EP1074155A2 - Network coupling unit for a communications system - Google Patents

Abstract

Data can be transmitted between networks with different topologies (data network, communications network) connected to the network coupling unit (IGATE) through a network coupling unit (IGATE) configured as a subscriber interface module by means of the communications system (PBX). To this end, the network coupling unit (IGATE) has a unit (BW-R) for evaluating routing information obtained from the transmitted data, a unit (VM-R) for target-oriented data transmission depending on evaluation results and a unit (KV-R) for data format adaptation.

Description

description

Network coupling unit for a communication system

Due to the increasing flexibility of working conditions in terms of time and space, the number of employees who do not perform their professional tasks at their workplace in the company is constantly increasing. From "The virtual office" telcomreport, Issue 4, 1997, Siemens AG Berlin and Munich, it is known that for the effective completion of tasks outside the company, access to the local data resources of the company (in the literature also with ^λ remote LAN '') and on the other hand access to the communication features offered in the company's local communication network (also referred to in the literature as ^x remote PBX ') is necessary regardless of the location of the employee. The features include those in addition to the standard ones , for example, ISDN-oriented communication network provided features, such as setting up a conference call or signaling a message input.

In current communication systems, connection options to a communication network brought up to the communication system are realized, for example, by means of primary multiplex connection units arranged therein, which are also referred to as S ₂ M connections. The communication network can be implemented, for example, by an ISDN-oriented communication network (Integrated Services Digital Network). For access via the ISDN-oriented communication network to a local data network, for example an Ethernet LAN (local area network) connecting several personal computers, an external network coupling unit connected to a further S ₂ M connection is often used in the literature as ^λ Router 'denotes - a connection between the ISDN-oriented communication network and the local data network realized. For this purpose, the ^y router 'is equipped both with an S ₂ M ^_ interface and with a standard LAN interface, the S _2M interface with the output of the S _2M connection unit of the communication system and the LAN interface of the router' is connected to the local data network.

With regard to its essential function, a ^λ router 'realizes layer 3 (network layer) of the OSI reference model (Open Systems Interconnection), with the help of a' router 'physically networks with different topologies of layers 1 (physical layer) and 2 (data link layer) ) are connected - for example, Ethernet LAN and ISDN-oriented communication network. In order to convey data packets between the networks connected to a 'router', the address details contained in the routing information of the data packets - destination and origin address - are interpreted and evaluated by a control device located in the ^λ router. The data packets are then converted in accordance with the protocol for transmission.

In order to be able to provide the performance features implemented by the communication system and made available on internal subscriber lines on an external terminal, for example a terminal connected to the communication system via an ISDN-oriented communication network, in the same way as on an internal terminal - as in the frame des ^λ Teleworkings' - has already been proposed in the German patent application with the file number P19808368.8, terminal-oriented signaling information, as is usually transmitted as part of a signaling protocol between the communication system and internal terminals connected to it, between the communication system and the external terminal via a further user data connection set up in addition to the user data connection (for example a first ISDN-oriented B channel) fertilizer (e.g. a second ISDN-oriented B channel).

The external terminal is connected via the further user data connection to a computer connected to the local data network (often referred to in the literature as 'teleworking server'), which controls the transmission of the terminal-oriented signaling information between the communication system and the external terminal. The data format of the user data connection is converted in an external 'router', e.g. the data format of an ISDN-oriented B channel to the data format of the local data network.

In general, an S ₂ M interface comprises on the one hand 30 user data channels, which are designed as ISDN-oriented B channels with a transmission rate of 64 kbit / s, and on the other hand, a signaling channel, which is an ISDN-oriented D channel with a transmission rate of 64 kbit / s is designed. This means that the S ₂ M interface for connecting the external 'router' is only optimally used for larger local data networks. In the case of smaller local data networks, the user data channels of the S _2M interface are physically occupied by the connection of the 'router' and any available transmission capacities cannot be used for other purposes, for example for connecting a communication terminal.

The present invention is based on the object of specifying measures which optimize access to a local data network connected to a communication system, in particular as part of 'teleworking'.

