CN1859380B

CN1859380B - Method for obtaining off line message

Info

Publication number: CN1859380B
Application number: CN2005101024536A
Authority: CN
Inventors: 牟伦建; 王珏
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2005-07-28
Filing date: 2005-09-09
Publication date: 2011-12-07
Anticipated expiration: 2025-09-09
Also published as: CN1859380A

Abstract

The present invention discloses off line message obtaining method, used in adopting SIP/SIMPLE protocol instant message system. It contains when client-side registers to system and receives instant message (IM) server transmitted off line message notifying, executing the following steps: client-side originating obtaining off line message content request to said IM server; said IM server obtaining said client-side off line message content and down issuing to the client-side. The present invention combines current technologic off line message transmission and storage process to make off line message process into a complete solution scheme.

Description

Offline message acquisition method

Technical Field

The present invention relates to an instant message service in the field of mobile communication and Internet (Internet), and more particularly, to a method for a user to acquire an offline message stored in a system using a session initiation protocol/instant message and an instant message system existing using an extended session initiation protocol (SIP/SIMPLE protocol).

Background

Instant Messaging (IM) services can be developed over mobile communication networks, Internet networks, etc., including existing 2G (2nd Generation, 2nd Generation mobile network), 2.5G, future 3G (3rd Generation, 3rd Generation mobile network), and Multimedia Subsystem (IMs).

The instant messaging service belongs to a mobile data service of a Presence service (Presence) -based person-to-person, person-to-group message class.

The OMA international standards organization makes a standard for mobile instant messaging, and there are two types of instant messaging systems in the current standard specification version. The first type is an instant messaging system based on a Wireless Village (WV) protocol, which can support 2.5G/3G networks based on a protocol carried by a hypertext transfer protocol/Wireless access protocol/short messaging protocol (HTTP/WAP/SMS); the second type is an instant messaging system based on Session Initiation Protocol (SIP)/instant messaging and presence service extension session initiation protocol (SIMPLE), which supports an IMS-based IP network based on a protocol of SIP/SIMPLE bearer.

There are client usage scenarios in SIP/SIMPLE based instant messaging systems: the sending client sends the instant message to the receiving party, at this time, if the receiving party is not on-line, the receiving party IM server needs to store the offline message (referred message), and then when the receiving party client registers to the SIP/IP Core network and gets on-line to the receiving party server, the server can notify the receiving party client of the offline message.

In the prior art, there are two sending methods of instant messages:

first, instant messaging is sent by SIP MESSAGE message, as shown in fig. 1, client a represents the client sending the offline message; the IM server A is an IM server to which the client A belongs; the core network A is a home network of the client A, and the specific process comprises the following steps:

1. a client A sends SIP MESSAGE a Request to a core network A to Request for sending an IM message, wherein a message body part of a SIP MESSAGE message carries specific content of the instant message, a Request-URI comprises an address of a client B (message receiver), and a message header of a SIP MESSAGE message comprises a feature code (feature-tag), for example, "+ g.im.message", which indicates that the instant message service is requested;

2. the core network A forwards the received SIP MESSAGE message to the IM server A;

3. the IM server a sends an instant Message to the client B, and the specific sending process refers to a flow shown in fig. 3 that receives and stores the instant Message through SIP MESSAGE messages, or a flow shown in fig. 4 that receives and stores the instant Message through an MSRP (Message Session Relay Protocol) transmission channel;

4. IM server A receives confirmation message 202Accepted from the network to which client B belongs, which indicates that IM server B of the network to which client B belongs receives the instant message;

5. the IM server A returns SIP acknowledgement message 202Accepted to the core network A;

6. the core network a forwards the SIP message to the client a.

