KR20050040246A - Interworking system and method for between application server of ip network and pstn - Google Patents

Abstract

The present invention improves the interworking method between the PSTN, which is a public telephone network, and the application server of the IP network that transmits data based on the Internet protocol, and bypasses the route so that the interworking between the PSTN and the application server of the IP network can be performed even when a complex failure of the network occurs. It is about technology that can be.

To this end, the present invention, in the system applied to the IP network interworking with the PSTN, the SIGTRAN protocol stack and the SIP protocol stack is provided, the primary route for the signal processing gateway (SG) and the primary route for the soft switch An application server configured with a secondary route; An SG communicating with the PSTN based on an SS7 protocol, connecting the PSTN to an IP network, communicating with the application server based on the SIGTRAN protocol, and having a primary and secondary route to the application server; And a soft switch configured to communicate with the SG based on the SIGTRAN protocol, to communicate with the application server based on the SIP protocol, and to set the primary and secondary routes to the application server.

Description

Interworking system and method for between application server of IP network and PSTN}

The present invention relates to an interworking system and method between a public switched telephone network (PSTN) and an application server of an IP (Internet Protocol) network. The present invention relates to a technique for improving the interworking method between application servers and performing bypass routing so that interworking between the PSTN and the application server in the IP network is possible even when a complex network failure occurs.

1 is a network diagram and protocol stack diagram for interworking between a conventional PSTN and an application server of an IP network. The network includes a service switching point (SSP) 111 and a signal transfer point (STP) 121 for constructing a PSTN. 131, a signal processing gateway (hereinafter referred to as SG: Signaling Gateway) (221, 231), a soft switch 211, and an application server (241, 251) for constructing an IP network.

The SSP 111 is a service exchanger that processes an intelligent network service call in the PSTN, and the STP 121 relays a signal exchange between the SSP 111 and the SG 221 of the IP network through a signaling system 7 (SS7). Signal relay exchange.

The SGs 221 and 231 exchange signals with the STPs 121 and 131 through the SS7 protocol, and exchange the signals with the soft switch 211 of the IP network through the SIGTRAN protocol.

When the soft switch 211 is requested to connect to a specific application server from the SG 221, the soft switch 211 performs a switching operation so that the call is connected to the application server, the application server (241, 251) to the requested call It performs a function to provide a specific additional service.

The protocol stack mounted on each component described above is as follows.

The SSP 111 includes a protocol stack including a message transfer part 1 (MTP1) layer, an MTP 2 layer, an MTP 3 layer, a signaling connection control part (SCCP) layer, a transmission control application part (TCAP) layer, and an application layer. STP (121, 131) is mounted on the SS7 protocol stack consisting of MTP layer 1, MTP layer 2, MTP layer 3, and SCCP layer, SG (221, 231), MTP layer 1, MTP layer 2, MTP SSIG protocol stack consisting of three layers and SCCP layer, Internet Protocol (IP) layer, Stream Control Transmission Protocol (SCTP) layer, MTP3 User Adaptation (M3UA) layer, and SIGnaling TRANsport (SIGTRAN) protocol stack consisting of SCCP layer In addition, the application servers 241 and 251 have a SIP protocol stack including an IP layer, a User Datagram Protocol (UDP) / Transmission Control Protocol (TCP) layer, a Session Description Protocol (SDP) and a Session Initiation Protocol (SIP) layer, and an application layer. Mounted on the soft switch 211 The SIGTRAN protocol stack consists of IP, SCTP, M3UA, SCCP, TCAP, and application layers, and the SIP protocol stack consists of IP, UDP / TCP, (SDP) SIP, and application layers.

When the PSTN subscriber dials the telephone number for connection to the application server in the network configured as described above, the PSTN SSP 111 recognizes that it is the intelligent network service of the IP network from the number dialed by the subscriber, and is SS7 protocol (TCAP / SCCP / Generates an MTP3 / MTP2 / MTP1 based inquiry message and sends it to the SG 221 or 231 via the STP 121 or 131, and the SG 221 or 231 uses the SS7 protocol based (TCAP / SCCP / MTP3 / MTP2). / MTP1) is converted into a SIGTRAN protocol (TCAP / SCCP / M3UA / SCTP / IP) based inquiry message and transmitted to the soft switch (211).

