WO2001076270A1 - Display of the extension number on calling a centrex group user - Google Patents

Abstract

The invention relates to a method and a telephone system, for the display of internal subscriber numbers on a telecommunication device. On making an outgoing call from internal subscribers (EN1 - EN3) on a telecommunication device (TKA), to external subscribers (EC1 - EC3), connected to the telecommunication device (TKA), by means of a telecommunication network (NET), a subscriber number (en1) for the calling internal subscriber (EN1) is determined by an exchange (VSA), from a number sent by the telecommunication device on the caller's side. Said subscriber number is transmitted to the remote station (EC1) being called, where said number is repeated on a suitable terminal, for example, shown on a display.

Description

_ANZE IG _ED ER EXTENSION NUMBER WITH CALL FOR CENTREX GROUPS Telnehmer

description

Method and telephone system for displaying internal connection numbers of a telecommunications system

The invention relates to methods for displaying connection ^¬ number of internal connections of a telecommunication system to external terminals, which are assigned via a telecommunication network by means of a established to switching center of the telecommunication system.

The invention further relates to a telecommunications system for displaying connection numbers of internal connections of a telecommunications system to external connections, the external connections being assigned to the telecommunications system via a telecommunications network by means of a switching center set up for this purpose.

Finally, the invention also relates to a telecommunications system and a switching center for a telecommunications system.

With the help of so-called Centrex groups ("Central Office Exchange Service *; see also: Bocker, Peter: Digital networks for voice, text, data, video and multimedia communication, Springer, 1997), it is possible to switch existing private branch exchanges to external ones Expand participants. These external subscribers are set up, for example, as normal individual connections in a public telecommunications network, but these can also be connections to another private branch exchange which are assigned to the existing private branch exchange via a (public) telecommunication network. If a subscriber dials an extension number assigned to a terminal of the private branch exchange from an external connection, a connection is established to this terminal and the extension number of the calling, external terminal is shown on the display of the selected terminal Participant or terminal displayed. The called part ^¬ participants can recognize hand the displayed number, that it is at the calling party to a subscriber of the Centrex group.

It should be noted at this point that in the following text, internal connections are always understood to be connections that are directly assigned to a telecommunications system, while external connections are to be understood as connections that are assigned to this telecommunications system as part of a Centrex group. The use of the terms

"Internal * and" external * are used primarily to make the text easier to read, since within the framework of Centrex groups, of course, two or more telecommunications systems can also be combined to form a Centrex group via a public telecommunications network. In this case, the calling connection of a telecommunications system is simply referred to as an internal connection and the called connection of another telecommunications system is referred to as an external connection, as is also the case with individual connections. With regard to the use of the word "assigned", it should also be noted here that, of course, in two or more telecommunications systems of a Centrex group, it cannot be clearly said which system is assigned to which. In this case, the designation is also used that the connections or telecommunication systems which are called are assigned to the system from which the call takes place.

If the call does not come from but to an external subscriber to the Centrex group, the problem arises that the display of the called terminal does not show the extension number of the calling subscriber, but rather the public number in the form of the external line number + area code + number of the private branch exchange + Extension number, ie 0 01 2501 24553 is displayed and not the extension number 24553. The called party is is in the situation that he does not recognize that the call is an internal call.

Furthermore, many end devices can store the call number of a calling subscriber, which can then be called back if necessary, for example by pressing a redial key. If, however, the public telephone number, not just the extension number stored so will not be established for an internal connection with a recall, but an expensive re ^¬ public connection.

It is an object of the invention to solve the above-mentioned problem in private branch exchanges which are expanded by external connections.

This object is achieved according to the invention by means of the method mentioned at the outset in that

In the case of an outgoing call from an internal connection to an external connection from a number on the caller's side signaled by the telecommunications system, a connection number assigned to the calling connection is determined by a switching center,

• the connection number is signaled in addition to a telephone number as an additional number by the exchange in the telecommunications network, and

• The additional number and the call number are transmitted to the external connection via the telecommunications network, so that the connection number of the calling connection is output on the external connection.