In a second manner, the instant message is sent through the MSRP transmission channel, as shown in fig. 2, the specific process includes:

1. the client A sends SIP INVITE (SIP request) request to the core network A, requesting to establish MSRP session channel in order to send instant message; the request comprises information such as a local URL, a port, an IP address and the like of the client A;

2. the core network A sends the SIP INVITE message to the IM server A;

3. the IM server A prepares to establish connection with the client A, returns a SIP200OK response message which comprises information such as a port number, a URL (uniform resource locator), an IP (Internet protocol) address and a message type which can support MSRP (mobile subscriber protocol) establishment, and sends the information to the core network A;

4. the core network A forwards the SIP200OK message to the client A;

5. the client A confirms that the SIP200OK is received and responds to the SIP ACK message to the core network A;

6. the core network A forwards the message to the IM server A;

7. the method comprises the steps that MSRP connection is established between a client A and an IM server A, and the client A sends an MSRP authorization request to the IM server A through an MSRP transmission channel;

8. the IM server A returns a MSRP200OK response message of the authorization request through a transmission channel;

the

steps

7 and 8 are optional flows, when the client A needs to receive the message sent by the IM server A, the steps are executed, if the flow does not exist, the MSRP connection between the client A and the IM server A is established in the step 9;

9. the client A SENDs an MSRP SEND message to the IM server A through the MSRP transmission channel, and SENDs the content of the instant message; the message contains a Content Type (Content-Type) and a corresponding XML (extensible markup language) Content, and indicates that an instant message is to be sent;

10. IM server A returns 200OK response message through MSRP transmission channel, which represents that server receives message;

11. the IM server a sends the instant message to the client B, and the specific sending process refers to the process shown in fig. 3 of receiving and storing the instant message through SIP MESSAGE message, or the process shown in fig. 4 of receiving and storing the instant message through MSRP transmission channel;

12. after the client A finishes sending the instant message, the client A sends an SIP BYE message to the core network A to finish the session, and the MSRP connection is disconnected;

13. the core network A forwards the SIP BYE message to an IM server A;

14. the IM server A responds to the SIP200OK message to the core network A;

15. the core network A forwards the response message to the client A and disconnects the MSRP connection.

In the prior art, there are two ways for receiving and storing an offline instant message:

in a first mode, the instant message is received and stored through SIP MESSAGE messages, as shown in fig. 3, a client B, IM server B of the SIP/SIMPLE instant message system and a core network B are in the same home network of the client B, and the specific process includes:

1. an IM server A receives a request of a client A for sending an instant message to a client B;

2. the IM server A sends SIP MESSAGE a Request to the core network A, the Request-URI comprises the address of the client B, the SIP message header comprises a feature-tag (feature-tag), such as "+ g.im.message", which indicates that the instant message service is requested;

3. according to the address of the client B, the core network A sends SIP MESSAGE request to the core network B to which the message receiving end belongs;

4. the core network B sends SIP MESSAGE request to the IM server B;

5. if the IM server B judges that the current state of the client B is an offline state, the IM server B stores the instant Message into a Message Storage entity (Message Storage); the storage entity is a logical entity, and can be physically integrated with the IM server or separated into two entities; the storage format can be a database, a file mode and the like;

6. the IM server B responds to the SIP202Accepted message to the core network B, which indicates that the IM server B receives the instant message but does not successfully send the instant message to the client B;

7. the core network B forwards the response message to the core network A;

8. the core network A forwards the response message to the IM server A;

9. after receiving the message, the IM server A returns a response message to the client A.

In a second way, the instant message is received and stored through the MSRP transmission channel, as shown in fig. 4, the specific process includes:

2. the IM server A establishes MSRP connection with the IM server B, and the establishing flow of the MSRP transmission channel is similar to the steps 1-6 shown in the figure 2;

3. IM server A SENDs MSRP SEND message through MSRP transmission channel, and SENDs instant message to IM server B;

4. the IM server B judges that the state of the client B is offline, judges that the information of the user needs to be stored offline according to the setting of the user, the strategy of an operator and the like, and stores the instant information into an information storage server;

5. the IM server B returns a 200OK response message to the IM server A through the MSRP transmission channel;

6. after receiving the message, the IM server A returns a response message to the client A.

In the prior art, an instant messaging system conforming to the SIP/SIMPLE IM standard only relates to the above-described offline message sending technology and storage technology, but does not relate to a method how an offline message receiving end acquires an offline message stored in the system. That is, the offline message acquisition process has not been implemented in the prior art, and a complete offline message solution is not provided.

