CN1283082C - Method for implementing media gateway control protocol application adaptive compatibility - Google Patents

Abstract

The present invention relates to a method for implementing the compatible application and adaptation of a media gateway control protocol. A unified media gateway controlling application program interface (MGCAPI) is used between an independent protocol adaptive layer and a shared service process layer of two kinds of media gate control protocols (MeGaCo/H. 248, MGCP) for communication; the MGCAPI adopts transaction as a basic unit of interface interaction information and adopts a hierarchical nested data structure of transaction, action, orders and descriptors; the interface message of the MCAPI is converted with respective media gateway control protocol message on the protocol adaptive layer to be converted into protocol data units processed by respective protocol stack, and the protocol data units decoded by respective protocol stack are converted to MCAPI information. The development process of MGC and MG can be increased by the present invention, the upgrade extension of a product is convenient, and the maintenance cost of MGC and MG is also reduced.

Description

MGCP is used the implementation method of adaptive compatibility

Technical field

The present invention relates to communication technical field, relate in particular to the implementation method that a kind of MGCP is used adaptive compatibility.

Background technology

MGC (Media Gateway Controller) and MG (media gateway) are two key members among the NGN (next generation network).MGC is responsible for CCF, and MG is responsible for the service bearer function, realize by this calling out separating of control plane and service bearer plane, thus abundant shared network resource, simplified apparatus upgrading and professional expansion, and reduce development and maintenance cost greatly.

MGCP is the main agreement of communicating by letter between MGC and the MG, present widely used have MeGaCo/H.248 and two kinds of agreements of MGCP.Wherein, MGCP agreement (V1.0) is worked out in October, 1999 by IETF (the Internet engineering duty group), and MeGaCo/H.248 agreement (V1.0) is worked out in November, 2000 by IETF (the Internet engineering duty group) and ITU (International Telecommunications Union).

MeGaCo/H.248 and MGCP agreement have very big similitude on function, but at aspects such as call model, command parameter, message structures many differences are arranged also.Therefore the formulation of MGCP relatively early has first-strike advantage on popularity of using and equipment supportive; And therefore the formulation of MeGaCo/H.248 more has development potentiality at aspects such as completeness, compatibility and autgmentabilities based on reference and optimization to MGCP.

One has extensive adaptability and good expansionary MGC or MG, should support these two kinds of same quasi-protocols of MeGaCo/H.248 and MGCP simultaneously, thereby realize networking solution flexibly and powerful service expansion capability.

Be illustrated in figure 1 as existing MGCP and use adaptive independent system schematic diagram, prior art adopts separately independently protocol Data Unit data structure, two kinds of protocol stacks of MeGaCo/H.248 and MGCP respectively provide independently use adaptive, also promptly two kinds of agreements all have separately independently protocol stack, protocol adaptation and Business Processing, shown in empty frame among Fig. 1.

Because two kinds of agreements of MeGaCo/H.248 and MGCP are used separately independently data structure, two covers just must be arranged, and fully independently the protocol stack application is adaptive, and the adaptive system of then whole application is actually the simple superposition of two cover independent systems.Simultaneously, because the MGCP agreement is used ABNF grammer (text message) encoding and decoding, H.248 agreement can be used ABNF grammer or ASN.1 grammer (binary message) encoding and decoding, like this, in order to finish the order of business side, the conversion of parameter and concrete protocol Data Unit (protocol Data Unit be the foundation of protocol stack coding and the form of expression of decoded protocol message), the operation layer designer must accurately understand the MGCP agreement and/or the protocol Data Unit of agreement H.248, and the concrete structure of protocol Data Unit and content closely depend on this two cover grammer and the two concrete application of cover grammer in different agreement, therefore, business side designer must spend the encoding and decoding grammer ABNF of plenty of time and energy study MGCP agreement and H.248 the encoding and decoding grammer ABNF and the ASN1 of agreement, increased the weight of the burden of product development so undoubtedly greatly, the maintenance cost of MGC and MG also increases simultaneously; And because business module and agreement grammer close coupling, the extending space of module is very little, expands very inconvenient.

Summary of the invention

Technical problem to be solved by this invention is: overcome two kinds of MGCPs of MeGaCo/H.248 and MGCP among existing MGC or the MG and adopt and independently use exploitation difficulty that adaptive system brings and the deficiency that is difficult for expansion separately, the implementation method that provides a kind of MGCP to use adaptive compatibility, thus make things convenient for the upgrading of product to expand.

