KR20040043735A - A method for inter-working of the aaa server and separated accounting server based on diameter - Google Patents

Abstract

PURPOSE: A method for interworking an accounting server separated from a diameter-based AAA authentication server is provided to separate a server for authentication and authority apply from an accounting server, thereby reliably connecting the authentication server with the accounting server as synchronizing the servers. CONSTITUTION: An authentication server(41) authenticates a user, generates data related to an authentication success reason or an authentication failure reason, and completes an authentication/authority verification process(S1). The authentication server(41) transmits basic information including session information and session activation information including supplementary information to an accounting server(42)(S2). An AAA client(43) generates new accounting data to generate an ACR(Account Request) message, and transmits the ACR message to the authentication server(41)(S4). The authentication server(41) transmits the ACR message to the accounting server(42)(S5). The accounting server(42) stores the ACR message, and transmits an ACA(Account Answer) message to the authentication server(41)(S6), then transmits the ACA message to the AAA client(43)(S7). The authentication server(41) transmits a session complete message to the accounting server(42)(S8). The accounting server(42) transmits a response message(S9).

Description

A METHOD FOR INTER-WORKING OF THE AAA SERVER AND SEPARATED ACCOUNTING SERVER BASED ON DIAMETER}

The present invention relates to a technology for providing a service for authentication, authorization, and billing of a subscriber who wants to receive a service by connecting to a network connected to a mobile communication system and a wired communication system, and more particularly, in a wired / wireless network. In the AAA server that provides authentication, authorization, and billing services for a server, authentication and authorization server and billing server are separated, and the authentication and authorization server (hereinafter referred to as a certificate server) and the billing server are linked together. It is about a method of processing. In particular, the present invention relates to a network interworking method using a diameter protocol that is being standardized as a next-generation protocol in the AAA protocol.

In general, AAA is a technology for providing services of authentication, authorization, and accounting of subscribers who want to receive services by accessing a network connected to a communication service provider of a mobile communication system and a wired communication system. Authentication is the verification of a user's identity before allowing access to the network.In order to clearly identify a user, authentication involves a combination of user name / password, secret key, and biological method (e.g. fingerprint). The unique data the user has is used. The AAA server compares the authentication data provided by the user with user-related data in its database, and if the contents match, the AAA server permits access to the network. . Authorization (Authorization) is to determine what permissions and services to allow for users who are allowed to use the network, including the determination of IP addresses, applications and protocols to be provided. The authentication and authorization are generally performed together in the operating environment of the AAA server. Accounting collects information about the user's resource usage, which is used for billing, accounting and capacity expansion.

In particular, in a mobile communication system, AAA should be implemented by interworking a home network and a visited network. The biggest advantage of mobile communication is that it enables users to communicate with anyone anytime, anywhere through roaming or handoff technology. When using roaming or handoff IP based wireless Internet, Mobile IP protocol is used for IP assignment and mobile network support. In a mobile communication supporting Mobile IP, a user must authenticate on a visited network in order to automatically select and access a wireless LAN public network or a mobile communication network by using a dual mode mobile phone or a PDA when roaming. (Authentication) and IP must be assigned before you can use it. In addition, accounting technology is applied between networks for billing of user usage, and Authorization technology is used for security technology for roaming user's authority. Here, the ID for identifying the user or the mobile terminal applies NAI (Network Access Identifier) expressed in the form of user @ realm. Visiting networks analyze the NAI to identify the user's home network and perform user identification, authentication, authorization verification and billing functions. As a prior patent on a method of utilizing AAA in such a mobile communication system, Korean Patent Application No. 2000-065166 discloses a differential security policy method for user authentication and non-repudiation in wireless data communication. In addition, there have been active researches on the method for building AAA based on PKI. (Reference: Kwan-Yeon Kim et al., "A Study on PKI-based AAA Implementation for Mobile Wireless Network", JCCI2002, Apr. 24, 2002) (Vol.1, Proceedings pp v-! 1.1 ~ 4))

As described above, the RADIUS protocol has been used as a protocol used in AAA servers for authentication, authorization, and billing services for subscribers in wired and wireless networks. The RADIUS was developed by Livingston Enterprise in mid-1990 to provide authentication and billing services for its Network Access Server (NAS) equipment. It was then standardized in 1996 by the IETF RADIUS Working Group, which documented the protocol basic functionality and message format as RFC2138. The RADIUS protocol is a protocol for a small network device that supports only a few subscribers requiring server-based authentication. It is not suitable for AAA services for carriers that must support a large number of users simultaneously on various technology bases. In addition, there is a disadvantage in that it cannot securely expand capacity because it does not support AAA service among ISPs. The protocol developed to solve these shortcomings is the diameter protocol.

