KR100871953B1 - Media gateway and method for processing calls in a media gateway - Google Patents

Abstract

Disclosed are a media gateway and a call processing method for forming a channel through two main processors under the control of a soft switch supporting call control and routing functions. According to one embodiment, while operating one of the MP (Main Processor) 1 and the MP2 in the active mode to perform the normal call processing, the other is operated in the standby mode to back up the call information, operating in the active mode The call information of the MP is backed up by the software operating in the standby mode to synchronize the data. In the media gateway, for example, when MP2 is mounted and installed to operate MP2 in standby mode, MP2 requests MP1 for status / call information and backs it up. Verify that a mode switch has occurred during backup, and switch to active mode or maintain standby mode. If the call information is changed while the MP1 is operating in the active mode, the changed call information is backed up to the MP2 through a megaco message. In addition, when the MP1 operating in the active mode fails or exits, the standby mode MP2 is switched to the active mode. At this time, the related resource can be released by scanning the state change from the hook-off to the hook-on which occurred while the MP2 is switching to the active mode and reporting the hook-on information to the soft switch. Through this configuration, the call information of the main processor operating in the active mode in the media gateway can be backed up to the main processor in the standby mode by software, and in case of a failure, the main processor in the standby mode is switched to the active mode to perform the call processing. You can keep it normal.

Media gateway, megaco, protocol, message, main processor, backup

Description

MEDIA GATEWAY AND METHOD FOR PROCESSING CALLS IN A MEDIA GATEWAY}

1 is a block diagram of a conventional media gateway and a soft switch.

3 is a block diagram illustrating a media gateway and a soft switch according to an embodiment.

4 is a software block diagram of a main processor of the media gateway of FIG.

5 is a flowchart illustrating a method of backing up call information when a standby main processor is installed, according to an exemplary embodiment.

6 is a message flow diagram of the call information backup method of FIG.

7 is a flowchart illustrating a mode switching method of a standby main processor according to an exemplary embodiment.

8 is a message flow diagram of the mode switching method of FIG.

9 is a diagram illustrating a transmission unit of a megaco message.

* Explanation of symbols for the main parts of the drawings

 1: Media Gateway 2: Soft Switch

10: Firmware 20: Main Processor 1

30: main processor 2 21, 31: register

22, 32: state management unit 23, 33: megaco processing unit

24, 34: subscriber processing unit 25, 35: storage unit

40: vocoder card 50: subscriber card

The present invention relates to a media gateway, and more particularly, to a media gateway and a call processing method for performing call processing through two main processors under the control of a soft switch supporting call control and routing functions.

The next-generation network, which is emerging as a hot topic in the wired network field, has been proposed to solve the excessive traffic caused by the increase in the number of high-definition multimedia media and Internet users and to realize various services. Network, PSTN), Internet, Asynchronous Transfer Mode (ATM), and wireless networks by simplifying and configuring them into one common network to provide various multimedia services integrating voice and data. .

This next-generation network includes a media gateway including an access gateway and a trunk gateway, and a soft switch for controlling the media gateway. An access gateway is a device required to connect ordinary telephone users of wired / wireless networks, such as public switched telephone networks (PSTNs), to a packet network (VoIP or VoATM), and converts voice data from a general telephone to a packet network. Trunk gateway is a device for interworking PSTN and packet network (VoIP or VoATM). It is a device that can transmit a large amount of data generated from public telephone network to packet network. The media gateway is a data conversion equipment for the transfer of data between heterogeneous networks that follow different standards, and is connected with a general switched telephone network to connect a general public telephone subscriber station with a packet delivery network. Soft switch is a device that performs interworking function between packet network and existing wired / wireless network. It transmits signals between heterogeneous networks and performs routing, number translation, and resource management related to call processing. At this time, the media gateway and the soft switch communicate using the MEGACO (MEdia GAteway COntrol) protocol. The MEGACO protocol, recommended by IETF RFC 3015 and ITU-T H.248, is a protocol used by soft switches to control physically separated media gateways.