The present invention solves the problems of the technologies described above the technical scheme that is adopted to be:

This MGCP is used the implementation method of adaptive compatibility, may further comprise the steps:

At two kinds of MGCPs (MeGaCo/H.248, MGCP) independently between protocol adaptation layers and the shared Business treatment, adopt unified media gateway controlling application programming interfaces (MGCAPI) to communicate, described MGCAPI adopts the base unit of affairs as interactive interfacing information, and adopts the classification nested data structure of affairs, action, order, descriptor;

Described MCAPI interface message is carried out and the conversion of MGCP message separately in protocol adaptation layers, the protocol Data Unit that the MCAPI message conversion can be handled for protocol stack separately, and the protocol Data Unit after the protocol stack decoding is converted to MCAPI message separately.

The classification nested data structure of described affairs, action, order, descriptor is meant that a MCAPI message comprises affairs, and described affairs are made up of affairs head and affairs body, comprise several action in the affairs body; Action is made up of action head and action body, comprises several orders in the action body; Order is made up of command header and command body, comprises several descriptors in the command body; A descriptor is made up of descriptor head and descriptor body, comprises several attributes in the descriptor body.

If action in the affairs or order do not have correlation, then the gateway control application programming interfaces as the base unit of interactive interfacing information, and adopt the classification nested data structure of action, order, descriptor or order, descriptor with action or order.

Comprise following field in the described affairs head: protocol name, version number, message direction, connection identifier number, action number, transaction number, request confirm that immediately mask, code/decode format mask, option sign, request confirm field, message-length, optional information error description symbol immediately.

Comprise following field in the described action head: action type, order number, pass chain store, option flag, action length, optional information length.

When the action type is asked for action, whether option flag indication action request exists, if exist, also comprise in the described action head: associated priority mask, urgent affinity mask, topology request mask, associated priority field, urgent related indication field, topology request number, topological descriptor; Whether another option flag indication relating attribute audit request exists, if exist, also comprises in the described action head: topological descriptor, associated priority field, urgent related indication field.

When the action type was the action response, whether option flag indication action staging error descriptor existed, and as if existing, also comprises the corresponding error descriptor in the described action head; Whether another option flag indication action response exists, if exist, also comprise in the described action head: associated priority mask, urgent affinity mask, topology request mask, associated priority field, urgent related indication field, topology request number, topological descriptor.

Comprise following field in the described command header: command type, descriptor number, destination node number, order optional mask, wildcard response mask, destination node tabulation mask, order optional attribute field, wildcard response flag, order length, destination node parameter.

Comprise following field in the described descriptor head: descriptor number and descriptor length.

Beneficial effect of the present invention is: media gateway controlling application programming interfaces of the present invention are with the fundamental structural unit of affairs as interactive information, can abundant compatible MeGaCo/H.248 and the message structure of two kinds of agreements of MGCP, guarantee effectively that simultaneously the order correlation is with the integrality of affairs as the effective range information needed.In fact this architecture has used for reference the classification nested structure of MeGaCo/H.248 agreement " affairs-action-order-descriptor ", for application provides a kind of concept hierarchy the clear information organization form that is easy to progressive operation.

Data structure of the present invention can be described the protocol Data Unit of MeGaCo/H.248 and two kinds of agreements of MGCP, and the application handling process that meets MeGaCo/H.248 and two kinds of agreements of MGCP also promptly can mask MeGaCo/H.248 and the difference of two kinds of agreements of MGCP on data structure with the new data structure of this cover.Therefore, operation layer only need be handled a kind of MCAPI (media gateway controlling application programming interfaces) message, rather than will handle MeGaCo/H.248 message and MGCP message respectively.

The gateway control application programming interfaces are with the command set of MeGaCo/H.248 protocol command collection as interaction data, can demonstrate fully this agreement in advantage, effectively satisfy the management and the demand for control of current and following new business realization aspects such as the higher abstractness of business and better autgmentabilities.And the MGCP agreement can be by the conversion of call model and substituting of order and parameter, with smaller cost realization self information form and the conversion between the gateway control application programming interfaces information format.Final effect is exactly that Business Processing only need be understood gateway control application programming interfaces information, also is a kind of information of similar MeGaCo/H.248 agreement, actually or and need not too much to pay close attention to protocol adaptation MeGaCo/H.248 MGCP agreement.

