WO2007098647A1

WO2007098647A1 - A method and means for implementing package prepaid in cdma system

Info

Publication number: WO2007098647A1
Application number: PCT/CN2006/000987
Authority: WO
Inventors: Xiuli Xu; Feng Kou
Original assignee: Zte Corporation
Priority date: 2006-03-04
Filing date: 2006-05-16
Publication date: 2007-09-07
Also published as: CN101031009A

Abstract

A method and means for implementing packet prepaid in CDMA system, the method comprises: (1) the prepaid server PPS and the service control point SCP are incorporated, the account information is in the service control point SCP; (2) the prepaid client PPC interacts on the information of the user prepaid access and end information with the service control point SCP through the authentication authorization and accounting AAA server, manages the authentication and billing of the packet prepaid service of the user. The system implements the information interaction between the prepaid server and the service control point without the interface by incorporating the service control point SCP and prepaid service PPS, it makes the prepaid client side directly interact with the service control point through the authentication authorization and accounting server, so that the packet prepaid function can be implemented.

Description

Method and device for implementing packet pre-payment by code division multiple access system

The present invention relates to the field of mobile communications, and in particular, to a method and apparatus for implementing packet pre-paid in a CDMA (Code Division Multiple Access) system. Background technique

CDMA is a commonly used multiple access modulation technique based on wideband spread spectrum technology. CDMA2000 is one of the main modes of third-generation mobile communications. It not only provides high-quality voice services, but also provides high-speed packet data transmission services.

Figure 1 is a network structure diagram of a conventional CDMA2000 system, in which a BTS (Base Transceiver System) establishes a wireless coverage area for mobile terminal communication, and a BSC (Base Station Controller) can be used for each BTS. The PCF (Packet Control Function Node) is used to forward data between the radio subsystem and the PDSN (Packet Data Service Node). The PDSN is an interface module for the CDMA system to access the Internet. Between the PDSN and the PCF is an R-P interface (R-P, Radio-Packet), that is, an A10/A11 interface, A10 is a data channel, and Al1 is a control channel. The PDSN provides access services for users of the CDMA system. The user authenticates, authorizes, and charges through the PDSN to AAA (Authentication, Authorization and Accounting). HA (Home Agent) and PDSN provide access and mobility management for MIP (Mobile IP, Mobile IP) users.

The CDMA system provides both voice and packet data services for users, and supports both prepaid and postpaid billing methods. For the voice, the prepaid service is relatively mature, and the MSC (Mobile Switching Center) interacts with the SCP (Service Control Point) to implement the prepaid function. The packet data service is a data service mode that has been developed on a large scale in recent years. The implementation of the prepaid payment for the user's packet data service can be controlled by using the same device SCP as the voice to achieve the unification of the user account.

Prepaid services can be implemented through PPC (PrePaid Client, Prepaid Client) and HPS (PrePaid Server, Prepaid Server). For prepaid services, rate conversion refers to the length or flow of the user's account amount converted to achieve prepayment based on duration or traffic. Data business. The PPS is responsible for transmitting the quota-converted quota information to the PPC to implement pre-paid control for the user. When the actual business is launched, different rates can be provided for users according to different time periods. At this time, the rate switching problem at different time periods is involved.

In the CDMA system, the packet prepaid function is implemented. For a prepaid user with a simple IP, the PPC is implemented on the PDSN. For a prepaid user of the MIP, the PPC can be implemented not only on the PDSN but also on the HA. In order to achieve unified account and packet prepaid accounts for the same user, the user account is stored in the SCP, and the PPC interacts with the PPS and the SCP to implement the packet prepaid service.

The Chinese patent "Code Division Multiple Access Packet Prepaid Implementation Method" of CN03145175.6 describes a method for implementing packet prepaid in a CDMA network, which describes a prepaid server PPS and a service control point. An interface is established between the SCPs. When the intelligent service user with the account information on the SCP uses the packet prepaid service, the PDSN in the CDMA system interacts with the AAA and the PPS, and the PPS authenticates and deducts the SCP through the interface. . The prepaid fee client PPC is implemented by the packet data service node PDSN; the prepaid server PPS is separately set or combined with the AAA.