The soft switch 211 converts an inquiry message based on the SIGTRAN protocol (TCAP / SCCP / M3UA / SCTP / IP) into an inquiry message based on the SIP protocol ((SDP /) SIP / (UDP / TCP / SCTP) / IP). Send to the application server (241 or 251).

The application server 241 or 251 receiving this generates a response message based on the SIP protocol ((SDP /) SIP / (UDP / TCP / SCTP) / IP) and transmits it to the soft switch 211, and the soft switch 211. ) Converts the response message based on the SIP protocol ((SDP /) SIP / (UDP / TCP / SCTP) / IP) into a response message based on the SIGTRAN protocol (TCAP / SCCP / M3UA / SCTP / IP). 231), and the SG 221 or 231 converts the response message based on the SIGTRAN protocol (TCAP / SCCP / M3UA / SCTP / IP) into the response message based on the SS7 protocol (TCAP / SCCP / MTP3 / MTP2 / MTP1). To the SSP 111 via the STP 121 or 131.

At this time, when the PSTN SSP 111 queries and responds to the IP network application server 241 or 251, the IP network SG 221 or 231 uses the SS7 protocol (TCAP / SCCP / MTP3 / MTP2 / MTP1) based inquiry message to SIGTRAN. Protocol messages (TCAP / SCCP / M3UA / SCTP / IP) should be converted into query messages and SIGTRAN protocol (TCAP / SCCP / M3UA / SCTP / IP) based response messages should be converted to SS7 protocol (TCAP / SCCP / MTP3 / MTP2 /). MTP1) is converted into a response message.

In addition, in the soft switch 211, an inquiry message based on the SIGTRAN protocol (TCAP / SCCP / M3UA / SCTP / IP) is an inquiry message based on the SIP protocol ((SDP /) SIP / (UDP / TCP / SCTP) / IP). In addition, the response message based on the SIP protocol ((SDP /) SIP / (UDP / TCP / SCTP) / IP) must be converted into a response message based on the SIGTRAN protocol (TCAP / SCCP / M3UA / SCTP / IP). Signal delay due to encapsulation and decapsulation occurs between protocol conversion (SS7 protocol and SIGTRAN protocol, SIGTRAN protocol and SIP protocol), and load on SG 221 or 231 and softswitch 211 It has the disadvantage of being weighted.

In addition, the quality of the intelligent network service through the query and response from the PSTN to the IP network application server (241 or 251) is the rootset between the SG (221 or 231) and the soft switch 211 (a3 link set and a4 link set), soft switch Depending on the reliability of the root set (a1 linkset and a2 linkset) between the 211 and the application server 241 or 251, there is a problem in that a service cannot be provided in the event of a complex failure in this section.

On the other hand, the IP network soft switch 211 recognizes that it is an intelligent network service from the number dialed by the subscriber, and generates an inquiry message based on the SIP protocol ((SDP /) SIP / (UDP / TCP / SCTP) / IP). Or 251), and the application server 241 or 251 that receives the IP message generates a response message based on the SIP protocol ((SDP /) SIP / (UDP / TCP / SCTP) / IP) and then performs an IP network. Transfer to the soft switch 211. The quality of the intelligent network service through the query and response from the IP network soft switch 211 to the application server 241 or 251 is the root set between the soft switch 211 and the application server 241 or 251 (a1 link set or a2 link set). It depends on the reliability of, and there is a problem that can not provide services in the case of a complex failure in this section.

Accordingly, the present invention has been made to solve the above-mentioned conventional problems, and implements the SIGTRAN protocol stack (TCAP / SCCP / M3UA / SCTP / IP) in the application server to directly access the application server with the SIGTRAN protocol in the IP network SG. It aims to improve the quality of service by reducing the number of nodes and protocol conversions through the system by configuring IP rootsets and improving routing methods.

In addition, the present invention is a complex failure occurs in the IP network section when the query and response from the PSTN SSP to the IP network application server or when the query and response from the soft switch of the IP network to the application server in the IP network section In this case, another purpose is to stably provide intelligent network services by configuring bypass routing.