Disclosure of Invention

The invention provides an off-line message acquisition method, which is applied to an instant message system adopting SIP/SIMPLE protocol and is used for solving the problem of incomplete off-line message flow in the prior art.

The method of the invention is applied to an instant message system which adopts a session initiation protocol SIP/instant message and has a SIMPLE session initiation protocol, and the method comprises the following steps: when a client side is registered in a system and receives an offline message notification sent by an Instant Message (IM) server, the following steps are executed:

A. a client initiates a request for acquiring the content of an offline message to the IM server;

B. and the IM server transmits the off-line message content of the client stored in the system to the client.

According to the method of the invention, the client requests the IM server to obtain the offline message content through SIP MESSAGE message; the IM server sends the off-line message content to the client through SIP MESSAGE message or Message Session Relay Protocol (MSRP) transmission channel.

According to the method of the present invention, the message header of the SIP MESSAGE message sent by the client includes a feature code requesting to obtain the content of the offline message.

According to the method of the invention, the SIP MESSAGE message transmitted between the client and the IM server is forwarded through the core network to which the client belongs.

According to the method, the client requests the IM server to acquire the content of the offline message through the MSRP transmission channel; and the IM server issues offline message content to the client through the MSRP transmission channel.

According to the method of the invention, the client sends the MSRPSEND message through the MSRP transmission channel to request to acquire the content of the offline message, and the message contains the content type and the corresponding extensible markup language (XML) content to indicate that the acquisition of the content of the offline message is requested.

According to the method of the invention, the IM server sends the MSRPSEND message through the MSRP transmission channel, and the off-line message content is sent to the client.

According to the method, the client side obtains the offline message content from the IM server by sending a hypertext transfer protocol (HTTP) request; and the IM server carries the offline message content of the client through the 200OK response message and issues the offline message content to the client.

The method of the invention also comprises the step of sending an offline message delivery report to the system after the IM server issues the offline message content.

The sending, by the IM server, the offline message delivery report to the system specifically includes:

a', after receiving the message receiving response of the client, the IM server sends the delivery report to the IM server to which the offline message sending end belongs;

b', the IM server to which the offline message sending end belongs forwards the delivery report to the client side sending the offline message.

According to the method of the present invention, the delivery report is carried by a SIP NOTIFY message.

The step A' comprises the following steps:

a' 1, an IM server to which an offline message receiving end belongs sends SIP NOTIFY message carrying a delivery report to a core network to which the offline message receiving end belongs;

a' 2, the core network to which the off-line message receiving end belongs forwards the SIP NOTIFY message to the core network to which the off-line message sending end belongs;

a' 3, the core network to which the off-line message sending end belongs forwards the SIP NOTIFY message to the IM server to which the off-line message sending end belongs;

the step B' comprises the following steps:

b' 1, the IM server to which the off-line message sending end belongs forwards the SIP NOTIFY message to a core network to which the off-line message sending end belongs;

b' 2, the core network to which the off-line message sending end belongs forwards the SIP NOTIFY message to the client side sending the off-line message.

In the step A', the IM server to which the off-line message receiving end belongs sends the delivery report through an MSRP transmission channel established between the IM server to which the off-line message sending end belongs;

in the step B', the IM server to which the offline message sending end belongs forwards the delivery report through an MSRP transmission channel established between the IM server and the client sending the offline message.

According to the method of the invention, the MSRP transmission channel is an established channel or a newly established channel.

According to the method of the present invention, after the delivery report is transmitted, the MSRP transmission channel is disconnected or reserved.

The invention has the following beneficial effects:

(1) the method for acquiring the content of the offline message fills up the technical blank of the processing process of the offline message in the prior art, and enables the processes of sending, receiving, storing and informing the offline message in the prior art to be combined with the acquiring process of the offline message to form a complete solution of the offline message.

