FIELD OF THE INVENTION

This application relates to the communication technology and in particular, to a method of communication for SIP (Session Initiation Protocol), a selection device and SFC (Subsequent Filter Criteria) enabler.

BACKGROUND

Nowadays, initial filter criteria inside an SIP AS (Application Server) offer capability to distribute the logic based on configured rules. These rules are static in nature and needs to be configured prior to establishment of calls. For example, a rule like PAI (P-Asserted ID) starts from "sip:+49".
In a distributed system, each AS can be represented by multiple boards/processes running as separate instances. The same service instances will be running inside multiple boards to provide scalability.

Selectors or Application Routers are responsible for routing dialog messages to an application server instance. Once a dialog is established, new messages inside the same dialog are governed by rules of SIP.
IMS (IP Multimedia Subsystem) services are complicated in nature and each service logic can have many network initiated out of dialog messages (e.g. all users join to a conference or the same AS instance must cater to user which is logged in via third party registration). These types of logic are complicated and selection logic and concept of state is required inside SIP selector.
However, it has no way to know the register and invite is correlated for the SIP selector in the prior art, additional complexity is existed in terms of shared database usage and cost of solution is increased due to use of database.

SUMMARY

Embodiments of the present invention pertain to a method of communication for SIP, a selection device and SFC enabler. The aim is to decrease additional complexity and cost of solution.

According to a first aspect of the embodiments of the present invention, there is provided a method of communication for SIP, the method includes:

receiving, by a selection device, a registration message from a user equipment;

sending, by the selection device, the registration message to anapplication server;

receiving, by the selection device, an update message from a SFC enabler, wherein the update message
is sent by the SFC enabler based on feedback information of the application server; and

updating, by the selection device, selection criteria of SIP according to the update message, wherein the update message includes correlated information of the application server and the user equipment.

According to a second aspect of the embodiments of the present invention, there is provided a method of communication for SIP, the method includes:

receiving, by a SFC enabler, feedback information of an application server; wherein the feedback information is sent by the application server based on a registration message of a user equipment;
sending, by the SFC enabler, an update message to a selection device so that selection criteria of SIP in the selection device are updated.

According to a third aspect of the embodiments of the present invention, there is provided a selection device, applied for SIP, the selection device includes:

a first receiving unit, configured to receive a registration message from a user equipment;

a first sending unit, configured to send the registration message to an application server;

a second receiving unit, configured to receive an update message from a SFC enabler, wherein the update message is sent by the SFC enabler based on feedback information of the application server; and

an updating unit, configured to update selection criteria of SIP according to the update message, wherein the update message includes correlated information of the application server and the user equipment.

According to a fourth aspect of the embodiments of the present invention, there is provided a SFC enabler, applied for SIP, the SFC enabler includes:

a fourth receiving unit, configured to receive feedback information of an application server; wherein the feedback information is sent by the application server based on a registration message of a user equipment;

a third sending unit, configured to send an update message to a selection device so that selection criteria of SIP in the selection device are updated.

The advantages of the present invention exist in that: additional complexity and cost of solution can be decreased by using SFC enabler to update selection criteria in registration process.

These and further aspects and features of the present invention will be apparent with reference to the following description and attached drawings. In the description and drawings, particular embodiments of the invention have been disclosed in detail as being indicative of some of the ways in which the principles of the invention may be employed, but it is understood that the invention is not limited correspondingly in scope. Rather, the invention includes all changes, modifications and equivalents coming within the spirit and terms of the appended claims.
Features that are described and/or illustrated with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments and/or in combination with or instead of the features of the other embodiments.

It should be emphasized that the term "comprises/comprising" when used in this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

Many aspects of the invention can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present invention. To facilitate illustrating and describing some parts of the invention, corresponding portions of the drawings may be exaggerated in size, e.g., made larger in relation to other parts than in an exemplary device actually made according to the invention. Elements and features depicted in one drawing or embodiment of the invention may be combined with elements and features depicted in one or more additional drawings or embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views and may be used to designate like or similar parts in more than one embodiment.