The invention provides a kind of interface unification and expansion and use adaptive method easily, compatible MeGaCo/H.248 and these two kinds of mainstream media's gateway control protocols of MGCP provide a perfect solution simultaneously for MGC and MG, thereby greatly accelerate the development process of MGC and MG, make things convenient for the upgrading expansion of product, and reduce the maintenance cost of MGC and MG.

Description of drawings

Fig. 1 uses adaptive independent system schematic diagram for existing MGCP;

Fig. 2 uses adaptive compatible system schematic diagram for MGCP of the present invention;

Fig. 3 is a media gateway controlling application programming interfaces message structure schematic diagram of the present invention;

Fig. 4 is a descriptor body nested structure schematic diagram of the present invention.

Embodiment

With embodiment the present invention is described in further detail with reference to the accompanying drawings below:

Be illustrated in figure 2 as MGCP of the present invention and use adaptive compatible system schematic diagram, the compatible system of the present invention is made up of transport layer (Transport Layer), transmission adaptive (TransportAdapater), protocol stack (Protocol Stack), protocol adaptation (Protocol Adapater), media gateway controlling application programming interfaces (Media Gateway Control Application ProgramInterface), Business Processing (Service Process), media resource (Media Resource) several sections.

Two kinds of MGCPs of MeGaCo/H.248 and MGCP have separately independently protocol stack (PS) and protocol adaptation (PA).Protocol stack is mainly finished the codec functions of agreement, MeGaCo/H.248 agreement optional text (following ABNF) or two kinds of code encoding/decoding modes of binary system (following ASN.1), and the MGCP agreement has only the text code encoding/decoding mode.Two protocol adaptation modules are finished the parsing and the assembling of protocol message at the data structure of data structure, agreement notion and the media gateway controlling application programming interfaces (MCAPI) of protocol stack separately, the difference of agreement notion, and the conversion of information parameter.

Two kinds of agreement common transmitted of MeGaCo/H.248 and MGCP adaptive (TA).Transmit the adaptive shielding of finishing transport layer (TL) otherness, the MeGaCo/H.248 agreement is optional based on TCP (transmission control protocol), UDP (User Datagram Protoco (UDP)) or SCTP (SCTP) transmission, and the MGCP agreement can only be transmitted based on udp protocol.

Two kinds of agreement common business of MeGaCo/H.248 and MGCP are handled (SP).Business Processing is carried out the adaptive of protocol information and operation flow, in the conversion of finishing under the calling control of MGC between the MG institute carrying media stream, is the actual operator that MG goes up every media resource (MR).

Two kinds of agreements of MeGaCo/H.248 and MGCP independently between protocol adaptation and the shared Business Processing, adopt unified media gateway controlling application programming interfaces (MGCAPI) to communicate.The media gateway controlling application programming interfaces are the otherness of operation layer shielding protocol layer, make to use adaptive these two kinds of MGCPs of compatibility simultaneously.

Since MeGaCo/H.248 and MGCP agreement all with affairs (Transaction) as the base unit of organizing message, and identify with affairs numbering (Transaction No), in the agreement operations dependencies between instructions also with affairs under it as maximum effective range.But can comprise a plurality of affairs in the single message of MeGaCo/H.248 agreement, and can only comprise single affairs in the single message of MGCP agreement.In addition, because the MGCP agreement and H.248 the protocol Data Unit of agreement be the complexity nested pointer chain list structure, be appreciated that this nested structure, just it must be understood that the concrete application of ABNF and ASN.1 grammer in the agreement the inside, in order to make the MCAPI interface message simple in structure, reduction agreement grammer is to the restriction of data structure, the present invention has adopted the nested datagram structure of layering of a cover simple flat, media gateway controlling application programming interfaces (MGCAPI) adopt the base unit of affairs as interactive interfacing information, are followed successively by action then, order, descriptor, descriptor attribute, the nested data structure of descriptor attribute value.

Be illustrated in figure 3 as media gateway controlling application programming interfaces message structure schematic diagram of the present invention, a gateway control application programming interfaces information comprises affairs, and affairs are made up of affairs head and affairs body, comprise several action in the affairs body; Action is made up of action head and action body, comprises several orders in the action body; Order is made up of command header and command body, comprises several descriptors in the command body; A descriptor is made up of descriptor head and descriptor body, comprises several attributes in the descriptor body; An attribute can also comprise several property values.