The account information of the CDMA system user is stored in the authentication, authorization and accounting server AAA and the service control point SCP. If the prepaid server PPS is set separately from the AAA, the PPS entity needs to be added to the network, and the PPS needs to be further Store user information. This not only increases the complexity of the networking and more interface interactions, but also inevitably leads to duplication of information and possible inconsistencies.

In addition, in the CDMA system, the authentication, authorization, and accounting server AAA assumes the user's authentication, authorization, and accounting functions, and the AAA not only processes the authentication, authorization, and accounting functions of all post-paid users, but also prepaid. User information is also processed. If the PPS is set in AAA, it will inevitably increase the load on the AAA. Invention disclosure

The technical problem to be solved by the present invention is to provide a method and a device for implementing packet pre-payment by using a code division multiple access system by using an existing CDMA network device, so as to achieve the unification of voice prepaid and packet prepaid in a CDMA network.

In order to solve the above technical problem, the present invention provides a CDMA system for implementing packet prepaid ' The mobile switching center MSC interacts with the service control point SCP to implement the cost control of the user voice prepaid service, and the packet data serving node PDSN interacts with the authentication, authorization and accounting server AAA to provide the user with packet data access; The feature is that it includes the following steps:

Step A: The prepaid server PPS is integrated with the service control point SCP, and the account information is at the service control point SCP;

Step B: The prepaid client PPC interacts with the service control point SCP through the user prepaid access and end messages through the authentication, authorization, and accounting server AAA to perform authentication and fee management of the user's packet prepaid service.

The prepaid client PPC in the step B is a packet data serving node PDSN or a home agent HA.

In the step B, the interaction between the authentication, authorization, and accounting server AAA and the service control point SCP is performed by using Radius (Remote Authentication Dial-In User Service).

Further, the message that the authentication, authorization, and accounting server AAA interacts with the service control point SCP includes:

a) access request/response message;

b) initial quota request request/response message;

c) online quota update request/response message;

d) Business End Request/Response message.

Further, the access request/response message and the initial quota request request/response message may be combined.

The process of the access message of the prepaid client PPC interacting with the service control point SCP through the authentication, authorization, and accounting server AAA in the step B includes the following steps:

Step 1: The prepaid client PPC sends an access request message to the authentication, authorization, and accounting server AAA, where the message carries the prepaid capability of the prepaid client PPC;

Step 2: Authentication, Authorization, and Accounting Server AAA determines that the user is a prepaid user, and forwards the access request message to the service control point/prepaid server SCP/PPS;

Step 3: The service control point/prepaid server SCP/PPS checks the status of the user account. If the user is allowed to access, return the authorization response message receiving the access to the authentication, authorization, and accounting server AAA; otherwise, return the denied access. The response message is sent to the authentication, authorization and accounting server AAA; Step 4: The authentication, authorization and accounting server AAA will access the service control point SCP The message is forwarded to the prepaid client PPC.

Further, the service control point/prepaid server SCP PPS in the step 3 carries the initial quota allocated to the user in the authorization response message received by the authentication, authorization, and accounting server AAA.

If the service control point SCP does not allocate a quota when the user accesses the request, the process of the above-mentioned interactive access message further includes the following steps:

Step 5: The prepaid client PPC sends an initial quota application request message to the authentication, authorization, and accounting server AAA;

Step 6: Authentication, Authorization, and Accounting Server AAA forwards the initial quota application request message to the service control point/prepaid server SCP/PPS;

Step 7: Service Control Point/Prepaid Server SCP PPS grants the user a quota and sends an initial quota application response message to the authentication, authorization, and accounting server AAA;

Step 8: Authentication, Authorization, and Accounting Server AAA forwards the initial quota application response message to the prepaid client PPC.

Further, if the prepaid client PPC is implemented by the packet data serving node PDSN, before the step 5, the packet data serving node PDSN and the authentication, authorization, and accounting server AAA perform interaction of the charging start information.

In the step B, if the prepaid client PPC determines that the user requested quota is used up and needs to re-request the quota, the prepaid client PPC further passes the authentication, authorization, and accounting server AAA and the service control point SCP. Interacting online quota update messages, the interaction process includes the following steps:

Step 9: The prepaid client PPC sends an online quota update request message to the authentication, authorization, and accounting server AAA, where the message carries the used quota information.

