CN105813228A - Communication method and related device based on SIP over TCP/TLS - Google Patents

Abstract

The present application relates to the communication field, in particular to the communication technology based on SIP over TCP/TLS. In one communication method, after the network is interrupted, both the mobile terminal and the SBC keep the call service on and the SBC does not release the session resources allocated for the mobile terminal. After the network recovers, the SBC uses the association information provided by the mobile terminal to check the validity of the association. If the detection is successful, the SBC uses the session resources allocated for the mobile terminal before the network interruption to initiate periodic registration with the CSCF. After the network recovers, the mobile terminal also sends media stream data to the SBC, so that the SBC can learn the first packet after the detection is successful. In this way, the terminal can implement the call service connection without re-initiating the call, which reduces service interruption time and improves service experience.

Description

Communication method and related device based on SIP over TCP/TLS

technical field

The present invention relates to the technical field of communication, and more specifically, relates to a communication technology based on SIPoverTCP/TLS.

Background technique

With the rapid development of intelligent terminals and VoIP, there are more and more applications of SIP calls based on IMS (IP Multimedia System IP Multimedia Subsystem).

The mobility, data security, and power consumption requirements of smart terminals require the use of SIPOverTCP/TLS. SIPOverTCP/TLS technology also involves Session Border Controller (SBC) and Call Session Control Function (CSCF) network elements.

During the mobile process of the terminal, situations such as flash disconnection, switching (Wifi, 3G/4G mutual switching), returning to the Wifi coverage area from the edge of Wifi (collectively referred to as network interruption) will cause TCP interruption. For SIPOverTCP audio and video calls For services, after TCP is interrupted, the terminal re-initiates registration and services to the SBC. The SBC will use the new contact address Contact header field to register with the CSCF. The CSCF finds out that it is a new ContactID, considers it a remote login, and deletes the existing call service and its session resources. If the call service needs to be continued, the terminal needs to re-initiate the call, which not only consumes traffic, but also increases service delay and greatly reduces user experience.

Contents of the invention

In view of this, the purpose of the embodiments of the present invention is to provide a communication method and related devices based on SIPoverTCP/TLS, so as to realize call service connection and reduce service delay.

On the one hand, the embodiment of the present application provides a communication method based on SIPoverTCP/TLS. In this method, after the network is interrupted, both the mobile terminal and the SBC keep the call service from hanging up, and the SBC does not release the session resources allocated for the mobile terminal. . After the network recovers, the SBC uses the association information provided by the mobile terminal to check the validity of the association. If the detection is successful, the SBC uses the session resources allocated for the mobile terminal before the network interruption to initiate periodic registration with the CSCF. After the network recovers, the mobile terminal also sends media stream data to the SBC, so that the SBC can learn the first packet after the detection is successful. Since the session resources used for periodic registration after recovery are the same as those before the interruption, the CSCF cannot perceive network changes and will not release existing call services. After the network is restored, the media stream can be transmitted immediately, and the new address after the network restoration is obtained through the first packet learning, and the destination address of the media stream sent by the subsequent SBC to the terminal side is also the new address. Since the call service will not be released before the timeout, and the first packet learning is performed again, the call service can be continued without re-initiating the call, and the service interruption time is reduced, and the service experience is improved.

In a possible design, after the association validity detection fails, the SBC reallocates session resources for the terminal, and uses the reallocated session resources to initiate periodic registration with the CSCF. Afterwards, the SBC will use the reallocated session resources to initiate periodic registration with the CSCF. This enables better communication.

In a possible design, no matter whether the association validity detection is successful or not, the SBC generates and returns an association ID used in the next association validity detection. More specifically, the association ID used for the next association validity check may be carried in the successful response message returned by the SBC. Further, taking the successful response message as an example, a nextAssociateId field may be added in the Contact header field of the successful response message, and the value in the nextAssociateId field is an association ID. By adding a new field in the existing SIP message to carry the association ID, the SBC process is simple and does not consume performance, and there is no additional signaling overhead. Alternatively, the above-mentioned association ID used for the next association legality detection may also be carried in the newly added SIP message returned by the SBC. This design does not need to change the format of the original SIP message. In one example, the association ID may be callID or servicecookie. In another example, the association ID may be generated by the SBC according to a set generation rule.

In a possible design, the SBC obtains the associated information by receiving a registration message carrying the associated information or a newly added SIP message carrying the associated information. More specifically, there may be an associateId field in the registration message or the new SIP message, and the field value is associated information. In this way, call connection can be realized better.

In a possible design, the above association legality detection may include: searching for a corresponding session resource according to the association ID, if found, the association legality detection is successful, otherwise, the association legality detection fails. In this way, call connection can be realized better.

In a possible design, the associated information also includes an MD5 value; the MD5 value is obtained by the terminal performing MD5Hash operation on a random password, and the random password is assigned to the SBC together with the associated ID before the network is interrupted. of the terminal. The SBC obtains the association information by receiving the RTCP message carrying the association information. In this embodiment, the RTCP message is used to activate the SBC to relearn the first packet of the media stream, which can reduce the disconnection time of the call after the recovery of the network flash disconnection.

In a possible design, the above association legality detection may include: searching for the corresponding session resource according to the association ID; performing MD5 verification on the MD5 value in the above RTCP message; if the corresponding session resource is found and the MD5 verification is successful, Then the association legality detection is successful, otherwise the association legality detection fails. The introduction of MD5 verification can improve the security of call connection.

In one possible design, the SBC will also generate and return an association ID and a random password to be used in the next association legitimacy check. As an example, the association ID and the random password may be carried in a SIP message returned by the SBC, for example, a successful response message (200OK message) or a new SIP message. More specifically, a nextAssociateId field may be added to the Contact header field of 200OK, and the value in the nextAssociateId field is an association ID. By adding a new field in the existing SIP message to carry the association ID, the SBC process is simple and does not consume performance, and there is no additional signaling overhead.

On the other hand, an embodiment of the present invention provides an SBC, and the SBC has a function of realizing the behavior of the SBC in practice of the above method. The functions described above may be implemented by hardware, or may be implemented by executing corresponding software on the hardware. The hardware or software includes one or more modules corresponding to the above functions.

