WO2005025143A1

WO2005025143A1 - Method of detecting the status of a media gateway controller by a media gateway

Info

Publication number: WO2005025143A1
Application number: PCT/CN2003/000754
Authority: WO
Inventors: Zhong Zhang; Sheng Liu; Taiming Ling
Original assignee: Utstarcom (China) Co. Ltd.
Priority date: 2003-09-05
Filing date: 2003-09-05
Publication date: 2005-03-17
Also published as: CN1820466A; CN100394744C; AU2003261630A1

Abstract

The invention relates to a method of detecting the status of a media gateway controller by a media gateway in the network of separating bearea and control. By increasing one protocol extending packet in the interface protocol used for communication between media gateway and media gateway controller, the said method comprises following steps: a) transmitting said protocol extending packet from a media gateway to a media gateway controller; b) receiving said protocol extending packet by the media gateway controller, and performing authentication of said media gateway according to the parameter in the protocol extending packet; c) according to the results of authentication to the media gateway by the media gateway controller, the said media gateway detects the link status of the media gateway controller; and d)repeating the above steps periodically. According to the invention, a media gateway can detect the status of a media gateway controller in real time. Once the media gateway controller has fault, the media gateway logs in a spare media gateway controller. This character can support well network double attribution function used to deal with the fault.

Description

Speculated by Media Gateway

METHOD OF STATUS OF MEDIA GATEWAY CONTROLLER TECHNICAL FIELD

The present invention generally relates to the field of communication technology, and more particularly, to a method for detecting a state of a media gateway controller by a media gateway in a next generation network. Background technique

In traditional switching networks, the functions or services provided to user terminals are directly related to the switch. For example, in the schematic diagram of the internal networking of the traditional switch shown in FIG. 1, the control signaling (shown in dotted lines) and voice / data bearer (shown in solid lines) are concentrated in the traditional switch 1. The traditional switch 1 constitutes the switching core of the traditional switching network. It can be seen from the figure that, for each user terminal 2, the traditional "call and control" function is integrated with the service, and the call control function for different service requirements is different. This traditional switch cannot separate control from voice / data bearer.

With the evolution of network technologies, especially the development of IP technologies and broadband networks represented by IP networks, the concept of next-generation networks (NGN) has emerged. NGN is a comprehensive, open network architecture that can provide multiple services such as voice, data, and multimedia. NGN can integrate communications, information, e-commerce, and transaction services on a unified packet network to meet diverse and personalized business needs, and to achieve integration with various business networks (PSTN / ISDN, PLMN, IN, Internet) to quickly provide new integrated services such as voice, data, and video services in the entire network.

NGN uses softswitch technology. Softswitch is a functional entity that provides real-time service call control and connection control functions for NGN. It is the core of next-generation network call and control. In a nutshell, softswitches separate the functional modules of traditional switches into Independent network components, each component is divided according to the corresponding function, using business and call control separation, call control and bearer separation technology, to achieve an open network structure, making services independent of the network. In terms of network architecture, NGN mainly separates the signaling control part and the voice / data bearer part of the traditional switch, and uses a standard media gateway control protocol such as H.248 / Megaco for interaction.

As shown in FIG. 2, FIG. 2 shows a schematic diagram of NGN internal networking. User terminal 2 (such as an IP phone and SoftPhone) is connected to different places through network 3 (usually an IP network), and control signaling (shown in dashed lines) is connected to soft switch 4 (also called a media gateway controller). The voice / data bearer (shown as a solid line) is connected to the media gateway 1. Softswitch is the control core of NGN. It is responsible for all call processing under its jurisdiction and controls media gateway resources. The media gateway converts the media in one network into the media format required by another network. For example, the voice / data bearer is exchanged according to the media gateway control signaling sent by the softswitch.

