CN100562044C

CN100562044C - Business nesting method based on public switched telephone network (PSTN)

Info

Publication number: CN100562044C
Application number: CNB2006101386512A
Authority: CN
Inventors: 马妍; 厉盛义; 刘晓甲; 黄文利
Original assignee: China United Network Communications Group Co Ltd
Current assignee: China United Network Communications Group Co Ltd
Priority date: 2006-11-08
Filing date: 2006-11-08
Publication date: 2009-11-18
Anticipated expiration: 2026-11-08
Also published as: CN1980290A

Abstract

The present invention discloses a kind of business nesting method based on public switched telephone network (PSTN), and described public switched telephone network (PSTN) adopts the end-remittance office structure of full traffic tandem, and the method comprising the steps of: A) end office (EO) sends to customer call the tandem exchange with Service Switching Point function; B) described tandem exchange with Service Switching Point function sends service inquiry to subscriber data center; C) described subscriber data center returns the information that has service access code, visit indication and called number; D) after described Service Switching Point triggers this business according to described service access code, judge that described visit indicates whether to be Stop message, if not then continue to send service inquiry, execution in step C) to described subscriber data center; E) if described visit indication is a Stop message, described Service Switching Point is removed the visit indication, and by the called number replay call after the described visit indication.Adopt technical scheme of the present invention can distinguish calling and called service.

Description

Business nesting method based on public switched telephone network (PSTN)

Technical field

The present invention relates to field of telecommunications, refer to a kind of business nesting method especially based on public telephone switching network.

Background technology

At present, be subjected to the shunting of mobile and packet voice along with traditional voice transmission, telecommunication market increasingly competitive, especially even more serious for the impact of Public Switched Telephone Network, the growth point of new professional and income is constantly sought by public switched telephone network (PSTN) operator.

The business of public switched telephone network (PSTN) mainly is divided into basic service, supplementary service and IN service three classes.Wherein, basic service and supplementary service all can directly be provided by switch, and basic service comprises local service, long-distance service, fax or the like, and supplementary service comprises calling transfer, Call Waiting or the like; IN service refers to and can not directly be provided and need be passed through external equipment by switch, comprise SSP (Service Switch Point, Service Switching Point) and intelligent service platform SCP (Service Control Point, service control point) business that cooperation could realize, as business such as 300,201,800, and the triggering of IN service needs the user to dial specific access code to realize.

In recent years, because market demand and business innovation, some have occurred and can not dial the IN service that access code is realized by the user, we are referred to as intelligent signing service, such as for caller class business such as fixed prepaid fees, end office (EO) can not the identification services attribute, the IN service of no access code can't be triggered up; And for shaking, please called class business such as bell, because service attribute is with called relevant, giving orders or instructions end office (EO) and middle switch all can't its service attribute of perception, can not before calling is landed, SSP be delivered in calling and carry out the corresponding business triggering and handle, make the called series intelligent service of the whole network can't carry out substantially.Therefore, the whole network that the traditional PSTN network at first will solve intelligent signing service (comprising caller signing service and called signing service) triggers problem, makes all users of local network can both apply for and use the signing service of being opened.

In addition, because public switched telephone network (PSTN) operator has developed multiple intelligent signing service, just may have professional situation such as a plurality of IN service of user applies, basic service and an intelligent signing service, therefore, the traditional PSTN net also will solve the problem of business nesting.How solving the problem of business nesting in public switched telephone network (PSTN), is one of important topic of present industry research.

At present, China Telecom has proposed a kind of intelligent service nested method that solves, and its Chinese number of patent application is " CN200510035347.0 ", and denomination of invention is " a kind of realization public telephone net user intelligent service trigger method ".This patent application has proposed following solution:

In public telecom network, increase comprehensive intelligent user property register, be connected with signaling link between each network element in this intelligent subscriber property register and the telecommunications network, deposit the corresponding relation and the signatory attribute of IN service of Subscriber Number and its physical number in this intelligent subscriber property register, the professional triggering may further comprise the steps:

The office that makes a start sends to comprehensive intelligent user property register with calling and carries out service inquiry, and comprehensive intelligent user property register is inquired about first IN service access code and returned first IN service access code according to numbers of calling and called parties earlier; Make a start the office it is routed to the operation exchange contact, finish the processing of first IN service;

The operation exchange contact is inserted first IN service access code before called number, deliver to comprehensive intelligent user property register and carry out the IN service inquiry, comprehensive intelligent user property register returns second IN service access code, and the operation exchange node is finished second IN service according to second IN service access code and handled;

The operation exchange node is inserted N-1 IN service access code before called number, deliver to comprehensive intelligent user property register and carry out the IN service inquiry, comprehensive intelligent user property register returns N IN service access code, and the operation exchange node is finished N IN service according to N IN service access code and handled;

After finishing the calling and called IN service and triggering, the operation exchange node is at last to described comprehensive intelligent user property register request called subscriber's physical number, replay call.