(2) The invention provides a plurality of methods for acquiring the content of the off-line message, which comprises the steps of acquiring the content of the off-line message in an SIP message mode, an MSRP transmission channel mode and an HTTP request mode, so that the acquisition process of the off-line message can be selected according to the specific conditions of the current network, and the flexibility of the system is improved.

(3) After the receiving client side successfully acquires the content of the offline message, a delivery report can be sent to the sending client side of the offline message. The process of sending the delivery report makes the process of processing the offline message more complete.

(4) The off-line message delivery report sending mode comprises a SIP message mode and an MSRP transmission channel mode. The SIP message carrying mode is suitable for the delivery report with small information quantity, and the MSRP transmission channel mode is suitable for the delivery report with larger information quantity. If the MSRP tunnel has been established in the previous procedure, the delivery report is preferably sent using MSRP tunnel mode. Therefore, the sending modes of the multiple delivery reports provided by the invention can be flexibly selected according to the specific situation of the current network and the specific situation of the information quantity of the delivery reports.

Drawings

Fig. 1 is a flow chart of a client sending an instant message through an SIP message in the prior art;

FIG. 2 is a flow chart of a client sending an instant message through an MSRP transmission channel in the prior art;

fig. 3 is a flowchart of a receiver IM server receiving and storing an instant message through an SIP message in the prior art;

fig. 4 is a flow chart of receiving and storing an instant message by a receiver IM server through an MSRP transmission channel in the prior art;

FIG. 5 is a flow chart of the off-line message sending, storing, notifying and retrieving service of the present invention;

FIG. 6 is a flowchart of the client acquiring an offline message via a SIP message according to the present invention;

FIG. 7 is a flowchart illustrating a client side obtaining an offline message through an MSRP transmission channel according to the present invention;

FIG. 8 is a second flowchart of the client side obtaining the offline message through the MSRP transmission channel according to the present invention;

FIG. 9 is a flowchart illustrating a client obtaining an offline message via an HTTP request according to the present invention;

FIG. 10 is a flow chart of a client sending a delivery report via SIP message in accordance with the present invention;

fig. 11 is a flow chart of the client sending the delivery report through the MSRP transport channel according to the present invention.

Detailed Description

In an instant messaging system using the SIP/SIMPLE protocol, a complete service flow of sending, storing, notifying and acquiring an offline message, as shown in fig. 5, specifically includes:

1. the client A needs to send an instant message to the client B, and firstly, the client A sends the instant message to an IM server A to which the client A belongs;

2. the IM server A judges that the receiver client B belongs to the IM server B and forwards the message to the IM server B;

3. the IM server B judges whether the client B is on line or not, and if so, sends a message to the client B; otherwise, storing the message in a storage entity;

4. when the client B is on line, the IM server B sends an offline message notification to the client B;

5. if the receiver user needs to obtain specific message content, sending a request for obtaining the offline message through the client B;

6. the IM server B acquires the content of the offline message from the storage entity;

7. the IM server B issues the offline message content to the client B;

8. the client B returns a message receiving response to the IM server B;

9. the IM server B sends a delivery report to the IM server A;

10. IM server a forwards the delivery report to sender client a.

The above 9-10 are optional steps.

The client B can obtain the offline message in the following four ways, each of which is described in detail below.

The offline message acquisition mode is as follows: as shown in fig. 6, the client B, IM, in which the server B and the core network B are in the same home network of the client B, specifically includes:

1. the client B is on-line in an SIP mode and is registered to an IM server B and a core network B; the SIP registration message contains a feature code, such as: im.message, which indicates that an offline message service is requested;

2. the IM server B finds that the client B has the stored offline message, sends SIP MESSAGE the message to the core network B, and notifies that the offline message exists; the SIP MESSAGE message has a unique signature in its header, such as: + g.im.notify, indicating that an offline message is requested;

3. the core network B forwards the SIP MESSAGE notification message to the client B;

4. the client B knows the notification of the offline message through the unique feature code, and responds to the SIP200OK message to the core network B to indicate that the notification message is received;

5. the core network B forwards the response message to the IM server B;

the above steps 1-5 are the off-line message notification process of the prior art, and the following steps are the off-line message acquisition process of the present invention:

6. the client B sends SIP MESSAGE information to the core network B to request to obtain the offline information; the SIP header of the request message has a unique feature code, such as: + g.im.fetch, which indicates that the offline message content is to be acquired;

7. the core network B forwards the SIP message to an IM server B;

8. the IM server B responds to the SIP200OK message to the core network B to indicate that the acquisition request is received;

9. core network B forwards SIP200OK to client B;

10. the IM server B acquires the offline message from the offline message storage server; the off-line message storage server can be set with the IM service in a unified way, and the off-line message storage mode can be a database, a file mode and the like; the acquired message content includes but is not limited to: sender, receiver, time of transmission, message type, message size, encoding format, etc.;

11. the IM server B sends the offline message of the client B to the core network B through SIP MESSAGE messages;

12. the core network B forwards the message to the client B;

13. the client B responds to the SIP200OK message to the core network B, and the offline message content is received;

14. the core network B forwards the response message to the IM server B;

15. optional flow, if the sender requires to obtain the delivery report that the receiver successfully obtains the content of the offline message, the flow is available; flow of sending delivery report see fig. 10 and 11 for a description of the flow of "client B sends offline message delivery report".

And an offline message acquisition mode II: as shown in fig. 7, the client B, IM includes that the server B and the core network B are in the same home network of the client B, and specifically includes:

1-5, in the same way as the step 1-5 in the first mode, the client B is informed of the offline message after registering in the IM system;

6. the client B sends SIP MESSAGE message to the core network B to request to obtain the instant message content stored in the system when off-line; the SIP header of the request message has a unique feature code, such as: + g.im.fetch, which indicates that the offline message content is to be acquired;

7. the core network B forwards the message to an IM server B;

9. the core network B forwards the 200OK message to the client B;

10. the IM server B sends SIP INVITE information to the core network B to request to establish an MSRP transmission channel so as to send the stored offline information to the client B;

11. the core network B forwards the SIP INVITE message to the client B;

12. the client B responds to the SIP200OK message to the core network B, indicating receipt of the request;

13. the core network B forwards the SIP200OK message to the IM server B;

14. the IM server B confirms that the SIP200OK message is received and responds to the SIP ACK message to the core network B;

15. the core network B forwards the SIP ACK message to the client B;

16. the IM server B acquires the stored offline message content from the offline message storage server;

17. an MSRP transmission channel is established between an IM server B and a client B, and the IM server B SENDs the content of the offline message to the client B through an MSRP SEND message on the transmission channel; message content includes, but is not limited to: sender, receiver, time of transmission, message type, message size, encoding format, etc.;

18. the client B returns a 200OK message through the transmission channel, which indicates that the client receives the offline message;

19. the IM server B sends an SIP BYE message to the core network B to end the session and disconnect the MSRP connection;

20. the core network B forwards the message to the client B;

21. client B responds to SIP200OK message to core network B;

22. the core network B forwards the SIP200OK message to the IM server B, and the MSRP connection is disconnected;

23, selecting a flow, if the sender requires to obtain a delivery report that the receiver successfully obtains the content of the offline message, the flow is available; flow of sending delivery report see fig. 10 and 11 for a description of the flow of "client B sends offline message delivery report".

And an off-line message acquisition mode III: as shown in fig. 8, the client B, IM includes that the server B and the core network B are in the same home network of the client B, and specifically includes:

1-5, in the same way 1-5 of the first mode, after registering to the IM system, the client B is informed of the offline message;

6. the client B sends SIP INVITE information to the core network B to request the establishment of an MSRP channel so as to acquire the stored on-line information;

7. the core network B forwards the message to an IM server B;

8. the IM server B responds to the SIP200OK message to the core network B to indicate that the request is received;

9. the core network B forwards the SIP200OK message to the client B;

10. the client B confirms that the SIP200OK message is received and responds to the SIP ACK message to the core network B;

11. the core network B forwards the SIP ACK message to an IM server B;

