CN106713227A - Extensible WebRTC control protocol conversion gateway and conversion method thereof - Google Patents
Extensible WebRTC control protocol conversion gateway and conversion method thereof Download PDFInfo
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- CN106713227A CN106713227A CN201510777211.0A CN201510777211A CN106713227A CN 106713227 A CN106713227 A CN 106713227A CN 201510777211 A CN201510777211 A CN 201510777211A CN 106713227 A CN106713227 A CN 106713227A
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- signaling
- module
- control protocol
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- webrtc
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L69/00—Network arrangements, protocols or services independent of the application payload and not provided for in the other groups of this subclass
- H04L69/08—Protocols for interworking; Protocol conversion
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L12/00—Data switching networks
- H04L12/66—Arrangements for connecting between networks having differing types of switching systems, e.g. gateways
Abstract
The present invention discloses an extensible WebRTC control protocol conversion gateway and a conversion method thereof. The extensible WebRTC control protocol conversion gateway comprises a signal control protocol module and a format module; the signal control protocol module receives signals required to be converted, analyzes the signals, forwards the signals to the format module, generates signals conforming to a control protocol standard based on intermediate signal content from the format module and transmits the signals to a destination communication network; and the format module converts the signals transmitted from the signal control protocol module into intermediate signals and transmits the intermediate signals a target signal control protocol module. The WebRTC control protocol conversion gateway of the invention has the advantages of extensible structure, low-coupling, low cost, simple secondary development and short development cycle, and can realize conversion among a variety of control protocols and can support a variety of WebRTC control protocols in an extensible manner.
Description
Technical field
The present invention relates to a kind of expansible WebRTC control protocols transfer gateway and its conversion method, belong to
The communications field.
Background technology
WebRTC is a kind of multimedia realtime communication technology based on browser, and it is by multimedia processing capability
It is embedded into browser, defines series of standards JavaScript interface, web developer can basis
These API develop the webpage for possessing audio frequency and video real-time communication function.WebRTC and not specified specific letter
Agreement is made, but is voluntarily selected in development and application program by web developer.Existing various WebRTC controls
Agreement processed can be used for WebRTC application and developments, such as SIP, XMPP, ROAP, Jingle.WebRTC
Signaling control protocol transfer gateway plays the role of important and meaning for realizing different WebRTC IACs
Justice.
In the prior art, a WebRTC control protocol transfer gateway is only capable of completing two kinds of WebRTC controls
The conversion of agreement, it is impossible to realize the conversion of three kinds and above WebRTC control protocols, and, WebRTC
The structure of control protocol transfer gateway is not expansible.
The content of the invention
For the part of above shortcomings in the prior art, the technical problem to be solved in the present invention is to provide one
Expansible WebRTC control protocols transfer gateway and its conversion method is planted, for completing various WebRTC
Conversion between control protocol.
The technical scheme that is used to achieve the above object of the present invention is：A kind of expansible WebRTC controls
Protocol conversion gateway, including：
First signaling control protocol module, for receiving the signaling that need to be changed, parsing signaling and forward signaling
To Format modules；
Format modules, for the Signalling conversion of sending the first signaling control protocol module into middle signaling,
And send to the second signaling control protocol module middle signaling；
Second signaling control protocol module, the middle signaling content generation symbol from Format modules for basis
The signaling of purpose consensus standard is closed, and is sent to purpose communication network.
The first signaling control protocol module includes：
First network packet parsing module, for parsing the network message comprising signaling, the signaling that will be obtained is passed
To the first signaling resolution module and the first signaling forwarding module；
First signaling resolution module, for parsing the signaling that first network packet parsing module is transmitted, obtains letter
Make and be not belonging to the information of middle signaling in head field and be passed along the first database association module；
First database association module, for the data that the first signaling resolution module is transmitted to be stored in into database
In；
First signaling forwarding module, for by the signaling that first network packet parsing module is transmitted send to
Format modules.
The Format modules include：
Routing module, for receiving the signaling that the first signaling control protocol module is sent, and is transmitted to letter by signaling
Make formatting module；The destination address in the middle signaling changed according to signaling format module is additionally operable to, will
Middle signaling is forwarded to the second signaling control protocol module；
Signaling format module, for the Signalling conversion that transmits routing module into middle signaling.