In order to achieve the above object, an interworking system between an application server of a PSTN and an IP network according to the present invention is provided with a SIGTRAN protocol stack and a SIP protocol stack in a system applied to an IP network interoperating with a PSTN. An application server in which the primary and secondary routes for the SG and the primary and secondary routes for the soft switch are set; An SG communicating with the PSTN based on an SS7 protocol, connecting the PSTN to an IP network, communicating with the application server based on the SIGTRAN protocol, and having a primary and secondary route to the application server; And a soft switch configured to communicate with the SG based on the SIGTRAN protocol, to communicate with the application server based on the SIP protocol, and to set the primary and secondary routes to the application server.

In the interworking method between the PSTN and the application server of the IP network according to the present invention, when the application server of the IP network is called from the PSTN, and the SS7 protocol based query message is transmitted from the PSTN, the query message is converted into the SIGTRAN protocol based. A first step of determining whether the primary route to the application server is normal; If the primary route is normal, sending a query message based on the SIGTRAN protocol to the application server through the primary route; If a failure is detected in the first route, transmitting the SIGTRAN protocol based query message to a soft switch, and converting the query message based on a SIP protocol to the application server; A fourth step of the application server generating a response message to the SG based on the SIGTRAN protocol if the primary route to the SG is normal and transmitting the SG to the SG through the primary route; And if a failure is detected at the primary route to the SG, a response message for the query message is generated based on a SIP protocol and transmitted to the soft switch, and the soft switch converts the query message to a SIGTRAN protocol based on the SG. It characterized in that it comprises a fifth process of transmitting to.

In addition, the interworking method between the PSTN and the application server of the IP network according to the present invention, when the application server is called from the IP terminal, the first step of the soft switch determines whether the primary route to the application server; If the primary route is normal, transmitting a SIP protocol based query message to the application server through the primary route; If a failure is detected in the first route, transmitting a query message based on the SIGTRAN protocol to the application server via SG; A fourth step of the application server generating a response message for the query message based on a SIP protocol if the primary route to the soft switch is normal, and transmitting the response message to the soft switch through the primary route; And a fifth process of generating a response message based on the SIGTRAN protocol and transmitting the response message to the soft switch via the SG when a failure is detected at the first route to the soft switch. do.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention in more detail.

2 is a network structure diagram illustrating an interworking system between a PSTN and an application server of an IP network according to an embodiment of the present invention.

Implement the SIGTRAN protocol stack (TCAP / SCCP / M3UA / SCTP / IP) in addition to the existing SIP protocol stack ((SDP /) SIP / (UDP / TCP / SCTP) / IP) on the application server 341 or 351. IP route set (a5 link set, a6) to enable direct SIGTRAN protocol (TCAP / SCCP / M3UA / SCTP / IP) inquiry and response message transmission between the IP network SG 321 or 331 and the application server 341 or 351. Link set, a7 link set, a8 link set).

In addition, the routing tables of the SGs 321 and 331 and the soap switch 311 are reconfigured to be bypassed with respect to the destination application server 341 or 351, and the routing tables of the application servers 341 and 351 also include the destination SG ( Reconfigure to enable bypass routing for 321 or 331 and softswitch 311.

The routing table of SG1 321 sets the a3 linkset as the primary route a5 linkset for the destination application server 1 341, the secondary route that is the bypass route, and the primary route for the destination application server 2 351. a6 linkset, set the a3 linkset as the secondary route that is the bypass route.

The routing table of SG 2 331 sets the a4 link set as the primary route a7 linkset for the destination application server 1 341, the secondary route that is the bypass route, and the primary route for the destination application server 2 351. a8 linkset, set the a4 linkset as the secondary route that is the bypass route.

The routing table of the soft switch 311 sets the a3 link set and the a4 link set as the primary route a1 link set for the destination application server 1 341 and the secondary route as the bypass route, and the destination application server 2 351. For the primary route a2 linkset, the a3 linkset and the a4 linkset are set as the secondary route which is the bypass route.

The routing table of Application Server 1 341 sets the link set a5 as the primary route for destination SG 1 321, the link set a1 as the secondary route as the bypass route, and the primary route for SG 2 331. Set a1 link set as a7 linkset, secondary route as the bypass route, and set a1 linkset as primary route as the primary route for the soft switch 311, and set a5 linkset and a7 linkset as the secondary route as the bypass route. do.