From as can be known above-mentioned, there is following defective in it:

At first, because it is to adopt " the operation exchange node is inserted first IN service access code before called number; deliver to comprehensive intelligent user property register and carry out the IN service inquiry; comprehensive intelligent user property register returns second IN service access code; the operation exchange node finishes according to second IN service access code that second IN service handle " mode, comprehensive intelligent user property register can not the differentiated service switching node inquiry be the business or the called service of caller, and any PSTN network users both can apply for that calling service also can apply for called service.

Secondly, when carrying out the IN service inquiry IN service ground inquiry of an IN service, can't learn when stop inquiry, be prone to endless loop.

Moreover SSP need remember the last access code that triggers business of intelligent service users, takies internal memory and the disposal ability of a large amount of SSP.

Summary of the invention

The problem to be solved in the present invention provides a kind of business nesting method based on public switched telephone network (PSTN) that can distinguish calling and called service.

In order to address the above problem, the technical scheme that the present invention is based on the business nesting method of public switched telephone network (PSTN) is:

Described public switched telephone network (PSTN) adopts the end-remittance office structure of full traffic tandem, and it comprises some end office (EO)s, somely has the tandem exchange of Service Switching Point function, professional control centre and a subscriber data center, and described method comprises the steps:

A) end office (EO) sends to customer call the tandem exchange with Service Switching Point function;

B) described tandem exchange with Service Switching Point function sends service inquiry to subscriber data center;

C) described subscriber data center returns the information that has service access code, visit indication and called number;

D) after described tandem exchange with Service Switching Point function triggers this business according to described service access code, judge that described visit indicates whether to be Stop message, if not then continue to send service inquiry, execution in step C) to described subscriber data center;

E) if described visit indication is a Stop message, the visit indication is removed by described tandem exchange with Service Switching Point function, and by the called number replay call after the described visit indication.

At described step C) after also comprise step C1) if described tandem exchange with Service Switching Point function can not trigger the represented business of described service access code, then described service access code is sent to the tandem exchange with Service Switching Point function that can handle described business.

Described visit indication comprises visit described subscriber data center indicating bit, calling and called service indicating bit and inquiry times position.

Described business comprises the nested of basic service, supplementary service, IN service, signing service.

Compared with prior art, the beneficial effect that the present invention is based on the business nesting method of public switched telephone network (PSTN) is:

At first, described in the method subscriber data center returns the information that has service access code and visit indication, described visit indication comprises calling and called service indication and inquiry times, so can know that from the calling and called service indication the represented business of described service access code is calling service or called service, the business nesting method that therefore the present invention is based on public switched telephone network (PSTN) can be distinguished calling and called service.

Secondly, this method has adopted step D) after described Service Switching Point triggers this business according to described service access code, judge that described visit indicates whether to be Stop message) if not then continue to send service inquiry, execution in step C to described subscriber data center; Also adopted step e) if described visit indication is a Stop message, described Service Switching Point is removed and is visited the number replay call of indicating by thereafter.That is to say, if described visit indication represented be Stop message, so just stop to send service inquiry, thereby adopt method of the present invention the situation of endless loop can not occur to described subscriber data center.

Moreover, SSP is as long as the service access code that returns according to subscriber data center triggers the represented business of this service access code and get final product, and needn't remember the access code of this service-user last time business of triggering, thereby saved the internal memory of SSP greatly, improved the disposal ability of SSP.

Description of drawings

Fig. 1 is a kind of schematic network structure of public switched telephone network (PSTN);

Fig. 2 is the flow chart that the present invention is based on the business nesting method of public switched telephone network (PSTN);

Fig. 3 be one embodiment of the present of invention based on the simple network schematic diagram of a public switched telephone network (PSTN);

Fig. 4 is the call flow diagram of finishing of one embodiment of the present of invention.

