CN103023979A - Inter-domain communication method of distributed IMS (multimedia subsystem) core net framework - Google Patents

Abstract

The invention discloses an inter-domain communication method under a distributed IMS core network architecture, comprising the following steps: a P-CSCF of a distributed IMS core network receives a request from a user, and the P-CSCF judges whether the type of the request is a registration request or a session request , if it is a session request, then the P-CSCF judges whether the user who initiates the registration request is registered according to the user registration information saved by itself, if registered, then the P-CSCF obtains the registration information of the user who initiated the session request on the P-CSCF, and then According to the routing information in the request, the request is forwarded to the S-CSCF where the user is registered, and the S-CSCF where the user is registered processes the session request according to the home domain of the called user. The method of the present invention is proposed based on the inter-domain communication standard provided by the 3GPP standard, which can ensure that the distributed IMS core network adopting the P2P technology has practical deployable and operable values.

Description

A method for inter-domain communication under a distributed IMS core network architecture

technical field

The invention belongs to the field of mobile Internet and telecommunication core network, and more specifically relates to an inter-domain communication method under the framework of a distributed IMS core network.

Background technique

When operators actually deploy and operate the IP Multimedia Subsystem (IMS) core network, they generally build a unified IMS network in units of regions or provinces according to the scale of users and the management system. With multi-domain networking, different domain names can be allocated according to regions, and the network has good scalability, which is suitable for large-scale networking. When the initial network scale is small, the IMS core network can be centrally set up to be responsible for the services of multiple domains, but this requires higher functions of the core network equipment; as the network scale expands, IMS core network elements can be set up in each domain . The so-called domain division is to meet two requirements: (1) The scale of a single core network should not be too large, otherwise the search management overhead will be high; (2) In order to maintain the independence of a single operating entity, such as the provincial first-level entities. The independent construction of provinces and the construction of IMS core networks by regional centers can meet the needs of cross-provincial operations, and inter-domain communication is possible. Therefore, the inter-domain communication function of the IMS core network is very important, and the 3GPP standard provides a clear standard specification for the inter-domain communication.

At present, the IMS core network adopts the centralized networking scheme in the 3GPP standard. The centralized networking will inevitably bring disadvantages such as single point of failure, performance bottleneck, poor scalability, and complicated node maintenance. The IMS core network of advanced distributed technology can better solve the above problems. Therefore, the existing IMS core network inter-domain communication methods are all based on the traditional centralized networking, but there is no corresponding standard method for the inter-domain communication of the IMS core network that adopts the P2P distributed technology networking.

Contents of the invention

Aiming at the defects of the prior art, the purpose of the present invention is to provide an inter-domain communication method under the distributed IMS core network architecture, which is proposed based on the inter-domain communication standard provided by the 3GPP standard, and can ensure the distributed communication method using P2P technology. The IMS core network has practical deployable and operable value.

In order to achieve the above object, the present invention provides an inter-domain communication method under a distributed IMS core network architecture, comprising the following steps:

(1) The P-CSCF of the distributed IMS core network receives the user's request;

(2) P-CSCF judges whether the type of request is a registration request or a session request, if it is a registration request, go to step (3), if it is a session request, go to step (4);

(3) The P-CSCF processes the registration request according to the home domain of the requesting user;

(4) P-CSCF judges whether the user who initiates the registration request is registered according to the user registration information saved by P-CSCF. If it has been registered, go to step (6), otherwise go to step (5);

(5) P-CSCF sends a response message to the user that the user is not registered and cannot conduct a session, and the process ends;

(6) The P-CSCF obtains the registration information of the user who initiates the session request on the P-CSCF, and then forwards the request to the S-CSCF where the user is registered according to the routing information in the request;

(7) The S-CSCF where the user is registered handles the session request according to the home domain of the called user.