Step 10: Authentication, Authorization, and Accounting Server AAA forwards the online quota update request message to the service control point/prepaid server SCP/PPS;

Step 11: Service Control Point/Prepaid Server SCP/PPS re-grants the user authorization quota and sends an online quota update response message to the authentication, authorization, and accounting server AAA according to the quota used by the user.

Step 12: The authentication, authorization, and accounting server AAA forwards the online quota update response message to the prepaid client PPC. In the step B, when the system terminates the user using the packet prepaid service, the process of the end message of the prepaid client PPC interacting with the service control point SCP through the authentication, authorization, and accounting server AAA includes the following steps:

Step 13: The prepaid client PPC sends a service end request message to the authentication, authorization, and accounting server AAA, and the message carries the used quota information.

Step 14: Authentication, Authorization, and Accounting Server AAA forwards the Service End Request message to the Service Control Point/Prepaid Server SCP/PPS;

Step 15: Service Control Point/Prepaid Server SCP/PPS updates the account information of the user according to the quota used by the user, and simultaneously sends a service end response message to the authentication, authorization, and accounting server AAA;

Step 16: Authentication, Authorization, and Accounting Server The AAA forwards the Service End Response message to the Prepaid Client PPC.

Further, if the prepaid client PPC is implemented by the packet data serving node PDSN, in step 13, the service end request message sent by the packet data serving node PDSN to the authentication, authorization, and accounting server AAA is included in the end of charging. In the message, in the step 16, the service end response message sent by the authentication, authorization and accounting server AAA to the packet data serving node PDSN is included in the charging end response message.

Further, if the prepaid client PPC is implemented by the packet data serving node PDSN, before the step 13 or after the above step 16, the packet data service node PDSN and the authentication, authorization and accounting server AAA perform an charging end message. Interaction.

The present invention further provides a device for implementing packet prepaid in a CDMA system, comprising a packet data serving node PDSN, which implements access of a CDMA network user, and assumes a function of a prepaid client in a prepaid service, through a packet control function node PCF. Realize the connection with the airborne wireless interface;

- Home Agent HA, together with the packet data service node PDSN, provides access and mobility management for MIP users of the mobile internet platform;

An authentication, authorization, and accounting server AAA that implements authentication, authorization, and accounting functions for CDMA users;

A service control point SCP, which provides account management for prepaid users, rate conversion function for amount and duration or traffic conversion, and rate switching function at time points; a prepaid server PPS, configured to send the rate-converted quota information to the pre-paid client to implement pre-paid control for the user;

The service control point SCP is integrated with the prepaid server PPS, so that no interface information interaction between the prepaid server PPS and the service control point SCP is implemented, so that the prepaid client passes the authentication, authorization, and accounting server. The AAA directly interacts with the service control point SCP to implement the packet prepaid function.

The device for implementing packet pre-payment in the above CDMA system is characterized in that the interface between the service control point SCP and the authentication, authorization and accounting server AAA is a Radius interface.

Compared with the prior art, the present invention implements a packet pre-paid function by using an existing CDMA network device, and the pre-paid server PPS is integrated with the service control point SCP, and does not require an interface between the pre-paid server PPS and the service control point SCP. The prepaid client PPC directly interacts with the service control point SCP through the authentication, authorization, and accounting server AAA to implement the packet prepaid function, which provides great convenience for the networking of the packet prepaid service and the management of the user account.

Compared with the prior art, the present invention avoids repeated storage of user account information, simplifies the prepaid network; avoids burdening the authentication, authorization, and accounting server AAA devices; and has the least impact on the existing packet network. BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a diagram showing the existing network structure of a CDMA system;

2 is a network structure diagram of a CDMA system implementing a packet prepaid service;

FIG. 3 is a flowchart of processing for a CDMA system access user to provide a packet prepaid service; FIG. 4 is a flowchart of a process for requesting an initial quota when a CDMA system provides a prepaid service for a user;

Figure 5 is a process flow diagram when the CDMA system provides users with an online quota application for prepaid services;

Figure 6 is a flow chart showing the process of ending the use of the packet prepaid service by the CDMA system. The best way to implement the invention

The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

In the following embodiments, for convenience of description, the prepaid client PPC is a packet data service node. The PDSN is an example. Similarly, when the user accesses the CDMA system by using the mobile internet platform MIP, the prepaid client can also be implemented by the home agent HA, so that when the packet data service node PDSN does not have the prepaid capability, if the HA has the prepaid capability, the MIP users offer prepaid services.

