Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L61/00—Network arrangements, protocols or services for addressing or naming
  • H04L61/45—Network directories; Name-to-address mapping
  • H04L61/4505—Network directories; Name-to-address mapping using standardised directories; using standardised directory access protocols
  • H04L61/4511—Network directories; Name-to-address mapping using standardised directories; using standardised directory access protocols using domain name system [DNS]
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L61/00—Network arrangements, protocols or services for addressing or naming
  • H04L61/45—Network directories; Name-to-address mapping
  • H04L61/4557—Directories for hybrid networks, e.g. including telephone numbers

Definitions

• the present invention relates to a routing method for restoring a call to a non-standard number in a network including a routing mechanism for standard numbers.
• the invention applies in particular to any end-to-end SIP signaling network whose routing relies on the ENUM technology, capable of carrying services based on non-E.164 numbering as short numbers or belonging to private numbering plans.
• IMS IP Multimedia Subsystem
• networks based on IMS architectures apply routing mechanisms different from those traditionally used in switched telephone networks (PSTNs). These IMS mechanisms are essentially based on a particular function of the Domain Name System (DNS), called ENUM, which, in this context, makes it possible to translate a telephone number into a SIP identifier called URI (Uniform Resource Identifier). ”) Natively mutable in networks using the SIP protocol, which is the case of IMS architectures.
• DNS Domain Name System
• SIP protocol which is the case of IMS architectures.
• the ENUM function described in the IETF RFC 3761 standard, makes it possible to know, by querying the DNS system using a standard telephone number in accordance with the international standard ITU E.164, the possible multimedia identifiers for joining a correspondent. .
• the result of an ENUM request can be one or more URIs with their processing order and their preference.
• URIs are then used to reference resources or services associated with the E.164 standard number such as, for example, an e-mail address, a web page, a directory service, fixed or mobile reference numbers, or an alias of Voice over IP, videophone or instant messaging for SiP or H.323 protocols.
• a call established using an E.164 standard number in an IMS network is performed according to the following routing mechanism.
• an S-CSCF Cluster Session Control Function
• an S-CSCF server having determined that the called number complies with the standard E.164, converts this number into an expression, a domain name, serving as a basis for querying the ENUM function, which will respond to the request with at least one URI.
• the S-CSCF server builds the expression "9.8.7.6.5.4.3.2.1.3.3” to concatenate it to another "root” domain name ( a predefined root) and obtain the full name "9.8.7.6.5.4.3.2.1.3.3.root”.
• RFC 3761 defines the root value as "e164.arpa”. Once concatenated, the fully qualified domain name thus formed is "9.8.7.6.5.4.3.2.1.e164.arpa”. Note that the IMS also allows you to set your own root as a parameter of the SIP server.
• the root domain name "e164.arpa” thus represents the root of a tree structure of the ENUM translation database associating at least one URI identifier with the expression provided by the S-CSCF server.
• the ENUM function searches in the translation database whose root is "e164.arpa” or URI identifiers corresponding to the expression received when (s) exist (s).
• a URI identifier returned to the SIP server by the ENUM function is for example of the type "sip: dupond@provider.com” where "provider.com” is a domain name.
• the call setup request is then routed to another SIP server associated with the domain "provider.com".
• This IMS SIP server which is the entry point to the network associated with the domain name "provider.com” is generally called I-CSCF (I for "Interrogating").
• the routing logic is as follows: any IMS subscriber has an entry in the ENUM database, a number that is not present in this database must not be routed to an IMS server such as N-CSCF, but to a destination outside the IMS network.
• ENUM does not consider hosting non-standard numbers belonging to a numbering plan other than the E.164 international numbering plan. Therefore, when a non-standard number is used to address a destination in the IMS network, it is not present in the ENUM tree, and the routing can not be performed according to the mechanism just described. but requires a special mechanism dedicated to this new dialing configuration.
• This dedicated mechanism may consist of complicating the number analysis methods at the level of the SIP servers S-CSCF or defining a default route, for example imposing the transit via the switched network RTC.
• the S-CSCF server detects that this short number can not be present in the ENUM database and that, therefore, the destination of the call does not belong to the SIP network, In this case, the S-CSCF server refrains from making a request to the ENUM function and directly directs the call to the switched network RTC.
• the call is then processed by complex routing mechanisms known to RTC networks that need not be further described here.
• the current mechanisms in IMS architectures are subject to a constraint that limits their use to only standard numbers in the E.164 international format, because they base the DNS ENUM database tree on a predefined single root, in General the root "e164.arpa" mentioned above. It is therefore impossible to use it to analyze non-standard E.164 numbers such as short numbers of the subscriber dial plan or a private numbering plan, for example, and to send this type of destination without an ad-hoc mechanism. in an IMS network.
• the technical problem to be solved by the object of the present invention is to propose a routing method for establishing a call to a non-standard number in a network including a routing mechanism for standard numbers associating, in a translation base, standard numbers a tree structure capable of providing a standard number at least one routing identifier in the network, which would treat non-standard numbers as easily as standard numbers, avoiding the use of a complex ad-hoc mechanism, for example a routing to an external network, such as the RTC network cited in the solution example presented above.
• the solution to the technical problem posed consists, according to the invention, in that, a specific root (“domain”) being associated with at least one category of non-standard numbers, and a specific tree structure being constructed on said specific root (" domain ”) in said translation database (DNS ENUM), the method comprises the following steps:
• the method according to the invention consists in providing, via the signaling used when establishing the call to a non-standard number, the specific root associated with this category of non-standard numbers.
• the invention involves enriching the translation base, such as the ENUM database, of complementary tree structures constructed from specific roots, a specific root being associated with a given category of non-standard numbers. For example, to private short numbers of the internal numbering plan to an XYZ 1 company constituting a nonstandard number category, we can associate in the translation database a specific root such as "XYZ” or "xyz.com", just as the root "e164.arpa" is associated with E.164 standard numbers.
• said specific root is transmitted as a given value to the context parameter ("phone-context") defined in the IETF RFC 3966 standard.
• the invention also relates to a translation base intended to associate standard numbers with a tree structure capable of supplying a standard number with a routing identifier in a network, which is remarkable in that said translation database also contains at least one associated tree structure. to non-standard numbers.
• the invention also relates to a terminal requesting a non-standard number in a network including a routing mechanism for standard numbers associating standard numbers with a tree structure capable of supplying a standard number with at least one routing identifier in the network. remarkable in that said terminal is capable of providing, during a call sent to a non-standard number, said non-standard number accompanied by a specific root of a specific tree structure associated with a non-standard number category to which belongs said non-standard number.
• the invention also relates to a call server intended to receive a call establishment request from a terminal in a network including a routing mechanism for standard numbers associating standard numbers with a tree structure capable of providing a number standard at least one routing identifier in the network, wherein a specific root ("domain”) is associated with at least one non-standard number category, and a specific tree structure being constructed on said specific root ("domain") in said database (DNS)
• said call server comprises the means for:
• the invention further relates to a routing server for establishing calls in a network including a call number routing mechanism associating, in a translation database, at least one category of call numbers with a root a tree structure capable of providing a call number with at least one routing identifier in the network, characterized in that, a specific root ("domain") being associated with at least one non-standard number category, and a specific tree structure being built on said specific root
• said routing server comprises means for:
• the invention relates to a computer program product downloadable from a communication network and / or stored on a computer readable medium and / or executable by a microprocessor, characterized in that it comprises program code instructions for carrying out the process according to the invention.
• the invention finally relates to a computer program product downloadable from a communication network and / or stored on a computer readable medium and / or executable by a microprocessor, notable in that it includes program code instructions for executing the operations performed by the routing server according to the invention.
• FIG. 1 is a diagram illustrating the exchanges between an SIP server S-CSCF and a DNS database ENUM.
• FIG. 2 represents a routing algorithm associated with the diagram of FIG. 1.
• non-E.164-compliant numbers must be conveyed in call setup messages with a parameter defining the context in which they may be interpreted.
• This context parameter for example the "phone-context" parameter as defined in the IETF RFC 3966 standard, makes it possible to specify the perimeter within which the number conveyed must be interpreted and outside which it is not valid.
• This context parameter can be valuated by different types of entities during the call, in particular the call terminal itself or a server initiating the call.
• the method according to the invention constructs for non-standard numbers not belonging to the E.164 plane the ENUM DNS request associated with a given category of non-standard numbers from the name of a specific root assigned to that category in the context parameter, for example "phone-context" of the URI present in the Request-URI field of the call setup message. For this request to succeed, a corresponding specific tree structure based on this root is previously created in the ENUM database where non-standard numbers of the intended category are associated with SIP URIs.
• the SIP server S-CSCF then formulates a request from the expression "4.3.2.1. xyz.com ".
• the ENUM database performs a search in a specific tree structure whose root is "xyz.com” and sends back to the S-CSCF server the URI identifier "sip: abc@xyz.com".
• the call setup request is then routed through the standard PIMS routing mechanisms to an I-CSCF server associated with the "xyz.com” domain.
• the SIP server On receipt of such a call setup request, the SIP server having determined that the requested number is not an E.164 number queries the DNS ENUM database having previously concatenated the sequence "3.2.1.3. numerocourt.operateur.com ". The ENUM server is therefore interrogated on the domain "3.2.1.3. numerocourt.operateur.com "and responds with a routing identifier value that has been previously provided, for example" s ' ⁇ : service @ operator. com Surrey
• any entity can then easily route calls to non-standard E.164 numbers in I 1 IMS, without the need for a specific number analysis.
• this new specific tree in which will be stored all non-standard numbers interpretable in the same dial plan.
• a new specific DNS tree can be created in which non-standard numbers can be associated with a SIP URI, naturally routable in SIP networks.
• Each new tree will derive from a proper root specific to the dialing context designated by the domain name carried by the "phone-context" parameter.
• Another embodiment is to create a dedicated SIP parameter to convey the specific ENUM root information to be used, for example "enum-root”.
• the parameter "phone-context" always present would then simply give an indication of the context while the new parameter would carry the specific ENUM root domain name associated with this context.

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• Engineering & Computer Science (AREA)
• Computer Networks & Wireless Communication (AREA)
• Signal Processing (AREA)
• Telephonic Communication Services (AREA)
• Data Exchanges In Wide-Area Networks (AREA)

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• 2007
  • 2007-05-03 WO PCT/FR2007/051211 patent/WO2007132108A2/fr active Application Filing
  • 2007-05-03 EP EP07765992A patent/EP2030418A2/de not_active Withdrawn

Non-Patent Citations (1)

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