In a possible design, the structure of the SBC includes: a processor and a memory, and the processor executes the above method by running a software program stored in the memory and calling data stored in the memory.

In yet another aspect, an embodiment of the present invention provides a terminal, and the terminal has a function of implementing the CSU behavior in practice of the above method. The functions described above may be implemented by hardware, or may be implemented by executing corresponding software on the hardware. The hardware or software includes one or more modules corresponding to the above functions.

In a possible design, the structure of the terminal includes: a processor, a memory, and the processor executes the software program stored in the memory and calls the data stored in the memory to at least execute: after the network is interrupted , keep the call service on the terminal side from being released; after the network recovers, send association information to the SBC; the association information is used for the SBC to perform association legality detection, wherein the association information includes at least an association ID, and the association The ID indicates the session resource allocated by the SBC to the terminal before the network interruption, and after the association validity detection succeeds, the session resource indicated by the association ID will be used by the SBC to initiate periodic registration with the CSCF; After the network recovers, transmit the media stream data corresponding to the call service to the SBC, the media stream data is sent with a new address, and the first packet in the media stream data is used for the SBC to learn the new address.

In yet another aspect, an embodiment of the present invention provides a computer storage medium for storing computer software instructions used by the above-mentioned SBC, which includes a program designed to execute the above-mentioned aspect.

In another aspect, an embodiment of the present invention provides a computer storage medium for storing computer software instructions used by the above-mentioned terminal, which includes a program designed for executing the above-mentioned aspect.

In the embodiment of the present invention, after the network is interrupted, both the mobile terminal and the SBC keep the call service without hanging up, and the SBC does not release the session resource allocated for the mobile terminal. After the network is restored, the mobile terminal provides association information to the SBC, and the SBC uses the association information to perform association legality detection. If the detection is successful, the SBC uses the session resources allocated for the mobile terminal before the network interruption to initiate periodic registration with the CSCF. Since the session resources used for periodic registration after recovery are the same as those before the interruption, the CSCF cannot perceive network changes and will not release existing call services. After the network is restored, the media stream can be transmitted immediately, and the new address after the network restoration is obtained through the first packet learning, and the destination address of the media stream sent by the subsequent SBC to the terminal side is also the new address. Since the call service will not be released before the timeout, and the first packet learning is performed again, the call service can be continued without re-initiating the call, and the service interruption time is reduced, and the service experience is improved.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

FIG. 1 is a schematic diagram of an application scenario provided by an embodiment of the present invention;

Fig. 2a-2b, Fig. 3, Fig. 4a-4c, Fig. 5a-5b, Fig. 6 are interactive example diagrams of the communication method based on SIPoverTCP/TLS provided by the embodiment of the present invention;

Figure 7a and Figure 7b are schematic diagrams of a possible structure of an SBC provided by an embodiment of the present invention;

FIG. 8 is a schematic diagram of a possible structure of a terminal provided by an embodiment of the present invention;

FIG. 9 is a schematic diagram of another possible structure of an SBC or a terminal provided by an embodiment of the present invention.

detailed description

The embodiment of the present invention provides a communication method and a related device based on SIPoverTCP/TLS, so as to realize the call service connection after the network recovery, and at the same time, do not reduce the processing performance of the SBC or other IMS network elements.

The related devices involved in the embodiment of the present invention include a mobile terminal, an SBC and a CSCF.

Figure 1 shows an application scenario of the above-mentioned mobile terminal (MB), SBC and CSCF: the mobile terminal recovers after being interrupted during the movement process, such as network disconnection or network switching, and its public network address changes from IP1 to IP2.

It should be noted that FIG. 1 exemplarily shows one mobile terminal, and in an actual application scenario, the number of mobile terminals is not limited to one, and there may be more. In addition, the change of the IP network accessed by the mobile terminal can also be considered as network switching.

Among them, the mobile terminal is mainly responsible for logging in to the server, initiating a call, and sending audio and video RTP media streams.

The SBC is mainly responsible for terminal access signaling and media agency.

The CSCF is mainly responsible for user login and signaling control during multimedia call session processing.

It should be noted that the SIP protocol is a Client/Server protocol, so SIP messages can be specifically divided into two types: request messages and response messages.

The SIP request message that the present invention relates to is as follows:

INVITE: Indicates that the calling user initiates a session request and invites other users to join a session. It can also be used to update the session after the call is established (the INVITE is also called Re-invite at this time);

ACK: confirms that the final response to the INVITE request has been received;

REGISTER: Indicates to register the address information listed in the To field.

The response message in the SIP protocol is used to respond to the request message, indicating the success or failure status of the call. The response message involved in the present invention is as follows:

200: Successful response (OK);

401: Unauthorized (Unauthorized).

The embodiments of the present invention will be further described in detail below based on the above-mentioned common aspects involved in the present invention.

An embodiment of the present invention provides a communication method based on SIPoverTCP/TLS, and a mobile terminal, BSC, and CSCF based on this method.

The solution provided by the embodiment of the present invention will be described below with reference to Fig. 2a and Fig. 3 .

Figure 2a is an interactive schematic diagram of the communication method provided by the embodiment of the present invention, which generally includes several sub-processes: initial registration process, call process, network interruption process, re-registration process after network recovery, and call connection process.

Figure 3 shows signaling interaction.

Among them, the initial registration process may include the following parts:

Part 200: The terminal (UE) uses SipOverTcp/TLS to register according to the standard procedure.

The SYN and ACK messages in Figure 3 reflect the TCP link building process.

In the initial registration part, the SBC will allocate session resources for the terminal, the session resources include contactID (represented by contactID1 in Figure 3), and initiate periodic registration to the CSCF (initiate a REGISTER message, which includes contactID1).

It should be noted that periodic registration is used to maintain the registration session, which is equivalent to heartbeat.

During the initial registration, the signaling for the interaction among the three involves the REGISTER message, 401 response message and 200OK message.

Part 201: After the registration is successful, the SBC returns the association identification (ID) to the terminal.

Specifically, the association ID may be carried in a SIP message returned by the SBC, for example, a successful response message (200OK message). Specifically, a nextAssociateId field may be added to the Contact header field of 200OK, and the value in the nextAssociateId field is an association ID. By adding a new field in the existing SIP message to carry the association ID, the SBC process is simple and does not consume performance, and there is no additional signaling overhead.

