CN101222652B

CN101222652B - Method for selecting call routing in full IP bearing telecommunication network

Info

Publication number: CN101222652B
Application number: CN2007101530734A
Authority: CN
Inventors: 黄世碧
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2001-08-29
Filing date: 2001-08-29
Publication date: 2010-09-29
Anticipated expiration: 2021-08-29
Also published as: CN1407761A; CN101222652A; CN100428707C

Abstract

The present invention provides a method for selecting call routing in all-IP bearing telecommunication network. Direct call routing selection from end office to end office is realized by utilizing the prior database service system storing a corresponding relation table for telephone numbers and IP addresses of terminal access network equipment. When the method of the present invention is implemented, functional entities such as tandem offices in the prior telecommunication network do not need to be arranged in an all-IP telecommunication network, which simplifies the network, saves the investment for building the network. In addition, the present invention also provides convenience for the operation and maintenance work for the database in the process of increasing and deleting users.

Description

In the communication network of full IP bearing, carry out the method for call route selecting

Technical field

The present invention relates to telecommunications and internet arena, especially relate to the method for in the communication network of full IP bearing, carrying out call route selecting.

Background technology

Present circuit-switched network generally is a multistage network structure, directly inserts the user by end office (EO), and tandem exchanges at different levels realize interoffice speech channel tandem exchange.In the three-level network structure as shown in Figure 1, first and second level is a toll switching center, and the third level is a local network switching center.Primary centre (DC1), promptly provincial switching center, function mainly be the inter-provincial long-distance traffic of making a return journey of switching place province, and the long distance terminal traffic of place local network.The function of secondary switching center (DC2) mainly is the long distance terminal traffic of mediation place local network.Local network is provided with the switching center of two grades of tandem exchange and end office (EO).The function of tandem exchange is the traffic between the tandem local network end office (EO), also can tandem local network end office (EO) and toll telephone office between toll traffic.Mix tandem exchange and also will be responsible for dredging local subscriber's terminating traffic.The function of end office (EO) mainly is mediation local subscriber's a terminating traffic.

Calling route selection in circuit-switched network is to carry out in the mode of hop-by-hop Route Selection, call-originating end office switch carries out route analysis according to called number, obtain the next switch of outgoing direction during route analysis according to the configuration data on the switch, next switch carries out same route analysis routing again, and the hop-by-hop routing finally determines to make a call initiation end office (EO) to landing the path of end office (EO) like this.Owing to adopt each switch of hierarchical network structure only to interconnect, so the routing data configuration is fairly simple, only comprises the route analysis data of going to neighboring switch and gets final product with limited switch.

Along with the progressively maturation of IP packet network technologies, the IP packet network can be used for business such as voice-bearer, data, multimedia, and traditional circuit-switched network and packet network merge gradually.After the telecommunications bearer network adopts IP network, needn't carry out the tandem step by step and the exchange of speech channel because in IP network, can realize end-to-end communication as circuit-switched network, therefore tandem exchange's functional entity of circuit tandem step by step just need not be set in IP network.But, bring the another one problem again after the cancellation tandem exchange functional entity, the IP address that should directly obtain called end office when carrying out the calling route analysis of called number in each call-originating end office is to set up session connection end to end.In communication network, telephone number generally uses the numbering of the E.164 defined of International Telecommunication Union to encode, E.164 be the coded system of a stratification, want to inquire about the database of a called number and corresponding end office (EO) IP address from the IP address that called number directly obtains called end office.But under this flat network configuration, there is the route of a large amount of end office (EO)s in the network in an end office (EO), and therefore, this data-base recording is many in the IP Telecommunication Network network, and this database is difficult to realize in each end office (EO).

Summary of the invention

The objective of the invention is to overcome the deficiencies in the prior art part, a kind of method of carrying out call route selecting in the communication network of full IP bearing is provided.