The routing table of Application Server 2 351 sets a6 linkset as the primary route for the destination SG 1 321, a2 linkset as the secondary route as the bypass route, and a primary route for the SG 2 331. Set a2 linkset as the primary route for the a8 linkset and the secondary route, and set a2 linkset as the primary route for the soft switch 311, and set a6 linkset and a8 linkset as the secondary route as the bypass route. do.

Next, a method of interworking with the PSTN and the application server of the IP network in the interworking system between the PSTN and the application server of the IP network according to an embodiment of the present invention will be described in detail.

When the subscriber dials a telephone number for calling a specific application server of the IP network, for example, application server 1 341, the SSP 111 of the PSTN recognizes that it is an intelligent network service of the IP network from the number dialed by the subscriber and recognizes the SS7 protocol ( Generates a TCAP / SCCP / MTP3 / MTP2 / MTP1 based inquiry message and sends it to the SG 221 or 231 via the STP 121 or 131, and the received SG 221 or 231 receives the SS7 protocol (TCAP). / SCCP / MTP3 / MTP2 / MTP1) based query messages are converted into SIGTRAN protocol (TCAP / SCCP / M3UA / SCTP / IP) based query messages and are directly connected to the destination application server 1 (341) (a5, a7). To send). Here, when the SG receiving the inquiry message based on the SS7 protocol (TCAP / SCCP / MTP3 / MTP2 / MTP1) is SG 1 321, the SIGTRAN protocol (TCAP / SCCP / M3UA / SCTP / IP) is used as the root (a5). If the SG receiving the inquiry message based on the SS7 protocol (TCAP / SCCP / MTP3 / MTP2 / MTP1) is the SG 2 331, the SIGTRAN protocol (TCAP / SCCP / Send inquiry message based on M3UA / SCTP / IP).

The application server 341 receiving this generates a response message based on the SIGTRAN protocol (TCAP / SCCP / M3UA / SCTP / IP), and then transmits it to the SG 221 or 231 using a directly connected route (a5, a7). The SG 321 or 331 converts the response message based on the SIGTRAN protocol (TCAP / SCCP / M3UA / SCTP / IP) into the response message based on the SS7 protocol (TCAP / SCCP / MTP3 / MTP2 / MTP1). Or to the SSP 111 via 131.

Although the interworking method between the PSTN and the application server 1 341 of the IP network has been described with reference to FIG. 3, the interworking between the PSTN and the application server 2 351 of the IP network is also performed by the same process as described above.

According to the interworking method as described above, the service quality can be improved by reducing the number of nodes and the protocol conversion through the system because the system does not pass through the soft switch 311.

4 illustrates a method for interworking between a soft switch and an application server in an interworking system between a PSTN and an application server of an IP network according to an embodiment of the present invention.

When the subscriber of the IP network dials the telephone number for connection with the application server 2 (351), the soft switch 311 of the IP network recognizes that it is an intelligent network service from the number dialed by the subscriber, and the SIP protocol ((SDP /) SIP / A query message based on (UDP / TCP / SCTP) / IP) is generated and transmitted to the application server 2 (351). Application server 2 (351) receiving this generates a response message based on the SIP protocol ((SDP /) SIP / (UDP / TCP / SCTP) / IP) and transmits it to the soft switch 311. This is the same as the conventional method.

5, 6, and 7 are diagrams for describing a bypass routing path when a complex failure occurs in an IP network.

Referring to FIG. 5, it is assumed that a failure occurs in the primary routes a5, a6, a7, and a8 between the SGs 321 and 331 and the application servers 341 and 351. In FIG. 5, a broken line means a broken link.

When the subscriber dials a phone number for calling a specific application server of the IP network, for example, application server 1 341, the SSP 111 of the PSTN recognizes that it is an intelligent network service of the IP network from the number dialed by the subscriber. Generates a TCAP / SCCP / MTP3 / MTP2 / MTP1 based inquiry message and sends it to the SG 221 or 231 via the STP 121 or 131, and the received SG 221 or 231 receives the SS7 protocol (TCAP). / SCCP / MTP3 / MTP2 / MTP1) based query message is converted into SIGTRAN protocol (TCAP / SCCP / M3UA / SCTP / IP) based query message, and then the primary route to destination application server 1 (341) (a5, As the failure in a7) is detected, it transmits to the secondary routes a3 and a4. Here, when the SG receiving the inquiry message based on the SS7 protocol (TCAP / SCCP / MTP3 / MTP2 / MTP1) is SG 1 321, the SIGTRAN protocol (TCAP / SCCP / M3UA / SCTP / IP) is used as the root (a3). If the SG receiving the inquiry message based on the SS7 protocol (TCAP / SCCP / MTP3 / MTP2 / MTP1) is the SG 2 331, the SIGTRAN protocol (TCAP / SCCP / Send inquiry message based on M3UA / SCTP / IP).

