SE519438C2 - Dynamic allocation of addresses and address translation in a communication network consisting of at least two different subnetworks - Google Patents

Abstract

A method and an apparatus for enabling the redirection of calls made to a terminal in a first subnetwork to a physical connection in a second subnetwork, said subnetworks constituting parts of a communications network having incompatible addressing standards. The apparatus according to the invention comprises means for dynamically allocating an address in said first subnetwork to an address in said second subnetwork. According to the invention units in the respective subnetwork are used to register associations between the addresses according to the different addressing systems.

Description

5 1 9 4 5 8 2 Between different types of telephone networks, the numbering plans are usually coordinated so that each network has its own nuinine series. In this way, the addressing of terminals in telecommunication networks is usually clear and unambiguous, even if the terminals are in different subnets. This is not always the case between other types of networks.

There are no known solutions to enable forwarding, for example. of telephone calls made to terminals in a telecommunication network, to terminals in a data communication network.

Object of the invention It is therefore an object of the invention to improve the possibilities for voice communication between two sub-networks in a communication network when the addressing systems in the two sub-networks are not coordinated.

SUMMARY OF THE INVENTION This object is achieved according to the invention by a communication network comprising at least a first and a second subnet connected by at least one connection means, which subnets use different addressing systems, characterized in that it comprises first address means for dynamically assigning a first address in the first the subnet to a logical address in the second subnet and forwarding calls to the first address to the logical address in the second subnet, and second address means for assigning the logical address in the second subnet to a physical address in the second subnet and forwarding calls to the logical address of the second subnet to the physical address of the second subnet.

The object is also achieved by a method in a communication network comprising at least a first and a second subnet, which subnets use different addressing systems and are interconnected by at least one connection unit, which method comprises the following steps: an association is created between a logical address for a terminal in the second subnet and a logical and / or physical address in the first subnet, an association is created between the logical address of the terminal in the second subnet and the current physical address in the second subnet , - when a call is made to the terminal in the second subnet from a calling terminal in the first or second subnet: the number is resolved to find the associated logical address of the terminal, l the connection to the connection means is forwarded, the number is resolved to find the associated physical address of the terminal, is connected to the terminal using the current address.

In this way, calls to a terminal having an address in a first subnet can be forwarded to a second subnet even if the addressing systems of the two subnets are not compatible.

According to a preferred embodiment, the first subnetwork is a data communication network according to the IP protocol, the second subnetwork is an intelligent telecommunication network and the connecting means is a gateway.

According to a preferred embodiment, the association between the logical address in the data communication network and the logical and / or physical address in the telecommunication network is made in a node in the data communication network.

In this case, the node can be a gatekeeper for use in a data communication network, such as an IP network. It can also be a SIP server or an ILS server a data communication network.

According to another preferred embodiment, the association between the logical address in the data communication network and the logical and / or physical address in the telecommunications network is made in a node in the telecommunication network.

In this embodiment, the node may be a switching control point in a telecommunication network. It can also be a home location register in a mobile telecommunications network. 10 15 20 25 30 u. N. . .. i. . ~ ».S n s. s. ~. .. n. v s v. . i v.. .i v. nu v »s n. =. . .n u .. v .p v. r ... ... . ~. s. f v .v. . .. s ~. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be described in more detail in the following, with reference to the accompanying drawings, in which: Figure 1 is a schematic overview view of the drawings. a network according to a first embodiment of the invention, Figure 2 shows, in more detail, a network according to a second embodiment of the invention, Figure 3 is a fate diagram of steps performed for registering an IP telephone temporarily in the network according to the first embodiment, Figure 4 is a step diagram of steps performed to register an IP telephone temporarily in the network according to the second embodiment, Figure 5 is a step diagram of steps performed to call a temporarily registered IP phone in the network according to the invention, Figure 6 is a fate diagram of steps performed to deregister an IP telephone temporarily registered in the network according to the invention.

Detailed Description of Embodiments Figure 1 shows an example of a network configuration in which the invention may be practiced.

A first 1 and a second 3 subnetworks which form part of an overall communication network are interconnected by means of at least one interworking unit or connection unit 5, designed to adapt the communication between the two subnetworks. The first and second subnet may be, e.g. a telecommunication network 1 and a data communication network 3 interconnected through a gateway 5 in a well known manner.