In the event that a call is set up from a connection of the telecommunications system to a remote station assigned to the telecommunications system, for example by means of a Centrex switching center, the invention is used In addition to the calling party number *, which is known to be formed from a telecommunications system number and the connection number and has the number type "national ^* ", an additional number ("additional calling party number *") is transmitted to the called party and there at one output corresponding terminal device, such as shown on a display.

In this case, a switching center which is directly assigned to the telecommunications system is expediently used to determine the connection number from the caller's number and to signal it to the telecommunications network.

The connection number of the calling connection can be determined in a simple manner in the switching center if the connection number is signaled to the switching center by the telecommunication system as the caller-side number.

It is advantageous if the number of the caller's number is signaled as "unknown". In this case, the number signaled by the telecommunications system is checked in the exchange and, in accordance with the applicable standards (ETSI 300 092-1), there remains in a message to be signaled by the exchange in the telecommunications network (“Initial Address Message *) in addition to a number for the number provided an information field for additional information.

If "unknown ^* " is therefore signaled as the number type of the caller's number, the additional number can be entered in addition to the telephone number by the switching center in a message which is signaled by the switching center to the telecommunications network.

The switching center uses the additional number of the number transmitted by the telecommunications system as the number type. te number type "unknown * the calling party side number signaled ^¬ Siert.

In the sense of a simple implementation of the method according to the invention, it is advantageous if the telecommunication system is configured accordingly in order to signal the connection number signaled by the calling internal connection and as its number type “unknown” into the telecommunication network or to the switching center to transfer.

In the above sense, it is also advantageous if the switching center is set up by means of software programming to signal the connection number signaled by the telecommunication system as an additional call number and as its number type the number type "unknown" signaled by the telecommunication system in the telecommunication network.

The additional number is signaled by the switching center to the telecommunications network using ISDN signaling.

According to the invention, the aforementioned object is also further achieved with a telecommunication system mentioned at the outset in that a switching center is set up to

To determine a connection number assigned to the calling connection in the case of an outgoing call from an internal connection to an external connection from a number on the caller's side signaled by the telecommunications system,

• signal the connection number in addition to a telephone number as an additional number in the telecommunications network, and • to transmit the additional number and the telephone number to the external connection via the telecommunications network, so that the connection number of the calling connection is output on the external connection.

Further advantageous embodiments of the telecommunications system can be found in the dependent claims 11 to 18.

The invention is explained in more detail below with reference to the drawing. In this the single figure shows a telephone system according to the invention for realizing a method according to the invention.

The figure shows a telecommunications network NET with exchanges VSA, VSC, VST. The exchange VSA is, for example, an ISDN subscriber exchange, to which a private telecommunications system TKA with the internal extension lines EN1-EN3 is assigned. Connections EC1-EC3 are also assigned to the telecommunications network via the switching centers VST remote stations GEG and via the switching center VSC.

The switching center VSC is a so-called Centrex switching center ("Central Exchange Office *), by means of which the existing telecommunications system TKA with the internal connections EN1 - EN3 can be expanded to include external terminals ECl - EC3 of the public telecommunications network. The exchange VSC can be, for example, a so-called EWSD (“Electronic Dialing System Digital *) of the applicant, which essentially consists of a coordination processor _, several (digital) subscriber line units (“ Line Units * or “Digital Line Units * ), Connection groups (LTG, "line / trunk group *) for connecting subscriber lines and connecting lines, a so-called switching network (SN," switching network *) for switching through the connections, 00 κ> OP o Cπ O π o Cπ

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Problems then arise when a call is set up from a connection EN1-EN3 with connection numbers enl-en3 of the telecommunications system TKA to a connection EC1-EC3 assigned to the telecommunications system TKA via a Centrex switching center VSC. In this case, about one

A call from the ENl connection does not show the connection number enl of the calling connection, but the public number consisting of the area code, the telephone number tkr of the telecommunications system and the connection number enl, which leads to the problems and disadvantages mentioned above with existing Centrex Leads groups.

These problems are now remedied by means of the invention in that a switching center, generally the switching center VSA directly assigned to the telecommunications system TKA, is set up by means of software programming to determine the connection number enl of the calling connection EN1 from the number signaled by the telecommunications system and to transmit this connection number as an additional number to the actual call number to the called connection EC1.