According to the invention, this object is achieved with the features of patent claim 1. An essential advantage of the network coupling unit according to the invention is that its design as a unit that can be integrated in the communication system, compared to an arrangement with an external 'router', considerably simplifies the system. Since the bidirectional time-multiplex-oriented coupling connections of the switching matrix module are connected directly to the local data network connected to the communication system via the network coupling unit or via the conversion unit arranged therein, data packets transmitted to the communication system or to the network coupling unit can be networks connected to the communication system - for example between an ISDN-oriented communication network and an Ethernet LAN - are transmitted via the network coupling unit arranged in the communication system using only the communication system. The arrangement of the network coupling unit in the communication system means that an economically complex connection of an external 'router' - for example an 'ISDN router' - including the S _2M interface of the communication system necessary for connecting the external 'router' can be dispensed with, and thus also Inexpensive switching connection between a local data network - for example an Ethernet LAN - and the communication network - for example an ISDN-oriented communication network - can be created.

Another advantage of the network coupling unit according to the invention is that by concentrating the system components required for router functionality and for 'teleworking' on a common assembly, the program-related changes relating to their function are simple and without interfering with the central control of the communication system can be made.

Another advantage of the network coupling unit according to the invention is that the implementation of the necessary for a router functionality and for a 'teleworking' -ended system components on a common assembly nikationsnetz for providing realized by the communication system performance to an external Endgerat a Kommu ^¬, only a payload (instead of two payload data) for the transmission of useful data and of endgerateoπentierten Signalisierungsmformatio- NEN between the external Endgerat and the network coupling unit must be built.

Advantageous developments of the invention are specified in the subclaims.

By arranging a DTMF recognition unit and an output unit for stored voice messages or text messages on the network coupling unit, the performance features implemented by the communication system can also be provided on any external terminal devices - and not only on terminal devices designed for 'teleworking'.

Em exemplary embodiment of the invention is explained in more detail below with reference to the drawing.

Show:

1: a structural diagram for the schematic representation of a communication system with a network coupling unit arranged thereon; 2: a structural diagram for the schematic representation of the essential functional units of the network coupling unit;

3: a structural diagram for the schematic representation of two communication systems according to FIG. 1 arranged in a communication network.

1 shows a schematic illustration of a communication system PBX with a network coupling unit arranged in it and configured as a subscriber line unit IGATE. The PBX communication system has further participants. Network connection units - a first and a second connection unit ABG1, ABG2 are shown by way of example - for connecting communication terminals or for a connection to further communication systems arranged in a communication network KN. Furthermore, the communication system PBX contains one, several bidirectional, time-multiplex-oriented coupling connections KAl, ..., KAk having coupling field module KN, whereby the time-division-oriented coupling connections KAl, ..., KAk as PCM- Connections (pulse code modulation) - also referred to as PCM highways, speech highways or S _2M connections. Each PCM highway comprises 30 user channels, which are designed as ISDN-oriented B channels (I_ntegrated Services Digital Network) with a transmission rate of 64 kbit / s, and secondly, a signaling channel, which is an ISDN-oriented D channel is designed with a transmission rate of 64 kbit / s. Via the coupling connection KAk, the switching matrix module KN is connected to a bidirectional, time-division-oriented PCM interface PCMS of the network coupling unit IGATE. Via the further PCM connections KAI, KA2, the switching network module KN is connected to a bidirectional, time-division-oriented connection SK of the first and the second connection unit ABG1, ABG2.

Furthermore, a control unit STE having a plurality of control connections SA1, ..., SAk is arranged in the communication system PBX. The control unit STE is connected to a control input SM of the switching matrix module KN via a control connection SAk. Via the further control connections SA1, ..., SA3, the control unit STE is connected on the one hand to an HDLC interface HDLCS arranged on the network coupling unit IGATE and on the other hand to control connections SM of the first and the second connection unit ABG1, ABG2.

At a mains connection NA - for example, a bidirectional, time multiplex-oriented terminal S _2M ^_ - the first arrival End unit ABG1 is a communication network KN consisting of a plurality of communication systems connected to one another - for example an ISDN-oriented communication network. A first external terminal KE1 with a data processing device DV, which is configured, for example, as a personal computer or as a plug-in card for an existing terminal, and a second external terminal KE2 are connected to the communication network KN. At a first subscriber connection TI - for example at an S ₀ connection (2B + D, ie 2 ISDN-oriented user data channels and an ISDN-oriented signaling channel) - the second connection unit ABG2 has a first internal terminal KE3 with a communicating Call system internal call number 6833 and a second internal terminal KE4 with a call system internal call number 4711 connected to a second subscriber line T2.

A local area network LAN - e.g. an Ethernet LAN (Local Area Network) - is connected to the IGATE network coupling unit via a LAN interface LANS. Through the local network LAN, several computers D-S, TW-R, e.g. 'Personal Computer' or 'Multimedia Workstations' - connected.