12. the client B sends an MSRP send message to the IM server B through the established MSRP transmission channel, where the message includes a Content Type (Content-Type) and a corresponding XML Content, and indicates that an offline message is to be acquired, for example: the Content-Type is:

application/vnd.im.msrp + xml, the contents of xml are:

<？xml version＝″1.0″encoding＝″UTF-8″？>

<msrp xnlns＝″um:oma:params:xml:ns:im:msrp″

xmlns:xsi＝″http://www.w3.org/2001/XMLSchema-instance″

xsi:schemaLocation＝″urn:oma:params:xml:ns:im:msrp″>

</message>

</msrp>

13. the IM server B returns a 200OK message through the transmission channel, which indicates that the IM server B receives the message;

14. the IM server B acquires message contents from an offline message storage server;

15. the IM server B SENDs an MSRP SEND message to the client B through the transmission channel, wherein the message contains the content of the offline instant message;

16. the client B returns a 200OK message through the channel, which indicates that the client receives the message;

17. after receiving the off-line information, the client B sends SIP BYE information to the core network B to end the session and disconnect the MSRP connection;

18. the core network B forwards the message to an IM server B;

19. the IM server B responds to the SIP200OK message to the core network B;

20. the core network B forwards the message to the client B, and the end is connected with the MSRP;

21. optional flow, if the sender requires to obtain the delivery report that the receiver successfully obtains the content of the offline message, the flow is available; flow of sending delivery report see fig. 10 and 11 for a description of the flow of "client B sends offline message delivery report".

And the off-line message acquisition mode is four: as shown in fig. 9, the client B, IM, in which the server B and the core network B are in the same home network of the client B, specifically includes:

6. the client B sends an HTTP request to the IM server B to request to acquire the content of the offline message;

7. the IM server B acquires message contents from an offline message storage server;

8. the IM server B responds to the response message 200OK of the HTTP request to the client B and takes the content of the offline message;

9. optional flow, if the sender requires to obtain the delivery report that the receiver successfully obtains the content of the offline message, the flow is available; flow of sending delivery report see fig. 10 and 11 for a description of the flow of "client B sends offline message delivery report".

The client B may send the offline message delivery report in two ways:

the first delivery report sending mode: client B sends the delivery report by SIP message, as shown in fig. 10, client A, IM server a is in the home network of client a together with core network a; the client B, IM includes a server B and a core network B co-located in a home network of the client B, and specifically includes:

1. after the client B successfully receives the content of the offline message, a response message is returned to the IM server B, and the message contains a delivery report;

2. the IM server B sends SIP NOTIFY information to the core network B, the information contains a delivery report and informs the client B of successfully receiving the information;

3. the core network B forwards the message to the core network A to which the sending end belongs according to the address of the client A which sends the offline message;

4. the core network A forwards the message to the IM server A;

5. after receiving the delivery report, the IM server A responds to the core network A with a SIP200OK message, which indicates that the delivery report is received;

6. the core network A forwards the message to the core network B;

7. the core network B forwards the message to an IM server B;

8. the IM server A sends SIP NOTIFY information to a core network A, and the information comprises a delivery report;

9. the core network A forwards the SIP NOTIFY message to the client A;

10. the client A responds to the SIP200OK message to the core network A, and the delivery report is received;

11. the core network a forwards the SIP200OK message to the IM server a.

Delivery report transmission mode two: the client B sends the delivery report through the MSRP transmission channel, as shown in fig. 11, the client A, IM has the server a and the core network a in the home network of the client a; the client B, IM includes a server B and a core network B co-located in a home network of the client B, and specifically includes:

2. the IM server B establishes an MSRP transmission channel with the IM server A; if an MSRP transmission channel already exists between the two channels, the existing channels can be preferably multiplexed;

3. IM server B sends MSRPREPORT message to IM server A through MSRP transmission channel, reporting successful message received by client B;

4. the IM server A establishes MSRP transmission with a client A; if an AMSRP transmission channel exists between the IM server A and the client, the existing channel can be multiplexed;

5. IM server A transmits MSRP REPORT message to client A through MSRP transmission channel;

6. optional flow, after sending the delivery report, if there is no session to use the MSRP transmission channel between the client a and the IM server a, the channel may be disconnected, or the channel may be maintained for use in subsequent other message transmissions;

7. optionally, after sending the delivery report, if there is no session that needs to use the MSRP transmission channel between IM server a and IM server B, the channel may be disconnected, or the channel may be maintained for use in subsequent other message transmissions.