BRIEF DESCRIPTION OF THE DRAWING

The drawings are included to provide further understanding of the present invention, which constitute a part of the specification and illustrate the preferred embodiments of the present invention, and are used for setting forth the principles of the present invention together with the description. The same element is represented with the same reference number throughout the drawings.
In the drawings:

Figure 1 is a flowchart of the registration/invite process in the existing technology;

Figure 2 is a flowchart of the method of an embodiment of the present invention;

Figure 3 is another flowchart of the method of an embodiment of the present invention;

Figure 4 is a flowchart of the registration/invite process in the present invention;

Figure 5 is a flowchart of the method of an embodiment of the present invention;

Figure 6 is a schematic diagram of the selection device of an embodiment of the present invention;

Figure 7 is another schematic diagram of the selection device of an embodiment of the present invention;

Figure 8 is a schematic diagram of the SFC enabler of an embodiment of the present invention.

DETAILED DESCRIPTION

The many features and advantages of the embodiments are apparent from the detailed specification and, thus, it is intended by the appended claims to cover all such features and advantages of the embodiments that fall within the true spirit and scope thereof. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the inventive embodiments to the exact construction and operation illustrated and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope thereof.
The preferred embodiments of the present invention are described as follows in reference to the drawings.

Figure 1 is a flowchart of the registration/invite process in the existing technology. This figure illustrates the flow of registration of a user and invocation of a new call by the same user once registered.

As shown in Figure 1, for example, configured rule is: PAI starts with "sip:+491214". There are a user equipment A, an AS selector, a database and at least two application server instances: ASInstance1 and ASInstance2.

First, the user equipment A logs in IMS network and a registration message (REGISTER) is triggered to S-CSCF (Serving CSCF, not shown in the Figure 1). The S-CSCF performs third party registration to an AS.
Second, the AS selector receives the REGISTER and applies selection logic, then sends the REGISTER to one of application server instances, such as ASInstance1. The ASInstancel1adds call state in the database and replies 200 OK which is sent to S-CSCF.

Third, A sends an invite message (INVITE) to S-CSCF when A wants to call another user equipment B. S-CSCF sends the INVITE to the AS selector.

Fourth, the AS selector checks the INVITE and selects one of application server instances (for example, based on load balancing strategies), such as ASInstance2 since it has not way to know the previous REGISTER and this INVITE is correlated.

Fifth, the ASInstance2 doesn't know if the user equipment A is registered until some shared data is used (for example, ASInstance2 will extract call state from the database). ASInstance2 will send 302 to the AS selector when it knows A has registered in ASInstance1. The selector will check its redirect and send the INVITE to the ASInstance1.

Currently the mechanism consists of costly database operation and additional signaling messages which increases the cost of solution. So, additional complexity is existed in terms of shared database usage and cost of solution is increased due to use of database.

This invention intends to address the shortcomings mentioned above by defining a suitable way to change selection logic dynamically.
Embodiment 1

This embodiment of the present invention provides a method of communication for SIP (Session Initiation Protocol), applied in a selection device of AS.

Figure 2 is a flowchart of the method of an embodiment of the present invention. As shown in Figure 2, the method includes:

Step 201, the selection device receives a registration message from a user equipment;

Step 202, the selection device sends the registration message to an application server;

Step 203, the selection device receives an update message from a SFC (Subsequent Filter Criteria) enabler, wherein the update message is sent by the SFC enabler based on feedback information of the application server;

Step 204, the selection device updates selection criteria of SIP according to the update message, wherein the update message includes correlated information of the application server and the user equipment.