2 shows a schematic representation of the essential functional units of the network coupling unit IGATE. The network coupling unit IGATE has a LAN connection unit LAN-AE with a LAN interface LANS, the LAN interface LANS being connectable to the local network LAN. The network coupling unit IGATE also has a PCM connection unit PCM-AE with a bidirectional, time-division-oriented PCM interface PCMS, the PCM interface PCMS being connectable to the coupling connection KAk of the switching matrix module KN of the communication system PBX. Furthermore, the PCM connection unit PCM-AE ^"has a module switching matrix module which is connected to the PCM interface PCMS

BG-KN on. A DTMF recognition unit DTMF and an output unit S-AE are also present in the PCM connection unit PCM-AE. orderly. The DTMF recognition unit DTMF is used to recognize and evaluate control information received via a user data connection in the form of DTMF signals via the PCM interface PCMS. The output unit S-AE is used to transmit stored voice messages via a user data connection to an external terminal KE2.

Furthermore, a signaling unit SE with an HDLC interface HDLCS is arranged on the network coupling unit IGATE. The signaling unit SE can be connected to the control connection SA1 of the control unit STE of the communication system PBX via the HDLC interface HDLCS. The LAN connection unit LAN-AE, the PCM connection unit PCM-AE and the signaling unit SE are each connected via a connection UA to a connection EL, EP, ES of a conversion unit MH arranged on the network coupling unit IGATE.

The conversion unit MH has a control unit SU. With the help of the control unit SU, data transmitted between the local area network LAN and the user data channels of the user interface brought to the network coupling unit IGATE are transmitted to the network coupling unit IGATE or to the LAN connection unit LAN-AE or the PCM connection unit PCM-AE or the signaling unit SE Communication network KN transmitted.

For this purpose, the control unit SU of the conversion unit MH has an evaluation unit BW-R for evaluating routing information containing m data to be transmitted - ie target and source data - and a switching unit VM-R for transmitting the data from and to the local network LAN or from and to the communication network KN depending on the evaluation result. Furthermore, a conversion unit KV-R of the control unit SU converts signaling information in accordance with the protocol. For this purpose, in the case of data to be transmitted to the local area network LAN, the signaling information received at the signaling unit SE converted into appropriate routing information and the user data arriving at the PCM connection unit PCM-AE, together with the routing information formed, converted into format-correct data, ie data adapted to the LAN format, and transmitted to the LAN connection unit LAN-AE.

For an exchange of data between the local area network LAN connected to the network coupling unit IGATE and the communication network KN, the LAN connection unit LAN-AE or the LAN interface LANS is a unique, i.e. assigned worldwide valid identification or address. Since the applications implementing the data exchange - e.g. a software module implementing data exchange - the LAN connection unit LAN-AE has several, on different levels of the OSI reference model

Valid identifications or addresses are assigned to the levels of the OSI reference model. The LAN connection unit LAN-AE is assigned a unique, module-specific LAN identification ac. The module-specific LAN identification mac realizes a hardware address of the LAN interface LANS located on layer 1 of the OSI reference model and is stored in a non-volatile memory PROM arranged on the network coupling unit IGATE.

In addition, the LAN connection unit LAN-AE is assigned a unique logical network identification or network address ipag. This is 4 bytes long and represents an address of layer 3 of the OSI reference model - for example an Internet protocol address. The logical network identification ipag identifies both the LAN connection unit LAN-AE and the local network LAN connected to the LAN connection unit LAN-AE. The logical network identification ipag is stored in a memory area SP1 of a volatile memory SPF arranged on the network coupling unit IGATE.

The network coupling unit IGATE additionally has a control unit STW, which has a protocol unit PROT and a Has filter unit FWALL. The control STW is connected via control connections SW to the LAN connection unit LAN-AE, the PCM connection unit PCM-AE, the signaling unit SE of the conversion unit MH and the memories PROM and SPF. The PROT protocol unit realizes the transmission of data to be transmitted between the local area network LAN, the communication network KN and internal terminals KE3, KE4 connected to the communication system PBX. The PROT protocol unit contains the Internet-specific protocols TCP / IP (Transmission Control Protocol /

Internet Protocol), H.323 as well as the PPP protocol (Point-to-Point Protocol) designed for the transport of TCP / IP data packets and H.323 data packets via a point-to-point connection and for H.320 protocol designed for the transmission of voice and data via an ISDN-oriented connection.