In addition, the association ID can also be carried in the newly added SIP message. Further, the nextAssociateId field can be set in the Contact header field of the newly added SIP message, and the value in the nextAssociateId field is the association ID. At this point, it is necessary to redefine the detection interface and associated information. In this way, the original SIP message format will not be changed.

The association ID may indicate the session resource allocated by the SBC to the terminal, or in other words, the association ID represents the correspondence between the terminal and the session resource allocated by the SBC.

The association ID can be used for the next association legality detection, which will be introduced later in this article.

The SBC can generate an association ID according to the set generation rules and return it to the terminal. In fact, the terminal only transparently transmits the association ID, and the SBC can customize the content of the association ID.

The calling process is reflected in the 202 part. Reference may be made to existing technologies such as call establishment and media stream data transmission, and details are not described here. It should be noted that the current address of the media stream data is IP1. After a subsequent network outage and recovery, its address will be changed to IP2.

The address here specifically refers to the IP address of the public network NAT corresponding to the terminal. In fact, most terminals send messages in the wifi scenario, and the IP address used is a private network IP address. After the media stream or data sent by the terminal reaches the public network, it will correspond to the IP address of the public network NAT. This address is initially SBC and The terminal does not know. The SBC needs to learn the IP header of the media stream or data (that is, the initial few IP packets), obtain the IP address of the public network NAT corresponding to the terminal, and record it.

Call procedure signaling involves at least an INVITE message and a 200OK message.

The network interrupt handling process may include the following parts:

Part 203: After the network is interrupted, the terminal does not immediately release the call on the terminal side (holding VoIP), the purpose of which is to keep the call from hanging up.

More specifically, the terminal can keep the existing call service on the terminal side for 15-30 seconds (or longer or shorter) without releasing it.

Section 204: After the SBC detects an abnormal TCP on the terminal side, it does not release the corresponding session resources before waiting for a timeout, and at the same time keeps the call service corresponding to the terminal from being released (that is, the call does not hang up).

In part 204, the association ID corresponding to the terminal is not released before the waiting timeout.

In other embodiments of the present invention, if the wait times out, the SBC will release the associated ID, session resource and call service corresponding to the terminal.

Specifically, since the terminal generally sends media streams during a normal call, the SBC can release the associated ID, session resource, and call service after no media stream times out, and does not release the associated ID before no media stream times out , session resources and call services.

Of course, if the SBC detects no abnormality, the association ID remains unchanged.

The re-registration process after network recovery may include the following parts:

Part 205: After the network is restored, the terminal initiates the registration.

In an example, referring to FIG. 3 , the association ID allocated by the SBC may be carried in the registration message. More specifically, an associateId field may be added in the REGISTER message, and the value of the field is the value in the nextAssociateId field of part 201.

In another example, a newly added SIP request message may also be used to carry the association ID. More specifically, the associateId field can be set in the newly added SIP message, and the value of the field is the value in the nextAssociateId field of the 201 part.

Part 206: SBC uses association ID for association legality detection.

More specifically, the SBC can search for the corresponding session resource according to the association ID. If found, the association legality detection is successful; otherwise, the association legality detection fails.

Part 207: If the association legality detection is successful, the SBC initiates periodic registration with the CSCF using the session resource indicated by the association ID.

More specifically, the SBC will use the previous ContactID1 to initiate periodic registration with the CSCF. Because the ContactID1 remains unchanged before and after the network interruption, the CSCF cannot perceive the network change and will not release the existing call.

In other embodiments of the present invention, referring to FIG. 2 b , if the detection of association validity fails, the SBC will re-allocate session resources for the terminal (section 2071 ). As mentioned above, the session resource includes contactID, and the reallocated contactID may be called contactID2.

Afterwards, the SBC will use the reallocated session resource (contactID2) to initiate a periodic registration with the CSCF (section 2072).

Section 208: The SBC generates and returns an association ID to be used in the next association validity check.

In an example, the SBC may carry the association ID used in the next association validity check in the nextAssociateId of the registered 200OK. In addition, 200OK may also carry an association legality detection flag assFlag, which is used to notify the terminal whether the association legality detection is successful.

It should be noted that no matter whether the association legality detection is successful or not, the SBC will generate and return the association ID used in the next association legality detection.

The call connection process may include the following parts:

Part 209: The terminal transmits the media stream data corresponding to the call service.

In an example, the terminal may transmit the media stream data corresponding to the call service after confirming that the detection of association validity is successful.

As mentioned above, the 200OK may carry the association legality detection flag assFlag, which is used to notify the terminal whether the association legality detection is successful. The terminal can confirm whether the association legality detection is successful according to the assFlag.

In another example, the terminal may also send the association information and the media stream data at the same time, and the terminal stops sending the media stream data after confirming that the detection of association validity fails. Those skilled in the art can flexibly design according to actual needs.

It should be noted that before the network interruption, the current address of the media streaming data is IP1, and in part 209, the address is changed to IP2, which is the new address.

Part 210: SBC learns the first packet of media stream data to obtain a new address.

More specifically, the SBC will find the relevant call service according to the current user number of the mobile terminal, support receiving the media stream data of the call service from the new address, learn the first packet of the media stream data, and obtain the new address.

Afterwards, the SBC will receive the relevant data of the above-mentioned call service at the new address. The destination address of the media stream sent by the SBC to the terminal side is also the new address.

The first package learning is a relatively mature technology, so I won't repeat it here.

Part 211: The terminal initiates a re-Invite and maintains the original call.

The re-invite is initiated to maintain the session heartbeat of the call, and try to keep the information on the terminal and the server side consistent.

It should be noted that there is also a re-Invite process in the prior art, but it is driven by a timer and may have to wait for a long time. In this embodiment, the re-Invite is initiated after the network recovers.

It should be noted that after the association validity detection fails, the SBC will no longer perform the first packet learning, and the call will be interrupted. Therefore, referring to FIG. 2 b , after confirming that the association validity detection fails, the terminal will not initiate a re-Invite.