The form of the middle signaling is designed according to the signaling type being related in application, and specific requirement is：In
Between the information that carries of signaling on the one hand ensure the foundation of communication session, on the other hand maximize succinct.
The second signaling control protocol module includes：
Second network message parsing module, for the signaling that the second signaling resolution module is generated to be packaged into network
Message, is forwarded to purpose communication network；
Second signaling resolution module, for calling the second database association module, in acquisition signaling head field not
Belong to the information of middle signaling, the signaling of target protocol standard is met according to the generation of middle signaling, and will generation
Signaling be transmitted to the second network message parsing module；
Second database association module, for the instructions query database according to the second signaling resolution module, with
The information of middle signaling is not belonging in the signaling head field for obtaining storage in database；
Second signaling forwarding module, for receiving the middle signaling that Format modules are transmitted, and by middle signaling
It is forwarded to the second signaling resolution module.
A kind of conversion side of expansible WebRTC control protocol transfer gateways according to claim 1
Method, comprises the following steps：
If the first signaling control protocol module is received sent using X as the WebRTC applications of control protocol
Network message, wherein comprising X signalings, then the first signaling control protocol module is to the network message solution that receives
Analysis, obtains X signalings；
First signaling control protocol module is not belonging to the information of middle signaling in extracting field of lifting one's head in X signalings
And store；
X signalings are forwarded to Format modules by the first signaling control protocol module；
X Signalling conversions are middle signaling by Format modules, and the target address information in middle signaling
Judge the X signalings target signaling type to be converted into, middle signaling is sent to the second signaling control protocol mould
Block；
Session id information of the second signaling control protocol module in middle signaling, inquiry database in whether
There is the information data of the session, if so, then extracting session information, and target signaling is generated according to middle signaling；
If no, the session information in middle signaling is preserved to database；
Target signaling Y is packaged into network message by the second signaling control protocol module, is forwarded to network.
The first signaling control protocol module is to control to assist by the first signaling to the network message parsing for receiving
Discuss the first network packet parsing module completion of inside modules.
The first signaling control protocol module is not belonging to middle signaling in extracting field of lifting one's head in X signalings
Information is simultaneously stored, specially：The first signaling resolution module in first signaling control protocol module is in X signalings
Middle extraction is lifted one's head and the information of middle signaling is not belonging in field, and by the first signaling control protocol module
First database association module is stored it in database.
X Signalling conversions are middle signaling by the Format modules, and the destination address in middle signaling
Information judges the X signalings target signaling type to be converted into, and middle signaling is sent to the second signaling and controls to assist
View module, specially：
The routing module of Format modules receives X signalings；
The signaling format module of Format modules is changed to X signalings, is converted into and is preset lattice
The middle signaling of formula, and middle signaling is issued into routing module；
Routing module judges the X signalings target signaling class to be converted into according to target address information in middle signaling
Type, middle signaling is sent to the second signaling control protocol module.
Session id information of the second signaling control protocol module in middle signaling, in inquiry database
Whether the information data of the session is had, specially：
Second signaling forwarding module of the second signaling control protocol module receives the middle letter that Format modules are sent
Order, forwards it to the signaling resolution module of the second signaling control protocol module；
Session id information of the signaling resolution module of the second signaling control protocol module in middle signaling is called
Whether the second database association module, have the session information in inquiry database.
The present invention has advantages below and beneficial effect：The present invention would be limited to by introducing Format modules
The gateway architecture of two kinds of WebRTC control protocols conversions expands to the various WebRTC control protocols conversions of support
Gateway architecture so that gateway architecture is expansible, lower coupling, easy to maintain, and development cost is low, two
Secondary exploitation is simple, and the construction cycle is short.
Brief description of the drawings
Fig. 1 is the embodiment schematic diagram of gateway architecture of the invention；
Fig. 2 is the example structure schematic diagram of signaling control protocol module of the invention；
Fig. 3 is the embodiment schematic diagram of Format modular structures of the invention；
Fig. 4 is the flow chart of method for converting protocol of the invention.
Specific embodiment
Below in conjunction with the accompanying drawings and embodiment the present invention is described in further detail.