The basic structure of NGN is generally divided into: service layer, control layer, transmission layer and access layer. Among them, the control layer mainly completes functions such as succession control and resource management, and its core is a softswitch, also called a media gateway controller (MGC). The media gateway controller performs bearer control, resource control, and management on the media gateway (MG). The interface between the media gateway controller and the media gateway uses, for example, the Media Gateway Control Protocol (MGCP) or the H.248 / Megaco protocol. The MGCP protocol is an earlier media gateway control protocol defined by the IETF (Internet Engineering Task Force). The H.248 / Megaco protocol is a media gateway control protocol developed by the IETF, ITU-T, and is used for communication between the media gateway controller and the media gateway. In addition, the H.248 / Megaco protocol cooperates with other protocols to complete various NGN services.

Each message in the H.248 / Megaco protocol contains one or more transactions. A "Transaction" is constituted by "request" and "response". Each transaction contains one or more contexts. Each context contains one or more commands. The context defines the connection between some terminals. The context is Parameters describing the topology and media mixing / exchange between the terminals can be made, for example, by

Add command to create, or delete by Subtract command, Move command. H.248 / Megaco contains several commands, such as Add, Subtract, Move, Modify, Audit Value, Audit Capability, Notify, Service Change commands. Various commands implement various services through the parameters they carry. Commands under the H.248 / Megaco protocol are independent of the underlying transport protocol.

In the next generation network (NGN), there are many media gateways (MG) based on the media gateway control protocol H.248 / Megaco protocol. These gateways are distributed in the homes of enterprises or users. They have the characteristics of wide area, large volume, and dynamic IP. . However, in the current NGN network, because the H.248 / Megaco protocol is mainly used for transmission over the user datagram protocol (UDP) in the fixed network, the UDP protocol does not have the link detection function of the transport layer, and H.248 / Megaco The protocol also does not define whether the media gateway can initiate a message to detect the link state of the softswitch, so that after the media gateway controller fails and restarts, the media gateway cannot know the media gateway control in time without the user actively calling The status of the device, the relevant user as the called party will be affected. In this case, for example, it will prevent others from calling the affected user. Summary of the invention

An object of the present invention is to solve the existing problems in the prior art that the media gateway cannot detect the link state of the media gateway controller because the protocol for communication between the media gateway controller and the media gateway has nothing to do with the underlying transmission protocol. defect.

Another object of the present invention is to add a detection function of a media gateway controller to a media gateway based on the H.248 / Megaco protocol.

In order to achieve the above object, according to the present invention, a method for detecting a state of a media gateway controller by a media gateway is provided, which is characterized in that a protocol extension package is added to an interface protocol for communication between the media gateway and the media gateway controller, The method includes the following steps: a) the media gateway sends the protocol extension package to the media gateway controller; b) the media gateway controller receives the protocol extension package and completes the authentication of the media gateway according to the parameters carried in the protocol extension package;

c) determining the link state of the media gateway controller according to the authentication result of the media gateway controller by the media gateway controller; and

d) Repeat the above steps regularly.

Preferably, the step of authenticating the media gateway by the media gateway controller includes: checking whether the IP address in the protocol extension packet sent by the media gateway is consistent with the data configured in the media gateway controller.

Preferably, the protocol extension package includes a request event and a result event, wherein the result event further includes a result of the media gateway controller's legality detection of the media gateway.

Preferably, the Notify command in the H.248 / Megaco protocol carries the parameters in the protocol extension package to complete the detection of the status of the media gateway controller by the media gateway.

Preferably, the media gateway controller communicates with the media gateway through

H.248 / Megaco protocol, or communication through MGCP protocol.

Preferably, the method further includes starting a timer while the media gateway sends a protocol extension packet to the media gateway controller, or after a delay interval.

Preferably, the timer is reset after detecting a successful response from the media gateway controller.

Preferably, after a failure response of the media gateway controller is detected, an alarm message is sent and registered with the standby gateway.

Preferably, after detecting that the media gateway controller fails to respond more than a predetermined number of times, or after the timer time is set to exceed a predetermined time period, sending an alarm message and registering with the standby gateway.