In the embodiment of the present invention, after the network is interrupted, both the mobile terminal and the SBC keep the call service without hanging up, and do not release the session resources allocated for the mobile terminal. After the network is restored, the mobile terminal provides association information to the SBC, and the SBC uses the association information to perform association legality detection. If the detection is successful, the SBC uses the session resources allocated for the mobile terminal before the network interruption to initiate periodic registration with the CSCF. Since the session resources used for periodic registration after recovery are the same as those before the interruption, the CSCF will not be aware of network changes and will not release existing call services. After the network is restored, the media stream can be transmitted immediately, and the new address after the network restoration is obtained through the first packet learning, and the destination address of the media stream sent by the SBC to the terminal side is also the new address. Since the call service will not be released before the timeout, and the first packet learning is performed again, the call service can be continued without re-initiating the call, and the service interruption time is reduced, and the service experience is improved.

In other embodiments of the present invention, session information can also be used as the associated ID, for example, CallID (CallID is a random character string generated according to certain rules) or servicecookie (server-side session mapping information) can be used as the associated ID.

Please refer to another interaction flow shown in Figure 4a and Figure 4b:

In part 400: the terminal (UE) uses SipOverTcp/TLS to register according to the standard procedure.

Figure 4b shows signaling interaction.

Section 400 is similar to Section 200 and will not be repeated here.

It should be noted that, if CallID is used as the association ID, the SBC does not need to generate the association ID specifically, nor does it need to add the nextAssociateId field in the returned SIP message as in the embodiment (part 201) shown in Figure 2a, 2b and Figure 3 .

Section 401: The terminal initiates the call.

Reference may be made to existing technologies such as call establishment and media stream data transmission, and details are not described here.

Part 402: After the network is interrupted, the terminal does not immediately release the call on the terminal side (holding VoIP), the purpose of which is to keep the call from hanging up.

Part 402 is similar to part 203, and will not be repeated here.

Part 403: After the SBC detects that the TCP on the terminal side is abnormal, it does not release the corresponding session resources before waiting for a timeout, and at the same time keeps the call service corresponding to the terminal from being released (that is, the call does not hang up).

Part 403 is similar to part 204, and will not be repeated here.

Part 404: After the network is restored, the terminal initiates registration.

In the re-registration process, since the CallID needs to be carried in the REGISTER message originally, there is no need to add an associateId field in the REGISTER message as in the embodiment (205 part) shown in Figure 2a, 2b and Figure 3, so Processing of the SBC can be further simplified.

Section 405: the SBC uses the association ID (namely callID) to perform association legality detection.

More specifically, the SBC can search for the corresponding session resource according to the association ID. If found, the association legality detection is successful; otherwise, the association legality detection fails.

Section 406: If the detection of the validity of the association is successful, the SBC uses the session resource indicated by the association ID to initiate periodic registration with the CSCF.

Section 406 is similar to Section 207 and will not be repeated here.

In other embodiments of the present invention, referring to Fig. 4c, if the detection of association validity fails, the SBC will re-allocate session resources for the terminal (section 2061). As mentioned above, the session resource includes contactID, and the reallocated contactID may be called contactID2.

Afterwards, the SBC will use the reallocated session resource (contactID2) to initiate periodic registration with the CSCF (section 2062).

Section 407: The SBC returns a SIP message.

The SIP message may carry an association legality detection flag assFlag, which is used to notify the terminal whether the association legality detection is successful.

Part 408: the terminal transmits the media stream data corresponding to the call service.

In an example, the terminal may transmit the media stream data corresponding to the call service after confirming that the association legality detection is successful, and after confirming that the association legality detection fails, the terminal will not start transmitting the media stream data corresponding to the call service operation (Fig. 4c).

In another example, the terminal may also send the association information and the media stream data at the same time, and after confirming that the association validity detection fails, the terminal stops sending the media stream data. Those skilled in the art can flexibly design according to actual needs.

Part 409: If the association legality detection is successful, the SBC learns the first packet of the media stream data to obtain a new address.

Section 409 is similar to Section 210 and will not be repeated here.

Part 410: If the association legality detection is successful, the terminal initiates a re-Invite and maintains the original call.

Section 410 is similar to Section 211, and will not be repeated here.

Figure 5a and Figure 6 show another exemplary interaction flow of the above-mentioned communication method (Figure 6 embodies the signaling interaction involved in the interaction flow shown in Figure 5a), which generally includes several sub-processes: initial registration process, call process, network interruption processing process, first packet re-learning process after network recovery, and call connection process. Figure 6 shows signaling interaction. It should be noted that the interaction between the SBC and the CSCF is the same as that of all the foregoing embodiments, therefore, the interaction between the SBC and the CSCF is omitted in FIGS. 5 a and 6 , and for relevant details, refer to all the foregoing embodiments.

Among them, the initial registration process may include the following parts:

Part 500: The terminal (UE) uses SipOverTcp/TLS to register according to the standard procedure.

In the initial registration part, the SBC will allocate session resources for the terminal, and initiate periodic registration to the CSCF (initiate a REGISTER message, which includes contactID).

After the periodic registration is successful, the SBC will return a 200OK message.

Different from the initial registration process shown in Fig. 2a, 2b and Fig. 3, in the initial registration process of this embodiment, the association ID is not returned, but the association ID is returned during the calling process.

The call process includes at least the following parts:

Part 501: After successful registration, the terminal sends an INVITE message to the SBC to establish a call;

Section 502: The SBC generates and returns an association ID and a random password (pwd) to the terminal.

The association ID and the random password can be carried in the SIP message returned by the SBC, for example, a successful response message (200 OK for invite message). Specifically, a nextAssociateId field may be added to the Contact header field of 200OK, and the value in the nextAssociateId field is an association ID and a random password (pwd). By adding a new field in the existing SIP message to carry the association ID and the random password (pwd), the SBC process is simple without consuming performance, and there is no additional signaling overhead.

In addition, the association ID and the random password can also be carried in the newly added SIP message. Further, the nextAssociateId field can be set in the Contact header field of the newly added SIP message, and the values in the nextAssociateId field are the association ID and the random password. At this point, it is necessary to redefine the detection interface and associated information. In this way, the original SIP message format will not be changed.