Step (3) includes:

(3-1) The P-CSCF fetches the user information from the registration request, compares the domain name of the user's home domain with the domain name of the P-CSCF's own domain to determine whether the user belongs to the domain where the P-CSCF is located, and if so, proceed to step (3- 2), otherwise go to step (3-3);

(3-2) P-CSCF uses the user's IMPU as the key to perform P2P to obtain the address of the corresponding S-CSCF, and forwards the registration request to the S-CSCF, and then enters step (3-12);

(3-3) P-CSCF checks whether it has cached the I-CSCF address list of the user's home domain, if it has cached, then enters step (3-4), otherwise enters step (3-5);

(3-4) P-CSCF selects an available I-CSCF from the cached I-CSCF address list of the user's home domain, forwards the registration request to the I-CSCF, and then enters step (3-11);

(3-5) P-CSCF checks whether it has cached the I-CSCF address list of its own domain, if there is, then enters step (3-8), otherwise enters step (3-6);

(3-6) P-CSCF conducts P2P search within the domain using the domain name of its own domain as the key to obtain the I-CSCF address list;

(3-7) P-CSCF caches the found I-CSCF list of its own domain in memory;

(3-8) P-CSCF selects an available I-CSCF from the cached I-CSCF address list of its own domain, sends a request to the I-CSCF to find the I-CSCF address list of the user's home domain, and then enters the step (3-9);

(3-9) The I-CSCF receives the lookup request from the P-CSCF, and uses the domain name of the user's home domain as the key to perform a P2P lookup in the global domain to obtain the corresponding I-CSCF address list, and sends the found The result is returned to P-CSCF;

(3-10) The P-CSCF caches the I-CSCF address list according to the result returned by the I-CSCF, and selects an available I-CSCF, and forwards the registration request to the I-CSCF;

(3-11) According to the registration request from the P-CSCF, the I-CSCF in the user's home domain performs a P2P lookup using the user's IMPU as a key to obtain the address of the corresponding S-CSCF, and forwards the registration request to the S-CSCF. CSCF;

(3-12) S-CSCF handles the registration request according to the 3GPP standard procedures according to the received registration request.

Step (7) includes:

(7-1) The S-CSCF takes out the called user information from the session request, and compares the domain name of the user's home domain with the domain name of its own domain to determine whether its own domain is the home domain of the called user. If so, then Go to step (7-2), otherwise go to step (7-5);

(7-2) S-CSCF performs P2P search in its own domain with the called user IMPU as the key to obtain the S-CSCF address corresponding to the called user IMPU;

(7-3) The S-CSCF forwards the session request to the S-CSCF corresponding to the IMPU key value of the user in its own domain according to the found S-CSCF address registered by the called user;

(7-4) The S-CSCF corresponding to the IMPU key value of the called user receives the session request from the S-CSCF where the calling user is located, processes the session request according to the 3GPP standard procedure, and the process ends;

(7-5) The S-CSCF checks whether it has cached the I-CSCF address list of the called user's home domain, if found, then enters step (7-12), otherwise enters step (7-6);

(7-6) S-CSCF checks whether it has cached the I-CSCF address list of its own domain, if found, enters step (7-9), otherwise enters step (7-7);

(7-7) S-CSCF uses the domain name of its own domain as the key to perform P2P search to obtain the I-CSCF address list of its own domain;

(7-8) S-CSCF caches the found I-CSCF address list in memory;

(7-9) The S-CSCF randomly selects an available I-CSCF from the cached I-CSCF address list of its own domain, and initiates a request to the I-CSCF to find the I-CSCF address list of the called user's home domain ;

(7-10) According to the request from the S-CSCF to find the I-CSCF address list of the called user's home domain, the I-CSCF uses the domain name of the home domain as the key to perform P2P search in the global domain, and returns the search result to the S-CSCF CSCF;

(7-11) S-CSCF caches the search results from I-CSCF in I-CSCF in memory;

(7-12) S-CSCF selects an available I-CSCF from the I-CSCF address list, and forwards the session request to the I-CSCF of the called user's home domain;

(7-13) The I-CSCF of the called user's home domain performs a P2P lookup with the called user's IMPU as the key in its own domain according to the session request to obtain the corresponding S-CSCF address

(7-14) The I-CSCF in the home domain of the called user forwards the session request to the S-CSCF according to the search result;

(7-15) The S-CSCF corresponding to the IMPU key value of the called user receives the session request from the I-CSCF, processes the session request according to the 3GPP standard, and the process ends.