According to the method provided by the present invention, the media gateway can actively detect the connection and communication status of the media to the gateway controller. When the media gateway controller fails, Registering with the backup media gateway controller, this feature can well support the network home function in the event of a disaster. When a disaster occurs in the media gateway controller, through the method of the present invention, the media gateway can immediately learn the information that the current media gateway controller has failed, and immediately register the information with the backup media gateway controller, thereby registering the impact caused thereby. Reduced to a minimum. BRIEF DESCRIPTION OF THE DRAWINGS

The following describes specific embodiments of the present invention by referring to the drawings, in which:

Figure 1 shows a schematic diagram of the internal networking of a traditional switch;

Figure 2 shows a schematic diagram of the internal networking of the NGN;

FIG. 3 shows a flowchart of a method for detecting the status of a media gateway controller by a media gateway according to the present invention. detailed description

The following describes the preferred embodiments of the present invention in detail with reference to the accompanying drawings. Those skilled in the art know that by describing the embodiments of the present invention, various improvements, modifications, or replacements can be made to the present invention without departing from the principles of the present invention. .

Referring to FIG. 3, FIG. 3 shows a flowchart of a method for detecting a state of a media gateway controller by a media gateway according to the present invention. Specific embodiments of the present invention are described based on the H.248 / Megaco protocol, but the present invention is not limited thereto. The present invention is also applicable to other networks using a protocol similar to the H.248 / Megaco protocol between the media gateway and the media gateway controller, for example, in a network using the MGCP protocol.

As mentioned earlier, in the H.248 / Megaco protocol, each message includes one or more transactions, each transaction includes one or more contexts, and each context includes one or more commands. A "request" and "response" constitute a transaction. The connection between terminals is defined by the context. According to the present invention, The media gateway detects the status of the media gateway controller. The basic idea of the present invention is: In the interface protocol for communication between the media gateway controller and the media gateway, a new protocol extension package is defined, for example, when using H.248 / In the case of the egaco protocol as an interface protocol, a H.248 / Megaco protocol extension package is newly defined, which is referred to as the H.248 protocol heartbeat packet HeartBeat in this article. The Notify command in the H.248 / Megaco protocol is used to carry the extended protocol extension. Each parameter in the HeartBeat is included, and the parameters are authenticated to implement the detection of the state of the media gateway controller by the media gateway.

Hereinafter, the method for detecting the state of the media gateway controller by the media gateway according to the present invention is described in more detail through specific embodiments. The embodiment is described based on the H.248 / Megaco protocol. To this end, a parameter defined as the H.248 / Megaco protocol heartbeat packet HeartBeat is added to the Notify command under the H.248 / Megaco protocol. The H.248 / Megaco protocol heartbeat packet defined here is a request-response type protocol extension packet, which is a collection of heartbeat request events and heartbeat result events. The content defined in the heartbeat packet is used as a parameter of the Notify command. Parameter to complete the function of detecting the status of the media gateway controller by the media gateway.

The following illustrates the above process.

Assume that the configuration of the media gateway and media gateway controller is:

1. The IP address and port number of the media gateway: [123.123.123.4]: 55555

2. IP address and port number of the media gateway controller: [125.125.125.111]: 55555 Implementation based on H.248 / Megaco protocol H.248 / Megaco protocol of the present invention Heartbeat packet HeartBeat can be defined as follows:

Protocol extension package name: HeartBeat; Protocol extension package version: 1;

Events included in the protocol extension package:

1: Heartbeat request event (This parameter type is Event):

Heartbeat request event ID: hrtbtreq (0x0001)

Parameters: None Heartbeat result events (this parameter type is ObservedEvents):

Heartbeat result event identifier: hrtbtrlt (0x0001) This parameter is mainly used to obtain the result of detecting the validity of the heartbeat packet sent by the media gateway by the media gateway controller.

Type: enum is an enumerated type, which is a data structure that defines the various possible outcomes of the resulting event.