Embodiment

Shown in Figure 1, it is the schematic network structure that the present invention is based on the public switched telephone network (PSTN) that business nesting method was suitable for of public switched telephone network (PSTN), it adopts the end-remittance office structure of full traffic tandem, it comprises some end office (EO)s 1, some tandem exchange 2, professional control centre 3 and subscriber data center 4, toll switch 5, gateway exchanges 6 with Service Switching Point function, wherein:

End office (EO) 1 (LS, Local switch): be common stored-program control exchange, it connects user's telephone set below by twisted-pair feeder.The effect of end office (EO) is to provide access, feed to subsets, the basic talk business and the supplementary service that be responsible for finishing call treatment, realize the telephone subscriber.

Tandem exchange 2 (MS/SSP, Tandem Switch/Servise swtich point) with Service Switching Point function: be positioned in network above the end office (EO), main effect is to be responsible for tandem and to exchange user's communications path between different end office (EO)s.Usually adopt the 2M circuit to be connected between tandem exchange and end office (EO), communication protocol adopts Chinese Signaling System Number 7.Tandem exchange 2 also possesses the ability that IN service triggers, can by with the reciprocation of the professional SCP of control centre, realize IN service.Tandem exchange is the whole network " exchange, intelligence, management, charging, signaling " core, should possess following function:

(1) possess the ability of calling party data center: switch adopts ISUP Extended Protocol or INAP Extended Protocol or MAP Extended Protocol visit SDC, obtains user's IN service subscription data, judges that according to the IN service subscription data calling out the needs intelligent network handles.

(2) possess the ability that IN service triggers: tandem exchange's switch, require to possess IN service in principle and trigger ability, promptly possess the SSP function, trigger professional as early as possible.

(3) tandem exchange must be the switch of big capacity, high throughput, high reliability, and has perfect congestion control mechanism.

Professional control centre 3 (SCP.Service control point): the upper strata that is positioned at network, physical entity is minicomputer or server normally, loading intelligent service logic among the SCP, it is the nucleus equipment that IN service is realized, SSP obtains the professional instruction of carrying out by Intelligent Network Application Protocol visit SCP, the final IN service of realizing of the switch action in the SSP Control Network.

Subscriber data center 4 (SDC, subscriberdatacenter): be used to leave concentratedly one or more network user's database of information.Can be used for but be not limited to networks such as PSTN, PHS, NGN or 3G.It has at first preserved user's Subscriber Number, user type and network type information, and can also preserve user's various user data such as routing number, basic service, supplementary service, IN service CAMEL-Subscription-Information, customer position information according to different user types.For the mobile network, as PHS and 3G network, SDC is equivalent to HLR (user attaching register) and possesses the repertoire of HLR.

Toll switch 5 (TS, Toll switch): be the stored-program control exchange that is used to dredge toll traffic.

Gateway exchange 6 (GW, Gateway switch): be to be used for the critical point switch that interconnects with other operators, telex network between different operators needs to connect by gateway exchange, to satisfy requirements such as authentification of user, inter-network settlement and supervision.

As shown in Figure 2, the business nesting method that the present invention is based on public switched telephone network (PSTN) comprises the steps:

A) end office (EO) 1 sends to customer call the tandem exchange 2 with Service Switching Point;

B) described tandem exchange 2 with Service Switching Point sends service inquiry to subscriber data center 4;

C) described subscriber data center 4 returns the information that has service access code and visit indication, and described visit indication comprises calling and called service indication and inquiry times;

D) described tandem exchange 2 with Service Switching Point function is triggered to professional control centre 3 according to described service access code with business; After executing this business, Service Switching Point tandem exchange 2 judges that described visit indicates whether to be Stop message, if not then continue to send service inquiry, execution in step C to described subscriber data center 4);

E) if described visit indication is a Stop message, the number replay call of indicating by is thereafter visited in tandem exchange's 2 removals with Service Switching Point.

From the above, the user is during by public switched telephone network (PSTN) and other user's communications, the user goes up at the conversation instrument (phone or mobile phone) of oneself and dials the other side's number, calling (the other side's number of being dialled) with the user after end office (EO) 1 receives sends to the tandem exchange 2 with Service Switching Point, the Service Switching Point of tandem exchange 2 sends the IN service inquiry to subscriber data center 4, just whether inquiring calling user and called subscriber applied for professional, subscriber data center 4 returns to the information that one of Service Switching Point has service access code and visit indication, service access code is a kind of numbering of business, the visit indication comprises calling and called service indication and inquiry times, that is to say, in the visit indication, can learn that the business of this service access code representative is calling service or called service, and this is inquired about is for which time inquiry, the phenomenon to certain professional repeated trigger or leakage triggering therefore can not occur.