1 shows a configuration of a conventional media gateway and a soft switch. As shown in FIG. 1, the media gateway 100 generally includes a firmware 110, a first main processor (hereinafter referred to as 'MP1') 120, and a second main processor (hereinafter referred to as 'MP2') ( 130, backup cards 125 and 135 for backing up and storing call information of the vocoder card 140, the MP1 120, and the MP2 130. The firmware 110 includes a program for detecting a failure and a hernia state of the MP1 120 and the MP2 130. The MP1 120 and the MP2 130 function as call processing in a redundant manner.

2 illustrates software components operating on MP1 120 and MP2 130. Referring to FIG. 2, the MP1 120 and the MP2 130 each include a register, a state manager, a megaco processor, and a subscriber processor. Referring to FIG. 2, a call processing process of a general calling party through the media gateway 100 and the soft switch 200 will be described. The subscriber processor 124 detects a hook flash when the subscriber picks up the phone or notifies the megaco processor 123 of the hook flash (300). The megaco processor 123 reports the hook-off to the soft switch 200 (301), and the soft switch 200 transmits a response message to the megaco processor 123 (302). The megaco processor 123 instructs the vocoder card 140 to transmit the dial tone (303). When the subscriber presses the called number, the vocoder card 140 detects the called number and reports it to the megaco processor 123 (304). The megaco processor 123 collects the number and reports it to the soft switch 200. (305). The soft switch 120 requests a connection to another media gateway to which the subscriber of the called number is connected. In order to allocate resources, the soft switch 200 instructs the megaco processor 123 of the media gateway to which the calling subscriber is connected to create a real-time transport protocol (RTP) channel (306). The megaco processor 123 requests the vocoder card 140 to generate a channel for connection to the call (307). When the vocoder card 140 generates a voice channel, the megaco processor 123 performs the soft switch 200. Answer 308. At this time, when the terminating process is completed on the called side, a ring back tone is transmitted from the called media gateway to the calling media gateway (309). When the called party picks up the phone, the soft switch 200 instructs the vocoder card 140 to stop ringback tone transmission, and the caller and the called party's voice call path are connected (310). When the caller (or called party) hangs up, the subscriber processing unit 124 of the calling media gateway 100 reports the hook-on to the megaco processing unit 123 (311), instructs the channel to release, and instructs the user to disconnect the call. Require. Then, the megaco processor 123 reports the hook-on to the soft switch 200 (312), and releases the associated resources. That is, as shown in the figure, the megaco processor 123 reports the hook-on to the soft switch 200 (312) and instructs the vocoder card 140 to release the channel (314), thereby connecting the voice connected between the caller and the called party. The currency path is terminated (315).

However, in the related art, the backup cards 125 and 135 in the media gateway 100 are mounted on the back of the main board (not shown) on which the MP1 120 and the MP2 130 are mounted. The backup card 125 of the MP1 120 and the backup card 135 of the MP2 130 communicate with each other through an Ethernet channel to back up and synchronize call information. Therefore, since the conventional MP1 120 and the MP2 130 must include separate backup cards 125 and 135 in order to back up call information, the unit price increases. In addition, as the MP1 120 and the MP2 130 process the call in a redundant manner, any one of the megaco processing unit 123 of the MP1 120 and the MP2 130 performs unnecessary call processing, which is inefficient.

An object of the present invention is to provide a media gateway and a call processing method capable of software backup of call information of a main processor operating in an active mode in a media gateway to a main processor in a standby mode.

Another object of the present invention is to provide a media gateway and a call processing method thereof capable of maintaining a normal call processing by switching a main processor in a standby mode to an active mode when a failure occurs.

It is still another object of the present invention to provide a media gateway and a call processing method capable of preventing unnecessary resource occupation by releasing related resources by notifying the soft switch of a subscriber who has been hooked off while the main processor in the standby mode is switched to the active mode. To provide.