Value of the heartbeat result event: This value is the detection result given by the media gateway controller based on the legality detection of the heartbeat packet. Then, the determined detection result is sent to the media gateway. As follows, the detection results returned by the media gateway controller to the media gateway include:

0x00: Successful, indicating that the media gateway controller successfully authenticated the media gateway;

0x01: Failed-InvalidMGW, indicating that the current media gateway is an illegal media gateway;

0x02: Failed-OtherReason, indicating that the current media gateway rejected the heartbeat request event for other reasons. The authentication process based on the add-on protocol extension package, that is, by checking whether the IP address in the protocol extension package matches the data configured on the softswitch, the necessary steps used are (general example of communication between MGC and MG):

step 1:

The MG initiates a heartbeat packet request message to the MGC: The MG sends a Notify command requesting an event to the MGC, allocates a transaction identifier 100 and an event request identifier 300 for this, requests the MGC to perform a legality check and returns a heartbeat result event (HeartBeat / hrtbtrit). At the same time when the heartbeat request message is sent, or after a delay, the MG starts a timer T1. The timer may be, for example, a software timer, which may be directly called by software through an interface function of an operating system (such as VxWORKS, etc.). The period of the timer can be configured by the maintenance station, for example.

The operation of step 1 can be programmed as follows:

MEGACO / 1 [123.123.123.4]: 55555

Transaction = 100 {

Context--{

Notify = root {

Events = 300 {HeartBeat / hrtbtreq}

}

Among them, the protocol used is "MEGACO", and the version number of the protocol is "1". Softswitch IP address: 123.123.123.4; port number: 55555. The transaction ID is "100". The ID of the request event is "300", which represents the ID of the event "HeartBeat / hrtbtreq". The Notify command sets the identity endpoint ID to "root", which represents the entire gateway. Step 2:

When the MGC receives the Notify command sent by the MG, it starts to verify the validity of the gateway. That is, it checks whether the IP address in the heartbeat packet matches the data configured on the softswitch. After the validity verification is completed, the MGC returns a corresponding response result to the MG, and the response result is sent back to the MG by using the Notify command of the response type. In the Notify command of this response type, the event parameter is the gateway legality authentication result. The transaction ID 100 in the Notify command of the response type is consistent with the Notify transaction ID sent by M0, and the event ID 300 is also consistent with the event ID of the request message.

The operation of step 2 can be programmed as follows: MEGACO / 1 [125.125.125.111〗: 55555

Reply = 100 {

Context = ― {Notify = root {

ObservedEvents = 300 {HeartBeat / hrtbtrlt}

}

Among them, "Reply" represents the response message, whose transaction ID is "100", which is the same as the transaction ID in the request message; the event ID is "300", which represents the "heartbeat result event HeartBeat / hrtbtrlt", and It is the same as the event ID in the heartbeat request message. Step 3:

After receiving the heartbeat response, the MG checks the returned heartbeat response result. If the response is successful, for example, the value of the heartbeat result event is "0x00", which indicates that the gateway authentication is successful, and the status of the media gateway controller is normal. In this case, Reset the timer. If it is a failure response, for example, the value of the heartbeat result event is "0x01", or the value of the heartbeat result event is "0X02", the background maintenance personnel should be notified to solve the problem. At the same time, the current gateway is notified to register with the standby gateway.

For example, the above steps can be repeated periodically by setting a timer to achieve the real-time detection of the MGC status by the MG. The timer interval setting can be manually configured. Preferably, the timer is set with reference to network traffic in a manner that does not increase too much traffic load as much as possible. In the case of abnormal communication between MGC and MG:

At this time, the MG's timer will expire. After the timer expires, the MG resends the Notify message. And reset the timer at the same time. After resending N times (N can be configured through the maintenance station), the MG considers that the MGC link status is abnormal, and alerts and registers with the standby gateway. The specific steps are as follows: The operation of step 1 can be programmed as follows:

MEGACO / 1 [123.123.123.4]: 55555

Transaction = 100 {

Context--{

Notify = root {

Events = 300 {HeartBeat / hrtbtreq}

}

Among them, the protocol used is "MEGACO", and the version number of the protocol is "1". Softswitch IP address: 123.123.123.4; port number: 55555. The transaction ID is "100". The ID of the request event is "300", which represents the ID of the event "HeartBeat / hrtbtreq". The Notify command sets the identity endpoint ID to "root", which represents the entire gateway.