The FWALL filter unit provides a safety decoupling of the networks LAN, KN connected to the IGATE network coupling unit. The filter function implemented in the filter unit FWALL checks data access from the local network LAN to a possibly further local network within the communication system, and data access via the communication network KN to the local network LAN for authorization. For the implementation of the filter functions, both the origin and destination addresses contained in the routing information of the data to be transmitted are checked for admissibility (this check is often referred to in the literature as a source and destination check). When checking the originating address, the call number of the calling communication terminal is checked against a list (not shown) with predetermined, authorized call numbers (is often referred to in the literature as subscriber authentication) and thus impermissible connections when a connection is established via the communication network KN prevented via the communication network KN. Furthermore, the logical network identification ipag of data packets arriving at the LAN connection unit LAN-AE is checked. If the source address for the off ^¬ exchange authorized data via the network coupling unit IGATE, the destination address contained in the routing information under the above criteria is checked. In addition, an authentication check of the source address can be carried out using the PAP (Password Authentication Protocol) and CHAP (Challange Handshake Authentication Protocol) protocols provided in the PPP protocol.

After a successful run of the data through the filter functions, i.e. After determining the authorization of the data exchange between the communication terminals designated by the origin and destination address, the routing functions implemented on the network coupling unit IGATE or on the conversion unit MH and the protocol unit PROT will result in the destination address or logical network identification contained in the data ipag rated. If the local network LAN is determined by the logical network identification ipag, the data are conveyed accordingly in the aforementioned manner via the conversion unit UE.

The volatile memory SPF also has a third memory area SP3 for storing logical target network identifications ipel, ..., ipek from further communication systems arranged in the communication network or the local networks connected to them, which are used for data exchange with the local one Network LAN or with the communication terminals connected to the local network LAN are provided. For this purpose, in a fourth memory area SP4 of the volatile memory SPF assigned to the third memory area SP3, a communication network identification rnl,..., Rnk from corresponding network coupling units arranged in the further communication systems is stored. Each logical destination network identification ipel, ..., ipek stored in the third memory area Sp3 is at least one communication network identification rnl, ..., rnk assigned. By the control unit STW he _d network coupling unit IGATE arranged more Konvertie ^¬ approximation unit KVK-R is at, IPEL to a valve disposed in the communication network KN communication system to be transmitted data corresponding stored in the third memory area SP3 destination logical network identification, ... , ipek determined and based on the assigned communication network identification rnl, ..., rnk stored in the fourth memory area SP4, a corresponding user data connection is established via the communication network KN.

So that further communication systems arranged in the communication network KN can establish a corresponding user data connection to the communication system PBX or to the network coupling unit IGATE, the network coupling unit IGATE is assigned a unique communication network identification rnw, which is stored in a second memory area SP2 of the volatile memory SPF.

The exchange of data between local networks LAN1, LAN2 connected to a network coupling unit IGATE1, IGATE2 and between a local network LAN1 and an external terminal KE11 connected to a communication network KN is to be explained in more detail using the structure diagram shown in FIG. The structure picture shows a schematic representation of two communication systems PBX1, PBX2 arranged in a communication network KN and configured according to FIG. Both communication systems PBX1, PBX2 are connected to the communication network KN via a PCM connection unit PCM-AE1, PCM-AE2. Both communication systems PBX1, PBX2 have a network coupling unit IGATE1, IGATE2 according to FIG. 2.

The network coupling unit IGATE1 arranged in the first communication system PBX1 has a first ^" LAN connection unit LAN-AE1 with a - not shown - LAN interface. The first LAN connection unit LAN-AE1 is a four byte long, logical network identification ipagl = 139.1 .20.0 assigned arranges. The network coupling unit IGATE2 arranged in the second communication system PBX2 has a second LAN connection unit LAN-AE2 with a - not shown - LAN interface. A logical network identification ipag2 = 140.7.27.0 is assigned to the second LAN connection unit LAN-AE2. In the following, only logical network identifications ipag or the internet protocol addresses assigned to the individual units or local networks are considered, ie the transport realized in layers 3 and 4 of the OSI reference model or the transport carried out therein arranged TCP / IP protocols controlled exchange of data packets explained in more detail.