The diameter can be defined as a lightweight, extensible, peer-based AAA protocol for providing AAA services for new policies, roaming with existing technologies such as PPP, and new technologies such as Mobile IP. The diameter is similar to RADIUS in that it supports Attribute / Value pairs and proxies, but it has the disadvantage that Attribute Value does not exceed 255 bytes in RADIUS, and only 255 messages can be maintained before RADIUS receives the confirmation message. Solved. The Diameter supports larger Attribute / Value lengths, and the Diameter Server can send as many messages as the Network Attached Storage (NAS) can handle and provide reliable Windows communication-based transport for failures. Support. In addition, the RADIUS server cannot send a message unless the client requests it, but the diameter may send a message when the diameter server needs to inform the charging or connection termination of the NAS. In addition, the Diameter has improved retransmission and failover capabilities, provides better network resilience than RADIUS, and provides end-to-end security techniques that RADIUS does not support. The diameter, which supports roaming and MobileIP networks, is currently being standardized at the IETF in draft form.

Diameter protocols having the above characteristics can be broadly classified into base protocols and application technologies including authentication, authorization verification, and billing functions. Applications defined to date include extended RADIUS applications, Mobile IPv4 applications, Mobile IPv6 applications, NASREQ (IMT-2000, WLAN) applications, and IP-based multimedia applications to be used for access in routers. Afterwards, the diameter ensures scalability so that new applications can be added as new services emerge. In addition, the requirements required by the underlying protocol are separately defined.

In this way, the Diameter protocol is a structure in which the application protocol is configured based on the base protocol, and the base protocol itself is charged. Therefore, if the current standard protocol is implemented, all functions of the AAA server, that is, authentication, This means that authorization or charging must be implemented on one server. FIG. 1 is a diagram of a network of carriers composed of an AAA server that performs all functions of authentication, authorization, and billing processing. A subscriber (or user) 13 who joins a carrier network connects to an AAA client 12. Then, the AAA client 12 receives the subscriber's username and password and transmits the encrypted access request message to the AAA server 11. The AAA server 11 transmits a response message for the connection request to the AAA client 12 when it matches and checks whether it matches the contents stored in its DB, and rejects the connection request if it does not match. Send to AAA client 12. In this case, unlike the authentication or authorization verification procedure without traffic load, the charging processing function performs the charging record processing, backup storage, and real-time charging application that take up a lot of load periodically, so that the charging processing function of the AAA server 11 Due to the load, there is a disadvantage in that it performs a lot of functions for authentication and authorization verification.

In order to solve this drawback, as mentioned above, the base protocol of the diameter protocol basically includes a billing data processing function, but it is preferable to separate the billing processing function into an independent server having a separate storage device. . In particular, since the base protocol of the diameter protocol includes the function of transmitting the charging data to a corresponding realm without binding to a specific charging server, the AAA server using the diameter protocol has an authentication server and a charging server. Designing in a separate structure has many advantages. However, authorization verification is performed here at the authentication server.

As such, when the authentication server and the billing server are separated, the sessions for the authentication function and the billing function use the same session ID, so the session management should be synchronized even in the separate billing server and can be linked to the status of the authentication server. Management needs to be addressed and additional load control algorithms are required.

The present invention is proposed to satisfy the need for interworking between the authentication server and the charging server separated from each other using the diameter protocol as described above, and the reliable connection between the authentication server and the charging server, authentication server and charging An object of the present invention is to provide a method for interworking with an authentication server and a billing server capable of synchronizing a server and managing a billing server network including a plurality of billing servers.

FIG. 1 is a diagram illustrating a network of a service provider including a diameter based AAA server performing all functions of authentication, authorization, and billing.

2 is a diagram illustrating a communication service provider network to which a charging processing structure separated from a diameter-based AAA authentication server according to the present invention is applied.

3 is a configuration diagram of an AAA framework in which charging processing is separated from an AAA server according to the present invention.