A number of terminals 7, 9 are connected to the first subnet. The first subnetwork can be any type of communication system, such as an ISDN network, a data communication network or a cellular telecommunication network. The first network also includes a call routing means 11, which is any node in the subnet that can connect, or forward, calls in the subnet or between subnets. In an intelligent telecommunication network, the call routing means is a service control 20 25 30 i. . .. ... . . . .. ... .. .. .. ... . . . . . . . ,. .. .. ... . . . . . - - - »-. .. .. .. al. 5 point ”SCP. In a cellular telecommunication network, the call routing means is a Home Location Register (HLR) and / or a Visitor Location Register (VLR).

A number of terminals 13, 15 are connected to the second subnetwork 3. The second subnet 3 comprises, or is connected to, a registration means 17, such as a gatekeeper in an IP telephone system according to H.323.

In the usual manner, the registration means 17 comprises, inter alia, a first table 18 which associates physical addresses in the network, such as IP addresses, with logical addresses, such as an IP telephone number. In known ways, IP addresses can be assigned permanently or temporarily to logical addresses. The registration means usually has a number series, or domain, assigned to it, so that it can recognize terminals belonging to its own number series or domain as terminals which it is to serve.

In order to enable terminals registered in the first subnet to roam into the second subnet, according to the invention, the registration means 17 also comprises a list 19 of available numbers which can be temporarily assigned to guests in the second subnet. The registration means 17 also comprises a second table 20 in which the temporarily assigned numbers can be associated with IP addresses. When such a registration is made, the registration means also informs the call routing means 11 in the first subnet of the number which has been temporarily assigned to a guest from the first subnet.

The call routing means 11 registers the temporarily assigned number and the number to which it has been assigned, in a table 21. The IP telephone number may be a logical number configured to identify one or your physical connections, such as an OZO number in Sweden. It can also be a regular telephone number according to the E-164 standard, which identifies a physical connection. In this case, the standard call divert service can be used to divert the phone number to the IP phone. This has the disadvantage that the call is always connected through the local exchange to which the physical connection denoted by the telephone number is connected, which can make a call to the IP telephone more expensive, in 10 15 20 25 30 m. ... . ~ ~ .f »- i. v »nu v. e. v | u v »v ia - -1 u. -v u: u v u - n .f- 1 ... -. v, u .. 1 u. i r »i 1 1. 1 .v «v» n f. , - 1 .. u: r ... . . u. . . 6 especially if the IP phone is far away from the physical connection, but is still possible. In both cases, the call routing node can be a control node, "Service Control Point" SCP in an intelligent network.

The number can also be a number in a mobile telephone network. In this case, the call routing node is the home register CPR in which the telephone number is registered.

Figure 2 shows an embodiment of the invention. In this embodiment, the first and second subnets are a telecommunication network 101 and 101, respectively. a data communication network 103, interconnected by at least one gateway 105. In this embodiment, the telecommunication network 101 is a public switched telephony network (PSTN) and the data communication network 103 is an IP network, such as the Internet. A number of telephones 107, 109 are connected to the telecommunication network 101 via cables.

The telecommunication network 101 comprises at least one call routing means 111. In an intelligent network, this call routing means is usually a control mode SCP or a combined exchange and control node SSCP. In other types of networks, there may be other types of nodes, as discussed below.

The IP network includes a number of terminals 113, 115. It also includes a gatekeeper 117 in a well known manner. The gatekeeper 117 handles, among other things, the associations between IP addresses and IP telephone numbers, in a table 118. How IP addresses are assigned pennially or dynamically is well known to those skilled in the art. In this embodiment, SCP 111 includes a list 119 of available IP telephone numbers in the domain of the gatekeeper 117, which may be dynamically associated with telephone numbers in the domain of SCP 111. The gatekeeper also includes a table 120 for handling associations between IP telephone numbers assigned in this manner and IP addresses in the IP network.

As an example, it is assumed that the IP addresses have the format xxxxx, the IP telephone numbers, ie. the telephone numbers in the gatekeeper's 117 domain, belong to the number series 900-xxxx, and the telephone numbers in the telecommunication network, ie. in SCP's lll domain, the number series belongs to the 700-xxxx, where each x represents an arbitrary number. In this case, 10 15 20 25 30 includes n. N. O i tu H. . f «t. v. s t ut» n 1. I. n I v u x v vi t n. v »» v 1. o n ~. 1 r in .m v - | f. »~> 1 |. 1, i 1 1 f r v »» = v »u - n r 1 t.,. .x ..,. . a. u 7 the gatekeeper 117 as before a table 118 which gives associations between IP addresses and IP telephone numbers. It also includes a table 120 with the same format, but where the registered IP telephone numbers are numbers taken from the list 119 of available numbers, which in this embodiment is formed in SCP 111. SCP 111 also includes a table 121 with associations between the numbers in SCP's domain, ie. numbers in the number series 700-xxxx and IP telephone numbers, ie. number in the number series 900-xxxx. In all examples, x indicates a number. The format shown is of course only intended as an example. The addresses and / or telephone numbers can be in any format, including a combination of alphanumeric or other characters.