Service Switching Point triggers this kind business according to the received service access code that gets.After this business is finished, Service Switching Point judges that the visit of returning from subscriber data center 4 indicates whether to be Stop message, if not Stop message, then Service Switching Point sends querying command to subscriber data center 4 once more, after subscriber data center 4 is received the order of inquiry business of Service Switching Point, return the information that has service access code and visit indication once more, Service Switching Point triggers this IN service according to this service access code that returns once more, the visit of judging this time then indicates whether to be Stop message, if not sending querying command again, move in circles like this, finish up to all business are all triggered.

For subscriber data center 4, when Service Switching Point after it sends the order of inquiry business, the service access code that inquires is returned to Service Switching Point, whether while subscriber data center 4 also will be inquired about one and also have the business of calling and called not to be returned, if the service access code of all calling and called has all returned to Service Switching Point, subscriber data center 4 just will be visited indication and will be changed to Stop message so, represent that promptly all service access codes all return to Service Switching Point.Service Switching Point receive trigger after the information that subscriber data center 4 returns professional, and the information of judging the visit indication is Stop message, then Service Switching Point no longer sends the order of inquiry business to subscriber data center 4, visits the other side's number replay call of indicating according to thereafter and notify tandem exchange 2 to remove.

As shown in Figure 2, the present invention is based on the business nesting method of public switched telephone network (PSTN) at described step C) after also comprise step C1) if described tandem exchange 2 with Service Switching Point function can not trigger the represented IN service of described service access code and then described service access code sent to the tandem exchange with Service Switching Point function 2 that can handle described business.

Not all Service Switching Point can both trigger all business, when the Service Switching Point that sends the service inquiry order can not trigger represented professional of service access code that subscriber data center 4 returns according to this inquiry, this Service Switching Point is just passed to the Service Switching Point that can trigger the represented business of this service access code with this service access code, triggers this business and inquires about next time by handling this professional Service Switching Point.

For the visit indication, comprise calling party data center indicating bit+calling and called service indicating bit+inquiry times position.Wherein, calling party data center indicating bit represents whether be the order of calling party data center; The calling and called service indicating bit is represented calling service or called service; Inquiry times represents it is which time inquiry.

For example: if visit indication represents with AI, AI=E0MN then, wherein, E0 is a calling party data center indicating bit, represents then that if not E0 this visit is not a calling party data center, but other parts.M is the calling and called service indicating bit, establishes when M is 1, and expression is a calling service; When M was 2, the expression called service certainly, can be represented with Any Digit, letter etc., as long as different calling service and called service can being distinguished of indication of calling service and called service.N is the inquiry times position, is inquiry for the first time as N=1, and N=2 is inquiry for the second time, or the like.

Can be " IN service access code+AI+ (called number) " for the form that is used for the information that data center returns, in the process of carrying out the querying triggering IN service, can singly the business of all calling services be returned earlier, and then singly the business of all called services is returned, perhaps interting to come, in any case, as long as the IN service of all calling and called services all can be returned.

Only be the overall process that example is described the business nesting method that the present invention is based on public switched telephone network (PSTN) below with the IN service.

(1) PSTN net end office (EO) 1 detects the user and makes a call, and calling is sent to tandem exchange 2, and after caller IAM message arrived tandem exchange 2, tandem exchange 2 initiatively carried out the calling service inquiry to SDC 4.

(2) subscriber data center SDC 4 gives tandem exchange's switching equipment 2 (being ssp simultaneously) by the form feedback query information of " IN service access code+visit indication (AI)+(called number) ", and SDC 4 also will judge the state of inquiry by the form of " AI+ called number ".AI representative visit indication, 2 byte longs.AI=E0MN, wherein E0 represents the indication of calling party data center (SDC) 4; What M represented to inquire about is caller or called service, and what represent to inquire about when M=1 is caller, and what represent to inquire about when M=2 is called; N represents the work flow of inquiring about, and N is arbitrary numeral of 1 to 9.When AI=E000, the expression calling and called service is all inquired about and is finished, i.e. position of rest is used to indicate the switching equipment next time of inquiring user data center 4 no longer.And remove E000 by tandem exchange 2, and continue by the called number behind the E000.E1 to E9, and other values of M and N are all standby as expansion.