4 is a flowchart illustrating a process of processing a billing service by an interworking method of a billing server separated from an AAA authentication server according to the present invention.

FIG. 5 is a block diagram illustrating a billing processing method separated from an AAA client that is an Access Point in a WLAN network communicating with an AAA server according to an embodiment of the present invention.

* Description of the symbols for the main parts of the drawings *

11: AAA Server 12, 43: AAA Client

13: subscriber (user) 21: AAA node

211, 31, 41, 53: authentication server 212, 32: billing server network

311: Diameter server base protocol

312 billing server network management module 321, 42, 52: billing server

51: access point (AP)

As a technical means for achieving the above object of the present invention, the present invention, the AAA server using a diameter protocol, the authentication server and a billing server network consisting of a plurality of billing server, the method of interworking with each other To

At the time of subscriber access, the first step of allocating and establishing a subscriber information verification session through the diameter base protocol of the authentication server to authenticate the subscriber, authorizing the authority of the authenticated subscriber, and the authentication and authorization of the subscriber A second step of identifying an accounting server to be accessed from the accounting server network through a diameter base protocol to obtain accounting information, and connecting the authentication server to the verified billing server through a diameter base protocol; A third step of the authentication server checking a storage state of the connected charging server through a diameter base protocol, transmitting a newly generated charging record to the connected charging server, and wherein the charging server stores the charging record; The server receives the session completion request from the authentication server and terminates the session. Performed it characterized in that it provides the Diameter based interlocking processing method of the charging server separate from the AAA authentication server comprises the step 4 to send a session termination message to the authentication server ends the authentication server and the session.

In addition, the authentication server is characterized in that it comprises a charging server network management module for managing the charging server network.

In addition, in the second step, in order to know the charging information of the subscriber who has completed the authentication and authorization, the authentication server may store the accounting information of the charging server that stores the charging information of the subscriber connected to the charging server network management module through a diameter base protocol. A first process of requesting confirmation, a second process of the billing server network management module checking the billing server to be accessed from the billing server network according to a request of the authentication server, and notifying the authentication server of the result; And a third step of the server connecting the session with the checked billing server through the diameter base protocol.

Hereinafter, with reference to the accompanying drawings, it will be described in more detail with respect to the interworking method of the authentication server and the billing server according to the present invention.

2 is a diagram illustrating a communication service provider network to which an authentication server and a billing server interworking method according to the present invention are applied. Referring to FIG. 2, the communication service provider network to which the authentication server and a billing server interworking method are applied according to the present invention. The AAA node 21 is configured to include an authentication server 211, and a billing server network 212 including a plurality of billing servers that are directly linked with the authentication server 211. In FIG. 1, the number of AAA servers themselves is increased to reduce the load of the billing server. In a carrier network to which the present invention described in FIG. 2 is applied, a plurality of billing servers are provided in one authentication server 211. By connecting the billing server network 212 is configured to increase the number of billing servers only to reduce the load of the billing server. The AAA node 21 may include a plurality of structures including one authentication server 211 and the billing server network 212 connected to the authentication server 211. The billing server network 212 collects and manages billing information of many connected subscribers, and stores and manages the information on the authentication server for which the session is authenticated and maintained, and auxiliary information of the client 22 and the terminal 23. In order to manage such information, information of a session processed in real time should be transmitted to the authentication server 211, and a supported service type and protocol must be managed, and information of a service policy security policy must also be managed. This is because the protocol itself of the communication service is various, and the billing details for various services are different. To find the target server requested for such interworking service, it should play a role of delivering policy information such as real-time session information, billing information, service quality of authentication and authorization between servers to enable the requested service.

FIG. 3 is a block diagram illustrating an AAA framework in which the billing server is separated according to the present invention. As shown in FIG. 3, the framework in which the billing server is separated is used to define individual rules for various distributed network technologies and platforms. Harmonize and enable systematic authentication, authorization verification and billing services. Referring to Figure 3 describes the configuration of the AAA framework in which the billing server according to the invention is separated as follows.