The present invention has utilized existing stratification in the IP network, distributed Database Systems, as DNS (DNS), X.500 NetWare directory services NetWare, ldap directory service system etc., comes the mapping table of storing phone number and corresponding end office (EO).The object of the present invention is achieved like this, and a kind of method of carrying out call route selecting in the communication network of full IP bearing is characterized in that, may further comprise the steps:

(1) calling server receipt of call obtains the called phone number;

(2) the calling server is being stored the request that telephone number and the DNS DNS of the mapping table of the IP address of accessing terminal to network equipment send the IP address of the corresponding called call server of inquiry called phone number according to the called phone number is existing in IP network;

(3) described calling server receives the IP address of the pairing called call server of called number of domain name service system DNS transmission;

(4) described calling server is directly set up session with called call server according to the IP address of the called call server that is obtained.

The present invention also provides a kind of network system, comprises,

First call server, first media gateway, second call server, second media gateway and DNS DNS,

Wherein, DNS DNS is used for the mapping table of the IP address of storing phone number and accessing terminal to network equipment, and according to the query requests that receives, the IP address of inquiry and feedback terminal access network device; This first call server is used to receive user's call request, obtains the called phone number; Send the request of the IP address of second call server of inquiring about called phone number correspondence to DNS DNS; Receive the IP address of pairing second call server of called phone number of this DNS DNS transmission, and directly set up session with the second corresponding call server according to this IP address; First media gateway and second media gateway are connected with second call server with first call server respectively, and the carrying that is used to finish the call session data is changeed and just changed processing.

Implement method of in the communication network of full IP bearing, carrying out call route selecting of the present invention, come the mapping table of storing phone number and corresponding end office (EO) by utilizing existing stratification in the IP network, distributed database management systems, therefore, the such functional entity of tandem exchange in the present communication network need not be set in the communication network of all-IP, can realize the direct calling Route Selection of end office (EO) to end office (EO), make network become more simple, the investment when having saved building network.When in addition, also having made things convenient for increase, deletion user to the Operation and Maintenance work of database.

Description of drawings

Fig. 1 is existing three grades of circuit-switched network structure charts;

Fig. 2 is among the embodiment of the inventive method, carries out the flow chart of call route selecting;

Fig. 3 is among the embodiment of the inventive method, adopts DNS to carry out the networking schematic diagram of call route selecting.

Embodiment

In one embodiment of the invention, employing be to utilize the DNS (DNS) on enterprise's network to carry out the method for call route selecting, thereby realize that directly obtaining its corresponding end office (EO) from telephone number hands over and melt machine IP address.In the RFC 2916 that IETF formulated, provided the method that telephone number is converted to the dns name word, may further comprise the steps:

1) according to E.164 encoding number is write entirely, as :+86-755-6540808

2) nonnumeric character is removed, as: 867556540808

3) between each numerical character, add a little, as: 8.6.7.5.5.6.5.4.0.8.0.8

4) order of space symbol is overturn, as: 8.0.8.0.4.5.6.5.5.7.6.8

5) " .e164.arpa " character string is put behind, can be converted to a dns name word to a telephone number by this method as 8.0.8.0.4.5.6.5.5.7.6.8.e164.arpa.Specifically can in the dns name word, use asterisk wildcard ' * ', represent telephone number dns name word with+86-755-654 beginning as * .4.5.6.5.5.7.6.8.e164.arpa.

RFC 2915 specification document of IETF have provided the naptr resource record formal definition in the DNS resource record (RR), and NAPTR has following several key:

1) (order) in proper order: the order of response when existing a plurality of NAPTR to write down when this territory has been specified single inquiry;

2) priority (preference): this territory provide when the order value of a plurality of NAPTR record the time the priority definition of which record of priority treatment;

3) sign (Flags) a: character string of representing by one or more numerals or alphabetic character.Each numeral or alphabetic character are represented a sign, and it provides the implication definition in relevant territory in the action of dns lookup next time and the record." A ", " U ", " S ", " P " four signs have been defined at present, " A " sign represents that dns lookup next time is the record of A, AAAA or A6 type, and next step is not dns lookup but follow-up regular expression (Regexp) territory of this record is a unified resource identifies (URI) for " U " sign expression;

4) service (service): provided next step and inquired about employed analysis protocol and analysis service, the form of service-domain is service_field=[[protocol] * ("+" rs)], wherein agreement Protocol is optional, rs represent the service can be 0 or a plurality of, between a plurality of services with+separate;

5) regular expression (Regexp): this territory is one of them of two alternate domains in the NAPTR record, provides and substitutes the expression formula that the original character string of client is used to construct inquiry next time;

6) the another one alternate domains of alternate domains (replacement): NAPTR record can provide the name that is used for next inquire address or NAPTR record according to the definition of mark domain.