Figure 1 is a diagram of the existing network structure of a CDMA system. Please refer to Figure 1, where:

The base station radio transceiver 111 establishes a radio coverage area for mobile terminal communication in the cell; the packet control function node 112 mainly implements an airborne wireless interface to connect with the packet data service node 113;

The packet data service node 113 implements access of CDMA network users, and assumes the function of the prepaid client PPC in the prepaid service;

The home agent 114 and the packet data service node 113 provide access and mobility management for MIP users;

The authentication, authorization, and accounting server 115 implements the authentication, authorization, and charging functions of the CDMA user; the mobile switching center 116 provides the access control of the CDMA voice user, and interacts with the service control node 117 to implement the prepaid service of the user voice. Cost control.

Service Control Point 117 provides account management for prepaid users, rate conversion for amount and duration or traffic conversion, and rate switching across time points.

The home location register 118 provides identity authentication for the user to access the CDMA network.

2 is a network structure diagram of a CDMA system implementing a packet prepaid service. Please refer to Figure 2, where:

The service control point SCP is implemented in conjunction with the prepaid server PPS, and the user account information is stored at the service control point 217.

When the user uses the packet prepaid service, the packet data service node 113 in the CDMA system interacts with the service control point 117 through the authentication, authorization, and accounting server 115 to perform user prepaid access, online quota update, and end message, to implement grouping. Pre-paid user authentication and expense management.

The interface between the service control point 217 and the authentication, authorization, and accounting server 115 is the Radius interface.

Figure 3 is a flow diagram of a process in which a CDMA system begins to provide a packet prepaid service to a user. Please refer to Figure 3:

When the CDMA system starts to provide packet prepaid services, the prepaid client PPC passes the The process of the AAA, the authorization, and the accounting server AAA interacting with the service control point SCP includes:

S301: The packet data serving node 113 sends an access request message to the authentication, authorization, and accounting server 115, where the message carries the pre-paid capability of the packet data serving node 113;

S302: The authentication, authorization, and accounting server 115 determines that the user is a prepaid user, and forwards the access request message to the service control point/prepaid server 217;

S303: The service control point/prepaid server 217 checks the status of the user account, and if the user is allowed to access, returns an authorization response message for accepting the access to the authentication, authorization, and accounting server 115, and the message carries the initial allocation to the user. Quota; otherwise, the response message rejecting the access is returned to the authentication, authorization, and accounting server 115;

S304: The authentication, authorization and accounting server 115 forwards the access response message of the service control point SCP to the packet data serving node 113.

Figure 4 is a process flow diagram of a request for an initial quota when a CDMA system provides a prepaid service to a user. Refer to Figure 4:

If the service control point SCP does not allocate a quota when the user accesses the request, the packet data service node PDSN needs to request an initial quota from the service control point SCP before providing the data transmission service to the user, and the interactive access message flow is further followed by The interaction process includes:

S401: The packet data service node 113 interacts with the authentication, authorization, and accounting server 115 to start charging.

S402: The packet data service node 113 sends an initial quota application request message to the authentication, authorization, and accounting server 115.

S403: The authentication, authorization, and accounting server 115 forwards the initial quota application request message to the service control point/prepaid server 217;

S404: The service control point/prepaid server 217 grants a quota to the user and sends an initial quota application response message to the authentication, authorization, and accounting server 115;

S405: The authentication, authorization, and accounting server 115 forwards the initial quota application response message to the packet data service node 113.

Figure 5 is a process flow diagram when the CDMA system provides the user with an online quota application for prepaid services. Please refer to Figure 5:

If the packet data serving node PDSN determines that the user requested quota is used up and needs to re-request the quota, the prepaid client PPC passes the authentication, authorization, and accounting server AAA and service. The control point SCP further interaction process includes:

S501: The packet data service node 113 sends an online quota update request message to the authentication, authorization, and accounting server 115, where the message carries the used quota information.

S502: The authentication, authorization, and accounting server 115 forwards the online quota update request message to the service control point/prepaid server 217;

S503: the service control point/prepaid server 217 re-grants the user authorization quota according to the quota used by the user, and sends an online quota update response message to the authentication, authorization, and accounting server 115;

S504: The authentication, authorization, and accounting server 115 forwards the online quota update response message to the packet data service node 113.