In this embodiment, the application server may be one of application servers; the selection device may be a selector of NGIN (Next Generation Intelligent Network), or may be an application router of SIP servlet. But it is not limited thereto and particular implement may be determined as actually required.
In this embodiment, in the registration process, by using SFC enabler, filter criteria inside AS selection logic may be changed dynamically.

That is to say, state inside the selection logic can be changed via AS dynamically. It requires selection logic to expose API (this API can be a SOAP request or any other propriety mechanism). The SFC enabler implements this API. As for the detail of API, please refer to the existing technology.

Figure 3 is another flowchart of the method of an embodiment of the present invention. It shows the registration and the invite process. As shown in Figure 3, the method includes:

Step 301, the selection device receives a registration message from a user equipment;

Step 302, the selection device sends the registration message to one of application server instances;

Step 303, the selection device receives an update message from a SFC enabler, wherein the update message is sent by the SFC enabler based on feedback information of an application server instance;

Step 304, the selection device updates selection criteria of SIP according to the update message.

Step 305, the selection device receives an invite message from the user equipment;

Step 306, the selection device sends the invite message to the application server instance based on the updated selection criteria.

In this embodiment, the selection device may further configure application rules dynamically by using the SFC enabler.

Figure 4 is a flowchart of the registration/invite process in the present invention. This figure illustrates the flow of registration of a user and invocation of a new call by the same user once registered.

As shown in Figure 4, the process includes:
Step 401, a user equipment A send a registration message (REGISTER) via network. The selector receives the REGISTER.

Step 402, the selector applies selection logic and sends the REGISTER to one of application server instances, such as ASInstance1.

Step 403, the ASInstance1 invokes a SFC enabler (SFCEnabler) and sends feedback information to the SFCEnabler. The selection criteria/rules determined by application logic may be passed.
Step 404, the SFCEnabler sends an update message to the selector, updates the selection criteria/rules inside the selector, so state inside the selection logic can be changed dynamically. Updated criteria indicate that all further messages from the user equipment should be sent to ASInstance1.
Step 405, the selector receives an invite message (INVITE) from the user equipment A and checks the INVITE.

Step 406, the selector selects ASInstancel1due to the updated selection criteria and sends the INVITE to the ASInstance1.

It can be seen from the above embodiment that additional complexity and cost of solution can be decreased by using SFC enabler to update selection criteria in registration process.

Embodiment 2

This embodiment of the present invention provides a method of communication for SIP, applied in a SFC enabler. This embodiment corresponds to the method of the above embodiment 1 and the same content will not be described.

Figure 5 is a flowchart of the method of an embodiment of the present invention. As shown in Figure 5, the method includes:

Step 501, the SFC enabler receives feedback information of an application server; wherein the feedback information is sent by the application server based on a registration message of a user equipment;

Step 502, the SFC enabler sends an update message to a selection device so that selection criteria of SIP in the selection device are updated.

Wherein, the update message includes correlated information of the application server and the user equipment.

It can be seen from the above embodiment that additional complexity and cost of solution can be decreased by using SFC enabler to update selection criteria in registration process.

Embodiment 3

This embodiment of the present invention provides a selection device for SIP. This embodiment corresponds to the method of the above embodiment 1 and the same content will not be described.
Figure 6 is a schematic diagram of the selection device of an embodiment of the present invention. As shown in Figure 6, the selection device 600 includes: a first receiving unit 601, a first sending unit 602, a second receiving unit 603 and an updating unit 604. Other parts of the selection device 600 can refer to the existing technology and not be described in the present application.

Wherein, the first receiving unit 601 is configured to receive a registration message from a user equipment; the first sending unit 602 is configured to send the registration message to an application server; the second receiving unit 603 is configured to receive an update message from a SFC enabler, wherein the update message is sent by the SFC enabler based on feedback information of the application server; and the updating unit 604 is configured to update selection criteria of SIP according to the update message, wherein the update message includes correlated information of the application server and the user equipment.

