CN112752260B

CN112752260B - Equipment and method for number-carrying network-transfer transmitting end inquiry

Info

Publication number: CN112752260B
Application number: CN201911050747.7A
Authority: CN
Inventors: 严学纯; 毛安平; 黄美华
Original assignee: China Telecom Corp Ltd
Current assignee: China Telecom Corp Ltd
Priority date: 2019-10-31
Filing date: 2019-10-31
Publication date: 2023-06-16
Anticipated expiration: 2039-10-31
Also published as: CN112752260A

Abstract

The invention relates to a method and equipment for carrying a number to a network to send a query. The method for carrying the number to send the end inquiry of the network comprises the following steps: based on the query request received from the serving call session control function S-CSCF of the calling subscriber' S home network, a number portability database NPDB in the server is queried to obtain the called subscriber attributes. The utility model also discloses a device for carrying number to change network sender inquiry, which comprises: a receiving module for receiving a query request from a service call session control function S-CSCF of a calling user home network; a number portability database NPDB for storing number portability data; and the query module is used for querying the NPDB based on the query request to acquire the attribute of the called user.

Description

Equipment and method for number-carrying network-transfer transmitting end inquiry

Technical Field

The invention relates to the field of tri-network convergence, in particular to equipment and a method for querying an IMS network number-carrying network forwarding sender.

Background

With the development of 4G network technology, mobile Voice service will evolve from 2G to Long Term Evolution (VoLTE) Voice over Long Term Evolution (Long Term Evolution), and currently, various operators in China are actively performing VoLTE number-carrying network-switching test points. The industrial signal department in 2010 has carried out the test point of carrying numbers and transferring networks in Tianjin and Hainan, has carried out the expansion test of carrying numbers and transferring networks in Jiangxi, hubei and Yunnan in 2014, and plans to open the service of carrying numbers and transferring networks in China.

VoLTE is a voice service based on the LTE network data domain of an IP multimedia subsystem (IP Multimedia Subsystem, IMS) network, which is composed of functional entities capable of providing multimedia services, not only for fixed broadband users but also for mobile users. In order to implement VoLTE number portability service, the IMS network needs to have the capability of opening the number portability service.

The key technology of the mobile user for opening the number portability is to query a number portability database (Number Portability Database, NPDB) and generally divide the two modes of an originating network query (also called an originating query) and a called network query (also called a receiving query) according to different query points. Industry standards prescribe that 2G mobile network voice service adopts an originating query mode, but currently no industry standard or enterprise standard related to the originating query of the number-carrying forwarding network exists in the 4G network, so that the need of researching related technologies of the originating query of the number-carrying forwarding network in the 4G network exists.

Disclosure of Invention

The invention provides equipment and a method for inquiring a number-carrying and network-transferring transmitting end and a method for establishing a number-carrying and network-transferring session, which enable number-carrying and network-transferring service to be provided under an IMS network.

According to an aspect of an embodiment of the present invention, there is provided a method for forwarding a number to a network, where the method includes: based on the query request received from the serving call session control function S-CSCF of the calling subscriber' S home network, a number portability database NPDB in the server is queried to obtain the called subscriber attributes.

According to an aspect of an embodiment of the present invention, there is provided a method for number portability session establishment, the method including: the server obtains the attribute of the called user by using the method for inquiring the number-carrying forwarding network transmitting end according to the embodiment of the invention; a session is established between the calling user and the called user by the S-CSCF of the calling user' S home network based on the obtained called user attributes.

According to an aspect of an embodiment of the present invention, there is provided an apparatus for carrying out a number forwarding network originating query, the apparatus including: a receiving module for receiving a query request from a service call session control function S-CSCF of a calling user home network; a number portability database NPDB for storing number portability data; and the query module is used for querying the NPDB based on the query request to acquire the attribute of the called user.

Other features of the present invention and its advantages will become apparent from the following detailed description of exemplary embodiments of the invention, which proceeds with reference to the accompanying drawings.

Drawings

In order to more clearly illustrate the embodiments of the invention or the technical solutions of the prior art, the drawings which are used in the description of the embodiments or the prior art will be briefly described, it being obvious that the drawings in the description below are only some embodiments of the invention, and that other drawings can be obtained from these drawings without inventive faculty for a person skilled in the art.

Fig. 1 shows a schematic diagram of an IMS architecture.