The "determination * of the connection number enl can be carried out in a particularly simple manner if the telecommunications system TKA is configured on the software side in such a way that it, as the number of the calling subscriber, only the connection number enl of the calling extension, ie. H. in the selected example the number enl = 24553 is signaled. It is furthermore advantageous if the status “UNKNOWN *”, ie unknown, is signaled as the number type (“type of number *, TON) of the number signaled by the telecommunications system TKA.

The call number is usually found as an entry in a message (“Initial Address Message *) IAM, which is signaled by the switching center VSA in the telecommunications network NET. This message IAM also contains another information field, in which in the event that no verification ("screening *) of the number on the caller side transmitted by the telecommunications system TKA takes place in the exchange VSA, from this an additional number is entered, which is formed according to the standards (ETSI 300 092-1) using the caller number. If, on the other hand, the caller number is checked in the exchange VSA, this field remains empty.

For the above-mentioned reason, the caller's number is signaled by the TKA telecommunication system with the number type TON = UNKNOWN. This number is checked in the VSA switching center (“screening *) and supplemented with a national number, i. H. the number type is set to "national *, TON = NATIONAL. The number formed according to this method is sent to the telecommunications network NET as the call number of the calling subscriber, that is to say as the “calling party number *”.

The telephone number, as already described above, is signaled as an entry in a message (“Initial Address Message *) IAM by the exchange VSA in the telecommunications network NET. The additional information field in the message IAM is empty due to the check as a result of TON = UNKNOWN of the caller's number, so that the connection number enl = 24553 of the calling connection ENl is used as an additional number in the exchange VSA for calls to an assigned Centrex connection ECl ("Additional calling party number *) can be entered.

The message IAM thus formed is signaled by the switching center VSA into the telecommunications network, to which the Centrex switching center VSC assigned to the called connection is transmitted, and from this the telephone number and the additional number are transmitted to the called connection without specifying a number type, so that the additional number enl is output on a suitable end device, for example on a display of the end device.

In accordance with the usual standards, the additional number with the number type TON = UNKNOWN, ie. H. with the number type of the caller's number.

In this context, it is important to mention that for the method according to the invention to work, it is necessary for the connection numbers enl - en3 of the internal connections and the connection numbers assigned to the external Centrex connections to be unique within the framework of the call number plan, so that the display of the additional number is clear. If, for example, the internal extension ENl has the connection number enl = 24553, no other internal or external connection may have the connection number 2, 24, 245, 2455 or 24553.

With the invention it can be achieved in a simple manner that in telecommunication systems which are expanded by means of Centrex switching centers by external connections EC1-EC3, at these external connections when calls from internal connections of the telecommunication system TKA always the extension or connection number of the calling party Is displayed. All that needs to be done is to configure the TKA telecommunications system, which is extended by external connections EC1 - EC3, so that in the case of a

Call to an external extension only the extension number is transmitted to the exchange VSA. The switching center must be programmed by the software so that it enters this extension number as an additional number in the message IAM signaled in the network, which extension number is then displayed on the terminal of the called connection.

However, it is not absolutely necessary that only the port number enl signals from the telecommunications system becomes. Since the telephone number tkr of the telecommunications system TKA is known in the switching center VSA, a number other than the connection number can also be signaled, and the connection number enl is determined therefrom in the switching center VSA and used for the method according to the invention.

At this point it should also be noted that the method according to the invention and the telephone system according to the invention can also be implemented by means of corresponding hardware solutions, and the claims are not directed solely to a software-based solution. However, software solutions are much cheaper and easier to implement, so they are usually preferred.

In order to better understand the invention, the numbers signaled by the telecommunications system TKA and the switching center VSA are shown, the numbers signaled by the switching center depending on the number signaled by the telecommunications system and the number of the transmitted number.

In the example shown in the table, it is assumed that the telecommunications system TKA is assigned a physical number tkr = 2501. The number of the local network of the telecommunication system is 01. Thus, for example, a switching center of the telecommunication systems can be reached at 01 2501 0.