Figure 6 is a flow chart showing the process of ending the use of the packet prepaid service by the CDMA system. Please refer to Figure 6:

When the CDMA system terminates the user's use of the packet prepaid service, the prepaid client PPC further interacts with the service control point SCP through the authentication, authorization, and accounting server AAA, including:

S601: The packet data service node 113 sends a service end request message to the authentication, authorization, and accounting server 115, where the message carries the used quota information.

S602: The authentication, authorization, and accounting server 115 forwards the service end request message to the service control point/prepaid server 217;

S603: The service control point/prepaid server 217 updates the account information of the user according to the quota used by the user, and simultaneously sends a service end response message to the authentication, authorization, and accounting server 115;

S604: The authentication, authorization, and accounting server 115 forwards the service end response message to the packet data service node 113;

S605: The packet data service node 113 interacts with the authentication, authorization, and accounting server 115 to end the charging.

In summary, the method for implementing packet pre-payment by a code division multiple access system proposed by the present invention adopts a convenient networking mode, has the least impact on the existing packet network, and provides a prepaid service for the CDMA system. Great convenience. Industrial applicability

The method for implementing packet pre-payment by the code division multiple access system of the invention is applicable to CDMA2000 IX, CDMA2000 EV-DO, CDMA2000 IX EV-DV system, and other similar networks A system that implements a prepaid function. The invention utilizes the existing CDMA network device, and the prepaid server PPS is integrated with the service control point SCP through the prepaid server PPC, and the prepaid client PPC directly interacts with the service control point SCP through the authentication, authorization and accounting server AAA to realize group prepayment. The fee function avoids the repeated storage of user account information, simplifies the prepaid network; avoids the authentication of the AAA device of the authentication, authorization and accounting server; greatly facilitates the networking and user accounts of the packet prepaid service. Management.

Claims

Claim

A method for implementing packet pre-payment in a CDMA system, applied to a system including a mobile switching center MSC, a service control point SCP, a packet data serving node PDSN, and an authentication, authorization, and accounting server AAA, wherein the mobile switching center MSC Interacting with the service control point SCP to implement the cost control of the pre-paid service of the user voice, the packet data service node PDSN interacts with the authentication, authorization, and accounting server AAA to provide the user with the packet data access, and the method further includes:

Step 1: Prepaid server PPS is integrated with the service control point SCP, and the account information is at the service control point SCP;

Step 2: The prepaid client PPC interacts with the service control point SCP through the authentication, authorization, and accounting server AAA to exchange user prepaid access and end messages, and performs authentication and fee management of the user's packet prepaid service. '

The method according to claim 1, wherein in the second step, the prepaid client PPC is a packet data serving node PDSN or a home agent HA.

The method according to claim 1, wherein in the second step, the prepaid client PPC interacts with the service control point SCP through the authentication, authorization, and accounting server AAA, and uses a Radius message to interact.

The method according to claim 1, wherein the message that the authentication, authorization, and accounting server AAA interacts with the service control point SCP includes:

Access request/response message;

Initial quota request request / response cancellation;

Online quota update request/response message;

Business end request/response message.

The method according to claim 4, wherein the access request/response message and the initial quota request request/response message are combined.

The method according to claim 1, wherein the process of the access message that the prepaid client PPC interacts with the service control point SCP through the authentication, authorization, and accounting server AAA in the second step includes: Step 301: The prepaid client PPC sends an access request message to the authentication, authorization, and accounting server AAA, where the message carries the prepaid capability of the PPC;

Step 302: authentication, authorization, and accounting server AAA determines that the user is a prepaid user, and forwards the access request message to the service control point/prepaid server 217;

Step 303: The service control point/prepaid server SCP/PPS checks the status of the user account. If the user is allowed to access, the authorization response message for accepting the access is returned to the authentication, authorization, and accounting server AAA; otherwise, the response to the denied access is returned. The message is sent to the authentication, authorization, and accounting server AAA. Step 304: The authentication, authorization, and accounting server AAA forwards the access response message of the service control point SCP to the prepaid client PPC.

The method according to claim 6, wherein in step 23, the service control point/prepaid server SCP/PPS returns to the authorization response message of the authentication, authorization and accounting server AAA for accepting access. Carry the initial quota assigned to the user.