Fig. 2 shows a schematic diagram of a call flow within a conventional IMS network domain.

Fig. 3 is a schematic diagram showing a query at the originating end of a number transfer network for a called subscriber with the attribute of a home network number not being carried out of the subscriber or a subscriber with his network number being carried in the subscriber according to an embodiment of the present invention.

Fig. 4 is a schematic diagram illustrating a query at the originating end of a number transfer network for a called subscriber with the attribute of a home network number carrying out a subscriber or for a subscriber not carrying in his network number according to an embodiment of the present invention.

Fig. 5 illustrates an overall flow diagram of a method for carrying out a forwarding network originating query in accordance with one embodiment of the present invention.

Fig. 6 shows a flow chart of a method for number portability session setup in accordance with one embodiment of the present invention.

Fig. 7 shows a block diagram of an example of a device for carrying out a forwarding network originating query, according to one embodiment of the present invention.

Detailed Description

Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that: the relative arrangement of the components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless it is specifically stated otherwise.

Meanwhile, it should be understood that the sizes of the respective parts shown in the drawings are not drawn in actual scale for convenience of description.

The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.

Techniques, methods, and apparatus known to one of ordinary skill in the relevant art may not be discussed in detail, but should be considered part of the specification where appropriate.

In all examples shown and discussed herein, any specific values should be construed as merely illustrative, and not a limitation. Thus, other examples of the exemplary embodiments may have different values.

It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further discussion thereof is necessary in subsequent figures.

The number portability technology is also called number portability and no number change by mobile phone, and specifically means that a user can change a contracted operator without changing his own mobile phone number and enjoy various services provided by the changed operator. The number-carrying and network-transferring system not only provides convenience for users, but also is beneficial to optimizing the market structure and promoting market competition and three-network integration, and has very important significance.

With the continuous development of 4G networks, the research of VoLTE (voice over Long term evolution) number portability technology becomes an important subject. The core service control network of VoLTE is an IMS network. The IMS network provides control for VoLTE, mainly completes functions of call control, service continuity, domain selection and the like, and enables end-to-end communication services such as voice, video and the like based on a packet domain to be realized.

Fig. 1 shows a schematic diagram of an IMS architecture. As shown in fig. 1, the IMS architecture comprises a service layer, a control layer, a bearer layer, and an access layer, and each layer comprises a plurality of functional entities. The call session control function (Call Session Control Function, CSCF) is the most important functional entity in the IMS architecture, and is responsible for registration, session establishment, session management, etc.

CSCFs fall into three types: a serving call session control function (Serving Call Session Control Function, S-CSCF) for managing session initiation protocol (Session Initiation Protocol, SIP) sessions and coordinating calls and session control with other IMS functional entities; an interrogating call session control function (Interrogating Call Session Control Function, I-CSCF) used as a point of contact in the IMS network for calls from other networks or from roaming users located in other networks; a proxy call session control function (Proxy Call Session Control Function, P-CSCF) acts as a portal for SIP terminals to access the IMS network.

In addition, as shown in fig. 1, the IMS architecture also includes a home subscriber server (Home Subscriber Server, HSS) that serves as a database system in the IMS network that stores all IMS users and their subscription data. The IMS architecture also contains an ENUM/DNS server, where an ENUM (e.164 number URI Mapping, e.164number uniform resource identifier Mapping) server is responsible for the conversion of telephone numbers to uniform resource locator (Uniform Resource Locator, URL) addresses, and a DNS (Domain Name System ) server is responsible for the resolution of URL addresses to IP addresses.

In an IMS network, the public user identity is an identity of the IMS user for communication, for routing of SIP messages, typically in the format of a SIP uniform resource identifier (SIP Uniform Resource Identifier, SIP URI) or a telephony uniform resource identifier (TEL URI). The TEL URI format is used to represent a traditional e.164number in the syntax of a URI. IMS subscribers often need to interwork with public switched telephone networks (Public Switched Telephone Network, PSTN), soft switching and 3G CS domain subscribers, while other networks use numbering rules of e.164 numbers.

Thus, in order to comply with the usage habits of the user, IMS users are required to support the numbering rules of e.164 numbers, i.e. to support representing the user in the format of TEL URI. However, in IMS networks, routing cannot be directly based on TEL URIs, but rather the TEL URIs need to be converted to SIP URIs first and then routed based on SIP URIs. Meanwhile, each IMS user is required to be assigned with the number of the SIP URI, so as to facilitate the use of the user and the routing of the message.