Since H.248 protocol stack module and the employed data structure of MGCP protocol stack module and cognitive agreement notion and MCAPI interface there is some difference, so adopt independently protocol adaptation module between protocol stack and the MCAPI interface: H.248 protocol adaptation module and MGCP protocol adaptation module.The protocol Data Unit of protocol massages after the protocol stack decoding must just can be converted to the data structure and the protocol parameter of MCAPI interface through the processing of protocol adaptation module; Otherwise the data structure of MCAPI interface and protocol parameter must just can be converted to the protocol Data Unit that protocol stack module can be understood through the processing of protocol adaptation module again.This socket of media gateway controlling application programming interfaces (MCAPI) is shared by protocol adaptation module and Service Processing Module.

Hereinafter be concrete use of MCAPI message data structure in the media gateway product is realized, the MCAPI data structure be described in detail in detail as example.

One, the data structure of affairs head, action head, command header

A, affairs head (Transaction Header)

Affairs are used to identify the public information of MCAPI message data structure affairs one-level, and critical field wherein includes but not limited to following content: protocol name (Protocol Name), version number (Version), message direction (Direction IND), connection identifier number (Association ID), action number (#ofActions), transaction number (Transaction ID), mask (IAR P) is confirmed in request immediately, code/decode format mask (Code_F), option sign (Choice), field (immAckRequired) is confirmed in request immediately, reserve bytes (Reserved), message-length (MessageLength) and optional information error description symbol (Error Descriptor) etc.A specific implementation of an affairs data structure is exemplified below:

Byte

Figure place

Describe

	7	6	5	4	3	2	1	0
										0	Protocol Name		Version				Direction IND		The public message head
1	Association ID(HH)
									2	Association ID(HL)
3	Association ID(LH)
									4	Association ID(LL)
5	#of Actions
									6	Transaction ID(HH)
7	Transaction ID(HL)
									8	Transaction ID(LH)
9	Transaction ID(LL)
									10	IAR_P	Reserved						Code_F
11	Choice
									12	immAckRequired
13	Reserved
									14	Reserved
15	Reserved
									16	Reserved
17	Reserved
									18	Reserved
19	Reserved
									20	Reserved
21	Message Length(H)
									22	Message Length(L)
	Error Descriptor																	Optional information

Parameter declaration is as follows:

1、Protocol Name，

Totally 2 of this parameters are used to indicate type of message, and possible value is:

00-H.248

01-MGCP

10-MNG//inside definition classification, the support maintenance managing queries

The 11-Retention Type

2、Version

Totally 4 of this parameters are used to indicate the protocol version numbering.

3、Direction IND

Totally 2 of this parameters are used to indicate message direction, and possible value is:

00-PM is to the request command of AM

01-PM is to the response of AM

10-AM is to the request command of PM

11-AM is to the response of PM

Annotate: PM refers to the protocol module (Protocol Module) below the MCAPI, and AM refers to the application module (Application Module) above the MCAPI.

4, Association ID indicates the connection identifier number under present MG or the MGC.

5, Transaction ID is a Transaction Identifier, and the scope in MGCP is 0-999999999, should distinguish protocol type when business module is handled and do respective handling.

6, IAR_P is the control mask, and whether IAR_P is used for expression when transaction response asks to confirm immediately (immAckRequired).

7, Reserved, reserved byte, this mainly is for the expansion of supported protocol and the specific demand of different product.

8, Code_F is a coded system indication mask, is 0 o'clock indication text formatting coding, is 1 o'clock indication binary format coding.

9, Choice has following selection, if Choice is 0, represents no optional information, the message header heel be action message; If Choice is 1, there is optional part expression message header back, and what optional part was filled out is the error description symbol (Error Descriptor) of a transaction-level, and there is not any action message in the message back; If Choice is 8, there is optional part expression message header back, and what optional part was filled out is the error description symbol (Error Descriptor) of a message-level, and there is not any action message in the message back.

10, immAckRequired promptly asks to confirm immediately, fills when iAR_P is effective.In addition, when Protocol Name was MNG, it represented other implications:

Be 0 o'clock, the destination node sign (Termination ID) that the presentation protocol stack is relevant according to association identification (Context Id) inquiry;

Be 1 o'clock, the presentation protocol stack is according to the relevant association identification (Context ID) of destination node sign (Termination ID) inquiry.

B, action head (Action Header)

Action is used to identify the public information of MCAPI message data structure action one-level, critical field wherein includes but not limited to following content: action type (Action Type), order number (#ofCommands), close chain store (Context ID), option flag (Flag1, Flag2), action length (Action Length), optional information length (Optional Information Length), action request (Action Request), relating attribute audit request (contextAttrAuditRequest), action response (Action Reply), action staging error descriptor (Error Descriptor), associated priority mask (P_P), urgent affinity mask (E_P), topology request mask (T_P), associated priority field (Priority), urgent related indication field (Emergency), topology request number (#of Topology), topological descriptor (Topology Descriptor) and reserved field (Reserved) or the like.