Through the above technical solutions conceived by the present invention, compared with the prior art, the present invention has the following beneficial effects:

(1) Realize the load balancing of core network functional nodes: In steps (3-2), (3-11), (7-2), (7-13), it can be reflected that the distributed IMS core network adopts P2P Distributed search is used to allocate nodes serving users, so as to ensure that user loads can be distributed on different nodes in a relatively balanced manner, ensuring that the system has a certain load balance.

(2) The original single point of failure of the IMS core network is eliminated: the core network after using P2P distribution will not cause service unavailability due to the failure of a single node, and has disaster tolerance to a certain extent.

(3) The distributed IMS core network has good scalability: using the P2P distributed core network can easily add new service nodes to provide services for users.

(4) Reduce the query load of the Home Subscriber Server (HSS for short): In this method, the search for the S-CSCF address where the user is registered no longer depends on querying the HSS but is obtained through the P2P distributed search inside the core network. It can be reflected in steps (3-2), (3-11), (7-2), and (7-13), thereby reducing the query load of the HSS.

Description of drawings

FIG. 1 is a flow chart of the inter-domain communication method under the distributed IMS core network architecture of the present invention.

Fig. 2 is a detailed flowchart of step (3) in the method of the present invention.

Fig. 3 is a detailed flowchart of step (7) in the method of the present invention.

FIG. 4 is a network topology structure diagram of a distributed IMS core network according to the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

As shown in Figure 1, the inter-domain communication method under the distributed IMS core network architecture of the present invention includes the following steps:

(1) The Proxy Call Session Control Function (P-CSCF) of the distributed IMS core network receives user requests.

(2) P-CSCF judges whether the type of request is a registration request or a session request, if it is a registration request, go to step (3), if it is a session request, go to step (4).

(3) The P-CSCF processes the registration request according to the home domain of the requesting user.

As shown in Figure 4, the actual deployment of the IMS is divided into provinces or each operation domain is established by the regional center. The P-CSCF in each domain, the Interrogating Call Session Control Function (Interrogating Call Session Control Function, referred to as I-CSCF), S-CSCF forms the operation domain shown in the small ring in the figure according to the Distributed Hash Table (DHT) algorithm. The nodes in the ring are divided into two types: one is the peer (Peer) node responsible for message routing and Data storage, the other is that the client (Client) node only joins the overlay network through the relevant Peer node, in which S-CSCF is used as a Peer node, and I-CSCF and P-CSCF are used as Client nodes to join the overlay network. Each domain is Domain A, Domain B, Domain C, etc. as shown in the figure. Then the I-CSCFs of each domain jointly form a global domain, that is, form the large ring global domain (GlobalDomain) in the figure according to the DHT algorithm. In the IMS core network, each user belongs to a certain domain, which is determined when the user opens an account, that is, the user's attribution domain, which is reflected in the figure as the domain where a small ring is located.

(4) P-CSCF judges whether the user who initiates the registration request is registered according to the user registration information saved by P-CSCF. If it has been registered, go to step (6), otherwise go to step (5).

(5) P-CSCF sends a response message to the user stating that the user is not registered and cannot conduct a session, and the process ends.

(6) The P-CSCF obtains the registration information of the user who initiated the session request on the P-CSCF, and then forwards the request to the S-CSCF where the user is registered according to the routing information in the request.

(7) The S-CSCF where the user is registered handles the session request according to the home domain of the called user.