Provide below the telephone number with+86-755-654 beginning be converted to the DNS resource record that the IP address is 202.119.102.12:

$ORIGIN*.4.5.6.5.5.7.6.8.e164.arpa.IN?NAPTR?10?10“A”“”“”xyz.com.cn

xyz.com.cn A?202.119.102.12

From above description as can be seen, the technology that telephone number is converted to corresponding IP address is comparative maturity, thereby can use the DNS service directly realizes end-to-end calling from the IP address that the called phone number inquiry obtains opposite end end office (EO) direct Route Selection when setting up the communication network of full IP bearing.

As shown in Figure 2, it is as follows to obtain the flow process of called call server IP address:

(1) the calling server carries out the DNS inquiry IP address with the called call server that obtains called phone user place according to the called phone number;

(2) the DNS system issues the calling server according to configuration data with the IP address of the pairing called call server of called phone number;

(3) the calling server is directly set up session with called call server according to the call control protocol (BICC) of the IP address applications bearer independent of called call server.

As shown in Figure 3, be to use the networking schematic diagram that the DNS system carries out call route selecting.Wherein, call server (Call Server) is finished the processing of calling and signaling protocol, and media gateway (MGW) is finished the carrying conversion process of call session data.Call server A and media gateway A constitute the A of end office (EO) and are responsible for the business that Access Network A goes up the user jointly, and call server B and media gateway B constitute the B of end office (EO) and be responsible for the business that Access Network B goes up the user jointly.When user A calling party B, user A at first initiates the setup call request to call server A, enclose the number of user B simultaneously, it is that the number of user B is passed to the IP address that dns server requires to inquire about called call server B that call server receives after the call request of user A called number, dns server is inquired about the IP address that obtains call server B according to the number of user B and is returned to call server A from data configuration, call server A obtains just can to use after the IP address of call server B call-independent control protocol bearing and sets up session with call server B and carry out follow-up calling control, finally carries to be connected for user A and user B foundation by two media gateway of two call servers control and carries out service communication.

Using NetWare directory services NetWare X.500 or ldap directory service system, to carry out the flow process of call route selecting similar to present embodiment with networking mode.

The communication network that this method can be applied to adopt IP network to set up is as the call route selecting of IP phone gateway in the R4 circuit domain of 3GPP and the fixed network.

Claims

1. a method of carrying out call route selecting in the communication network of full IP bearing is characterized in that, may further comprise the steps:

(1) calling server receipt of call obtains the called phone number;

(2) described calling server is being stored the request that telephone number and the DNS DNS of the mapping table of the IP address of accessing terminal to network equipment send the IP address of the corresponding called call server of inquiry called phone number according to described called number is existing in IP network;

(3) described calling server receives the IP address of the pairing called call server of called phone number of domain name service system DNS transmission;

2. method of carrying out call route selecting according to claim 1 is characterized in that: the domain name service system is stratification, distributed database management systems.

3. method of carrying out call route selecting according to claim 1 is characterized in that, described step (4) is specially:

Described calling server is directly set up session with called call server according to the call control protocol BICC of the IP address applications bearer independent of the called call server that is obtained.

4. a network system is characterized in that, comprise,

Wherein, domain name service system DNS is used for the mapping table of the IP address of storing phone number and accessing terminal to network equipment, and according to the query requests that receives, the IP address of inquiry and feedback terminal access network device; Described first call server is used to receive user's call request, obtains the called phone number; Send the request of the IP address of second call server of inquiring about called phone number correspondence to domain name service system DNS; Receive the IP address of pairing second call server of called phone number of domain name service system DNS transmission, and directly set up session with the second corresponding call server according to this IP address; Described first media gateway and second media gateway are connected with second call server with first call server respectively, are used to finish the carrying conversion process of call session data.

5. network system as claimed in claim 4 is characterized in that,

Domain name service system DNS is stratification, distributed database management systems.