Fig. 2 shows a schematic diagram of a call flow between a calling user and a called user within a conventional IMS network domain. As shown in fig. 2, the signaling flow path of the whole call needs to sequentially pass through the calling subscriber roaming network, the calling subscriber home network, the called subscriber home network and the called subscriber roaming network.

Referring to fig. 2, in step S1, a calling user initiates a session request, a session request message reaches an S-CSCF of a calling user' S home network via a calling user roaming network P-CSCF. Next, in step S2, the S-CSCF of the calling subscriber home network downloads the calling subscriber profile data from the HSS of the calling subscriber home network, between which the Diameter protocol may be used. In step S3, the S-CSCF of the home network of the calling subscriber triggers the subscription service of the calling subscriber, and the application server AS performs service logic control.

After the calling service is triggered, the called flow is entered. In step S4, the S-CSCF of the home network of the calling user can obtain the I-CSCF of the home network of the called user by querying the DNS server. It is noted that the specific procedure by which the S-CSCF of the calling subscriber 'S home network queries the I-CSCF of the called subscriber' S home network varies depending on the called number format. Specifically, in the case that the called number format is the SIP URI format, the S-CSCF of the calling subscriber home network directly queries the DNS server, and translates the SIP URI address of the called number into an IP address. Alternatively, in the case where the called number format is TEL URI format, the S-CSCF of the calling subscriber' S home network first queries the ENUM server, converts the TEL URI into a SIP URI by the ENUM server, then queries the DNS server with the SIP URI, and translates the SIP URI address into an IP address by the DNS server. That is, in the case where the called number format is the TEL URI format, a process of converting the TEL URI into the SIP URI is added as compared with the case where the called number format is the SIP URI format.

Next, in step S5, the I-CSCF of the home network of the called user obtains the S-CSCF registered by the called user by querying the HSS of the home network of the called user. In step S6, the S-CSCF of the called subscriber home network obtains called subscriber profile data from the HSS of the called subscriber home network. In step S7, the S-CSCF of the home network of the called user triggers the service migrated by the called user, and the AS performs service logic control. In step S8, the session request message is routed to the called subscriber roaming network to reach the called terminal. Then, in step S9, both the calling user and the called user perform resource negotiation and reservation. In step S10, the terminal of the called user rings. In step S11, the called user answers, so far a session establishment between the calling user and the called user in the IMS network is completed.

In order to realize the number portability service under the IMS network, the query NPDB is a key, and comprises two modes of an originating network query and a called network query. The originating network query belongs to an originating query mode, i.e. the NPDB is queried in a serving mobile switching center (Mobile Switching Center, MSC) where the calling subscriber is located, and the called network query belongs to a terminating query mode, i.e. the NPDB is queried in a gateway MSC of the network where the called subscriber is located. Currently, only related technologies related to a number-carrying network-transfer receiving end query under an IMS network exist. Regarding the number-carrying forwarding network sender query under the IMS network, no related industry specification or standard exists at present.

Therefore, the invention provides a technology for inquiring the number-carrying and network-transferring transmitting end under the IMS network, which is suitable for providing the number-carrying and network-transferring service while providing the VoLTE voice service for the 4G mobile user and is suitable for providing the number-carrying and network-transferring service for all mobile operators. Specifically, through modifying the ENUM/DNS server and the S-CSCF equipment, the NPDB is built in the ENUM/DNS server to increase the number carrying and network transferring identification for the user, and the routing code RN cell is added in the response message for inquiring the ENUM/DNS server, so that the S-CSCF of the home network of the calling user inquires the ENUM/DNS server, and the number carrying and network transferring service of the IMS network can be realized by utilizing an originating inquiry mode.

The principles and methods of a number portability forwarding network originating query in accordance with one embodiment of the present invention will be described in detail below with reference to fig. 3-5.

Specifically, according to this embodiment, the ENUM/DNS service receives a query request from the S-CSCF. In one case, if the called number in the query request is in TEL URI format, the ENUM server is utilized to query the NPDB for the called user attribute according to the called number. When the called user attribute indicates that the user is a user with a local network number (i.e. a user of a home network of a calling user) or a user with a network number (i.e. a user with a home network of a calling user) with other network numbers, the calling user and the called user belong to the same network, and then the ENUM server returns a SIP URI corresponding to the TEL URI to the S-CSCF. When the attribute of the called user indicates that the called user is a user with a local network number (i.e. the user with the home network of the calling user is carried out to other networks) or a user with the network number not carried in (the user with the home network of the calling user is carried in by other networks), the calling user and the called user belong to different networks, and then the ENUM server returns a routing code RN of the home network of the called user to the S-CSCF.