Furthermore, in the example given, the telecommunications system can also be reached under the virtual number 05 1707, the number 05 1707 being converted to 01 2501 in the public telecommunications network NET.

The table now shows which number (“calling party number ^* ) and, if applicable, which additional number (“ additional calling party number *) from the switching center VSA to the Telecommunications network are signaled. These numbers signaled by the switching center depend on which number the telecommunications system signals, which number type (International, INT; National, NAT; Subsc ^¬ riber, SUB; Unknown, UNK) has this number, and on whether the number in the Exchange is checked ("screened *) or not.

When calling from an extension of the telecommunications anläge, wherein in the example shown, the extension number is assigned to 24553, is of the telecommuni ^¬ signaled number from the number of the telecommunication system and the secondary tion plant-point number to the switching center, and formed from the number type TON of the number sent.

If, for example, the telecommunication system is configured so that the number is formed using the virtual number assigned to the telecommunication system TKA, and if the number type is “international *, TON = INT, the number transmitted to the exchange has the form 43 5 1707 24553 , This "virtual * number is now converted in the exchange to the physical number of the telecommunications system TKA. Thus, in the event that the number transmitted by the telecommunication system is checked (“screened *), the switching center calls the number (“ calling party number *) - according to the applicable standards (ETSI 300 092-1) - the number 1 2505 0 is sent to the telecommunications network NET, the field for the additional number (“additional calling party number *) remains free in this case. If, on the other hand, the number sent by the telecommunications system is not checked in the exchange, the exchange also sends the additional number 43 1 1707 24553 to the network in addition to the call number 1 2501 0.

The situation is similar if the telecommunication system does not send the virtual but the physical number with TON = INT, i.e. 43 1 2501 24553. If screening takes place in the exchange, the number 1 2501 24553 and no additional number is sent to the telecommunications network. If no screening takes place, the call number 1 2501 0 and the additional number 43 1 2501 24553 are signaled in the telecommunications network NET. The number in the exchange is always formed with TON = NAT and the additional number with the number type signaled by the telecommunications system, in the selected examples with TON = INT and signaled in the telecommunications network. Since - contrary to the representation in the table - the additional number - if it is signaled - is entered in the IAM message in the IAM ("Initial Address Message *) signaled by the exchange, the additional number and not the number is also entered is displayed on the called connection.

So that the extension number 24553 is now displayed when calling an external connection of the telecommunications system, the telecommunications system is configured so that it only signals the extension number 24553 with the number type "unknown", TON = UNK to the exchange as number. On the basis of TON = UNK, the number sent is screened and, in accordance with the applicable standards (ETSI 300 092-1), the number 1 2501 24553 and the additional number 24553 are entered in the number to be signaled by the switching center VSA in the NET network, the Number type of the additional number TON = UNK. The fictitious case that the number sent by the telecommunications system TKA is not checked in the switching center despite TON = UNK is also shown in the table. As can be seen, in this case the call number 1 2501 0 would be from

Switch entered in the IAM message, the field for the additional number would remain free in this case, so that the number 1 2501 0 and not the number of the calling extension would be displayed for the called line.