The SBC can generate an associated ID according to a set generation rule. The terminal only transparently transmits the association ID, and the SBC can customize the content of the association ID. In this embodiment, the association ID is server-cookie. For other related content of the association ID, please refer to the introduction of the aforementioned section 201, and details are not repeated here.

The network interrupt handling process may include the following parts:

Part 503: After the network is interrupted, the terminal does not immediately release the call on the terminal side (holding VoIP), the purpose of which is to keep the call from hanging up.

Section 504: After the SBC detects an abnormal TCP on the terminal side, it does not release the corresponding session resource and associated ID before waiting for a timeout, and at the same time keeps the call service corresponding to the terminal from being released (that is, the call does not hang up).

Parts 503-504 are the same as parts 203-204, and will not be repeated here.

It should be noted that, for the sake of simplicity, the network interruption processing process is omitted in FIG. 6 .

The first packet relearning process after the network recovery includes at least the following parts:

Section 505: the terminal sends an RTCP (Real-Time Transport Control Protocol) message carrying associated information to the SBC.

Steps 1, 2, and 4 in the first packet relearning process shown in FIG. 6 are standard protocol flows, where Nonce and nextnonce are used for authentication during registration. The third process corresponds to "the terminal sends an RTCP message carrying associated information to the SBC".

Association information includes association ID and MD5 value (that is, MD5-Auth). Wherein, the MD5 value is obtained by the terminal performing MD5Hash operation on the random password obtained during the calling process.

More specifically, an associateId field can be added in the RTCP message, and the field value is the associated ID and MD5 value returned in the 502 part.

Section 506: At the same time, the terminal sends the media stream corresponding to the calling service to the SBC.

It should be noted that, before the network is interrupted, the current address of the media stream data is IP1, and after recovery, the address is changed to IP2.

The address here specifically refers to the IP address of the public network NAT corresponding to the terminal. In fact, most terminals send messages in the wifi scenario, and the IP address used is a private network IP address. After the media stream or data sent by the terminal reaches the public network, it will correspond to the IP address of the public network NAT. This address is initially SBC and The terminal does not know. The SBC needs to learn the IP header (that is, the first packet) of the media stream or data, and obtain the IP address of the public network NAT corresponding to the terminal.

Part 507: SBC uses association ID and MD5 value to perform association legality detection.

Specifically, the SBC searches for the corresponding session resource according to the association ID, and performs MD5 verification on the MD5 value in the RTCP message; if the corresponding session resource is found and the MD5 verification is successful, the association validity detection is successful; otherwise, the association validity Detection failed.

Among them, MD5 verification can include:

The SBC uses the random password previously assigned to the terminal to perform MD5 Hash calculation to obtain the MD5 value. To distinguish it from the MD5 value sent by the terminal, the MD5 value generated by the terminal and sent to the SBC may be called the first MD5 value, and the MD5 generated by the SBC may be called the second MD5 value.

The SBC compares the first MD5 value with the second MD5 value, and if the two are equal, the MD5 verification succeeds, otherwise the MD5 verification fails.

Part 508: If the association legality detection is successful, the SBC supports receiving media stream data from a new address, relearns the first packet of the media stream data, and obtains a new address.

In an example, after the association validity detection is successful, the SBC will also use the session resource indicated by the association ID to initiate periodic registration with the CSCF.

In other embodiments of the present invention, please refer to FIG. 5 b , if the detection of association validity fails, the SBC will re-allocate session resources for the terminal (section 5081 ). As mentioned above, the session resource includes contactID, and the reallocated contactID may be called contactID2. Afterwards, the SBC will use the reallocated session resource (contactID2) to initiate a periodic registration with the CSCF (section 5082).

It should be noted that if the association legality detection fails, the SBC will not perform the first packet learning, and discard the received media stream corresponding to the call service of the terminal (section 5083).

Section 509: The terminal initiates a re-Invite and maintains the original call.

Section 510: SBC generates and returns to the terminal the association ID and random password (pwd) used in the next association legality detection.

The association ID and the random password can be carried in the SIP message returned by the SBC, for example, a successful response message (200 OK for invite message). Specifically, a nextAssociateId field may be added to the Contact header field of 200OK, and the value in the nextAssociateId field is an association ID and a random password (pwd). By adding new fields in the existing SIP message to carry the association ID and the random password (pwd), the SBC process is simple and does not consume performance, and can and does not increase signaling overhead.

In addition, the association ID and the random password can also be carried in the newly added SIP message. Further, the nextAssociateId field can be set in the Contact header field of the newly added SIP message, and the values in the nextAssociateId field are the association ID and the random password. At this point, it is necessary to redefine the detection interface and associated information. In this way, the original SIP message format will not be changed.

It should be noted that no matter whether the association legality detection is successful or not, the SBC will generate and return the association ID used in the next association legality detection.

In this embodiment, the RTCP message is used to activate the SBC to relearn the first packet of the media stream, which can reduce the disconnection time of the call after the recovery of the network flash disconnection. In addition, this embodiment introduces MD5 verification, which can improve the security of call connection.

It should be noted that, in order to realize the continuity of the network flash call. Currently, the STG tunnel solution is generally adopted, and this solution requires the establishment of a tunnel between the mobile terminal and the STG server. Among them, the STG server is deployed separately or the SBC has a built-in STG server, and the mobile terminal side needs to be embedded with the STG client. After the program starts, one or more tunnels are established between the mobile terminal and the STG server, and SIP messages and media stream data are transmitted over the tunnels.

When the network recovers, the STG client embedded in the mobile terminal re-establishes the tunnel. The information such as the virtual IP and port provided by the STG client to the service remains the same as before, and the service does not reflect network interruption. In this way, the SIP message and media stream data can continue to be transmitted without being aware of the process of network interruption, thereby achieving call continuity.

However, the cost of deploying the STG server alone is very high. However, the built-in STG server in the SBC will seriously affect the performance of the SBC, causing the ability of the SBC to support it to drop sharply. In addition, in the solution of adopting the STG tunnel, it is necessary to wait for the tunnel to be successfully established before the connection can be made, which increases the time for service interruption.