A first local area network LAN1 is connected to the first LAN connection unit LAN-AE1, via which a communication terminal KE10 is connected to the network coupling unit IGATE1 or to the first communication system PBX1. The logical network identification, i.e. the standardized internet protocol address is according to version 4, i.e. it consists of 4 bytes structured. Here, the local network can be clearly identified by the addressing information comprising the first 3 bytes and the communication terminal KE10 can be identified in the local network by the addressing information comprising the last byte. By assigning the Internet protocol address ipagl = 139.1.20.0 to the first LAN connection unit LAN-AE1, both the first LAN connection unit LAN-AEl and the associated first local area network LANl are ipag = by the first three bytes 139.1.20 identified. The KE10 communication terminal connected to the first local area network LAN1 accordingly has the Internet protocol address ipag = 139.1.20.1.

A second local area network LAN2 is connected to the second LAN connection unit LAN-AE2, via which a communication terminal KE12 is connected to the network coupling unit IGATE2 or to the second communication system PBX2. The second lo- connected to the second LAN connection unit LAN-AE2 The Internet protocol address ipag = 140.7.27 is assigned to the network LAN2. This is the second local area network LAN2 ^¬ connected communication terminal KE12 accordingly has the Internet Protocol address ipag = 140.7.27.1 on. Furthermore, an external communication terminal KE11 is connected to the communication network KN, which has the Internet protocol address ipag = 172.16.0.8.

In the case of data to be transmitted from the communication terminal KE10 connected to the first communication system PBX1 to the communication terminal KE12 connected to the second communication system PBX2 - indicated by a dotted line VI - these have the Internet protocol address ipag = 139.1.20.1 as the original address and the internet protocol address ipag = 140.7.27.1 as the destination address. On the basis of the destination address, with the aid of the evaluation and switching units KNK-R, VM-R arranged on the network coupling unit IGATE1, the call number of the network coupling unit IGATE2 arranged in the second communication system PBX2 is determined and a corresponding user data connection is established to the network coupling unit IGATE2 addressed by the call number. By means of the evaluation and switching units BW-R, VM-R arranged on the network coupling unit IGATE2, the transmitted data packets are transmitted to the second local area network LAN2 or to the communication terminal device KE12 in accordance with the destination address ipag = 140.7.27.1.

In the case of data to be transmitted from the external communication terminal KE11 connected to the communication network KN to the communication terminal KE10 connected to the first communication system PBX1 - indicated by a dashed line V2 - in a first step, one is based on the call number of the network coupling unit IGATE1 in the first communication system PBX1 User data connection ^" between the external communication terminal KEll and the network coupling unit IGATE1 arranged in the first communication system PBX1. The transmitted data have the Internet protocol _Ad ress ipag = 172.16.0.8 as the origination address and the Inter net ^¬ protocol address ipag = 139.1.20.1 to as the destination address. The data packets transmitted are arranged in accordance with the destination address ipag = by the evaluation and switching units BW-R, VM-R arranged on the network coupling unit IGATE1

139.1.20.1 transmitted to the first local area network LAN1 or to the communication terminal KE10.

The interaction of the essential system components required for 'teleworking' will be explained in more detail below with reference to FIGS. 1 and 2:

In order to provide performance features realized by the communication system PBX and available at internal subscriber connections TI, T2 to an external communication terminal connected to the communication network KN and designed for 'teleworking', terminal-oriented signaling information is provided which is based on a signaling protocol Cornet-TS, as is usually the case when exchanging signals between internal terminals KE3,

KE4 and the communication system PBX is available based between the external communication terminal and the communication system PBX transmitted. The transmission of the terminal-oriented signaling information between the external communication terminal and the communication system PBX is controlled, for example, by a computer arranged in the local area network LAN - referred to below as the teleworking computer TW-R.

If, for example, a 'teleworking' registration is initiated by a subscriber on the first external terminal KE1, a user data connection DV - shown in dashed lines in FIG. 1 - between the first external terminal KE1 and the ^" teleworking computer TW-R via the network coupling unit IGATE the first connection unit ABGl, the switching matrix module KN and the network coupling unit IGATE. _F is ÜR the application of the first external terminal KEl at the telephoto ^¬ working machines TW-R by the subscriber, for example, the communication-system-internal telephone number of a subscriber associated internal terminal - for example, the number 4711 of the second internal terminal KE4 - and an associated subscriber-specific identification number PIN (Private Identification Number) - for example the PINA. The registration information is transmitted to the teleworking computer TW-R via the user data connection DV. If the subscriber is not assigned an internal terminal KE3, KE4 connected to the PBX communication system, the telephone number of a fictitious connection port - that is a purely logically available connection port of the PBX communication system that has only hardware components and has no hardware components - can alternatively be transmitted.