It is a kind of expansible WebRTC control protocol transfer gateway knots of the embodiment of the present invention referring to Fig. 1
Structure schematic diagram；WebRTC control protocol transfer gateway structures expansible described in the embodiment of the present invention include：
First signaling control protocol module, Format modules and the second signaling control protocol module；
Described the first signaling control protocol module receive need to change signaling, parsing signaling and signaling is forwarded
To Format modules, the control protocol standard is met according to the middle signaling content generation from Format modules
Signaling and send to purpose communication network；
The Signalling conversion that described Format modules send the first signaling control protocol module into middle signaling,
And send to the second signaling control protocol module middle signaling.
Fig. 2 is referred to, is the control protocol modular structure schematic diagram of the embodiment of the present invention；The embodiment of the present invention
The first signaling control protocol module includes：
First network packet parsing module；
First signaling resolution module；
First database association module；
First signaling forwarding module；
Wherein, first network packet parsing module is used to parse the network message comprising signaling, the letter that will be obtained
Order is transmitted to the first signaling resolution module, the first signaling forwarding module.
Wherein, the first signaling resolution module is used to parse signaling, and the key message obtained in signaling head field is passed
To the first database association module.
Wherein, the data that the first signaling resolution module is transmitted are stored in database by the first database association module.
Wherein, the first signaling forwarding module by the signaling that first network packet parsing module is transmitted send to
Format modules.
The second signaling control protocol module includes described in the embodiment of the present invention：
Second network message parsing module；
Second signaling resolution module；
Second database association module；
Second signaling forwarding module；
Wherein, the second network message parsing module is additionally operable to the signaling encapsulation for generating the second signaling resolution module
Into network message, network is forwarded to.
Wherein, the second signaling resolution module is additionally operable to call the second database association module, in acquisition head field
Key message, generates the consensus standard signaling, and standard signaling is transmitted into network message solution according to middle signaling
Analysis module.
Wherein, the second database association module is additionally operable to the instructions query data according to the second signaling resolution module
Storehouse, obtains key message in head field.
Wherein, the second signaling forwarding module is additionally operable to receive the middle signaling that Format modules are transmitted, and by
Between signaling be forwarded to the second signaling resolution module.
Fig. 3 is referred to, is the Format modular structure schematic diagrams of the embodiment of the present invention；Embodiment of the present invention institute
Stating Format modules includes：
Routing module；
Signaling format module；
Wherein, routing module is used to receive the signaling that the signaling control protocol module is sent, and signaling is passed
Give Format modules；Routing module is additionally operable to the destination address in signaling, and middle signaling is forwarded into phase
Answer signaling control protocol module.
Wherein, the Signalling conversion that signaling format module will be received is into middle signaling.
Wherein, the form of the middle signaling is designed to contrast each WebRTC control protocol, wherein taking
On the one hand the information of band ensure the foundation of communication session, on the other hand maximizes succinct.
The form of middle signaling is designed according to the signaling type being related in application, and specific requirement is：Centre letter
Make the information for carrying on the one hand ensure the foundation of communication session, on the other hand maximize succinct.
Middle signaling uses JSON data forms, is divided into initial row (startline), head field (headers)
With the part of message body (body) three.It is below specific design example：
Embodiment 1：The middle signaling format of JSEP and SIP conversions
Embodiment 2：The middle signaling format of JSEP, SIP, XMPP conversion also can be using the lattice of embodiment 1
Formula.The information included in the middle signaling of embodiment 1 can be used to set up session, and various control protocols are believed
Exclusive information is made to be put into the own database of each control protocol module.