As shown in Figure 2, step (3) in the inter-domain communication method under the distributed IMS core network architecture of the present invention includes:

(3-1) The P-CSCF fetches the user information from the registration request, compares the domain name of the user's home domain with the domain name of the P-CSCF's own domain to determine whether the user belongs to the domain where the P-CSCF is located, and if so, proceed to step (3- 2), otherwise go to step (3-3).

(3-2) The P-CSCF uses the user's public user identity (IP Multimedia Public Identity, IMPU for short) as the key to perform P2P to obtain the address of the corresponding S-CSCF, and forwards the registration request to the S-CSCF, and then Go to step (3-12).

(3-3) P-CSCF checks whether it has cached the I-CSCF address list of the user's home domain, and if so, proceeds to step (3-4), otherwise proceeds to step (3-5).

(3-4) P-CSCF selects an available I-CSCF from the cached I-CSCF address list of the user's home domain, forwards the registration request to the I-CSCF, and then enters step (3-11).

(3-5) P-CSCF checks whether it has cached the I-CSCF address list of its own domain, and if so, proceeds to step (3-8), otherwise proceeds to step (3-6).

(3-6) P-CSCF performs P2P search within the domain using the domain name of its own domain as the key to obtain the I-CSCF address list.

(3-7) The P-CSCF caches the found I-CSCF list of its own domain in memory.

(3-8) P-CSCF selects an available I-CSCF from the cached I-CSCF address list of its own domain, sends a request to the I-CSCF to find the I-CSCF address list of the user's home domain, and then enters the step (3-9).

(3-9) The I-CSCF receives the search request from the P-CSCF, and uses the domain name of the searched user's home domain as the key to perform a P2P search in the global domain (as shown in the Global Domain in Figure 4) to obtain the corresponding I - CSCF address list, and return the found result to P-CSCF.

(3-10) The P-CSCF caches the I-CSCF address list according to the result returned by the I-CSCF, and selects an available I-CSCF, and forwards the registration request to the I-CSCF.

(3-11) According to the registration request from the P-CSCF, the I-CSCF in the user's home domain performs a P2P lookup using the user's IMPU as a key to obtain the address of the corresponding S-CSCF, and forwards the registration request to the S-CSCF. CSCF.

(3-12) S-CSCF handles the registration request according to the 3GPP standard procedures according to the received registration request.

As shown in Figure 3, step (7) in the inter-domain communication method under the distributed IMS core network architecture of the present invention includes:

(7-1) The S-CSCF takes out the called user information from the session request, and compares the domain name of the user's home domain with the domain name of its own domain to determine whether its own domain is the home domain of the called user. If so, then Go to step (7-2), otherwise go to step (7-5).

(7-2) The S-CSCF performs a P2P search within its own domain using the called user IMPU as a key to obtain the S-CSCF address corresponding to the called user IMPU.

(7-3) The S-CSCF forwards the session request to the S-CSCF corresponding to the IMPU key value of the user in its own domain according to the found S-CSCF address registered by the called user.

(7-4) The S-CSCF corresponding to the IMPU key value of the called user receives the session request from the S-CSCF where the calling user resides, processes the session request according to the 3GPP standard procedure, and the process ends.

(7-5) The S-CSCF checks whether it has cached the I-CSCF address list of the called user's home domain, and if found, proceeds to step (7-12), otherwise proceeds to step (7-6).

(7-6) The S-CSCF checks whether it has cached the I-CSCF address list of its own domain, and if found, proceeds to step (7-9), otherwise proceeds to step (7-7).

(7-7) The S-CSCF uses the domain name of its own domain as the key to perform P2P search to obtain the I-CSCF address list of its own domain.

(7-8) The S-CSCF caches the found I-CSCF address list in memory.

(7-9) The S-CSCF randomly selects an available I-CSCF from the cached I-CSCF address list of its own domain, and initiates a request to the I-CSCF to find the I-CSCF address list of the called user's home domain .