A specific implementation of an action data structure is exemplified below:

Byte	Figure place								Describe
											7	6	5	4	3	2	1	0
0	Reserved						Action Type		Public action head
										1	#of Commands
2	Context ID(HH)
										3	Context ID(HL)
4	Context ID(LH)
										5	Context ID(LL)
6	Flag1	Flag2	Reserved
										7	Action Length(H)
8	Action Length(L)
										9	Optional Information Length(H)
10	Optional Information Length(L)
											ContextRequest/ContextReply								Optional information
	ContextAttrAuditRequest/Error Descriptor								Optional information

Optional information is described as follows:

Situation one: when action type (Action Type) was asked (Context Request) for action, what Flag1 represented was whether the action request exists, if the indication existence, optional information thes contents are as follows:

	P_P	E_P	T-P	Reserved	Optional information
							Priority(H)
	Priority(L)
							Emergency
	#of Topology
							Topology Descriptor

What Flag2 represented is whether relating attribute audit request (contextAttrAuditRequest) exists, if indication exists, optional information is as follows:

	T_P	E_P	P_P	Reserved	Optional information
						Topology
		Emergency
						Priority

Situation two: when the action type responded (Context Reply) for action, what Flag1 represented was whether action staging error descriptor (Error Descriptor) exists, if indication exists, the optional information content is exactly the corresponding error descriptor; What Flag2 represented is whether the action response exists, if indication exists, optional information is as follows:

	P_P	E_P	T_P	Reserved	Optional information
							Priority(H)
	Priority(L)
							Emergency
	#of Topology
							Topology Descriptor

Above-mentioned parameter is described as follows:

1、Action Type

Totally 2 of this parameters, being used for indication is action request or action response, and other, possible value is:

The 00-request of taking action

The 01-response of taking action

Other value-reservations

2, if Flag1 and Flag2 are 0, then the optional information partial-length of back is 0.

3, whether T_P, E_P, P_P indicate topological descriptor (Topology Descriptor), urgent associated flag (Emergency), related priority sign (Priority) to exist respectively.

4., Action Length is meant the total length of this action.

5, Optional Information Length refers to the length of optional additional information, and this length is the position that navigates to first order (command) for convenience.

C, command header (Command Header)

Order is used to identify the public information of MCAPI message data structure order one-level, and critical field wherein includes but not limited to following content: command type (Command Type), descriptor number (#of Descriptors), destination node number (#ofTermination IDs), order optional mask (O_P), wildcard response mask (WR_P), destination node tabulation mask (TL_P), order optional attribute field (optional), wildcard response flag (wildcard return), order length (Command Length), destination node parameter (Termination ID Parameter) and reserved field (Reserved).

A specific implementation of command header data structure is exemplified below:

Byte	Figure place								Describe
											7	6	5	4	3	2	1	0
0	Command Type																		The common command head
									1	#of Descriptors
2	#of Termination IDs
									3	O_P	WR_P	TL_P	Reserved
4	optional
									5	wildcad return
6	Command Length(H)
									7	Command Length(L)
	TerminationID Parameter 1																	Optional information
										……
	TerminationID Parameter N

Parameter declaration is as follows:

1、Command Type

This parameter is used to indicate the type of order, possible value:

0x01-increases request (Add Request)

The 0x02-request of moving (Move Request)

0x03-revises request (Modify Request)

0x04-removal request (Subtract Request)

0x05-ability audit request (Audit Capability Request)

0x06-value audit request (Audit Value Request)

0x07-notice request (Notify Request)

The professional change of 0x08-asked (Service Change Request)

0x81-increases response (Add Reply)

0x82-moves response (Move Reply)

0x83-revises response (Modify Reply)

0x84-deletion response (Subtract Reply)

0x85-ability audit response (Audit Capability Reply)

0x86-value audit response (Audit Value Reply)

0x87-push-notification-answer (Notify Reply)

The professional change of 0x88-responds (Service Change Reply)

2、#of Descriptors

Represent the descriptor number that comprises in this order.

3、#of Termination Ids

Represent the destination node number that this order comprises.