In another case, if the called number is in SIP URI format, the DNS server is used to query the NPDB according to the called number to obtain the called user attribute. When the called user attribute indicates that the user is a home network user or a user carried in by other networks, the DNS server returns the IP address of the I-CSCF of the home network of the called user to the S-CSCF, and when the called user attribute indicates that the user is a user carried out by the home network or a user not carried in by other networks, the DNS server returns the RN of the home network of the called user to the S-CSCF.

Fig. 3 and fig. 4 respectively show schematic diagrams for carrying a number forwarding network originating query according to one embodiment of the present invention in the case that the called subscriber attributes are different.

Fig. 3 is a schematic diagram showing a query at the originating end of a number transfer network for a called subscriber with the attribute of a home network number not being carried out of the subscriber or a subscriber with his network number being carried in the subscriber according to an embodiment of the present invention. It is easy to understand that the called party belongs to the same network as the calling party in case the called party attribute indicates that the subscriber is not a subscriber to be carried out by the home network number or that his network number is carried in.

According to this embodiment, referring to fig. 3, the S-CSCF of the calling subscriber' S home network initiates a query request to an ENUM/DNS server, which determines the called number format in response to the query request.

According to this embodiment, if the called number format is TEL URI format, the ENUM server converts the called number from TEL URI format to SIP URI format and returns the SIP URI to the S-CSCF of the calling subscriber' S home network. Then, the S-CSCF of the calling user home network continues to initiate inquiry to the DNS server by using the SIP URI, and the DNS server returns the IP address of the I-CSCF of the called user home network corresponding to the SIP URI to the S-CSCF of the calling user home network in response to the inquiry request.

Alternatively, according to this embodiment, if the called number format is the SIP URI format, the DNS server returns the IP address of the I-CSCF of the called user home network corresponding to the SIP URI directly to the S-CSCF of the calling user home network.

In some embodiments, the IP address of the I-CSCF corresponding to the SIP URI may be cached in the S-CSCF of the home network of the calling user, in which case the S-CSCF of the home network of the calling user may directly obtain the IP address of the I-CSCF of the home network of the called user from the SIP URI without querying the DNS server.

The S-CSCF of the calling user home network then routes according to the acquired IP address of the I-CSCF, thereby establishing a session between the calling user and the called user.

Fig. 4 is a schematic diagram of a number portability query with a user attribute of a home network number portability user or a user not having his network number portability, according to an embodiment of the present invention. It is easy to understand that the called user belongs to a different network than the calling user in case the called user attribute indicates that the user is a home network number carry-out user or that his network number is not a carry-in user.

According to this embodiment, referring to fig. 4, the S-CSCF of the calling subscriber' S home network initiates a query to an ENUM/DNS server, which determines the called number format in response to the query request.

According to this embodiment, if the called number format is TEL URI format, the ENUM server returns a response message to the S-CSCF of the calling subscriber' S home network, where an RN field is added to the response message, where the RN field is used to indicate the current home operator network of the called subscriber.

Alternatively, if the called number format is SIP URI format, the DNS server returns a response message to the S-CSCF of the home network of the calling user, where an RN field is added in the response message, where the RN field is used to indicate the current home operator network of the called user.

The S-CSCF of the calling user home network then routes to the called user home network according to the acquired RN, thereby establishing a session between the calling user and the called user.

Having described the process of a number portability origination query under different called subscriber attributes with reference to fig. 3 and 4, an overall flow of the number portability origination query according to an embodiment of the present invention will be described with reference to fig. 5.

Fig. 5 illustrates an overall flow diagram of a method for carrying out a forwarding network originating query in accordance with one embodiment of the present invention. Note that only the main steps of the carrier head-end query will be described below, and it should be understood that the method of the carrier head-end query according to this embodiment naturally includes other necessary steps.

According to this embodiment, as shown in fig. 5, the S-CSCF of the calling subscriber' S home network sends a query request to the ENUM/DNS server in step S501. Next, in step S502, the ENUM/DNS server receives a query request from the S-CSCF of the calling subscriber' S home network.