According to an embodiment, the MP1 and the MP2 are operated in an active mode for performing normal call processing and a standby mode for backing up call information, respectively, and when the MP1 fails, the MP1 is switched to the active mode to perform normal call processing. Software data is backed up by MP2 to synchronize data. When the backup of the call information is initialized, while the MP1 is operating in the active mode, the MP2 of the standby mode is mounted and mounted in the media gateway and the MP2 performs the backup of the call information of the MP1. At this time, the MP2 requests the call information from the MP1 to back up the call information.When the call information backup is completed, the MP2 checks whether a mode change occurs during the backup of the call information, and switches to the active mode or changes the current standby mode. Keep it. If the call information is changed while the MP1 is operating in the active mode, the changed call information is backed up to the MP2 through a megaco message. Also, the MP2 in the standby mode is switched to the active mode in order to maintain the call processing when the MP1 which is operating in the active mode fails or disengages. At this time, the hook-on scan is performed on the subscriber who was hooked off before the MP2 is switched to the active mode, and the related resources can be released by reporting the hook-on generated during the MP2 to the active mode to the soft switch.

Hereinafter, various embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, in the following description, when there is a risk of unnecessarily obscuring the gist of the present invention, a detailed description of well-known functions and configurations will be omitted.

3 is a block diagram of a media gateway 1 and a soft switch 2 according to an embodiment. As shown in FIG. 3, the soft switch 2 may be implemented by applying a standard interface to a control function among functions of a gateway system for interworking between different networks. The media gateway 1 is a network element in charge of exchange transmission under the control of the soft switch 2, and converts the information transmitted from the telephone line and the data packets transmitted from the Internet. That is, the media gateway 1 performs a path control function for transmitting user information, mutual media conversion between the pulse code conversion stream of the PSTN, and the Internet packet. In the next-generation communication network, the soft switch (2) and the media gateway (1) serve as a core node directly connecting the Internet network and the PSTN network, and data transmission and reception between the two systems through an interface according to standard protocols such as the Megaco protocol. This can be done.

The media gateway 1 includes a memory in which the firmware 10 is stored, a first main processor (hereinafter referred to as 'MP1') 20, a second main processor (hereinafter referred to as 'MP2') 30, and a vocoder card. 40 and a subscriber card 50 to which subscriber telephone lines are connected. The program stored in the firmware 10 is loaded and operated in the MP1 20 or the MP2 30, and the data on the failure, hernia or mounting of the MP1 20 or the MP2 30, or the operator command is stored in the MP1 20. ) Or in the register of MP2 (30).

One of the MP1 20 and the MP2 30 operates in an active (or standby mode) while the other operates in a standby mode (or an active mode), and performs a call processing function. For example, the active mode MP1 (or MP2) performs normal call processing, the standby mode MP2 (or MP1) performs only the synchronization of the megaco state and data with the active mode MP1 (or MP2), and the call. No processing. In this case, the megaco state means a connection state between the media gateway 1 and the soft switch 2, and the up state generated when the media gateway 1 registers with the soft switch 2 and receives a response. It includes a down state that occurs when the connection state between the media gateway 1 and the soft switch 2 is lost. In the present embodiment, when the MP1 20 operates in the active mode and the MP2 30 is initially set to operate in the standby mode, when the failure of the MP1 20 occurs, the MP2 30 records the failure information recorded in the register. It can be set to automatically switch to active mode based on this.

4 is a software configuration diagram that operates for call processing in the MP1 20 and the MP2 30 in the media gateway 1 of FIG. As shown in FIG. 4, the MP1 20 or the MP2 30 stores the registers 21 and 31, the state management units 22 and 32, the megaco processing units 23 and 33, and the subscriber processing units 24 and 34. Include. Each of the MP1 20 and the MP2 30 is connected to storage units 25 and 35 storing call information. Storage units 25 and 35 may comprise, for example, RAM.

The registers 21 and 31 store information related to a failure occurrence by a program stored in firmware, information about an operator command, a failure of an MP in an active mode, and a hernia. The subscriber processing units 24 and 34 detect the hook on / off of the subscriber telephone and notify the megaco processing units 23 and 33. The state managers 22 and 32 detect an active / standby state of the vocoder card 40 in which the vocoder channel is duplicated and a mounting / separation state of the subscriber card 50.