Figure 7 is another schematic diagram of the selection device of an embodiment of the present invention. As shown in Figure 7, the selection device 700 includes: a first receiving unit 601, a first sending unit 602, a second receiving unit 603 and an updating unit 604. As described in above content.
As shown in Figure 7, the selection device 700 further includes: a third receiving unit 705 and a second sending unit 706.

Wherein, the third receiving unit 705 is configured to receive an invite message from the user equipment; the second sending unit 706 is configured to send the invite message to the application server instance based on the updated selection criteria.

In this embodiment, the selection device may be a selector of NGIN (Next Generation Intelligent Network), or may be an application router of SIP servlet.

In this embodiment, the selection device may further include: a configuration unit (not shown in figure), the configuration unit is configured to configure application rules dynamically by using the SFC enabler.
It can be seen from the above embodiment that additional complexity and cost of solution can be decreased by using SFC enabler to update selection criteria in registration process.

Embodiment 4

This embodiment of the present invention provides a SFC enabler for SIP. This embodiment corresponds to the method of the above embodiment 2 and the same content will not be described.
Figure 8 is a schematic diagram of the SFC enabler of an embodiment of the present invention. As shown in Figure 8, the SFC enabler 800 includes: a fourth receiving unit 801, a third sending unit 802. Other parts of the SFC enabler 800 can refer to the existing technology and not be described in the present application.

Wherein, the fourth receiving unit 801 is configured to receive feedback information of an application server; wherein the feedback information is sent by the application server based on a registration message of a user equipment; the third sending unit 802 is configured to send an update message to a selection device so that selection criteria of SIP in the selection device is updated.

In this embodiment, the update message includes correlated information of the application server and the user equipment.

This embodiment of the present invention further provides a communication system, the communication system includes: a plurality of application server instances, a selection device and a SFC enabler. Wherein the selection device is described as embodiment 3; and the SFC enabler is described as embodiment 4.

It can be seen from the above embodiment that additional complexity and cost of solution can be decreased by using SFC enabler to update selection criteria in registration process.

It should be understood that each of the parts of the present invention may be implemented by hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods may be realized by software or firmware that is stored in the memory and executed by an appropriate instruction executing system. For example, if it is realized by hardware, it may be realized by any one of the following technologies known in the art or a combination thereof as in another embodiment: a discrete logic circuit having a logic gate circuit for realizing logic functions of data signals, application-specific integrated circuit having an appropriate combined logic gate circuit, a programmable gate array (PGA), and a field programmable gate array (FPGA), etc.

The description or blocks in the flowcharts or of any process or method in other manners may be understood as being indicative of comprising one or more modules, segments or parts for realizing the codes of executable instructions of the steps in specific logic functions or processes, and that the scope of the preferred embodiments of the present invention comprise other implementations, wherein the functions may be executed in manners different from those shown or discussed, including executing the functions according to the related functions in a substantially simultaneous manner or in a reverse order, which should be understood by those skilled in the art to which the present invention pertains.

The logic and/or steps shown in the flowcharts or described in other manners here may be, for example, understood as a sequencing list of executable instructions for realizing logic functions, which may be implemented in any computer readable medium, for use by an instruction executing system, device or apparatus (such as a system including a computer, a system including a processor, or other systems capable of extracting instructions from an instruction executing system, device or apparatus and executing the instructions), or for use in combination with the instruction executing system, device or apparatus.

The above literal description and drawings show various features of the present invention. It should be understood that those skilled in the art may prepare appropriate computer codes to carry out each of the steps and processes as described above and shown in the drawings. It should be also understood that all the terminals, computers, servers, and networks may be any type, and the computer codes may be prepared according to the disclosure to carry out the present invention by using the apparatus.
Particular embodiments of the present invention have been disclosed herein. Those
skilled in the art will readily recognize that the present invention is applicable in other
environments. In practice, there exist many embodiments and implementations. The
appended claims are by no means intended to limit the scope of the present invention to the
above particular embodiments. Furthermore, any reference to "a device to..." is an explanation of device plus function for describing elements and claims, and it is not desired that any element using no reference to "a device to..." is understood as an element of device plus function, even though the wording of "device" is included in that claim.