A check on the registration of the first external terminal KE1 takes place on the basis of a list (not shown) which is stored in the teleworking computer TW-R and which contains the telephone numbers or code numbers PIN authorized for 'teleworking'. Once the verification has confirmed the registration, the teleworking computer TW-R will send the first external terminal KE1 a fictitious connection port - e.g. the fictitious connection port FP with the internal call number 3200 - assigned to the network coupling unit IGATE. At the same time, by activating the 'call forwarding' feature implemented by the PBX communication system, all calls directed to the internal connection port designated by the internal communication system number are redirected to the fictitious connection port FP of the network coupling unit IGATE.

In addition, all terminal-oriented signaling information to be transmitted from the control unit STE of the communication system PBX to the second internal terminal KE4 (internal communication system number 4711) - the registration of the first external terminal KE1 on the communication system provided PBX system with the number of the second internal kommunikationssystemmternen Endgerats KE4 - ven to the fikti ^¬ _A nschlußport FP (with the kommunikationssystemmternen Ru _f number 3200) redirected the Netzkopplungsemheit IGATE. The terminal-oriented signaling information is transmitted from the control unit STE of the communication system PBX to the network coupling unit IGATE, from which it is forwarded to the first external terminal KE1 in the manner described above.

By transmitting terminal-oriented signaling information based on the Cornet-TS signaling protocol to the first external terminal KE1, all the features realized by the communication system PBX m are made available to the first external terminal KE1 in the same way as the second internal terminal KE4. A transmission of terminal-oriented signaling information from the first external terminal KE1 - assuming that it has logged on to the communication system PBX - to the control unit STE of the communication system PBX is carried out in the same way in the opposite direction.

In the event of a connection being set up by the first external terminal KE1 - assuming it has registered with the PBX communication system - which is done, for example, by lifting the handset on the first external terminal KE1 - with a further (internal or external) terminal - for example with the first internal terminal KE3 - A connection establishment message is transmitted via the user data connection DV to the teleworking computer TW-R. The teleworking computer TW-R forwards a connection establishment message for the fictitious connection port FP of the network coupling unit IGATE to the control unit STE of the communication system PBX. Thereupon a first step from the control unit STE of the communication system PBX is a partial connection between the fictitious connection port FP of the network coupling unit IGATE and the switching matrix module KN of the communication system PBX by occupying a constructed free useful channel of which Netzkopplungsemheit IGATE with the _K ouble unit KN interconnecting PCM highways.

In a next step, the teleworking computer TW-R transmits a readiness message to the first external terminal KE1 via the user data connection DV. The first external terminal KE1 then sends in a reply message the number assigned to the first external terminal KE1 in the communication network KN to the teleworking computer TW-R. In a further step, a further partial connection to the first external terminal KE1 is set up, starting from a further fictitious connection port RP of the network coupling unit IGATE (often referred to in the literature as a remote port). After coupling the partial connection with the further partial connection in the BG-KN module coupling module of the network coupling unit IGATE, a dial tone sounds at the first external terminal (signals the readiness to give dialing information).

The KEl then entered on the first external terminal

Dialing information - for example 6833 for the first internal terminal KE3 - is transmitted via the user data connection DV to the network coupling unit IGATE and from there forwarded to the control unit STE of the communication system PBX. The control unit STE of the communication system PBX then sets up a terminal connection between the first internal terminal KE3 and the first external terminal KE1.

In the event of a connection being set up on the basis of a further (external or internal) terminal with the second internal terminal KE4, the first external terminal KE1 having to register with the telephone number of the second internal terminal KE4, which is internal to the communication system, is activated on the basis of the activated call forwarding for the second internal

Terminal KE4 of the communication system PBX a partial connection between the further terminal and the fictitious connection port F _{P of} the network coupling unit IGATE. In a night vi ^¬ sten step a providing ^¬ shaft is transmitted message to the first external Endgerat KEl via the payload DV from the teleworking computer TW-R. The first external terminal KE1 then sends in a response message the number assigned to the first external terminal KE1 in the communication network KN to the teleworking computer TW-R. In a further step, starting from the further fictitious connection port RP of the network coupling unit IGATE, a further partial connection to the first external terminal KE1 is set up. In a final step, the partial connection and the further partial connection are coupled in the module coupling field module BG-KN of the network coupling unit IGATE, as a result of which the terminal connection between the first external terminal KE1 and the further terminal is established.