In addition, the state managers 22 and 32 store state information on the active / standby mode of the MP1 20 and the MP2 30, and the MP1 20 and MP2 upon request of the megaco processor 23 and 33. Provide status information of 30. In addition, the state management units 22 and 32 can recognize the switching to the active / standby mode based on the information in the registers 21 and 31. When the MP2 20 is in the active mode and the MP2 30 is in the standby mode, when the MP2 30 is switched from the standby mode to the active mode, that is, the state manager 32 of the MP2 30 in the standby mode is registered. Upon reading the data of (31) and recognizing the switching to the active mode, the megaco processor 33 of the MP2 30 is notified of the switching to the active mode. On the other hand, the megaco processing part 33 requests the subscriber processing part 34 of the MP2 30 for a hook-on scan for the subscriber who was hooked off before mode switching. The hook-on scan request is for checking whether there is information that has not been reported from the standby subscriber processing unit 34 when information changed to the hook-on state occurs while the MP2 30 in the standby mode is switched to the active mode. The subscriber processing unit 34 of the MP2 30 reports the hook-on scan result to the megaco processing unit 33. The megaco processor 33 reports the hook-on report to the soft switch 2, and the soft switch 2 releases the related resources.

In addition, in the present embodiment, when the MP1 20 is in the active mode and the MP2 30 is in the standby mode, the megaco processor 33 of the MP2 30 is mounted at the time of initial startup by mounting and mounting the MP2 30. Requests the state manager 32 in an active / standby mode and recognizes that it is in standby mode in response. Next, the megaco processor 33 of the MP2 30 requests status / call information from the megaco processor 23 of the MP1 20 in the active mode, and the megaco processor 23 of the MP1 20 The response to the status / call information is transmitted to the megaco processor 33 of the MP2 30. At this time, the state information includes information on whether the linkage with the soft switch 2 is connected or not connected. The call information includes, for example, call information, IP, codec information and destination information, and maximum number of vocoder channels which are currently connected. Since the maximum number of vocoder channels is about 512 resource channels, the transmission time may take several seconds. Therefore, after the transmission of the status / call information is completed, the megaco processor 33 of the MP2 30 checks whether the mode is switched during the resource channel transmission. Receive a response requesting that it is in standby mode. The state manager 32 of the MP2 30 maintains the standby mode or switches to the active mode according to the response result. Subsequently, in response to the response result of the MP2 30 in the standby mode, the MP2 30 of the MP1 20 in the active mode is synchronized so that the MP2 30 backs up and synchronizes the megaco call information of the MP1 20. The nose processor 23 receives the megaco message from the soft switch 2, decodes and performs an action, and then backs up the call information to the megaco processor 33 of the MP2 30 in the standby mode. do. The megaco message is a message transmitted through a user data program (UDP) or a transmission control protocol (TCP). Referring to FIG. 9, which illustrates a transmission unit of a megaco message, a plurality of transactions 91 are included in one message. Are included in the transaction 91, and several (eg, two or less) contexts 93 are included, and several (eg, two or less) are included in the context 93. Termination of 95 is included.

At this time, in the present embodiment, in order to back up the megaco call information between the MPs 20 and 30 in the active / standby mode, the data is transmitted in the context unit. In the case of a transaction unit, the data size to be transmitted at one time exceeds 800 bytes (a signal provided by an OS (Operation System), which reliably transmits up to 800 bytes when transmitting data). When the data is transmitted in the termination unit, the data size is 300 bytes. However, the backup signal is greatly increased because the unit is small. Therefore, when the backup data is transmitted in a context unit, the data size is 600 bytes so that the data can be transmitted reliably and the number of backup signals is not increased. Therefore, in the present embodiment, the megaco call information is transmitted from the active mode MP1 20 to the standby mode MP2 30 to the megaco processing unit 33 in the standby mode in context units.

5 is a flowchart of a method of backing up call information when the MP2 30 is mounted in the standby mode according to an exemplary embodiment. As shown in FIG. 5, when the MP2 30 is attached to the media gateway 1 and initially started up (S1), the megaco processing unit 33 inquires the standby state management unit 32 whether it is an active mode or a standby mode. (S2). When the state manager 32 responds to the standby mode (S3), the megaco processor 33 of the MP2 30 (hereinafter, abbreviated as "standby") of the standby mode is the MP1 20 (hereinafter, referred to as "standby") of the active mode. Status / call information is requested from the megaco processing unit 23 (abbreviated as active ') (S4). The standby megaco processor 33 receives the maximum vocoder channel number from the active megaco processor 23 as a status / call information response and backs it up to the storage unit 35 (S5). When the backup is completed (S6), the standby megaco processor 33 inquires the standby state manager 32 again of the active / standby state (S7). This is to check whether the MP2 30 in the standby mode is switched to the active mode while the state / call information is backed up. The standby megaco processor 33 receives a response to the active / standby mode from the standby state manager 32 (S8). The standby megaco processor 33 maintains the standby mode or switches to the active mode according to the received response (S9).