The AAA framework according to the present invention includes an authentication server 31 and a charging server network 32 physically and logically connected to the authentication server 31. The authentication server 31 authenticates the subscriber by allocating and establishing the subscriber information verification session through the diameter base protocol 311 and authenticates the authority of the authenticated subscriber. The billing server network 32 is a network composed of a plurality of billing servers and is separated from the authentication server 31. The separate billing server is functionally independent of the authentication and authorization function, but is for recording the authentication and authorization user and the session used by the user. Therefore, the billing server is always linked with the authentication server 31 to collect and store information on the user's resource usage. This information is important data used for data such as usage fee, accounting and capacity expansion. In the network configuration to which the method according to the present invention is applied, the AAA node may include a plurality of AAA frameworks shown in FIG. 3.

In addition, the authentication server 31 is provided with a billing server network management module 312 to manage the billing server network 32. The billing server network management module 312 manages in real time the status of a plurality of billing servers in the billing server network 32 via a Simple Network Management Protocol (SNMP). In other words, the billing server may exist in a state such as a server fail or a reboot of the server or a network fail, and this information is monitored in real time by the billing server network management module 312 through SNMP. That is, the billing server network management module 312 monitors a plurality of billing servers in real time and checks the status information of the billing server to which the authentication server 31 transmits billing data, and requests the authentication server 31. In this case, it confirms the location of the billing server where the status is known. Then, the authentication server 31 connects to the billing server identified through the diameter base protocol 311 and transmits session information as basic information for billing processing to the connected billing server.

As described above, the billing server network management module 312 manages a plurality of billing servers in the billing server network management module through SNMP. At this time, the billing server network management module 312 existing in one authentication server 31 checks the status information by accessing the last connected billing server rather than simultaneously managing the states of a plurality of billing servers. Information about the billing server downloaded from the collected information is informed to all authentication servers by using SNMP. In addition, when the down billing server is recovered, all the authentication servers are notified again. In the billing server network management module 312, the currently activated billing server information, the disabled billing server information caused by the current failure, the activated interface path information of the billing server, and the inactive interface path of the billing server It stores and manages the information, the information of the billing server previously connected and successfully processed, the information of the other authentication server for notifying and sharing the faulty billing server information through SNMP, and the switching information generated by the failure.

Hereinafter, the operation and operation of processing the charging service in the authentication server and the charging server separated from each other according to the present invention configured as described above will be described in detail with reference to FIG.

First, in the first step, at the time of subscriber access, subscriber authentication is performed by allocating and establishing a subscriber information verification session through the diameter base protocol 311 of the authentication server 31, and authorizes the authority of the authenticated subscriber. The authentication server 31 compares the authentication data provided by the user and the user data possessed by the user through the diameter base protocol 311, and allows access to the network if the match is not matched. Finish the procedure. Subsequently, in the authorization process, the authorization procedure determines which authorizations and services are allowed to a user who has successfully authenticated. In the authorization procedure, an IP address, a filter for determining an application and a protocol to be provided, and the like are used. These authentication and authorization procedures are generally performed together in the AAA operating environment.

In the second step, the authentication server 31 accesses the billing server network management module 312 through the diameter base protocol 311 so as to know the billing information of the subscriber who has been authenticated and authorized in the first step. A billing server for requesting confirmation of a billing server storing billing information of one subscriber, and upon request of the authentication server 31, the billing server network management module 312 determines a billing server 321 to be accessed from the billing server network 32. It confirms and notifies the authentication server 31 of the result, and then the authentication server 31 connects with the confirmed billing server 32 through the diameter base protocol 311. In this case, a session activation procedure between the authentication server 31 and the billing server 321 may be included. The session activation procedure may include basic information including session information and peer server information for routing a billing message and a billing record. It is made through the transmission of the session activation information including auxiliary information including.

In the third step, the authentication server 31 checks the storage state of the connected billing server 321 through the diameter base protocol 311 and records the newly generated billing records in the connected billing server 321. ) And the charging server 321 stores the charging record.

In the fourth step, the charging server 321 receives the session completion request through the diameter base protocol 311 of the authentication server 31 to perform the session termination and sends a session end message to the authentication server 31. The session ends with the authentication server 31 by transmitting.

4 is a flowchart illustrating a billing service processing process by an authentication server and a billing server interworking method according to the present invention. Referring to FIG. 4, a subscriber first accesses an AAA client 43 for a network. The AAA client 43 receives the user's authentication information and transmits the authentication information to the authentication server 41. Then, the authentication server 41 authenticates the user and authenticates or authenticates the user to the AAA client. The authentication / authorization is completed by generating failure reason and related data and transmitting it to the subscriber (S1). This corresponds to the first step, and the connection between the AAA client 43 and the authentication server 41 is made through a diameter protocol.