However, the technical solution provided by the present invention does not need to establish a tunnel, and does not need to deploy an additional STG server or deploy an STG server in the SBC. IMS network elements such as CSCF do not need to perform additional processing, and the SBC does not increase too much processing, so that It will cause the processing performance of the SBC to degrade.

It should be noted that the above technical solutions are also applicable to TLS.

The foregoing mainly introduces the solutions provided by the embodiments of the present invention from the perspective of interaction between various devices. It can be understood that, in order to realize the above-mentioned functions, each device, such as SBC, terminal, etc., includes a corresponding hardware structure and/or software module for performing each function. Those skilled in the art should easily realize that the present invention can be realized in the form of hardware or a combination of hardware and computer software in combination with the units and algorithm steps of each example described in the embodiments disclosed herein. Whether a certain function is executed by hardware or computer software drives hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art may use different methods to implement the described functions for each specific application, but such implementation should not be regarded as exceeding the scope of the present invention.

Figure 7a shows a possible structural schematic diagram of the SBC involved in the above embodiment, including:

The holding unit 701 is configured to keep the session resource corresponding to the terminal from being released and keep the call service corresponding to the terminal from being released after the network interruption is detected and before the waiting timeout;

Wherein, the above-mentioned session resource is allocated to the terminal by the SBC before the network is interrupted; and the terminal will keep the call service on the terminal side from being released after the network is interrupted.

The first receiving unit 702 is configured to receive association information from the above-mentioned terminal, where the above-mentioned association information includes at least an association ID, and the above-mentioned association ID indicates the session resources allocated by the above-mentioned SBC to the above-mentioned terminal before the network interruption;

An association legality detection unit 703, configured to use the above association information to perform association legality detection;

A registration unit 704, configured to use the session resource indicated by the above-mentioned association ID to initiate periodic registration with the CSCF when the association legality detection is successful;

The second receiving unit 705 is configured to receive the media stream data corresponding to the above call service; the above media stream data is sent with a new address;

The learning unit 706 is configured to learn the first packet of the media stream data to obtain the new address.

In other embodiments of the present invention, referring to FIG. 7 b , the SBC may further include a generation unit 707 configured to generate and return an association ID used in the next association validity check.

Wherein, the holding unit 701 can be used to execute part 204 shown in Figures 2a and 2b, part 403 shown in Figures 4a and 4c, and part 504 shown in Figures 5a and 5b.

The first receiving unit 702 may be configured to receive association information sent by the terminal in part 205 shown in Figures 2a and 2b, part 404 shown in Figures 4a and 4c, and part 505 shown in Figures 5a and 5b.

The second receiving unit 705 can be used to receive the media stream data sent by the terminal in part 209 shown in Figure 2a, part 408 shown in Figure 4a, and part 506 shown in Figures 5a and 5b, and receive the media stream data sent by the terminal in other embodiments media stream data.

The association legality detection unit 703 can be used to execute part 206 shown in Figures 2a and 2b, part 405 shown in Figures 4a and 4c, and part 507 shown in Figures 5a and 5b.

The registration unit 704 can be used to execute part 200 and part 207 shown in Figure 2a, part 200, part 2071 and part 2072 shown in Figure 2b, part 400 and part 406 shown in Figure 4a, part 400 shown in Figure 4c, Part 4061 and part 4062, part 500 shown in Figure 5a, part 500, part 5081 and part 5082 shown in Figure 5b.

The learning unit 706 can be used to execute part 210 shown in FIG. 2a, part 409 shown in FIG. 4a, part 508 shown in FIG. 5a, and part 5084 shown in FIG. 5b.

The generating unit 707 can be used to execute part 201 and part 208 shown in Figure 2a and 2b, part 502 and part 510 shown in Figure 5a, part 502 and part 5083 shown in Figure 5b, in addition, the generating unit can also be used to execute Section 407 shown in 4a and 4c.

Fig. 8 shows a possible structural schematic diagram of a terminal involved in the above embodiment, including:

The holding unit 801 is configured to keep the call service on the terminal side from being released after the network is interrupted;

The first sending unit 802 is configured to send associated information to the SBC after the network is restored;

The above-mentioned association information is used for the above-mentioned SBC to perform association legality detection, wherein the above-mentioned association information includes at least an association ID, and the above-mentioned association ID indicates the session resources allocated by the above-mentioned SBC to the above-mentioned terminal before the network is interrupted. After the association legality detection is successful, The session resource indicated by the above-mentioned association ID will be used by the above-mentioned SBC to initiate periodic registration with the CSCF;

The second sending unit 803 is configured to transmit the media stream data corresponding to the above-mentioned call service to the above-mentioned SBC after the network is restored, the above-mentioned media stream data is sent with a new address, and the first packet in the above-mentioned media stream data is used for the above-mentioned SBC to learn the above-mentioned new address.

Wherein, the holding unit 801 can be used to execute part 203 shown in Figures 2a and 2b, part 402 shown in Figures 4a and 4c, and part 503 shown in Figures 5a and 5b.

The first sending unit 802 may be configured to execute part 209 shown in FIG. 2a, part 404 shown in FIGS. 4a and 4c, and part 505 shown in FIGS. 5a and 5b.

The second sending unit 803 may be used to execute part 205 shown in Figures 2a and 2b, part 408 shown in Figure 4a, part 506 shown in Figures 5a and 5b, and part 5085 shown in Figure 5b.

In other embodiments of the present invention, the above-mentioned terminal may further include a call unit, configured to complete call establishment and send media stream data during the call. The call unit can be used to implement part 202 and part 211 shown in Figure 2a, part 202 shown in Figure 2b, part 401 and 410 shown in Figure 4a, part 401 shown in Figure 4c, part 501 shown in Figure 5a and part 509, part 501 shown in Figure 5b.

Fig. 9 shows another possible structural diagram of the SBC/terminal involved in the above embodiment, including:

bus, controller/processor 1, memory 2, communication interface 3, input device 4 and output device 5. The processor 1, the memory 2, the communication interface 3, the input device 4 and the output device 5 are connected to each other through a bus. in:

A bus may include a pathway that carries information between various components of a computer system.