4, whether TL_P, WR_P, O_P are in order to indicate destination node tabulation (TerminationList), wildcard response (wildcardRetum), to order these information of optional sign (optional) to exist.If TL_P is 0, then the optional information partial-length of back is 0, otherwise the optional information content is destination node parameter (Termination ID Parameter) tabulation; If WR_P is 0, then the wildcard response contents of back is 0, otherwise is 1; If O_P is 0, then the optional sign content of the order of back is 0, otherwise is 1.

5, Command Length is meant the total length of this order.

Two, descriptor structure

Descriptor is used to identify the information of MCAPI message data structure descriptor one-level, and different descriptors has different content of parameter.A specific implementation of descriptor data structure is exemplified below:

A, the public structure of descriptor head (Descriptor Header)

Different descriptors all has public descriptor header structure, and critical field wherein includes but not limited to following content: descriptor ID (Descriptor ID), reserved field (Reserved), descriptor length (Length) or the like.

A specific implementation of descriptor head data structure is exemplified below

Byte	Figure place								Describe
											7	6	5	4	3	2	1	0
0	Descriptor ID								The common descriptor head
										1	Reserved
2	Length(H)
										3	Length(L)

Parameter declaration is as follows:

1, the numbering of Descriptor ID indication descriptor.

2, Reserved is an obligate information, can be used as various uses, for example number of parameters or the like.

3, Length indicates the byte length of this descriptor.

B, descriptor content (Descriptor Body)

Be illustrated in figure 4 as descriptor body nested structure schematic diagram of the present invention, comprise several attributes in the descriptor body; An attribute can also comprise several property values.

The level of nesting in the descriptor body may be more, and such as including a plurality of incidents (or a plurality of signal) in the descriptor, and each incident (or signal) comprises a plurality of attributes; Perhaps nested descriptor or the like in the descriptor body.At this moment also according to the nested thought of layering, from high-level successively nested to low level.

The detailed structure of descriptor is described for the example of an event descriptor (Events Descriptor) below.The critical field of event descriptor includes but not limited to following content: descriptor ID (Descriptor ID), event request number (#of Events Requests), descriptor length (Length), request ID (Request ID), stream ID mask (SID P), incident action mask (EA P), stream ID (Stream ID), bag ID (pkgId), event name (Event Name), event argument number (#of Parameter IDs), incident keeps activating mask (KA_P), embedded several figure descriptor masks (ED_P), the embedded second event descriptor mask (SE_P), embedded signal description symbol mask (SD_P), incident keeps activating field (KeepActive), embedded several figure descriptor first byte positions (DigitMap Descriptor Offset), the embedded second event descriptor first byte position (SecondEvents Descriptor Offset), embedded signal description symbol first byte position (Signals Descriptor Offset), event request length (Event Request Length), parameter I D (Parameter ID), the number of the value in the parameter (#of Value), parameter length (Parameter ID Length), the length (Value Length) of value, value (Value) and reserved field (Reserved) or the like.

A specific implementation of event descriptor data structure is exemplified below:

A), event descriptor structure

Byte	Figure place										Common headers is described
													7	6		5		4	3	2	1	0
0	Descriptor ID＝0x06
												1	#of Events Requests
2	Length (H): this descriptor total length
												3	Length(L)
4	Request ID(HH)																						Privately owned head
											5	Request ID(HL)
6	Request ID(LH)
											7	Request ID(LL)
8	SID_P		EA_P		Reserved																	The head of single request event
											9	Stream ID(SH)
10	Stream ID(SL)
											11	pkgId(HH)
12	pkgId(HL)

13	Event Name(LH)
							14	Event Name(LL)
15	#of Parameter IDs
							16	KA_P	ED_P	SE_P	SD_P	Reserved
17	KeepActive
							18	DigitMap Descriptor Offset(SH)
19	DigitMap Descriptor Offset(SL)
							20	SecondEvents Descriptor Offset(SH)
21	SecondEvents Descriptor Offset(SL)
							22	Signals Descriptor Offset(SH)
23	Signals Descriptor Offset(SL)
							24	Event Request Length(H)
25	Event Request Length(L)
							26	Parameter ID1(H)					Individual event parameter head
27	Parameter ID1(L)
						28	#of Value
29	Parameter ID 1 Length(H)
						30	Parameter ID 1 Length(L)
31	Value1 Length											The codomain of incident
							Value1
	……
							Value N Length
	Value N
							Parameter ID2(H)						Next event argument
	Parameter ID2(L)
							Parameter ID 2 Length(H)
	Parameter ID 2 Length(L)
							#of Value
	……
							DigitMap Descriptor...: embedded descriptor content
	SecondEvents Descriptor...: embedded descriptor content
							Signals Descriptor...: embedded descriptor content
	(with first request event)												Second request event content

B), event descriptor structural parameters explanation

1, the Descriptor id field is used for this descriptor of unique identification, is assumed to: 0x06.