(7-10) According to the request from the S-CSCF to find the I-CSCF address list of the called user's home domain, the I-CSCF uses the domain name of the home domain as the key to perform P2P search in the global domain (Global Domain in Figure 4) , and return the search result to the S-CSCF.

(7-11) The S-CSCF caches the search results from the I-CSCF in the I-CSCF memory.

(7-12) The S-CSCF selects an available I-CSCF from the I-CSCF address list, and forwards the session request to the I-CSCF of the called user's home domain.

(7-13) The I-CSCF of the called user's home domain performs a P2P lookup with the called user's IMPU as the key in its own domain according to the session request to obtain the corresponding S-CSCF address

(7-14) The I-CSCF in the home domain of the called user forwards the session request to the S-CSCF according to the search result.

(7-15) The S-CSCF corresponding to the IMPU key value of the called user receives the session request from the I-CSCF, processes the session request according to the 3GPP standard, and the process ends.

Applications:

In order to verify the feasibility and effectiveness of the method of the present invention, the method of the present invention is verified in a real environment. The experimental environment includes the installation of the CentOS release 5.6 operating system, the open source HSS system to implement FHoSS, the open source IMS experimental system Open IMS Core, and the standard IMS client Boghe. The experimental environment configuration is shown in Table 1.

Table 1

After the CSCF server is deployed according to the network topology proposed in the present invention (as shown in Figure 4), the user directly registers in the home domain and the user registers in the roaming domain, and checks whether the user can register in the two cases respectively. Complete the registration process. The result of the registration is: the user can normally register in the home domain and from the roaming domain, which means that this method handles the cross-domain registration process normally. Then use the registered account to test the session request, call the called user in the same domain and the user in a different home domain respectively, and check whether the user can establish a session and make a normal call. The test result is: regardless of whether the calling user and the called user belong to the same domain, the call can be made normally, which shows that this method is feasible for the cross-domain user session request processing flow.

After testing the above two experimental scenarios, the distributed IMS core network inter-domain communication method discussed in the present invention can effectively ensure cross-domain communication for users under the distributed IMS core network architecture.

It is easy for those skilled in the art to understand that the above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention, All should be included within the protection scope of the present invention.

Claims (3)

1. the inter-domain communication method under the distributed IMS core net framework is characterized in that, may further comprise the steps:

(1) P-CSCF of distributed IMS core net receives user's request;

(2) P-CSCF judges that the type of request is registration request or session request, if registration request then enters step (3), if the session request then enters step (4);

(3) P-CSCF is according to the user attaching territory processing register request of initiating request;

(4) P-CSCF judges that according to the user's registration information of self preserving whether the user who initiates registration request registers, if register, then enters step (6), otherwise enters step (5);

(5) P-CSCF sends to the user that the user is unregistered can't to carry out receiveing the response of session, and flow process finishes;

(6) P-CSCF obtains the log-on message of user on P-CSCF that initiates a session request, and then according to the routing iinformation in the request request is forwarded to the S-CSCF that the user registers the place;

(7) the user S-CSCF that registers the place processes the session request according to called subscriber's home domain.

2. inter-domain communication method according to claim 1 is characterized in that, step (3) comprising:

(3-1) P-CSCF takes out user's information from registration request, contrast user's home domain domain name and the domain name in territory, P-CSCF self place judge whether the user belongs to the territory at P-CSCF place, if belong to then enter step (3-2), otherwise enter step (3-3);

(3-2) P-CSCF carries out P2P with user's IMPU as key, obtaining the address of corresponding S-CSCF, and registration request is forwarded to this S-CSCF, then enters step (3-12);

(3-3) P-CSCF searches the I-CSCF address list that self whether is cached with the user attaching territory, if be cached with, then enters step (3-4), otherwise enters step (3-5);

(3-4) P-CSCF selects an available I-CSCF from the I-CSCF address list in the user attaching territory of buffer memory, and registration request is forwarded to this I-CSCF, then enters step (3-11);