H.323 data packets based on the PPP protocol transmit the language and the terminal-oriented signaling information between the network coupling unit IGATE and the first external terminal KE1. With the help of the H.323 protocol, the terminal-oriented signaling information to be transmitted and the language are compressed and m, data packets based on the TCP / IP protocol are converted.

After the end of the connection between the first external terminal KE1 and the other terminal connection, the further fictitious connection port RP of the network coupling unit IGATE is released by the teleworking computer TW-R and thus stands for a new connection between any terminal registered on the communication system PBX and another Terminal device available. The fictitious connection port FP of the network coupling unit IGATE, however, remains assigned to the first external terminal KE1 and is only released after the first external terminal KE1 has been deregistered by the subscriber. After logging off, the deactivation of call forwarding on the com- mumkationssystem PBX that the PBX munikationssystems Kom ^¬ _d from the control unit STE to the subscriber to be transmitted en random-oriented signaling information to the terminal port assigned to the subscriber internal Endgerats - the second internal example, to the connection port

Terminal KE4 with the communication system internal call number 4711 - transmitted.

To provide performance features implemented by the PBX communication system and available at internal subscriber connections TI, T2 to any external communication terminal connected to the communication network KN, control information in the form of DTMF signals (Dual Tone Multi Frequency) is transmitted via a voice Connection from the external terminal to the network coupling unit

IGATE communicates. For the DTMF signals, a characteristic signal is assigned to each key of a terminal, which signal is transmitted via the voice connection when the key is pressed. The signal differs in frequency and signal duration from the data usually transmitted via the voice connection, so that the signals can be identified and evaluated on the IGATE network coupling unit.

The external terminal can be connected via any communication network, e.g. an analog communication network, an ISDN-oriented communication network or a radio network can be connected to the communication system. The only requirements for the external terminal are that the DTMF dialing method (multi-frequency dialing method) for generating DTMF signals is supported by the external terminal.

To register the second external terminal KE2 with the communication system PBX, a subscriber, for example, enters a 'teleworking' number on the second external terminal KE2. A voice connection is then set up between the second external terminal KE2 and the network coupling unit IGATE. In order to identify the second external terminal KE2 on the communication system PBX, the output unit S-AE arranged on the network coupling unit IGATE transmits a first recorded voice message to the second external terminal KE2, which prompts the subscriber to send the second external terminal KE2 in Enter the network number assigned to the communication network KN - hereinafter referred to as manual identification. In addition, for authentication of the subscriber, the output unit S-AE transmits a second recorded voice message to the second external terminal KE2, which prompts the subscriber to enter a personal identification number PIN (Personal Identification Number). This form of DTMF signals transmitted over the voice connection and identification data are evaluated by the DTMF recognition unit DTMF and forwarded to the teleworking computer TW-R via the LAN connection unit LAN-AE. By means of the teleworking computer TW-R, the second external terminal KE2 is identified as identified, for example by an entry of the second external terminal KE2 in a list (not shown), provided this has not already been done in an earlier identification.

The code PIN transmitted in the authentication data is used to determine the internal subscriber connection port of the communication system PBX via which the subscriber would like to log on to the communication system PBX using a list (not shown) stored in the teleworking computer TW-R. If, for example, the PIN A is transmitted as part of the authentication, the second external terminal KE2 is registered for the second internal terminal KE4. In addition, the participant can be asked to provide a personal password. Was the number assigned to the second external terminal KE2 in the communication network KN, for example in the context of an ISDN connection (as part of the 'callmg party nu ber' feature), automatically transmitted from the second external terminal KE2 to the network coupling unit IGATE - hereinafter referred to as automatic identification - , the teleworking computer TW-R checks whether the second external terminal KE2 has already been identified, ie whether there is already an entry for the second external terminal KE2 in the list. If the second external terminal KE2 has not yet been identified, the output unit S-AE of the network coupling unit IGATE transmits the second recorded voice message to the second external terminal KE2, which prompts the subscriber to enter the personal identification number PIN and / or the personal password.

The identification number PIN transmitted by the subscriber can alternatively be assigned to a fictitious connection port of the communication system PBX. This means that even subscribers who are not assigned a physically available internal terminal can use the features of the PBX communication system on the external terminal.