The controller/processor 1 may be a general-purpose processor, such as a general-purpose central processing unit (CPU), a network processor (Network Processor, NP for short), a microprocessor, etc., or an application-specific integrated circuit (ASIC). , or one or more integrated circuits for controlling the program execution of the solution of the present invention. It can also be a digital signal processor (DSP), an application specific integrated circuit (ASIC), an off-the-shelf programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, and discrete hardware components. The controller/processor 1 can also be a combination that realizes computing functions, for example, a combination of one or more microprocessors, a combination of DSP and a microprocessor, and the like.

The program for executing the technical solution of the present invention is stored in the memory 2, and an operating system and other application programs may also be stored. Specifically, the program may include program code, and the program code includes computer operation instructions. More specifically, the memory 2 may be a read-only memory (read-only memory, ROM), other types of static storage devices that can store static information and instructions, random access memory (random access memory, RAM), or other types that can store information and instructions. Types of dynamic storage devices, disk storage, and so on.

The input device 4 may include a device for receiving data and information input by a user, such as a keyboard, a mouse, a camera, a scanner, a light pen, a voice input device, a touch screen, and the like.

The output device 5 may comprise a device that allows information to be output to a user, such as a display screen, a printer, a speaker, and the like.

The communication interface 3 may include using any means such as transceivers to communicate with other devices or communication networks, such as Ethernet, Radio Access Network (RAN), Wireless Local Area Network (WLAN) and the like.

The controller/processor of the SBC may be used to perform the processes in FIGS. . The controller/processor can also be used to realize the functions of the maintaining unit 701 , the first receiving unit 702 , the association legality detecting unit 703 , the registering unit 704 , the second receiving unit 705 , the learning unit 706 and the generating unit 707 .

The communication interface of the SBC is used to support the communication between the SBC and other devices. For example, to support the OBU to communicate with other devices shown in Figures 2a-2b, Figure 3, Figures 4a-4c, Figures 5a-5b, Figure 6.

The terminal's controller/processor can be used to perform the processes in FIGS. . The controller/processor of the RSU can also be used to realize the functions of the holding unit 801, the first sending unit 802, the second sending unit 803 and the calling unit.

The communication interface of the terminal is used to support the terminal to communicate with other devices. For example, it is used to support the terminal to communicate with other devices shown in FIGS. 2a-2b, 3, 4a-4c, 5a-5b, and 6.

It can be understood that Fig. 9 only shows a simplified design of an SBC or a terminal. In practical application, SBC or terminal can contain any number of transmitters, receivers, processors, controllers, memories, communication interfaces, etc., and all SBC or terminals that can realize the present invention are within the protection scope of the present invention .

The steps of the methods or algorithms described in conjunction with the disclosure of the present invention may be implemented in the form of hardware, or may be implemented in the form of a processor executing software instructions. The software instructions can be composed of corresponding software modules, and the software modules can be stored in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, mobile hard disk, CD-ROM or any other form of storage known in the art medium. An exemplary storage medium is coupled to the processor such the processor can read information from, and write information to, the storage medium. Of course, the storage medium may also be a component of the processor. The processor and storage medium can be located in the ASIC. Additionally, the ASIC may be located in the user equipment. Of course, the processor and the storage medium may also exist in the user equipment as discrete components.

Those skilled in the art should be aware that, in the above one or more examples, the functions described in the present invention may be implemented by hardware, software, firmware or any combination thereof. When implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a general purpose or special purpose computer.

The specific embodiments described above have further described the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention and are not intended to limit the scope of the present invention. Protection scope, any modification, equivalent replacement, improvement, etc. made on the basis of the technical solution of the present invention shall be included in the protection scope of the present invention.

Claims (26)