2, the Length field is used for representing the total bytes of descriptor.

3, #of Events Requests represents the request event number.

4, Request ID identification request event id.

5, whether SID_P represents to flow ID (Stream ID) and exists, and EA_P represents whether the incident action (event Action) of request event exists, if this position is 0, the optional part of then asking Event accordingly is for empty.

6, Stream ID represents to flow ID under the monitoring incident.

7, the bag ID under the pkgId identified event.

8, Event Name identified event ID.

9, the number of parameters that comprises in the #ofParameter IDs presentation of events.

10, KA_P, ED_P, SE_P, SD_P are bitmasks, and identified event keeps activating (Keep Active) respectively, whether embedded several figure descriptors (Event DM), second event descriptor (Second Events Descriptor), signal description symbol (Signals Descriptor) exists.

11, Keep Active presentation of events keeps activating field.

12, Digit Map Descriptor Offset represents embedded several figure descriptor first byte position.

13, Second Events Descriptor Offset represents the second embedded event descriptor first byte position.

14, Signals Descriptor Offset represents embedded signal description symbol first byte position.

15, Event Request Length field is represented the byte number that this event request takies.

16, Parameter ID is used for concrete parameter I D in the identified event.

17, " #of Values " field is represented the number of the value that this parameter comprises.

18, Value Length field represents that this is worth used byte number.

19, the Value field is represented a concrete value.

Owing to used for reference the H.248 notion of protocol events descriptor in a large number in this MCAPI event descriptor application example, therefore when the event descriptor structure of MGCP agreement is adapted for MCAPI message, it is adaptive to do some, be exemplified below (different descriptors has the adaptive notion of different needs, decides according to concrete agreement and application scenario):

1, the request mark of MGCP (Request Identifier) is indicated by the Request ID of this descriptor.

2, the request event of MGCP (Requested Events) is corresponding to the request event tabulation of this descriptor, the bag name of each MGCP incident correspondence, bag name during H.248 event name need be converted into, the event name coding is not if there is corresponding definition to expand H.248.

3, the several graph parameters among the MGCP can be fitted in several figure values (DigitMap Value) of embedded several figure descriptors of this descriptor, among the MGCP, do not give the number figure definition number map title at present, the description that can use physical port sign (Endpoint ID) is as the number map title.

Gateway control application programming interfaces message of the present invention is with the fundamental structural unit of affairs as interactive information, can abundant compatible MeGaCo/H.248 and the message structure of two kinds of agreements of MGCP, guarantee effectively that simultaneously the order correlation is with the integrality of affairs as the effective range information needed.In fact this architecture has used for reference the classification nested structure of MeGaCo/H.248 agreement " affairs-action-order-descriptor ", for application provides a kind of concept hierarchy the clear information organization form that is easy to progressive operation.For example: consider whether target application has the demand of taking action or ordering correlation for protocol message, and the fundamental structural unit that also can determine interactive information flexibly is still littler action of affairs or order.

The gateway control application programming interfaces are with the command set of MeGaCo/H.248 protocol command collection as interaction data, can demonstrate fully this agreement in advantage, effectively satisfy the management and the demand for control of current and following new business realization aspects such as the higher abstractness of business and better autgmentabilities.And the MGCP agreement can be by the conversion of call model and substituting of order and parameter, with smaller cost realization self information form and the conversion between the gateway control application programming interfaces information format.Final effect is exactly that Business Processing only need be understood gateway control application programming interfaces information, also is a kind of information of similar MeGaCo/H.248 agreement, actually or and need not too much to pay close attention to protocol adaptation MeGaCo/H.248 MGCP agreement.

If MGC or MG just realize some simple CCF, action in the protocol massages or order generally do not have correlation so, also be action in the affairs it doesn't matter or single affairs in only act separately, on order it doesn't matter or act separately in have only individual command, so, the information organization of gateway control application programming interfaces also is feasible with action or order as structural units, can adopt the classification nested data structure of action, order, descriptor or order, descriptor.

Present embodiment is concrete an application of media gateway controlling application programming interfaces message structure, the having or not of wherein concrete parameter, order that parameter is arranged and the concrete implication of parameter value can be distinguished to some extent for no applicable cases, but still belong to this patent invention category.