The method according to claim 1 or 6, wherein if the service control point SCP does not allocate a quota when the user accesses the request, the flow of the interactive access message further includes - step 402 the prepaid client The PPC sends an initial quota application request message to the authentication, authorization, and accounting server AAA;

Step 403 Authentication, Authorization, and Accounting Server AAA forwards the initial quota application request message to the service control point/prepaid server SCP/PPS;

Step 404 service control point / prepaid server SCP/PPS grants a quota to the user and sends an initial quota application response message to the authentication, authorization, and accounting server AAA;

Step 405 Authentication, Authorization, and Accounting Server The AAA forwards the initial quota application response message to the prepaid client PPC.

The method according to claim 8, wherein, if the prepaid client is implemented by the packet data serving node PDSN, the step 402 further comprises: step 401: packet data serving node PDSN and authentication The authorization and accounting server AAA performs the interaction of the charging start information.

The method according to claim 1, wherein if the prepaid client PPC determines that the user requested quota is used up and needs to re-request the quota, the prepaid client PPC in the second step passes the authentication, The authorization and accounting server AAA further interacts with the service control point SCP for online quota update messages, including: Step 501: The pre-paid client PPC sends an online quota update request message to the authentication, authorization, and accounting server AAA, where the message carries the used quota information.

Step 502 authentication, authorization, and accounting server AAA forwards the online quota update request message to the service control point/prepaid server SCP/PPS;

Step 503 service control point/prepaid server SCP/PPS re-grants the user authorization quota according to the quota used by the user and sends an online quota update response message to the authentication, authorization, and accounting server AAA;

Step 504 Authentication, Authorization, and Accounting Server AAA forwards the online quota update response message to the prepaid client PPC.

The method according to claim 1, wherein the process of the end message of the prepaid client PPC interacting with the service control point SCP through the authentication, authorization and accounting server AAA comprises the following steps:

Step 601 The prepaid client sends a service end request message to the authentication, authorization, and accounting server AAA, and the message carries the used quota information.

Step 602: Authentication, Authorization, and Accounting Server AAA forwards the service end request message to the service control point/prepaid server SCP/PPS;

Step 603 Service Control Point/Prepaid Server SCP/PPS updates the account information of the user according to the quota used by the user, and simultaneously sends a service end response message to the authentication, authorization, and accounting server AAA;

Step 604 Authentication, Authorization, and Accounting Server The AAA forwards the service end response message to the prepaid client PPC.

The method according to claim 11, wherein if the prepaid client PPC is implemented by the packet data serving node PDSN, in step 601, the packet data serving node PDSN is authenticated, authorized, and charged to the server. The service end request message sent by the AAA is included in the charging end message. In the step 604, the service end response message sent by the authentication, authorization, and accounting server AAA to the packet data serving node PDSN is included in the charging end response message. .

The method according to claim 11, wherein if the prepaid client PPC is implemented by the packet data serving node PDSN, before the step 601 or after the step 604, the packet data serving node PDSN and the authentication The interaction between the authorization and accounting server AAA performs the charging end message.

14. A device for implementing packet prepaid in a CDMA system, comprising:

A packet data service node (PDSN) implements access of users of the CDMA network, and assumes the function of the prepaid client in the prepaid service, and realizes the connection with the airborne wireless interface through the packet control function node;

A home agent HA, together with the packet data service node PDSN, provides access and mobility management for mobile internet platform users;

_Authentication, Authorization and Accounting Server AAA, which implements the authentication, authorization and accounting functions of CDMA users;

A service control point SCP, which provides account management for prepaid users, rate conversion function for amount and duration or flow conversion, and rate switching function at time points;

a prepaid server PPS, configured to send the rate-converted quota information to the pre-paid client to implement pre-paid control for the user;

The apparatus for implementing packet prepaid in a CDMA system according to claim 14, wherein the interface between the service control point SCP and the authentication, authorization, and accounting server AAA is a Radius interface.

The apparatus for implementing packet prepaid according to claim 15, wherein the service control point SCP and the authentication, authorization and accounting server AAA comprise an access request/response message and an initial quota application. The request/response message, the online quota update request/response message, and the Radius message of the service end request/response message interact.