As shown in Figure 2, to illustrate the invention, the terminals 107, 109 connected to the telecommunication network 101 are identified by numbers in the domain of the SCP, 700, 5678 and 700-2345. One of the terminals 113 connected to the data communication network 103 is identified by a number in the domain SCP 700-1234. The second terminal 115 connected to the data communication network 103 is identified by a number 900-3456 in the domain of the gatekeeper 117. This means that terminal 115 which has a number in the gatekeeper's domain only needs an IP address associated with its number, and that the association is registered in the first table 118. Terminal 113 with only one number in SCP's domain must first be assigned a number in the gatekeeper's domain, the assignment registered in SCP and then an IP address associated with the number in the gatekeeper's domain. The procedure for assigning numbers is described in more detail in connection with Figures 3 and 4.

Calls can be made from a terminal in the telecommunication network 101 to a terminal connected to the data communication network 103, or between two terminals connected to the data communication network. The procedure for making a call is described in more detail in connection with Figure 5.

In a third embodiment, which is not shown in the gurus, there is the list of numbers which can be assigned dynamically in the interconnecting means 5, resp. 105, instead of in a node in one of the subnets. 10 15 20 25 30 »| | The terminals connected to the data communication network may be terminals intended specifically for telephony in an IP network, or computers or computer terminals equipped with the hardware and software required for IP telephony.

Figure 3 is a fate diagram of steps performed to temporarily register an IP telephone in the network shown in Figure 1 and to ensure that any calls made to one or your specified numbers are routed to this IP telephone. It is assumed that the IP phone has a permanent IP address or has already been given a dynamic IP address before the procedure begins. The procedure for assigning dynamic IP addresses is well known to those skilled in the art.

Step S301: Step S302: Step S303: Step S304; Step S305: Step S306: The IP phone logs in to the registration body, ie. in the example shown in Figure 1, the gatekeeper. The login includes the phone number or numbers, and the IP address or host atom of the IP phone. Some or all of these numbers and addresses may be pre-entered in the login window in a manner that is common to login procedures.

If the number to be registered is in the domain of the registration body, go to step S306, otherwise, go to step S303.

Does the registration body have an associated number routing body for this domain? If yes, go to step S304, if not, go to step S308.

A number is taken dynamically from a subset of the previously unused numbers in the domain of the registration body.

The registration body informs the call routing body, ie. In the example shown in Figure 1, SCP, the assigned dynamic address is to be used to identify the IP telephone in question. This is indicated as a dashed line between the recording means and the call routing means in Figure 1.

The registration body associates the newly assigned number in the registration body with the IP address registered in the registration body. 10 15 20 25 30 m. In o n n i. »« ~ ».N i. n. on u »u; o 1 i I 1 n | . z- »n - 1 -f v v v v. n- 1-1 - s i u. ø-n n of f. n 1 - »t. I u» u | - u u t i. w U z- - | «A 'i 1 9 Step S307: The registration body confirms the registration of the IP telephone to the user of the IP telephone. End the procedure.

Step S308: Registration is denied. End the procedure.

In the discussion above, it has been assumed that the table of available numbers in the domain of the second subnet is found in the registration body of the other subnet. However, it can be located in any other node in the overall network, such as the call routing means or the collaboration means.

Figure 4 is a fl fate diagram of steps performed to register an IP telephone, i.e. corresponding to the procedure shown in Figure 2, assuming that the list of available numbers is handled by the call routing body.

Step S401: The IP phone logs in to the registration body, ie. in the example shown in Figure 2, the gatekeeper. The login includes the phone number or numbers, and the IP address or host computer of which the IP phone is located. Some or all of these numbers and addresses may be pre-entered in the login window in a manner that is common to login procedures.

Step S402: If the number to be registered is in the domain of the registration body, go to step S406, in another case, go to step S403.