It is the WebRTC control protocol transfer gateway conversion and control protocol streams of the embodiment of the present invention referring to Fig. 4
Journey schematic diagram；Wherein, X, Y are two kinds of WebRTC control protocols；Assuming that in the middle of the generation of Format modules
The form of signaling has determined.The WebRTC control protocol transfer gateway conversion and controls of the embodiment of the present invention
Agreement flow is specific as follows：
S401：X control protocol modules receive the net sent as the WebRTC applications of control protocol using X
Network message, wherein comprising X signalings；The network message parsing module of X control protocol modules is to the message that receives
Parsing, obtains X signalings, and X signalings are issued into signaling resolution module and signaling forwarding module；
S402：Signaling resolution module extracts the key message in its field to X signalings, such as Call-ID,
CSeq, Via, Contact, issue the storage of database association module, make during so as to the signaling for generating same session
With；
S403：The information that database association module storage signaling resolution module is sent；
S404：The X signalings that signaling forwarding module will be received are forwarded to Format modules；
S405：The routing module of Format modules receives X signalings；The signaling format module of Format modules
To X Signalling conversions, the middle signaling of the consolidation form for setting in advance is converted into, and by middle signaling
Issue routing module；
S406：Routing module judges that signaling will be converted into target signaling Y according to To fields in middle signaling, will
Middle signaling is sent to Y control protocol modules；
S407：The signaling forwarding module of Y control protocol modules receives the middle signaling that Format modules are sent,
Forward it to the signaling resolution module of Y control protocol modules；
S408：Session id information of the signaling resolution module of Y control protocol modules in middle signaling is called
Whether database association module, have the session information in inquiry database, if so, session information is then extracted,
And the Y signalings of standard are generated according to middle signaling；If no, the session information in middle signaling is preserved
To database；
S409：The network message parsing module of Y control protocol modules is by the signaling resolution of Y control protocol modules
The Y signalings of module generation are packaged into network message, are forwarded to network.
Claims (10)
1. a kind of expansible WebRTC control protocol transfer gateways, it is characterised in that including：
First signaling control protocol module, for receiving the signaling that need to be changed, parsing signaling and forward signaling
To Format modules；
Format modules, for the Signalling conversion of sending the first signaling control protocol module into middle signaling,
And send to the second signaling control protocol module middle signaling；
Second signaling control protocol module, the middle signaling content generation symbol from Format modules for basis
The signaling of purpose consensus standard is closed, and is sent to purpose communication network.
2. expansible WebRTC control protocol transfer gateways according to claim 1, its feature exists
In the first signaling control protocol module includes：
First network packet parsing module, for parsing the network message comprising signaling, the signaling that will be obtained is passed
To the first signaling resolution module and the first signaling forwarding module；
First signaling resolution module, for parsing the signaling that first network packet parsing module is transmitted, obtains letter
Make and be not belonging to the information of middle signaling in head field and be passed along the first database association module；
First database association module, for the data that the first signaling resolution module is transmitted to be stored in into database
In；
First signaling forwarding module, for by the signaling that first network packet parsing module is transmitted send to
Format modules.
3. expansible WebRTC control protocol transfer gateways according to claim 1, its feature exists
In the Format modules include：
Routing module, for receiving the signaling that the first signaling control protocol module is sent, and is transmitted to letter by signaling
Make formatting module；The destination address in the middle signaling changed according to signaling format module is additionally operable to, will
Middle signaling is forwarded to the second signaling control protocol module；
Signaling format module, for the Signalling conversion that transmits routing module into middle signaling.
4. expansible WebRTC control protocol transfer gateways according to claim 3, its feature exists
In the form of the middle signaling is designed according to the signaling type being related in application, and specific requirement is：In
Between the information that carries of signaling on the one hand ensure the foundation of communication session, on the other hand maximize succinct.
5. expansible WebRTC control protocol transfer gateways according to claim 1, its feature exists
In the second signaling control protocol module includes：
Second network message parsing module, for the signaling that the second signaling resolution module is generated to be packaged into network
Message, is forwarded to purpose communication network；
Second signaling resolution module, for calling the second database association module, in acquisition signaling head field not
Belong to the information of middle signaling, the signaling of target protocol standard is met according to the generation of middle signaling, and will generation
Signaling be transmitted to the second network message parsing module；
Second database association module, for the instructions query database according to the second signaling resolution module, with
The information of middle signaling is not belonging in the signaling head field for obtaining storage in database；
Second signaling forwarding module, for receiving the middle signaling that Format modules are transmitted, and by middle signaling
It is forwarded to the second signaling resolution module.
