KR20080070309A - Media gateway and method for processing calls in a media gateway - Google Patents

Abstract

A media gateway and a method for processing a call are provided to keep a call processing normally by switching a main processor in a standby mode into an active mode when errors occur. When an MP2(Main Processor 2) is installed at a media gateway, and driven firstly, a MEGACO(Media Gateway Control) processor inquires to a standby state controller whether the current state is the standby mode or the active mode (S2). If the current state is the standby mode(S3), the MEGACO processor of the MP2 in the standby mode asks for the state/call information to the MEGACO processor of the MP1 in the active mode(S4). The standby MEGACO processor receives the maximum number of vocoder channels from the MEGACO processor, and backs up the channel number into a storage(S5). If the backup procedure is completed(S6), the standby MEGACO processor inquires the active/standby state again to a standby state controller(S7). The standby MEGACO processor receives the answer about the state from a standby state controller(S8). The standby MEGACO processor keeps the standby mode or switches into the active mode, according to the answer received from a standby state controller(S9).

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 (303). 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. The soft switch 200 instructs the megaco processor 123 of the gateway to which the calling subscriber is connected to generate a Real-time Transport Protocol (RTP) channel to allocate resources. The megaco processor 123 requests the vocoder card 140 to generate a channel for connection to a call. When the vocoder card 140 generates a voice channel, the megaco processor 123 responds to the soft switch 200. . 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, instructs channel release (314), and the megaco processing unit 123. Call 315) to disconnect the channel. Then, the megaco processor 123 reports the hook-on to the soft switch 200 to release the related resources.

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 units 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') 10, a second main processor (hereinafter referred to as 'MP2') 20, 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 register 21. 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 M2 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 M2 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. Asks the state manager 32 for an active / standby mode and recognizes the standby mode as a response thereto. 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. Thereafter, according to the response result, while the MP2 30 is in the standby mode, the mega of the MP1 20 in the active mode is synchronized so that the MP2 20 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. A 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 single message includes several transactions 91. Is included in the transaction 91, and several (eg, two or less) contexts 93 are included in the transaction 91, and several (eg, two or less) are included in the context 93. Termination 95 is included.

At this time, in the present embodiment, in order to back up the megaco call information between MPs in the active / standby mode, 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 MP to the standby mode MP to the megaco processing unit 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, the megaco processor 33 inquires whether the standby state manager 32 is in an active mode or a standby mode (S2). ). When the state manager 32 responds to the standby mode (S3), the megaco processor 32 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 22 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 (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 a hook-on scan to the subscriber processor 34 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 and the MP2 is operated in an active mode for performing normal call processing, the other is in a standby mode for backing up call information, and the call information of the MP1 operating in the active mode is MP2 by software. By backing up and synchronizing the data to MP1, when MP1 fails, MP2 is converted to active mode to perform normal call processing. When MP1 is mounted in the standby mode while the MP1 is operating in the active mode, the MP2 requests the call information from the MP1 and backs up the call information. Determine if a switchover has occurred and either switch to active mode or maintain the current standby mode, depending on the verification. 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, the MP2 in the standby mode is switched to the active mode so that the MP1 which is operating in the active mode fails or maintains the call processing during the detachment. At this time, the megaco processor of the MP2 requests the hook-up scan to the hook-off subscriber to the subscriber processor, thereby releasing the related resources by reporting the hook-on generated during the conversion of the MP2 to the active mode to the soft switch.

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, The first and second main processors may include: a state management unit managing information on whether an active mode or a standby mode is provided; a megaco processing unit performing megaco-communication with the soft switch; and a hook-on / And a subscriber processing unit for detecting an off state and reporting to the megaco processing unit. The method of claim 2, When the call information is backed up, the megaco processor in the standby mode requests the active / standby mode to the state manager to recognize the standby mode, and requests the state / call information to the megaco processor of the main processor in the active mode. And store the response in the storage unit. The method of claim 1, When the call backup of the main processor in the standby mode is completed, the state manager requests a response of the active / standby state again and receives a response, and switches to the active mode or maintains the standby mode according to the response. The method of claim 4, wherein When the main processor in the standby mode is switched to the active mode, the state manager detects this and notifies the megaco processor to switch to the active mode, and the megaco processor requests a hook-on scan for the hook subscriber to the subscriber processor. And receiving a scan result and reporting a hook-on to the soft switch. The method of claim 2, Each of the first and second main processors includes a register for storing a failure state and hernia state information of the main processor, and the state manager reads the register to recognize a switching condition 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 performing call processing in the main processor in the standby mode, inquiring of a state management unit managing information on whether the active mode or the standby mode is in a 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, requesting an active / standby state from the standby mode management unit and receiving a response; 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, a transition condition to an active mode in the main processor in the standby mode; Notifying the megaco processor to switch to an active mode; Requesting and receiving hook-on scan information for a hook-off subscriber by a subscriber processor that detects a hook on / off state of the subscriber telephone by the megaco processor; Reporting, by the subscriber processor, the hook-on scan information to the megaco processor; And the megaco processor notifying hook-on of the soft switch. The method of claim 7, wherein 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, Recognizing a condition for switching from the standby mode to the active mode includes reading and detecting the register by the state manager.

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