The invention provides a cover MCAPI message data structure, the protocol Data Unit of MeGaCo/H.248 and two kinds of agreements of MGCP can be described, and the application handling process that meets MeGaCo/H.248 and two kinds of agreements of MGCP also promptly can mask MeGaCo/H.248 and the difference of two kinds of agreements of MGCP on data structure with the new data structure of this cover.Simultaneously, because protocol stack must use the protocol Data Unit at this agreement to come encoding and decoding, for the business side module is shielded and the tightly coupled protocol Data Unit of agreement, be convenient to separating of protocol stack coding/decoding module and protocol application module (being business module), the present invention strengthened in the data structure of protocol module and business module interface business side can cognitive notion, use clear and definite data structure describing message, affairs, action, order, descriptor, descriptor attribute and some argument structures, the notion of specific protocol grammer in the reduction protocol Data Unit, make operation layer only need handle a kind of MCAPI message, rather than to handle MeGaCo/H.248 message and MGCP message respectively, thereby be very easy to the upgrading expansion of product, reduced the maintenance cost of MGC and MG.

Claims (9)

1, a kind of MGCP is used the implementation method of adaptive compatibility, it is characterized in that, may further comprise the steps:

At two kinds of MGCP MeGaCo/H.248, MGCP independently between protocol adaptation layers and the shared Business treatment, adopt unified media gateway controlling application programming interfaces MGCAPI to communicate, described MGCAPI adopts the base unit of affairs as interactive interfacing information, and adopts the classification nested data structure of affairs, action, order, descriptor;

Described MCAPI interface message is carried out and the conversion of MGCP message separately in protocol adaptation layers, the protocol Data Unit that the MCAPI message conversion can be handled for protocol stack separately, and the protocol Data Unit after the protocol stack decoding is converted to MCAPI message separately.

2, MGCP according to claim 1 is used the implementation method of adaptive compatibility, it is characterized in that: the classification nested data structure of described affairs, action, order, descriptor is meant that a MCAPI message comprises affairs, described affairs are made up of affairs head and affairs body, comprise several action in the affairs body; Action is made up of action head and action body, comprises several orders in the action body; Order is made up of command header and command body, comprises several descriptors in the command body; A descriptor is made up of descriptor head and descriptor body, comprises several attributes in the descriptor body.

3, MGCP according to claim 1 and 2 is used the implementation method of adaptive compatibility, it is characterized in that: if action in the affairs or order do not have correlation, then the gateway control application programming interfaces as the base unit of interactive interfacing information, and adopt the classification nested data structure of action, order, descriptor or order, descriptor with action or order.

4, MGCP according to claim 2 is used the implementation method of adaptive compatibility, it is characterized in that: comprise following field in the described affairs head: protocol name, version number, message direction, connection identifier number, action number, transaction number, request confirm that immediately mask, code/decode format mask, option sign, request confirm field, message-length, optional information error description symbol immediately.

5, MGCP according to claim 2 is used the implementation method of adaptive compatibility, it is characterized in that: comprise following field in the described action head: action type, order number, pass chain store, option flag, action length, optional information length.

6, MGCP according to claim 5 is used the implementation method of adaptive compatibility, it is characterized in that: when the action type is asked for action, whether option flag indication action request exists, if exist, also comprise in the described action head: associated priority mask, urgent affinity mask, topology request mask, associated priority field, urgent related indication field, topology request number, topological descriptor; Whether another option flag indication relating attribute audit request exists, if exist, also comprises in the described action head: topological descriptor, associated priority field, urgent related indication field.

7, MGCP according to claim 5 is used the implementation method of adaptive compatibility, it is characterized in that: when the action type responds for action, whether option flag indication action staging error descriptor exists, if exist, also comprises the corresponding error descriptor in the described action head; Whether another option flag indication action response exists, if exist, also comprise in the described action head: associated priority mask, urgent affinity mask, topology request mask, associated priority field, urgent related indication field, topology request number, topological descriptor.

8, MGCP according to claim 2 is used the implementation method of adaptive compatibility, it is characterized in that: comprise following field in the described command header: command type, descriptor number, destination node number, order optional mask, wildcard response mask, destination node tabulation mask, order optional attribute field, wildcard response flag, order length, destination node parameter.

9, MGCP according to claim 2 is used the implementation method of adaptive compatibility, it is characterized in that: comprise following field in the described descriptor head: descriptor number and descriptor length.

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