Next, the ENUM/DNS server queries the NPDB in the ENUM/DNS server based on the query request received from the S-CSCF of the calling subscriber' S home network to obtain the called subscriber attributes. In some embodiments, the ENUM/DNS server may also return a response message to the S-CSCF of the calling subscriber' S home network based on the called subscriber attributes.

In some embodiments, the called user attribute indicates one of: the user of the calling user home network, the user of the calling user home network carried out to other networks, the user of other networks carried into the calling user home network, and the user of other networks not carried into the calling user home network. Wherein the called user attribute indicates that a user of the calling user home network or a user of other network carrying the calling user home network indicates that the called user belongs to the same network as the calling user, and the called user attribute indicates that the calling user home network carries out to a user of other network or a user of other network not carrying the calling user home network indicates that the called user belongs to a different network from the calling user.

Specifically, in some embodiments, the ENUM/DNS server determines whether the called subscriber number is in TEL URI format or SIP URI format, as shown in step S503.

When the called subscriber number is in TEL URI format, the NPDB is queried by the ENUM server to obtain called subscriber attributes, as shown in step S504.

Specifically, in step S505, the called subscriber attribute is determined by the ENUM server.

Then, as shown in step S506, when the called user attribute indicates that the user of the calling user home network (i.e., the home network user) or the user of other network carrying the calling user home network (i.e., the other network carrying user), the ENUM server returns the SIP URI of the called user number to the S-CSCF of the calling user home network. The S-CSCF of the calling subscriber' S home network then proceeds to query the ENUM/DNS server using the SIP URI.

Alternatively, as shown in step S507, when the called user attribute indicates that the calling user home network is ported to a user of another network (i.e., a home network ported-out user) or that another network is not ported to the calling user home network (i.e., a user not ported to the home network), the ENUM server returns the RN of the called user home network to the S-CSCF of the calling user home network.

When the format of the called user number is the SIP URI format, the NPDB is queried by the DNS server to obtain the called user attribute, as shown in step S508.

Specifically, in step S509, the called user attribute is determined by the DNS server.

Then, as shown in step S510, when the called user attribute indicates that the user of the calling user home network (i.e., the home network user) or the user of other network carrying the calling user home network (i.e., the other network carrying user), the DNS server returns the IP address of the I-CSCF of the called user home network corresponding to the SIP URI to the S-CSCF of the calling user home network.

Alternatively, as shown in step S511, when the called user attribute indicates that the calling user home network is ported to a user of another network (i.e., a home network ported-out user) or that another network is not ported to the calling user home network (i.e., a user not ported to another network), the DNS server returns the RN of the called user home network to the S-CSCF of the calling user home network.

In addition, in some embodiments, in the case of the previous query, the S-CSCF of the home network of the calling user may have the IP address of the I-CSCF corresponding to the SIP URI cached, in which case the S-CSCF of the home network of the calling user may directly obtain the IP address of the I-CSCF of the home network of the called user according to the SIP URI, without querying the DNS server.

Having described the overall flow of a number portability sender query in accordance with an embodiment of the present invention with reference to fig. 5, a specific flow of a method for number portability session establishment in accordance with an embodiment of the present invention will be described below with reference to fig. 6.

Fig. 6 shows a flow chart of a method for number portability session setup in accordance with one embodiment of the present invention. Note that only the main steps of the number portability session establishment will be described below, and it should be understood that the method of number portability session establishment according to the embodiment naturally includes other necessary steps.

As shown in fig. 6, in step S601, the called subscriber attribute is obtained by the ENUM/DNS server using the method of carrying out a forwarding end query as described above with reference to fig. 5.

Next, in some embodiments, a session is established between the calling user and the called user by the S-CSCF of the calling user' S home network based on the obtained called user attributes.

Specifically, as shown in step S602, a response message returned based on the called user attribute is received by the S-CSCF of the calling user' S home network from the server. Next, as shown in step S603, it is determined by the S-CSCF of the calling subscriber' S home network whether the response message contains an RN.

Then, in some embodiments, a session is established between the calling user and the called user by the S-CSCF of the calling user' S home network based on the determination.

Specifically, when the S-CSCF of the home network of the calling party determines that the response message contains the RN, the S-CSCF of the home network of the calling party establishes a session between the calling party and the called party according to the RN, i.e., routes the session request to the home network of the called party according to the RN, as shown in step S604.