Step 2: The timer expires and the MG does not receive a response from the Notify message. Retransmit the message from step 1, reset the timer at the same time, and increment the retransmission counter.

Step 3: Repeat Step 2 to check the retransmission counter. When the retransmission counter is greater than N, an alarm is generated and registered with the standby gateway. Stop the retransmission timer. According to the method of the present invention, the media gateway actively sends a message to the media gateway controller, such as a heartbeat packet message. Therefore, after the media gateway controller fails, the status of the media gateway controller can be known in time, and it can be timely sent to the standby gateway. registered. This feature can well support the dual-homing function of the network in the event of a disaster. The dual-homing function is a network self-healing design concept and is designed to provide protection to a certain network node after a failure. The so-called "attribution" refers to the superior office to which an end office belongs. "Dual-homing" refers to assigning two superior offices to an end office, so this office has two entrances to other offices, and its business requirements are also divided into two. Generally, the traffic in the office is divided into two. When one office fails, 50% of the traffic in the other office is still not affected. Although the dual-homing structure itself does not have recovery capabilities, after it is used with digital cross-connect equipment, if the office-to-backup optical fiber line has sufficient capacity, it can generally recover more than 50% of traffic through the backup superior office. Thereby, the media gateway and the user terminal are connected to two softswitches at the same time, such as softswitch1 and softswitch2. When one of the softswitches, such as Softswitch1, fails, the user terminal and the media gateway can obtain the information and register with the standby softswitch, such as Softswitch2, so as to minimize the impact on the result. The specific embodiments of the present invention have been described above with reference to the accompanying drawings. It should be understood that those skilled in the art can make various modifications in form and detail according to the principles of the present invention without departing from the scope defined by the appended claims of the present invention.

Claims

1. A method for detecting the status of a media gateway controller by a media gateway in a network with separate bearing and control, characterized in that a protocol extension package is added to an interface protocol for communication between the media gateway and the media gateway controller, The method includes the following steps:

a) the media gateway sends the protocol extension package to the media gateway controller; b) the media gateway controller receives the protocol extension package and completes the authentication of the media gateway according to the parameters carried in the protocol extension package;

c) determining the link state of the media gateway controller according to the authentication result of the media gateway by the media gateway controller; and

d) Repeat the above steps regularly.

1. The method according to claim 1, wherein the step of authenticating the media gateway by the media gateway controller comprises: checking the IP address in the protocol extension package sent by the media gateway and the IP address configured in the media gateway controller. Whether the data is consistent.

3. The method according to claim 1, wherein the protocol extension package includes a request event and a result event, wherein the result event further includes a result of the media gateway controller's validity check of the media gateway.

4. The method according to claim 1, further comprising: using a Notify command in the H.248 / Megaco protocol to carry parameters in the protocol extension package to complete the detection of the status of the media gateway controller by the media gateway.

5. The method according to claim 1, wherein the media gateway controller communicates with the media gateway through a H.248 / Megaco protocol.

6. The method according to claim 1, wherein the media gateway controller communicates with the media gateway through an MGCP protocol.

7. The method according to claim 1, further comprising: while the media gateway sends a protocol extension packet to the media gateway controller, or delaying a time interval After that, a timer is started.

8. The method according to claim 1, further comprising resetting a timer after detecting a successful response of the media gateway controller.

9. The method according to claim 1, further comprising, after detecting a failure response of the media gateway controller, sending an alarm message and registering with the standby gateway.

10. The method according to claim 1 or 9, characterized in that, after detecting that the media gateway controller fails to respond more than a predetermined number of times, or after the timer time is set to exceed a predetermined time period, sending an alarm message and registering with the standby gateway .