(3-5) P-CSCF searches the I-CSCF address list that self whether is cached with self territory, place, if be cached with, then enters step (3-8), otherwise enters step (3-6);

(3-6) P-CSCF domain name take self territory, place in the territory is searched as key carries out P2P, to obtain the I-CSCF address list;

(3-7) the I-CSCF tabulation in P-CSCF self territory, place that will find is buffered in the internal memory;

(3-8) P-CSCF selects an available I-CSCF from the I-CSCF address list in self territory, place of buffer memory, sends the I-CSCF address list request of searching the user attaching territory to this I-CSCF, then enters step (3-9);

(3-9) I-CSCF receives the search request from P-CSCF, searches as key carries out P2P in global field take the domain name in the user attaching territory of searching, and obtaining corresponding I-CSCF address list, and the result that will find returns to P-CSCF;

(3-10) P-CSCF is cached the I-CSCF address list according to the result that I-CSCF returns, and therefrom selects an available I-CSCF, and registration request is transmitted to this I-CSCF;

(3-11) I-CSCF in user attaching territory is according to from the registration request of P-CSCF, carries out P2P with user's IMPU as key and searches, and obtaining the address of corresponding S-CSCF, and registration request is forwarded to this S-CSCF;

(3-12) S-CSCF processes registration request according to the 3GPP normal process according to the registration request of receiving.

3. inter-domain communication method according to claim 1 is characterized in that, step (7) comprising:

(7-1) S-CSCF takes out called user information from the session request, with user's home domain domain name and self territory, place domain name contrast, judging whether called home domain with the place of self territory, place, if, then enter step (7-2), otherwise enter step (7-5);

(7-2) S-CSCF carries out P2P take called subscriber IMPU as key and searches in self territory, place, to get access to S-CSCF address corresponding to called subscriber IMPU;

(7-3) S-CSCF is according to the S-CSCF address of the called subscriber that finds registration, and the S-CSCF that the user IMPU key-value pair in self territory, place is answered transmits the session request;

(7-4) S-CSCF that answers of called subscriber IMPU key-value pair receives the S-CSCF session request from the calling subscriber place, according to the 3GPP normal process session request is processed, and process finishes;

(7-5) S-CSCF searches the I-CSCF address list that self whether is cached with called subscriber's home domain, if find, then enters step (7-12), otherwise enters step (7-6);

(7-6) S-CSCF searches the I-CSCF address list that self whether is cached with self territory, place, if find, then enters step (7-9), otherwise enters step (7-7);

(7-7) S-CSCF searches as key carries out P2P take the domain name in self territory, place, to obtain the I-CSCF address list in self territory, place;

(7-8) S-CSCF is cached to the I-CSCF address list that finds in the internal memory;

(7-9) S-CSCF is random from the I-CSCF address list in self territory, place of buffer memory selects an available I-CSCF, and initiates the I-CSCF address list request of searching called subscriber's home domain to this I-CSCF;

(7-10) I-CSCF, carries out P2P and searches, and lookup result is returned to S-CSCF take this home domain domain name as key according to the called subscriber's home domain I-CSCF address list request of searching from S-CSCF in global field;

(7-11) S-CSCF will be buffered in the internal memory from the lookup result I-CSCF of I-CSCF;

(7-12) S-CSCF selects an available I-CSCF from the I-CSCF address list, and the session request is transmitted to the I-CSCF of called subscriber's home domain;

(7-13) I-CSCF of called subscriber's home domain carries out P2P take called subscriber IMPU as key according to the session request and searches to obtain corresponding S-CSCF address in self territory, place

(7-14) I-CSCF of called subscriber's home domain is according to lookup result, and the session request is forwarded to this S-CSCF;

(7-15) S-CSCF that answers of called subscriber IMPU key-value pair receives the session request from I-CSCF, according to the 3GPP standard session request is processed, and process finishes.

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