FIG. 6 is a message flowchart in call information backup according to the method of FIG. 4. As shown in FIG. 6, when the MP2 30 is installed in the media gateway 1, the standby megaco processor 33 transmits a request message for an active / standby state to the standby state manager 32 (600). ). The standby state manager 32 responds to the standby megaco processor 33 in a standby state (601). The standby megaco processor 33 requests the active megaco processor 23 for status / call information (602). The active megaco processor 23 responds to the standby megaco processor 33 with status / call information (603). The standby megaco processor 33 requests active / standby again from the standby state manager 32 (604). The standby state manager 32 responds to the standby megaco processor 33 (605).

7 is a flowchart illustrating a mode switching method of a standby MP according to an embodiment. As illustrated in FIG. 7, when the standby state manager 32 reads the register 31 (S11) and recognizes the switch to the active mode, the standby megaco processor 33 notifies the standby megaco processor 33 of the switch to the active mode ( S12). The standby megaco processing unit 33 requests the standby subscriber processing unit 34 to request a hook-on scan for the hook-off subscriber (S13), and receives the hook-on information from the standby subscriber processing unit 34 (S14). The standby megaco processor 33 receiving the hook-on information notifies the hook-on of the soft switch 2 to release the associated resource (S15).

FIG. 8 is a message flowchart according to the mode switching method of FIG. 7. When the standby state manager 32 reads the register 31 and confirms the switch to the active mode, the standby megaco processor 33 notifies the switch to the active mode (800). The standby megaco processor 33 requests the standby subscriber processor 34 to request a hook-on scan for the hook-off subscriber (801). The standby subscriber processing unit 34 reports the hook-on scan result (802). The standby megaco processor 33 reports the hook-on to the soft switch 2 (803), and the soft switch 2 releases the associated resource.

As described above, one of the MP1 20 and the MP2 30 is operated in an active mode for performing normal call processing, and the other is operated in a standby mode for backing up call information, and the MP1 (20) operating in the active mode. By backing up and synchronizing the call information to the MP2 30 by software, the MP2 30 is switched to the active mode when a failure occurs in the MP1 20 so as to perform normal call processing. When the MP1 20 is operating in the active mode and the MP2 30 in the standby mode is removed and mounted, the MP2 30 requests the call information from the MP1 10 to back up the call information. When the information backup is completed, it is checked whether a mode change has occurred during the backup of the call information, and according to the result of the verification, the mode is switched to the active mode or the current standby mode is maintained. When the call information is changed while the MP1 20 is operating in the active mode, the changed call information is backed up to the MP2 30 through the megaco message. In addition, the MP2 30 in the standby mode is switched to the active mode so that the MP1 20 operating in the active mode fails or maintains the call process when dismounting. At this time, the megaco processing unit 33 of the MP2 30 requests the hook-on scan for the hook-off subscriber from the subscriber processing unit 34, thereby softening the hook on generated during the conversion of the MP2 30 to the active mode. ) To release the associated resources.

While the invention and its various functional components have been described in particular embodiments, the invention may be implemented in hardware, software, firmware, middleware, or a combination thereof, and the system, subsystem, components or sub-configurations thereof. It should be understood that they can be used as elements. If implemented in software, the elements of the invention are instructions / code segments for performing the necessary tasks. The program or code segments may be stored in a machine readable medium, such as a processor readable medium, a computer program product, or via a transmission medium or communication link by a computer data signal embodied in a carrier wave or a signal modulated by a carrier. Can be sent. Machine readable media or processor readable media may include any medium that can store or transmit information in a form readable and executable by a machine (eg, processor, computer, etc.).

In addition, while the present invention has been described in connection with some embodiments, it is to be understood that various modifications and changes can be made without departing from the spirit and scope of the invention as will be understood by those skilled in the art. You will need to know Also, such modifications and variations are intended to fall within the scope of the claims appended hereto.