Step S403: Should the number be registered in a domain for which the registration body has an associated call routing body? If yes, go to step S404, if not, go to step S408.

Step S404: The registration body asks the call routing body to assign a dynamic address and associate this dynamic number with the telephone number to be registered. The number routing means assigns a dynamic address taken from a subset of available numbers. The assigned dynamic address is now marked as busy and cannot be assigned to another telephone number.

Step S405: The call routing means informs the recording means of the new dynamic address. 10 15 20 25 30 Step S406: Step S407: Step S408:. - ». , n 519 458. ,. | . i p. The registration means associates the new dynamic address received from the call routing means with the IP address registered in the registration means.

The registration body confirms or denies the registration of the IP telephone to the user of the IP telephone. End the procedure.

Registration is denied. End the procedure.

Figure 5 shows the steps performed when someone makes a call that is forwarded to an IP telephone which is registered according to the procedure shown in Figure 2: Step S501: Step S502: Step S503: Step S504: Step S505: The calling party dials the desired telephone number .

The telephone number is recognized as one to be forwarded and is therefore forwarded to the call routing means which resolves the number and sends back the resulting number, which in this case will be a previously dynamically assigned number.

The gateway that handles the resulting number is identified, e.g. gateway 5 in Figure 1, and a call is connected through this gateway.

The gateway forwards the number to the registration body to be resolved to an IP address.

The call is connected to the IP address identified in step S504.

Figure 6 is a fate diagram of steps performed when the IP telephone is no longer to receive the calls to the affected telephone number: Step S601: The IP telephone is switched off, or a message is sent from the IP telephone to the registration body that the IP telephone is no longer to receive calls to a specific phone number.

If the IP telephone is switched off, all telephone numbers to be forwarded to this telephone will be deleted in the registration body and the forwarding means. If the IP telephone remains switched on, it can send a message to the registration body that one or more of the telephone numbers for which the IP telephone is no longer to be registered 5 Step S602: Step S603: Step S604: - ~ ~ <is 519 438 ll re shall be associated with it. Calls to other numbers can still be connected to the IP phone.

The registration body shall notify the call routing body that the association or associations shall be removed for the specified numbers.

The call routing means deletes the association or associations to be deleted.

The client is notified that the associations have been deleted. End of procedure ICII.

Claims (12)

1. 20 25 30 «| | 519 458 A patent communication network comprising at least a first and a second subnetwork connected by at least one connection means, which subnetworks use different addressing systems, characterized in that it comprises first address means for dynamically assigning a first address in the first subnetwork to a logical address in the second subnet and forwarding calls to the first address to the logical address in the second subnet, and second address means for assigning the logical address in the second subnet to a physical address in the second subnet and forwarding calls to the logical address in the second subnet to the physical address of the second subnet. A network according to claim 1, wherein the first and / or second address means is a gatekeeper for use in a data communication network. The network of claim 1, wherein the first and / or second address means is a home location register in a mobile telecommunications network. The network of claim 1, wherein the first and / or second address means is a switching control point in a telecommunication network. The network of claim 1, wherein the first and / or second address means is a SIP server in a data communication network. The network of claim 1, wherein the first and / or second address means is an ILS server in a data communication network. A method of a communication network comprising at least a first and a second subnet, the subnets having different addressing systems and being interconnected by at least one interconnecting means, characterized by the following steps: an association is created between a logical address of a terminal in the second subnet and a logical and / or physical address in the first subnet; an association is created between the logical address of said terminal in the second subnet and the current physical address in the second subnet; - when a call is made to said terminal in the second subnet from a calling terminal in the first or second subnet: - the number to find the associated logical address of the terminal is resolved, - the connection to the interconnection means is forwarded, - the number to find the associated physical address of the terminal, - a connection to the terminal is connected to the current address. The method of claim 7, wherein said first subnet is a data communication network according to the IP protocol, the second subnet is an intelligent telecommunication network and the interconnecting means is a gateway. A method according to claim 7, wherein said association between the logical address in the data communication network and the logical and / or physical address in the telecommunication network is made in a node in the data communication network. A method according to claim 8 or 9, wherein the association between the logical address in the data communication network and the logical and / or physical address in the telecommunication network is made in a node in the telecommunication network. The method of claim 10, wherein the telecommunication network is a PSTN network and said node in the telecommunication network is an SCP. The method of claim 10, wherein the telecommunications network is a cellular network and the node in the telecommunications network is a CPR.