In this case, the authentication server 41 always manages the states of the plurality of billing servers 42 through the billing server network management module, and inquires the state of the previously connected server first, and then the billing server network. The management module selects a server in which the state load of the current charging servers is as small as possible in response to the query of the authentication server 41, and transfers the ID and network interface information of the server to the authentication server 41. 41) attempts to connect to the charging server 42 responded by the charging server network management module. At this time, the authentication server 41 includes session information to the charging server 42 which has been responded. Transfer session activation information including basic information and auxiliary information including a billing record (S2) and the billing server 42 transmits a response to the session activation information to the authentication server 41. The. This corresponds to the second step described above.

Subsequently, as the third step, the AAA client 43 notifies whether the access to the resource requested by the subscriber is allowed or denied, and if the access is allowed, the AAA client 43 according to the service provided by the subscriber. Generates new charging data and generates an ACR (Account Request) message according to the diameter protocol and transmits it to the authentication server (S4). The authentication server 41 transmits the received ACR message to the charging server 42. (S5), the billing server 42 checks this and stores it in the billing database. The billing server 42 stores the received ACR message in the billing database and authenticates the ACA (Account Answer) which is a response message. The server 41 transmits (S6), and again the authentication server 41 transmits the ACA to the AAA client (S7).

Subsequently, as a fourth step, when the session is completed, the authentication server 41 transmits a session end message to the charging server 42 (S8), and the charging server 42 sends a response thereto to the charging server ( The session is terminated by sending (S9) to 42).

At this time, it is preferable to process the charging packet transmitted between the AAA client 43 and the authentication server 41 or between the authentication server 41 and the charging server 42 in realm units. That is, when the AAA client 43 binds the billing, if any of the billing servers accessible from the corresponding servernet domain may be processed, it is transmitted without access to a specific billing server, and vice versa. You can only bind to. Therefore, the proper charging policy can be used according to the status of the charging server at all times, preventing the loss of important charging packets, and selecting and transmitting the charging server according to the load status of the charging server. Can be. In addition, when all the charging servers are in a normal state, the previously connected charging server becomes the priority to be accessed, and when the charging server that becomes the priority is to fail, this fail status information is transmitted to the charging server network management module of the authentication server. The data is not transmitted from the billing server to the failed billing server. In order to implement such an operation, a plurality of preset connection paths are required when establishing a connection with a charging server. This is necessary in order to switch to another access path when a failure occurs in the connected charging server. This procedure may be implemented through the accounting server network management module described above.

FIG. 5 is a diagram illustrating a separate local billing server for interworking with an AAA client in which an access point (AP) accessed by a subscriber in a WLAN according to an embodiment of the present invention is a WLAN AP network. This shows the configuration that can handle billing by installing a separate local billing server. The access point 51 has a problem that it is difficult to store and process a relatively large amount of billing data because a light processor is installed and serves a smaller coverage than the base station range of the mobile communication network. Therefore, the billing data is preferably a structure that can be provided using a separate local billing server 52. The access point 51 generates a charging packet using the corresponding information from the subscriber session and is transmitted to the local charging server 52 through the socket interface 54. In the local billing server 52, a processor for transmitting to the diameter server proceeds and is made through an internet matching unit. Messages such as a request or response transmitted from the access point 51 are transmitted to the authentication server 53 after the routing information is added according to the domain routing table at the diameter client. The response message to the transmission from the access point 51, which is a diameter client of the Mobile IP application, may be sent by adding the status information of the local billing server 52 to the message. That is, the response message must be added with the status information added to the message.

In the network structure of the diameter client for the WLAN service, the process of installing a separate local charging server and processing the billing is as follows. First, after the result of the subscriber authentication and authorization is successfully confirmed, the basic function for billing processing is performed in the access point 51 which is the diameter client, and the generated session information of the subscriber is transmitted to the local billing server 52. do. Subsequently, the local billing server 52 connected to the access point 51 generates an ACR message according to the diameter protocol using the billing information based on the subscriber information and transmits the ACR message to the access point 51 again. Store in the billing record database. Subsequently, the access point 51 receiving the ACR message transmits ACR, which is billing information, to the AAA server 53, which is a peer, and receives a response. Subsequently, the response is again transmitted to the local billing server 52 via the access point 51 and the transmission information is stored together with the billing information. At this time, the charging information that failed to be transmitted is stored in a separate storage for retransmission according to the charging policy or for transmission through a batch session. Since it is difficult to mount a database engine in the actual access point 51, many local billing servers exist in the local area so that the billing information of many APs can be processed.