Claims

claims 1. Method for displaying connection numbers (enl, en2, en3) of internal connections (ENl - EN3) of a telecommunications system (TKA) on external connections (ECl - EC3), which are transmitted via a telecommunications network (NET) by means of a switching center (VSC) set up for this purpose are assigned to the telecommunications system (TKA), characterized in that • in the case of an outgoing call from an internal connection (ENl) to an external connection (ECl) from a number on the caller's side signaled by the telecommunications system (TKA), a connection number (enl) assigned to the calling connection (ENl) is determined by a switching center (VSA) . • the connection number (enl) in addition to a telephone number as an additional number is signaled by the exchange (VSA) into the telecommunications network (NET), and • The additional number and the phone number are transmitted via the telecommunications network (NET) to the external connection (ECl), so that on the external connection (ECl) the connection number (enl) of the calling connection (ENl) is output. 2. The method according to claim 1, characterized in that a switching center (VSA) directly assigned to the telecommunications system (TKA) is used to determine the connection number (enl) from the caller's number and to signal it to the telecommunications network (NET). 3. The method according to claim 1 or 2, characterized in that as the caller Number of the telecommunications installation (TKA), the connection ^¬ number (enl) is signaled to the switching center (VSA). 4. The method according to any one of claims 1 to 3, characterized in that "unknown *" is signaled as the number type of the caller's number. 5. The method according to any one of claims 1 to 4, characterized in that the additional number is entered in addition to the phone number of the switching center (VSA) in a message (IAM), which the switching center (VSA) in the telecommunications network (NET) is signaled. 6. The method according to claim 4, characterized in that of the switching center (VSA) as the number type of the additional number of the Telecommunications system (TKA) transmitted number type "unknown *" of the caller's number (enl) is signaled. 7. The method according to claim 3 or 4, characterized in that the telecommunication system (TPCA) is configured accordingly in order to send the connection number (enl) signaled by the calling internal connection (ENl) as well as its number type "unknown" to the Transfer agency (VSA). 8. The method according to any one of claims 1 to 7, characterized in that the switching center (VSA) is set up by means of software programming to that of the telecommunications system (TKA). signaled connection number (enl) as an additional call number and as their number type to signal the number type "unknown *" signaled by the telecommunications system (TKA) in the telecommunications network (NET) or to be entered in the message to be signaled (IAM). 9. The method according to any one of claims 1 to 8, characterized in that the additional number is signaled by the switching center (VSA) by means of ISDN signaling in the telecommunications network (NET). 10. Telecommunication system for displaying connection numbers (enl, en2, en3) internal connections (ENl - EN3) of a telecommunication system (TKA) to external connections (E1C - EC3), the external connections via a telecommunication network (NET) by means of a switching facility set up for this purpose - Place (VSC) of the telecommunications system (TKA) are assigned, characterized in that a switching center (VSA) is set up to • in the case of an outgoing call from an internal connection (ENl) to an external connection (ECl) from a number on the caller's side signaled by the telecommunications system (TKA) to determine a connection number (enl) assigned to the calling connection (ENl), • signal the connection number (enl) next to a phone number as an additional number in the telecommunications network (NET), and • to transmit the additional number and the call number via the telecommunications network (NET) to the external connection (ECl), so that the connection number (enl) of the calling connection (ENl) is output on the external connection (ECl). 11. Telecommunication system according to claim 10, characterized in that a switching center (VSA) directly assigned to the telecommunication system (TKA) is used from the caller's number To determine the port number (enl) and to signal to the telecommuni ^¬ nikationsnetz (NET). 12. Telecommunications system according to claim 10 or 11, characterized in that the telecommunications system (TKA) signals the connection number (enl) to the switching center (VSA) as the caller-side number. 13. Telecommunication system according to one of claims 10 to 12, characterized in that the caller-side number has "unknown *" as the number type. 14. Telecommunication system according to one of claims 10 to 14, characterized in that the switching center (VSA) is set up to enter the additional number in addition to the call number in a message (IAM) which is sent from the switching center (VSA) to the telecommunications network ( NET) is signaled. 15. Telecommunications system according to claim 13, characterized in that the switching center (VSA) is set up to signal the number type "unknown *" of the connection number (enl) transmitted by the telecommunications system (TKA) as the number type of the additional number. 16. Telecommunication system according to claim 12 or 13, characterized in that the telecommunication system (TKA) is configured accordingly to the connection number (enl) signaled by the calling internal connection (ENl) and as its number type "unknown" to the switching center (VSA ) to be transmitted. 17. Telecommunication system according to one of claims 10 to 16, characterized in that the switching center (VSA) is set up by means of software programming to enter the connection number (enl) signaled by the telecommunication system (TKA) as an additional call number and as its number type the number type "unknown *" signaled by the telecommunication system (TKA) into the telecommunication network ( NET) or to be entered in the message to be signaled (IAM). 18. Telecommunications system according to one of claims 10 to 17, characterized in that the switching center (VSA) is set up to signal the additional number by means of ISDN signaling in the telecommunications network (NET). 19. Telecommunication system (TKA) for a telecommunication system according to one of claims 10 to 18. 20. Exchange (VSA) for a telecommunications system according to one of claims 10 to 18.