(3) after SDC 4 receives first caller inquiry that tandem exchange 2 sends, return the 1st caller signing service access code, form is " an IN service access code 1+E011+ called number ".

(4) if the switching equipment of searching user's information itself just can trigger this IN service, then triggered IN service after, switching equipment is proceeded to inquire about next time thus; If the switching equipment of searching user's information itself can not trigger this IN service, then should deliver to corresponding business exchange point (SSP) equipment and carry out the IN service processing, next time, inquiry both can be proceeded by the Service Switching Point of trigger intelligent business, also can send former switching equipment back to and carry out.

(5) require SCP can correct identification id P message (message in the Signaling System Number 7) in the called party number parameter of " service access code+AI+ called number " form, service access code may be the byte of random length, AI is 2 bytes, is real called number behind the AI.SCP sends the destination routing address in the attended operation, should not comprise the IN service access code that this was handled, and is the form of " E011+ (called number) ".

(6) trigger in the destination routing address that professional SSP sees that SCP issues E011 is arranged, expression also will continue to inquire about SDC, SDC 4 abilities are then proceeded to inquire about next time if SSP itself possesses inquiry, then do not route the call to corresponding tandem switch and inquire about if do not possess query capability.Switch is delivered to SDC 4 application inquiries with called number " E011+ (called number) ", and SDC returns the 2nd service access code, and form is " IN service access code 2+E012+ (called number) ".SSP triggers the 2nd signing service.

(7) so repeatedly, all triggered up to all caller signing service.Because SSP or tandem exchange's switch 2 are not seen E000 and are stopped the inquiry sign, so can continue 4 inquiries to SDC.Be local call if this is called out, then SDC 4 will return first called signing service of called subscriber, and form is " IN service access code 1+E021+ (called number) ".Switch or the SSP of inquiry SDC 4 trigger the 1st called signing service; Continue inquiry SDC then, obtain the 2nd called signing service, form is " IN service access code 2+E022+ (called number) ", triggers the 2nd called signing service;

(8) called signing service inquiry to the last so repeatedly, SDC judges that this is last business, therefore the AI that issues is designated the E000 position of rest, and called number is revised as routing number, SSP triggers last signing service, and triggering in the destination routing address that professional SSP sees that SCP issues has E000, then no longer inquires about SDC, remove E000, and continue by the number behind the E000.

(9) when switching equipment is received the IAM message (message in the Signaling System Number 7) that contains Redirection Information (former called number) and need inquiring user data center (SDC) 4, send in the Query Information of SDC 4 and should comprise former called number information; When subscriber data center (SDC) 4 is received the Query Information that contains former called number information, represent that this is once relevant with forwarded calls inquiry, SDC 4 needs to judge it is to caller inquiry or called inquiry in conjunction with the called number parameter, if, then former called subscriber is inquired about as caller to the caller inquiry.In this case, the intelligent dialing business if former called subscriber has contracted, the IN service access code that changes before then SDC only returns and is applicable to.When SCP receives the startup DP that contains former call subscriber ID parameter, the user of former call subscriber ID correspondence is carried out logical process as caller.

Now solve the technical scheme that the business nesting method that the present invention is based on public switched telephone network (PSTN) is described in detail in detail based on the method for the happy bell business of the public switched telephone network (PSTN) problem nested with one number service with certain company.Wherein:

(1) please the bell business: be one by called subscriber's customization, when waiting for called answering, substitute the business of common ring-back tone for the calling subscriber provides one section music or audio.

(2) one number service: be the one number that operator offers the user, behind the user applies one number service, be that an available unique one number service number is as the correspondence with foreign country number, existing local mobile terminal, Personal Handyphone System, this locality or long-distance stationary telephone can get up with this one number service number binding, no matter how actual phone number to change, as long as other people know that the one number service number can get in touch.

(3) Subscriber Number (DN): Subscriber Number is the one number that operator distributes to the user, also is the visible number of user.When the user does caller, be the calling number that shows to the called subscriber; When the user does when called, be exactly the number that the calling subscriber dials; Simultaneously, user's Subscriber Number also is the number that operator charges to the user.For the one number service user, the DN number is exactly its one number service number.

(4) user's routing number (LRN): routing number is the number that is used for routing, and the equipment number of this number and switch is corresponding one by one.Equipment number is certain port or certain the bar subscribers feeder in the switch, is the network internal number, and the user is invisible.