When the amount of delivery report messages is small, the first way of sending the messages can be adopted, namely, the sending through the SIP messages is more appropriate. But if the MSRP transmission channel is already arranged between the IM server B and the IM server A, the existing MSRP transmission channel is preferably utilized to send the delivery report; if there is no MSRP channel between the two before sending the delivery report, then an MSRP channel needs to be newly established and then the delivery report is transmitted.

Through the above process description, the user can request to obtain the content of the offline message through the SIP message mode, the MSRP transmission channel mode and the HTTP request mode, and the offline message processing process becomes a complete solution by combining the sending and storing processes of the offline message in the prior art. Meanwhile, the invention provides a plurality of acquisition modes, thereby improving the flexibility of selection.

After the user of the receiver of the off-line message successfully receives the instant message, the user of the sender of the message can send a delivery report to the user of the sender of the message in a way of SIP message and a way of MSRP transmission channel. The SIP message mode is suitable for the delivery report with small information quantity, and the MSRP transmission channel mode is suitable for the delivery report with large information quantity. If the MSRP transmission channel is established, the MSRP transmission channel mode is preferably used for reporting the delivery report. The invention ensures that the message sending end can confirm that the receiving end successfully receives the message sent by the message sending end through the sending process of the delivery report, so that the off-line message processing process is more complete, and the service experience of the user is improved.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

1. An off-line message obtaining method is applied to an instant message system which adopts a session initiation protocol SIP/instant message and has a SIMPLE using an extended session initiation protocol, and is characterized in that when a client side is registered in the system and receives an off-line message notice sent by an instant message IM server, the following steps are executed:

B. the IM server sends the off-line message content of the client stored in the system to the client; wherein,

the client requests the IM server to acquire the content of the offline message through the MSRP transmission channel; the IM server issues offline message content to the client through an MSRP transmission channel;

the client SENDs MSRP SEND information through the MSRP transmission channel to request to obtain the content of the off-line information, and the information contains the content type and the corresponding XML content of the extended mark language to indicate the request to obtain the content of the off-line information.

2. The method of claim 1 wherein said client requests offline message content from said IM server via SIP MESSAGE message; and the IM server issues offline message content to the client through a SIP message or a Message Session Relay Protocol (MSRP) transmission channel.

3. The method of claim 2, wherein a header of the sip message sent by the client includes a feature code requesting to obtain the content of the offline message.

4. A method according to claim 2 or 3, wherein SIP MESSAGE messages transmitted between the client and the IM server are forwarded through the core network to which the client belongs.

5. The method of claim 1, wherein the IM server SENDs an MSRP SEND message through an MSRP transmission channel, and SENDs offline message content to the client.

6. The method of claim 1, wherein the client obtains offline message content from the IM server by sending a hypertext transfer protocol, HTTP, request; and the IM server carries the offline message content of the client through the 200OK response message and issues the offline message content to the client.

7. The method of claim 1 further comprising the step of sending an offline message delivery report to a system after the IM server issues the offline message content.

8. The method of claim 7, wherein the IM server sending an offline message delivery report to the system specifically comprises:

9. The method of claim 8, wherein the delivery report is carried by a SIP NOTIFY message.

10. The method of claim 9, wherein step a' comprises:

the step B' comprises the following steps:

11. The method according to claim 8, wherein in step a', the IM server to which the offline message receiving end belongs sends the delivery report through the MSRP transmission channel established between the IM server to which the offline message sending end belongs;

12. The method of claim 11, wherein the MSRP transport channels are established channels or newly established channels.

13. The method of claim 11, wherein the MSRP transmission channel is disconnected or reserved after the delivery report is transmitted.