Basically, the information to be stored in the diameter client for the billing process includes all preset access point information, currently active access point information, currently inactive access point information, and local The charging information of the subscriber to the access point and the information of the connected AAA server. In addition, a device that can be a diameter client in a mobile network such as IMT-2000 can be a PDSN or SGSN (GGSN), and it is equipped with a processor that can also perform direct billing function, but may require a separate billing server structure. have.

According to the present invention as described above, by providing a reliable connection method between the authentication server and the accounting server in processing the charge processing function that takes a heavy load in the accounting server separate from the base protocol of the diameter protocol based AAA server. There is an advantage to construct a stable and reliable network. In addition, according to the present invention, by configuring a billing server network consisting of a plurality of billing server and providing the interworking processing method, it is possible to provide reliability for the AAA function without adding an AAA server for an increasing billing processing function. There is an advantage.

The above description is only a description of specific embodiments of the present invention, and the present invention is not limited to these specific embodiments, and various changes and modifications of the configuration are possible from the above-described specific embodiments of the present invention. It will be apparent to those skilled in the art to which the present invention pertains.

Claims (8)

In the method of interworking with each other by separating the AAA server using the Diameter protocol into an authentication server and a billing server network composed of a plurality of billing servers, A first step of allocating and establishing a subscriber information verification session through a diameter base protocol of the authentication server to authenticate the subscriber and authorize the authority of the authenticated subscriber when the subscriber is connected; In order to know the billing information of the subscriber who has completed the authentication and authorization, the authentication server checks the billing server to be accessed from the billing server network through the diameter base protocol, and the authentication server checks the billing through the diameter base protocol. A second step of connecting with a server; A third step of the authentication server checking a storage state of the connected charging server through a diameter base protocol, transmitting a newly generated charging record to the connected charging server, and the charging server storing the charging record; And And a fourth step of receiving, by the billing server, the session completion request from the authentication server, terminating the session, and sending a session termination message to the authentication server to terminate the session with the authentication server. Interworking method of separate billing server. The method of claim 1, wherein the authentication server, And a billing server network management module for managing the billing server network. The method of claim 1, wherein the second step, A first step of the authentication server requesting confirmation of a billing server storing billing information of a subscriber connected to the billing server network management module through a diameter base protocol to know billing information of the subscriber who has completed the authentication and authorization; A second step of the accounting server network management module checking the accounting server to be accessed from the accounting server network and notifying the authentication server of the result according to the request of the authentication server; And And a third process of connecting the authentication server to the checked billing server through a diameter base protocol. The method of claim 2, wherein the billing server network management module, A billing server interworking method of a separate billing server and a diameter-based AAA authentication server, characterized in that for managing the status of a plurality of billing servers in the network using a Simple Network Management Protocol (SNMP). According to claim 2 or 3, The billing server network management module, When checking the billing server to be accessed from the billing server network, the previously accessed billing server is identified as the priority connection target, and if the billing server targeted as the priority connection is normally operated, the authentication server connects to the billing server targeted to the priority connection. To notify the billing server network management module of another authentication server and to switch the access path so that the authentication server can access another billing server when the billing server to be accessed first becomes a fail. The interlocking method of the billing server separated from the diameter-based AAA authentication server characterized in that. According to claim 2 or 3, The billing server network management module, It monitors the load status of each billing server in the billing server network in real time, and notifies the billing server with a small load when checking the billing server to be accessed from the billing server network by a request of the authentication server. Interworking method of separate billing server with diameter-based AAA authentication server. The method of claim 3, wherein the third process comprises: And a billing server separated from the diameter-based AAA authentication server, characterized in that it comprises a session activation procedure between the authentication server and the billing server. The method of claim 7, wherein the session activation procedure, Separated from the diameter-based AAA authentication server, characterized in that through the transmission of the basic information including the session information, the peer server information for routing the billing message, the session activation information including the auxiliary information including the billing record Interlocking method of billing server.