6. a kind of conversion of expansible WebRTC control protocol transfer gateways according to claim 1
Method, it is characterised in that comprise the following steps：
If the first signaling control protocol module is received sent using X as the WebRTC applications of control protocol
Network message, wherein comprising X signalings, then the first signaling control protocol module is to the network message solution that receives
Analysis, obtains X signalings；
First signaling control protocol module is not belonging to the information of middle signaling in extracting field of lifting one's head in X signalings
And store；
X signalings are forwarded to Format modules by the first signaling control protocol module；
X Signalling conversions are middle signaling by Format modules, and the target address information in middle signaling
Judge the X signalings target signaling type to be converted into, middle signaling is sent to the second signaling control protocol mould
Block；
Session id information of the second signaling control protocol module in middle signaling, inquiry database in whether
There is the information data of the session, if so, then extracting session information, and target signaling is generated according to middle signaling；
If no, the session information in middle signaling is preserved to database；
Target signaling Y is packaged into network message by the second signaling control protocol module, is forwarded to network.
7. method according to claim 1, it is characterised in that the first signaling control protocol module
Network message parsing to receiving is the first network packet parsing by the first signaling control protocol inside modules
What module was completed.
8. method according to claim 1, it is characterised in that the first signaling control protocol module
The information of middle signaling is not belonging in extracting field of lifting one's head in X signalings and stored, specially：First signaling
The first signaling resolution module in control protocol module is not belonging to middle letter in extracting field of lifting one's head in X signalings
The information of order, and stored it in by the first database association module in the first signaling control protocol module
In database.
9. method according to claim 1, it is characterised in that the Format modules are by X signalings
Be converted to middle signaling, and target address information in middle signaling judges the X signalings mesh to be converted into
Mark signaling type, middle signaling is sent to the second signaling control protocol module, specially：
The routing module of Format modules receives X signalings；
The signaling format module of Format modules is changed to X signalings, is converted into and is preset lattice
The middle signaling of formula, and middle signaling is issued into routing module；
Routing module judges the X signalings target signaling class to be converted into according to target address information in middle signaling
Type, middle signaling is sent to the second signaling control protocol module.
10. method according to claim 1, it is characterised in that the second signaling control protocol mould
Whether root tuber has the information data of the session, tool according to the session id information in middle signaling in inquiry database
Body is：
Second signaling forwarding module of the second signaling control protocol module receives the middle letter that Format modules are sent
Order, forwards it to the signaling resolution module of the second signaling control protocol module；
Session id information of the signaling resolution module of the second signaling control protocol module in middle signaling is adjusted
With the second database association module, whether there is the session information in inquiry database.
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| CN201510777211.0A CN106713227A (en) | 2015-11-13 | 2015-11-13 | Extensible WebRTC control protocol conversion gateway and conversion method thereof |
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ID=58931821
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113300936A (en) * | 2021-02-01 | 2021-08-24 | 阿里巴巴集团控股有限公司 | CDN node, edge node signaling adaptation method, device and storage medium |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1680940A (en) * | 2004-03-19 | 2005-10-12 | 张逶 | Inputting system and method in intenert website |
| US20150063557A1 (en) * | 2012-11-05 | 2015-03-05 | Genesys Telecommunications Laboratories, Inc. | System and method for web-based real time communication with optimized transcoding |
| CN104980398A (en) * | 2014-04-04 | 2015-10-14 | 中国电信股份有限公司 | Message distribution method between browser and IP multimedia subsystem (IMS), message distribution system between browser and IMS and signaling relay device |
-
2015
- 2015-11-13 CN CN201510777211.0A patent/CN106713227A/en not_active Withdrawn
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1680940A (en) * | 2004-03-19 | 2005-10-12 | 张逶 | Inputting system and method in intenert website |
| US20150063557A1 (en) * | 2012-11-05 | 2015-03-05 | Genesys Telecommunications Laboratories, Inc. | System and method for web-based real time communication with optimized transcoding |
| CN104980398A (en) * | 2014-04-04 | 2015-10-14 | 中国电信股份有限公司 | Message distribution method between browser and IP multimedia subsystem (IMS), message distribution system between browser and IMS and signaling relay device |
Non-Patent Citations (2)
| Title |
|---|
| 刘明栓: "WebRTC系统中信令子系统的设计与实现", 《中国优秀硕士学位论文全文数据库 信息科技辑》 * |
| 陈凯: "WebRTC对OTT的影响分析", 《电信网技术》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113300936A (en) * | 2021-02-01 | 2021-08-24 | 阿里巴巴集团控股有限公司 | CDN node, edge node signaling adaptation method, device and storage medium |
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Application publication date: 20170524 |