According to the above embodiments, the call information of the main processor operating in the active mode in the media gateway may be software-backed up to the main processor in the standby mode. In addition, when a failure occurs, the main processor in the standby mode may be switched to the active mode to maintain call processing normally. In addition, by switching the main processor in the standby mode to the active mode and performing a hook-on scan for the hooked-off subscriber, the soft switch is notified to release the related resources, thereby preventing unnecessary resource occupation.

Claims (11)

A media gateway that forms a channel and performs call processing under the control of a soft switch that supports call control and routing functions. First and second main processors that perform call processing while one operates in a standby mode while the other operates in an active mode; A storage unit for storing call information; During initial startup of the main processor operating in the standby mode among the first and second main processors, call information is requested and received from the main processor in the active mode to perform call information backup, and after the initial startup, the main processor in the active mode Notifies the main processor of the standby mode when the call information change occurs and stores the information in the storage unit. The method of claim 1, Each of the first and second main processors includes a state management unit that manages information on whether an active mode or a standby mode is provided, a megaco processing unit that performs call processing by performing megaco communication with the soft switch, and hooks on a subscriber telephone. Media gateway including a subscriber processor for detecting a / off state and reporting to the megaco processor. The method of claim 2, When the call information is backed up, the megaco processor recognizes the standby mode by requesting the state manager to the active / standby mode from the main processor in the standby mode, and receives a status / call from the megaco processor of the main processor of the active mode. The media gateway which requests information and stores the information in the storage unit. The method of claim 3, When the call backup of the main processor in the standby mode is completed, the megaco processor receives a response from the state manager to request an active / standby state from the standby mode, and switches to the active mode according to the response. Media gateway, or in standby mode. The method of claim 4, wherein When the main processor in the standby mode is switched to the active mode, the state manager detects the notification in the standby mode and notifies the megaco processor to switch to the active mode, and the megaco processor performs the subscriber processor. Requesting a hook-on scan for a hook-off subscriber and receiving a scan result to report the hook-on to the soft switch. The method of claim 2, Each of the first and second main processors may include a register for storing a failure state of the main processor and information regarding hernia status, wherein the state manager reads the register to recognize a condition for switching from a standby mode to an active mode. Media gateway. In the call processing method of a media gateway having a first and a second main processor to form a channel and perform call processing under the control of a soft switch that supports call control and routing functions. Operating one of the first and second main processors in an active mode and initial starting the other main processor in a standby mode; Requesting and receiving call information from the main processor in the standby mode to perform call information backup; And causing the main processor in the active mode to notify and store the main processor in the standby mode every time call information is changed. The method of claim 7, wherein The step of performing the call information backup, A megaco processing unit (hereinafter, referred to as a "megaco processing unit in standby mode") that performs call processing in the main processor in the standby mode manages information on whether the active mode or standby mode (hereinafter referred to as "standby"). The status management unit of the mode) to recognize the standby state; And requesting and storing status / call information from the megaco processing unit in the standby mode by the megaco processing unit performing the call processing in the active mode main processor. The method of claim 8, When the call information backup of the main processor in the standby mode is completed, the megaco processing unit in the standby mode receives a response by requesting an active / standby state to the state manager of the standby mode; Performing a transition to an active mode or maintaining a standby mode according to the response. The method of claim 9, Detecting, by the state manager of the standby mode, a transition condition from the standby mode to the active mode, notifying the megaco processor of the standby mode to switch to the active mode; The megaco processing unit of the standby mode transmits hook-on scan information to the subscriber processing unit (hereinafter, referred to as a standby standby processing unit) to detect a hook on / off state of the subscriber phone in the standby mode main processor. Requesting and receiving; Reporting, by the subscriber processing unit in the standby mode, the hook-on scan information to the megaco processing unit in the standby mode; And notifying the soft switch of the standby mode by the megaco processor in the standby mode. The method of claim 10, Each of the first and second main processors includes a register for storing a failure state and a hernia state of the main processor in an active / standby mode. And detecting a condition for switching from the standby mode to the active mode, wherein the state manager of the standby mode reads the register and detects the register.

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