Alternatively, when it is determined that the response message does not contain an RN, it is determined by the S-CSCF of the home network of the calling user whether the response message contains the IP address of the I-CSCF of the home network of the called user, as shown in step S605. Then, in some embodiments, a session is established between the calling user and the called user by the S-CSCF of the calling user' S home network based on the determination.

Specifically, when it is determined that the response message contains the IP address of the I-CSCF of the home network of the called user, as shown in step S606, a session is established between the calling user and the called user by the S-CSCF of the home network of the calling user according to the IP address of the I-CSCF of the home network of the called user, that is, the session request is routed to the home network of the called user according to the IP address of the I-CSCF of the home network of the called user.

Alternatively, as shown in step S607, when it is determined that the response message does not contain the IP address of the I-CSCF of the home network of the called user, the S-CSCF of the home network of the calling user obtains the IP address of the I-CSCF of the home network of the called user from the SIP URI of the called user number contained in the response message. The S-CSCF of the calling user home network then routes according to the IP address of the I-CSCF of the called user home network.

A method for a transnumber originating query and a method for a transnumber session establishment using a transnumber originating query according to one embodiment of the present invention have been described above. An apparatus for carrying out a forwarding network originating query according to one embodiment of the present invention will be described.

As shown in fig. 7, the device 700 for carrying out a forwarding-network originating query includes a receiving module 701, a number portability database NPDB 702, and a query module 703. In some embodiments, device 700 for carrying a number forwarding network originating query may be an ENUM/DNS server.

In some embodiments, the receiving module 701 is configured to receive a query request from an S-CSCF of a home network of a calling user, thereby triggering a user attribute query.

In some embodiments, number portability database NPDB 702 is used to store number portability data, which is built into device 700, adding a portability identifier to a user.

In some embodiments, the query module 703 is configured to query the NPDB to obtain the called user attribute based on the query request.

In some embodiments, the apparatus 700 for a transnumber network originating query may utilize the method of a transnumber network originating query described above to conduct a transnumber network originating query.

By using the method and the device, the number-carrying and network-transferring transmitting inquiry can be carried out in the IMS network, the number-carrying and network-transferring inquiry mode of the 2G mobile network is accepted, and the requirements of the mobile user number-carrying and network-transferring industry standard are met. According to the embodiment, only the functions of inquiring the user attribute and carrying the RN are added to the ENUM/DNS server, the function of routing based on the RN judgment is added to the S-CSCF, the number-carrying and network-transferring service across the operator network under VoLTE can be realized under the condition of not adding a new network element and a new message, and the method has the advantages of small change amount to the network, convenience for users to use, improvement of user experience and the like.

In addition, the method and apparatus of the present invention may be implemented in a number of ways. For example, the methods and systems of the present invention may be implemented by software, hardware, firmware, or any combination of software, hardware, firmware. The above-described sequence of steps for the method is for illustration only, and the steps of the method of the present invention are not limited to the sequence specifically described above unless specifically stated otherwise. Furthermore, in some embodiments, the present invention may also be embodied as programs recorded in a recording medium, the programs including machine-readable instructions for implementing the methods according to the present invention. Thus, the present invention also covers a recording medium storing a program for executing the method according to the present invention.

Thus far, the method and apparatus for a number portability sender query and the method for number portability session establishment according to the present invention have been described in detail. In order to avoid obscuring the concepts of the invention, some details known in the art have not been described. How to implement the solutions disclosed herein will be fully apparent to those skilled in the art from the above description.

The method and system of the present invention may be implemented in a number of ways. For example, the methods and systems of the present invention may be implemented by software, hardware, firmware, or any combination of software, hardware, firmware. The above-described sequence of steps for the method is for illustration only, and the steps of the method of the present invention are not limited to the sequence specifically described above unless specifically stated otherwise. Furthermore, in some embodiments, the present invention may also be embodied as programs recorded in a recording medium, the programs including machine-readable instructions for implementing the methods according to the present invention. Thus, the present invention also covers a recording medium storing a program for executing the method according to the present invention.

While certain specific embodiments of the invention have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the invention. It will be appreciated by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.