Although a particular preferred embodiment or embodiments have been shown and the present invention has been described, it is obvious that equivalent modifications and variants are conceivable to those skilled in the art in reading and understanding the description and drawings. Especially for various functions executed by the above elements (portions, assemblies, apparatus, and compositions, etc.), except otherwise specified, it is desirable that the terms (including the reference to "device") describing these elements correspond to any element executing particular functions of these elements (i.e. functional equivalents), even though the element is different from that executing the function of an exemplary embodiment or embodiments illustrated in the present invention with respect to structure.

Furthermore, although the a particular feature of the present invention is described with respect to only one or more of the illustrated embodiments, such a feature may be combined with one or more other features of other embodiments as desired and in consideration of advantageous aspects of any given or particular application.

WE CLAIM:
1. A method of communication for SIP (Session Initiation Protocol), the method
comprising:

receiving, by a selection device, a registration message from a user equipment;

sending, by the selection device, the registration message to an application server;
receiving, by the selection device, an update message from a SFC (Subsequent Filter Criteria) enabler, wherein the update message is sent by the SFC enabler based on feedback information of the application server; and

updating, by the selection device, selection criteria of SIP according to the update message, wherein the update message comprises correlated information of the application server and the user equipment.

2. The method according to claim 1, wherein the method further comprising:

receiving, by the selection device, an invite message from the user equipment;

sending, by the selection device, the invite message to the application server based
on the updated selection criteria.

3. The method according to claim 1 or 2, wherein the selection device is a selector of
NGIN (Next Generation Intelligent Network), or an application router of SIP servlet.

4. The method according to claim 1 or 2, wherein the method further comprising:

configuring, by the selection device, application rules dynamically by using the SFC
enabler.

5. A method of communication for SIP (Session Initiation Protocol), the method
comprising:

receiving, by a SFC (Subsequent Filter Criteria) enabler, feedback information of an application server; wherein the feedback information is sent by the application server based on a registration message of a user equipment;

sending, by the SFC enabler, an update message to a selection device so that selection criteria of SIP in the selection device are updated.

6. The method according to claim 5, wherein the update message comprises correlated information of the application server and the user equipment.

7. A selection device, applied for SIP (Session Initiation Protocol), the selection device comprising:

a first receiving unit, configured to receive a registration message from a user equipment;

a first sending unit, configured to send the registration message to an application server;

a second receiving unit, configured to receive an update message from a SFC enabler, wherein the update message is sent by the SFC(Subsequent Filter Criteria) enabler based on feedback information of an application server; and

an updating unit, configured to update selection criteria of SIP according to the update message, wherein the update message comprises correlated information of the application server and the user equipment.

8. The selection device according to claim 7, wherein the selection device further
comprising:

a third receiving unit, configured to receive an invite message from the user equipment;

a second sending unit, configured to send the invite message to the application server based on the updated selection criteria.

9. The selection device according to claim 7 or 8, wherein the selection device
further comprising:

a configuration unit, configured to configure application rules dynamically by using the SFC enabler.

10. A SFC enabler, applied for SIP (Session Initiation Protocol), the SFC
(Subsequent Filter Criteria) enabler comprising:

a fourth receiving unit, configured to receive feedback information of an application server; wherein the feedback information is sent by the application server based on a registration message of a user equipment;

a third sending unit, configured to send an update message to a selection device so that selection criteria of SIP in the selection device are updated.

11. The SFC enabler according to claim 11, wherein the update message comprises
correlated information of the application server and the user equipment.

12. A communication system, the communication system comprising: a plurality of
application server instances;

a selection device as claimed in any of claims 7-9; and a SFC enabler as claimed in claim 10 or 11.