1. A call method based on SIPoverTCP/TLS, characterized in that, comprising: After the SBC detects that the network is interrupted and before waiting for a timeout, the session resource corresponding to the terminal is not released, and the call service corresponding to the terminal is not released; wherein, the session resource is allocated by the SBC to the terminal before the network is interrupted. the terminal; the terminal keeps the call service on the terminal side from being released after the network is interrupted; The SBC receives association information from the terminal, the association information includes at least an association ID, and the association ID indicates the session resources allocated by the SBC to the terminal before the network interruption; The SBC uses the association information to perform association legality detection; If the association legality detection is successful, the SBC initiates periodic registration to the CSCF using the session resource indicated by the association ID; The SBC receives media stream data corresponding to the call service; the media stream data is sent with a new address; The SBC learns the first packet of the media stream data to obtain the new address. 2. The method of claim 1, further comprising: If the association validity detection fails, the SBC reallocates session resources for the terminal, and uses the reallocated session resources to initiate periodic registration with the CSCF. 3. The method according to claim 1, wherein the association legality detection comprises: searching for a corresponding session resource according to the association ID, if found, the association legality detection is successful, otherwise the association legality detection fails . 4. The method according to claim 3, wherein the receiving the association information from the terminal comprises: receiving a registration message or a new SIP message carrying the association information. 5. The method according to claim 1, further comprising: the SBC generates and returns an association ID used in the next association legality detection. 6. The method according to claim 1, wherein the receiving associated information from the terminal comprises: receiving the RTCP message carrying the associated information, the associated information also includes an MD5 value; the MD5 value is obtained by the terminal performing MD5Hash operation on a random password, and the random password is obtained by the SBC together with the The association ID is assigned to the terminal together. 7. The method according to claim 6, wherein the association legality detection comprises: Searching for a corresponding session resource according to the association ID; Carry out MD5 verification to the MD5 value in the RTCP message; If the corresponding session resource is found and the MD5 verification is successful, then the association legality check is successful; otherwise, the association legality check fails. 8. The method according to claim 7, further comprising: the SBC generates and returns an association ID and a random password used in the next association validity check. 9. The method of claim 5 or 8, wherein, The association ID used for the next association legality detection is carried in the success response message returned by the SBC or in the new SIP message; or, The association ID and random password used for the next association legality detection are carried in the success response message or the new SIP message returned by the SBC. 10. The method according to claim 1, wherein the association ID is callID or servicecookie. 11. A communication method based on SIPoverTCP/TLS, characterized in that, comprising: After the terminal is disconnected from the network, the call service on the terminal side will not be released; After the network recovers, the terminal sends association information to the SBC; the association information is used by the SBC to perform association legality detection, wherein the association information includes at least an association ID, and the association ID indicates that the SBC is in The session resource allocated to the terminal before the network interruption, after the association legality detection is successful, the session resource indicated by the association ID will be used by the SBC to initiate periodic registration with the CSCF; After the network recovers, the terminal transmits media stream data corresponding to the call service to the SBC, the media stream data is sent with a new address, and the first packet in the media stream data is used by the SBC to learn the State the new address. 12. The method according to claim 11, wherein the sending the association information to the SBC comprises: sending a registration message or a new SIP message carrying the association information to the SBC. 13. The method according to claim 11, wherein the sending associated information to the SBC comprises: The terminal sends an RTCP message carrying the association information to the SBC; The associated information also includes an MD5 value; the MD5 value is obtained by the terminal performing an MD5Hash operation on a random password, and the random password is assigned to the terminal together with the associated ID by the SBC before the network is interrupted . 14. A session border controller SBC, characterized in that, comprising: The holding unit is configured to keep the session resources corresponding to the terminal from being released after the network interruption is detected and before waiting for a timeout, and keep the call service corresponding to the terminal from being released; previously assigned to the terminal; the terminal keeps the call service on the terminal side from being released after the network is interrupted; A first receiving unit, configured to receive association information from the terminal, where the association information includes at least an association ID, and the association ID indicates the session resource allocated to the terminal by the SBC before the network interruption; An association legality detection unit, configured to use the association information to perform association legality detection; A registration unit, configured to use the session resource indicated by the association ID to initiate periodic registration to the CSCF when the association legality detection is successful; The second receiving unit is configured to receive media stream data corresponding to the call service; the media stream data is sent with a new address; The learning unit is configured to learn the first packet of the media stream data to obtain the new address. 15. The SBC according to claim 14, wherein the registration unit is also used for: When the association legitimacy detection fails, re-allocate session resources for the terminal, and use the re-allocated session resources to initiate periodic registration with the CSCF. 16. The SBC according to claim 15, wherein, in terms of association legality detection, the association legality detection unit is configured to: search for a corresponding session resource according to the association ID, if found, the association is legal If the validity check is successful, otherwise the association validity check fails. 17. The SBC according to claim 16, wherein, in terms of receiving associated information from the terminal, the first receiving unit is configured to: receive a registration message carrying the associated information or a newly added SIP messages. 18. The SBC of claim 14, further comprising: The generation unit is used to generate and return the association ID used in the next association legality detection. 19. The SBC according to claim 18, wherein, in terms of receiving associated information from the terminal, the first receiving unit is configured to: receive an RTCP message carrying the associated information, the The associated information also includes an MD5 value; the MD5 value is obtained by the terminal performing MD5 Hash operation on a random password, and the random password is assigned to the terminal together with the associated ID by the generating unit before the network is interrupted. 20. The SBC according to claim 19, characterized in that, in terms of association legality detection, the association legality detection unit is used for: Searching for a corresponding session resource according to the association ID; Carry out MD5 verification to the MD5 value in the RTCP message; If the corresponding session resource is found and the MD5 verification is successful, then the association legality check is successful; otherwise, the association legality check fails. 21. The SBC of claim 18 or 19, wherein, The association ID used for the next association legality detection is carried in the success response message or the new SIP message returned by the generating unit; or, The association ID and random password used for the next association legality detection are carried in the success response message or the newly added SIP message returned by the generating unit. 22. A terminal, characterized in that it comprises: The holding unit is used to keep the call service on the terminal side from being released after the network is interrupted; The first sending unit is configured to send association information to the SBC after the network recovers; the association information is used by the SBC to perform association legality detection, wherein the association information includes at least an association ID, and the association ID indicates The session resources allocated by the SBC to the terminal before the network interruption, after the association legality detection is successful, the session resources indicated by the association ID will be used by the SBC to initiate periodic registration with the CSCF; The second sending unit is configured to transmit media stream data corresponding to the call service to the SBC after the network is restored, the media stream data is sent with a new address, and the first packet in the media stream data is used for all The SBC learns the new address. 23. The terminal according to claim 22, wherein, in terms of sending associated information to the SBC, the first sending unit is configured to: send a registration message or a new registration message carrying the associated information to the SBC Add SIP message. 24. The terminal according to claim 22, wherein, in terms of sending associated information to the SBC, the first sending unit is configured to: sending an RTCP message carrying the associated information to the SBC; The associated information also includes an MD5 value; the MD5 value is obtained by the terminal performing an MD5Hash operation on a random password, and the random password is assigned to the terminal together with the associated ID by the SBC before the network is interrupted . 25. A session border controller SBC, characterized in that it includes a processor and a memory, wherein the processor executes at least Follow the steps below: After detecting network interruption and before waiting for timeout, keep the session resource corresponding to the terminal from being released, and keep the call service corresponding to the terminal from being released; wherein, the session resource is allocated by the SBC to the of the terminal; the terminal keeps the call service on the terminal side from being released after the network is interrupted; receiving association information from the terminal, where the association information includes at least an association ID, and the association ID indicates the session resource allocated to the terminal by the SBC before the network interruption; Using the association information to perform association legality detection; When the association legality detection is successful, use the session resource indicated by the association ID to initiate periodic registration with the CSCF; receiving media stream data corresponding to the call service; sending the media stream data with a new address; Learning the first packet of the media stream data to obtain the new address. 26. A terminal, characterized by comprising a processor and a memory, wherein the processor executes at least the following steps by running a software program stored in the memory and calling data stored in the memory: After the network is interrupted, the call service on the terminal side will not be released; After the network is restored, send association information to the SBC; the association information is used for the SBC to perform association legality detection, wherein the association information includes at least an association ID, and the association ID indicates that the SBC was before the network interruption The session resource allocated to the terminal, after the association validity detection is successful, the session resource indicated by the association ID will be used by the SBC to initiate periodic registration with the CSCF; After the network is restored, transmit the media stream data corresponding to the call service to the SBC, the media stream data is sent with a new address, and the first packet in the media stream data is used for the SBC to learn the new address .