Fig. 3 be this example based on the network structure of hypothesis, suppose to please the professional and one number service of bell and all load among the same SCP.

As shown in Figure 4, when the switch query SDC of tandem exchange, be that example describes in this example with the ISUP Extended Protocol:

(1) user A makes a call, and LS1 sends IAM message to MS/SSP, and wherein: the Cg territory is the routing number (LRN_A) of calling subscriber A, and the Cd territory is the Subscriber Number (DN_B) of called subscriber B;

(2) MS/SSP of tandem exchange inquiry SDC, signaling message IDP (Cg=LRN_A, Cd=DN_B)); It is ACM (Cg=DN_A) that SDC returns the inquiry called party information, REL (Cd=SACCRBT+E021+DN_B).

(3) MS/SSP of tandem exchange triggers the bell business of pleasing according to pleasing bell access code (SACCRBT), sends IDP to pleasing bell SCP, call segment=1;

(4) SCP begins to please the execution of bell service logic, at first sends RRBE and monitors that the caller incident is to SSP;

(5) SCP sends ICA simultaneously, and it is even called that RRBE, CWA use new call segment=2 to go, and monitors EDP19 and various other call events in RRBE;

(6) because, E0MN=E021 is not a position of rest, so SSP triggers called service inquiry once more, MS/SSP sends query messages to SDC, form is as follows: IAM (Cg=DN_A, Cd=E021+DN_B)

(7) SDC returns Query Information, and form is as follows: REL (Cd=SAC (UPT)+E000)

(8) SSP triggers one number service according to the service access code SAC (UPT) of one number service, sends IDP message to SCP;

(9) SSP continues calledly according to the ICA of SCP, sends IAM to called end office LS2;

(10) called terminal ringing, LS2 returns ACM to SSP;

(11) SSP gives one number service, the notice called free time of SCP to SCP report EDP19;

(12) SSP notifies the called free time of SCP to happy bell business report EDP19;

(13) SCP sends ETC message to SSP, and happy bell platform requires to continue;

(14) SSP sends ACM to originating switch, keeps calling out;

(15) SSP transmission IAM continues and pleases the bell platform;

(16) the IP platform returns ACM to SSP;

(17) SSP sends CPG to LS1;

(18) the IP platform sends ARI to SCP, requires to play happy bell;

(19) SCP sends PA to the IP platform;

(20) IP plays the happy bell of B, and the happy bell of B is heard in caller;

(21) called subscriber B off-hook, LS2 sends ANM to SSP;

(22) SSP reported event EDP07 is to pleasing the bell business, notice SCP called party answer;

(23) SCP sends DFCWA to SSP.

(24) SSP sends REL to IP;

(25) IP cuts off the happy bell of C, loopback RLC;

(26) SCP sends the call segment that MGCS connects LS2 and called subscriber C;

(27) SSP is with the speech channel successful connection, to SCP loopback MGCS_R;

(28) SSP returns ANM to LS1;

(29) SCP sends CWA to SSP in TC_END, makes to call out to continue;

(30) user A and user B converse.

In sum, employing the present invention is based on the technical scheme of the business nesting method of public switched telephone network (PSTN), can distinguish calling and called service, the endless loop of inquiry also can not occur sending, can save the internal memory of SSP again and improve its disposal ability to subscriber data center 4.

Claims

1, a kind of business nesting method based on public switched telephone network (PSTN), described public switched telephone network (PSTN) adopts the end-remittance office structure of full traffic tandem, it comprises some end office (EO)s, somely has the tandem exchange of Service Switching Point function, professional control centre and a subscriber data center, it is characterized in that described method comprises the steps:

2, the business nesting method based on public switched telephone network (PSTN) as claimed in claim 1, it is characterized in that, at described step C) after also comprise step C1) if described tandem exchange with Service Switching Point function can not trigger the represented business of described service access code, then described service access code is sent to the tandem exchange with Service Switching Point function that can handle described business.

As claim 1 or 2 described business nesting methods, it is characterized in that 3, described visit indication comprises visit described subscriber data center indicating bit, calling and called service indicating bit and inquiry times position based on public switched telephone network (PSTN).

As claim 1 or 2 described business nesting methods, it is characterized in that 4, described business comprises the nested of basic service, supplementary service, IN service, signing service based on public switched telephone network (PSTN).