The soft switch 311 which receives the inquiry message is based on the SIP protocol ((SDP /) SIP / (UDP / TCP / SCTP) / IP) based on the SIGTRAN protocol (TCAP / SCCP / M3UA / SCTP / IP). The message is converted into a query message and transmitted to the application server 1 341 through the primary route a1 for the application server 1 341.

Application server 1 (341) receiving the inquiry message generates a response message based on the SIP protocol ((SDP /) SIP / (UDP / TCP / SCTP) / IP) and sends it to the soft switch 311, and the soft switch ( 311) converts a response message based on the SIP protocol ((SDP /) SIP / (UDP / TCP / SCTP) / IP) into a response message based on the SIGTRAN protocol (TCAP / SCCP / M3UA / SCTP / IP), 221 or 231).

The SG 221 or 231 converts the SIGTRAN protocol based response message (TCAP / SCCP / M3UA / SCTP / IP) into the SS7 protocol (TCAP / SCCP / MTP3 / MTP2 / MTP1) based response message. Send a response message to the PSTN SSP (111).

FIG. 6 is a diagram illustrating a bypass routing path when a failure occurs in SG 1 321 and a failure occurs in primary routes a7 and a8 between SG 2 331 and application servers 341 and 351. In this case, the SG 2 331 transmits / receives a query message and a response message with the application servers 341 and 351 via the route a4 and the routes a1 and a2.

7 is a diagram illustrating a bypass routing path when a failure occurs in SG 2 331 and a failure occurs in primary routes a5 and a6 between SG 1 321 and application servers 341 and 351. In this case, the SG 1 321 transmits / receives a query message and a response message with the application servers 341 and 351 via the route a3 and the routes a1 and a2.

8, 9, and 10 are diagrams for describing a bypass routing path when a failure occurs in the primary routes a1 and a2 between the soft switch 311 and the application server 341 or 351 of the IP network.

As shown in FIG. 8, if a failure occurs in the primary routes a1 and a2 between the soft switch 311 and the application server 341 or 351 of the IP network, the soft switch 311 may use the SIGTRAN protocol (TCAP / SCCP). / M3UA / SCTP / IP-based query message is sent to the SG 321 or 331 via the secondary route (a3, a4), and the SG 321 or 331 is the SIGTRAN protocol (TCAP / SCCP / M3UA / SCTP / The IP-based query message is transmitted to the application server 341 or 351 through the primary routes a5 and a6.

Meanwhile, the application server 341 or 351 receiving the query message generates a response message (TCAP / SCCP / M3UA / SCTP / IP) based on the SIGTRAN protocol, and then uses the SG 321 through the primary routes a5 and a6. Or 331, and the SG 321 or 331 sends a response message based on the SIGTRAN protocol (TCAP / SCCP / M3UA / SCTP / IP) to the softs 311 through the secondary routes a3 and a4. Send it.

9 is a diagram illustrating a bypass routing path when a failure occurs in the primary routes a1 and a2 between the soft switch 311 and the application server 341 or 351 and a failure of the SG 1 321 occurs. In this case, the soft switch 311 transmits / receives the query message and the response message with the application servers 341 and 351 via the route a4 and the routes a7 and a8.

FIG. 10 is a diagram illustrating a bypass routing path when a failure occurs in the primary routes a1 and a2 between the soft switch 311 and the application server 341 or 351 and a failure occurs in the SG 2 331. In this case, the soft switch 311 transmits / receives a query message and a response message with the application servers 341 and 351 via the route a3 and the routes a5 and a6.

According to the present invention as described above, by installing the SIGTRAN protocol stack in the IP-based application server to allow the SG of the IP network to directly access the application server, reducing the number of nodes and protocol conversion through the system to improve the quality of service The effect is that you can.