Claims

1. A method for carrying a number forwarding network originating query, the method comprising:

receiving a query request from a service call session control function S-CSCF of a calling user home network;

judging whether the format of the called user number is a telephone uniform resource identifier TEL URI format or a session initiation protocol uniform resource identifier SIP URI format;

when the format of the called user number is TEL URI format, the E.164number uniform resource identifier mapping ENUM server in the server inquires the number portability database NPDB in the ENUM server to obtain the called user attribute;

when the called user attribute indicates that the user of the calling user home network or other networks carry in the user of the calling user home network, converting the called user number from TEL URI format to SIP URI format by the ENUM server, and returning the SIP URI of the called user number to the S-CSCF of the calling user home network;

when the called user attribute indicates that the calling user home network is carried out to a user of other networks or the user of other networks which are not carried into the calling user home network, the ENUM server returns a routing code RN of the called user home network to an S-CSCF of the calling user home network;

and when the format of the called user number is the SIP URI format, inquiring the NPDB in the DNS server by a domain name system DNS server in the server to acquire the attribute of the called user.

2. The method of claim 1, further comprising:

and the DNS server returns a response message to the S-CSCF of the home network of the calling user based on the called user attribute.

3. The method of claim 2, wherein,

when the called user attribute indicates that the calling user home network carries out to the users of other networks or the users of other networks not carrying into the calling user home network, the response message comprises a routing code RN of the called user home network.

4. The method of claim 2, wherein,

when the called user attribute indicates that the user of the calling user home network or other network is carried into the user of the calling user home network, the response message comprises the IP address of the inquiring call session control function I-CSCF of the called user home network.

5. The method of claim 4, further comprising,

and responding the query request received from the S-CSCF of the calling user home network by a domain name system DNS server in the server, and returning the IP address of the I-CSCF of the called user home network corresponding to the session initiation protocol uniform resource identifier (SIP URI) of the called user number to the S-CSCF of the calling user home network.

6. A method for number portability session establishment, the method comprising:

obtaining called user attributes by a server by using the method for inquiring the number-carrying forwarding network transmitting end according to claim 1;

a session is established between the calling user and the called user by the S-CSCF of the calling user' S home network based on the obtained called user attributes.

7. The method of claim 6, wherein establishing a session between the calling user and the called user based on the obtained called user attribute by the S-CSCF of the calling user' S home network comprises:

receiving a response message returned based on the called user attribute from a server;

determining whether the response message contains a routing code RN; and

based on the determination result, a session is established between the calling user and the called user.

8. The method of claim 7, wherein when it is determined that the response message contains the RN, a session is established between the calling user and the called user according to the RN by an S-CSCF of the home network of the calling user.

9. The method of claim 7, wherein when it is determined that the response message does not contain an RN,

determining, by the S-CSCF of the calling subscriber 'S home network, whether the response message contains an IP address of an interrogating call session control function, I-CSCF, of the called subscriber' S home network; and is also provided with

And establishing a session between the calling user and the called user by the S-CSCF of the home network of the calling user according to the judging result.

10. The method of claim 9, wherein

When the response message is judged to contain the IP address of the I-CSCF of the home network of the called user, the S-CSCF of the home network of the calling user establishes a session between the calling user and the called user according to the IP address of the I-CSCF of the home network of the called user; and is also provided with

When the response message does not contain the IP address of the I-CSCF of the home network of the called user, the S-CSCF of the home network of the calling user obtains the IP address of the I-CSCF of the home network of the called user according to the SIP URI of the called user number contained in the response message.

11. An apparatus for carrying a number forwarding network originating query, the apparatus comprising:

a receiving module for receiving a query request from a service call session control function S-CSCF of a calling user home network;

both the ENUM server and the DNS server comprise a number portability database NPDB for storing number portability data;

a query module, configured to query an NPDB in the ENUM server based on the query request when the format of the called subscriber number is TEL URI format, so as to obtain a called subscriber attribute; when the format of the called user number is SIP URI format, inquiring the NPDB in the DNS server to obtain the called user attribute;

the ENUM server is used for converting the called user number from TEL URI format to SIP URI format when the called user attribute indicates that the user of the calling user home network or other network carries in the user of the calling user home network, and returning the SIP URI of the called user number to the S-CSCF of the calling user home network; and returning a routing code RN of the home network of the called user to an S-CSCF of the home network of the calling user when the attribute of the called user indicates that the home network of the calling user is carried out to users of other networks or users of other networks which are not carried into the home network of the calling user.