domain information; A number-based routing processing unit for finding and routing to other provider networks to be routed through number translation; IMS-based network system comprising a. The method of claim 3, wherein The service interworking control device: A roaming control unit which is in charge of processing a request for registration through roaming by a terminal subscribed to another operator and controls a roaming registered terminal to route through the number-based routing processing unit; IMS-based network system, characterized in that it further comprises. The method of claim 3, wherein The service interworking control device: A session controller for periodically checking a connection state of a session and deleting unnecessary call session information; IMS-based network system, characterized in that it further comprises. The method of claim 3, wherein The service interworking control device: A Topology Hiding Inter-network Gateway (THIG) processing unit for encrypting routing information to conceal its own network from other providers; IMS-based network system, characterized in that it further comprises. The method of claim 3, wherein The service interworking control device: A diameter processor configured to acquire the address and port information of the IBG for media interworking in the call session control signaling message relay process, and to reconfigure the Session Description Protocol (SDP) based on this; IMS-based network system, characterized in that it further comprises. The method according to any one of claims 1 to 7, The service interworking control device: An operation GUI (Graphic User Interface) for providing a user interface for data input and output for network configuration and operator policy configuration for interworking with operators; An operation data processor configured to store data for network configuration and operator policy configuration input through the operation GUI and provide the stored data for interworking call processing; IMS-based network system, characterized in that it further comprises. In the call interworking method of the IMS-based network system, a) analyzing a Session Initiation Protocol (SIP) message received from an operator's control network and determining whether to interwork a call in a proxy or a bridge to back user agent (B2BUA) method; b1) if determined in a proxy manner by the step a), selecting an interworking node matching the signaling profile or policy of another provider network from the first routing group; b2) if it is determined by a conference bridge (B2BUA) method by step a), selecting an interworking node matching a signaling profile or policy of another provider network from a second routing group; c) relaying a call session control signaling message for routing to the interworking node selected by step b1) or b2); Active call interworking method according to the operator characterized in that it comprises a. The method of claim 9, The first routing group or the second routing group: A domain routing processor configured to find and route other provider networks to be routed using domain information; A static routing processing unit for finding and routing other provider networks to be routed according to a provider's interworking policy when there is no domain information; A number-based routing processing unit for finding and routing to other provider networks to be routed through number translation; Active call interworking method according to the operator characterized in that it comprises.

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