In addition, the present invention has the effect that it is possible to provide a stable intelligent network service by providing a bypass path in the event of equipment or link failure of the IP network.

On the other hand, the present invention is not limited to the above-described embodiment, but can be modified and modified within the scope not departing from the gist of the present invention, such modifications and changes should be regarded as belonging to the following claims. will be.

1 is a network configuration diagram and protocol configuration for interworking between the application server of the conventional PSTN and IP network.

2 is a network structure diagram illustrating an interworking system between a PSTN and an application server of an IP network according to an embodiment of the present invention.

3 is a view for explaining a method of interworking with the PSTN and the application server in the interworking system between the PSTN and the application server of the IP network according to an embodiment of the present invention.

4 is a view for explaining a method of interfacing with a soft switch and an application server in an interworking system between a PSTN and an application server of an IP network according to an embodiment of the present invention.

5 to 10 are diagrams for explaining a bypass routing state when a complex failure occurs in an IP network.

Claims (7)

In the system applied to the IP network interworking with the PSTN, An application server having a SIGTRAN protocol stack and a SIP protocol stack and configured with a primary and secondary route for the signal processing gateway (SG) and a primary and secondary route for the soft switch; An SG communicating with the PSTN based on an SS7 protocol, connecting the PSTN to an IP network, communicating with the application server based on the SIGTRAN protocol, and having a primary and secondary route to the application server; And A PSTN and IP configured to communicate with the SG based on the SIGTRAN protocol, to communicate with the application server based on the SIP protocol, and to set the primary and secondary routes for the application server. Interworking system between application servers in the network. The method of claim 1, The primary route for the SG set in the application server is a route directly connected to the SG, and the secondary route for the SG is bypassed to the SG via a soft switch in case of failure of the primary route. Interworking system between the PSTN and the application server of the IP network, characterized in that the configuration of the route. The method of claim 1, The primary route for the soft switch set in the application server is a route directly connected to the soft switch, and the secondary route for the soft switch is routed to the soft switch via the SG upon failure of the primary route. Interworking system between the PSTN and the application server of the IP network, characterized in that the configuration of the bypass route to be connected. The method of claim 1, The primary route for the application server set in the SG is a route directly connected to the application server, and the secondary route for the application server passes to the application server via the soft switch when the primary route fails. Interworking system between the PSTN and the application server of the IP network, characterized in that the configuration of the bypass route to be connected. The method of claim 1, The primary route for the application server set in the soft switch is a route directly connected to the application server, and the secondary route for the application server passes to the application server via the SG when the primary route fails. Interworking system between the PSTN and the application server of the IP network, characterized by configuring the bypass route to be connected. When the application server of the IP network is called in the PSTN, and the SS7 protocol-based query message is transmitted from the PSTN, after converting the query message to the SIGTRAN protocol, it is determined whether the primary route to the application server is normal. First process; If the primary route is normal, sending a query message based on the SIGTRAN protocol to the application server through the primary route; If a failure is detected in the first route, transmitting the SIGTRAN protocol based query message to a soft switch, and converting the query message based on a SIP protocol to the application server; A fourth step of the application server generating a response message to the SG based on the SIGTRAN protocol if the primary route to the SG is normal and transmitting the SG to the SG through the primary route; And If a failure is detected at the first route to the SG, a response message for the query message is generated based on the SIP protocol and transmitted to the soft switch, and the soft switch converts the query message to the SIGTRAN protocol to the SG. Interworking method between the PSTN and the application server of the IP network, comprising a fifth process for transmitting. A first step of determining whether the primary route to the application server is normal by the soft switch when the application server is called from the IP terminal; If the primary route is normal, transmitting a SIP protocol based query message to the application server through the primary route; If a failure is detected in the first route, transmitting a query message based on the SIGTRAN protocol to the application server via SG; A fourth step of the application server generating a response message for the query message based on a SIP protocol if the primary route to the soft switch is normal, and transmitting the response message to the soft switch through the primary route; And If a failure is detected at the primary route to the soft switch, the response message to the query message is generated based on the SIGTRAN protocol, and includes a fifth process of transmitting to the soft switch via the SG. Interworking method between PSTN and application server of IP network.