The registration of the second external terminal device KE2 is checked on the basis of a list (not shown) which is stored in the teleworking computer TW-R and which contains the telephone numbers or code numbers PIN authorized for the 'teleworking'. Once the verification has confirmed the registration, the teleworking computer TW-R assigns the fictitious connection port - for example the fictitious connection port FP with the telephone number 3200 within the communication system - to the network coupling unit IGATE from the second external terminal KE2. At the same time, by activating the 'Call forwarding' feature implemented by the PBX communication system, all of the internal subscriber connection ports (for example the.) Identified by the number within the communication system or by the PIN code are activated second subscriber line T2 of the second line unit ABG2 with the communication system internal call number 4711) calls directed to the fictitious connection port FP of the network coupling unit IGATE.

If the voice connection after logging in e.g. interrupted by hanging up the handset on the second external terminal KE2 (this corresponds to the normal case), a new identification (transmission of the number assigned to the second external terminal KE2 in the communication network KN) of the second external terminal KE2 on the communication system PBX is necessary in order to to establish a new voice connection to the IGATE network coupling unit. As part of manual identification, the authentication data must also be transmitted again.

In addition, terminal-oriented signaling information to be transmitted from the control unit STE of the communication system PBX to the second internal terminal KE4 - the registration of the second external terminal KE2 on the communication system PBX with the communication number internal to the communication system or code number of the second internal terminal KE4 is required - to the fictitious connection port FP of the network coupling unit IGATE redirected. The terminal-oriented signaling information is m described above

Way from the control unit STE of the communication system PBX via network coupling unit IGATE to the teleworking computer TW-R.

In the teleworking computer TW-R, a message transmitted by the control unit STE of the communication system PBX to the fictitious connection port FP (for example a terminal-oriented signaling information) is evaluated, and there are m cases in which this message is to be forwarded to the second external terminal KE2. converted into a voice message corresponding to the terminal-oriented signaling information. The voice message is then te voice connection is transmitted to the second external terminal KE2 and output there, for example via a loudspeaker. Furthermore, there is the possibility of transmitting text messages corresponding to the terminal-oriented signaling information to SMS-capable terminals (Short Message Service), in particular radio terminals. For this purpose, a message is transmitted to the responsible 'network provider', which transmits the corresponding text message to the terminal, on which the text message is output, for example on a display.

If a connection (initiation) with the second internal terminal KE4 is initiated on the basis of a further (external or internal) terminal, the second external terminal KE2 has to register with the communication system PBX with the telephone number or code number of the second internal terminal KE4 that is internal to the communication system the activated call forwarding a partial connection between the further terminal and the fictitious connection port FP of the network coupling unit IGATE. In a further step, a further partial connection is established between a further fictitious connection port RP of the network coupling unit IGATE and the second external terminal KE2 on the basis of the number of the second external terminal KE2 transmitted in the identification data in the communication network KN. In a final step, the partial connection and the further partial connection are coupled in the module coupling field module BG-KN of the network coupling unit IGATE, as a result of which a terminal connection is established between the second external terminal KE2 and the further terminal.

When a connection is set up with a further (internal or external) terminal caused by the second external terminal KE2, a voice connection is established with the further fictitious connection port RP of the network coupling unit IGATE by entering the 'teleworking' number again. After transmission of the identification data via the voice Connection is output by the output unit S-AE of the network coupling unit IGATE a recorded voice message to the second external terminal KE2, which informs the subscriber about possible user actions, such as outputting a voice message stored in the communication system PBX or establishing a terminal connection starting from the second external terminal KE2 with one further terminal device informed. By entering a significant key combination on the second external terminal KE2, control information corresponding to the key combination in the form of DTMF signals is transmitted via the voice connection to the network coupling unit IGATE, which signals to the communication system PBX that, starting from the fictitious connection port FP of the network coupling unit IGATE, a terminal unit connection is also present another terminal is to be set up. The control unit STE of the communication system PBX then establishes a partial connection between the fictitious connection port FP of the network coupling unit IGATE and the switching network module KN of the communication system PBX by occupying a free user channel of the PCM highway connecting the switching network module KN and the network coupling unit IGATE.

After coupling the voice connection with the partial connection in the module coupling field module BG-KN of the network coupling unit IGATE, the second external terminal KE2 sounds

Dial tone. The dialing information then entered on the second external terminal KE2 - for example 6833 for the first internal terminal KE3 - is transmitted in the form of DTMF signals to the network coupling unit IGATE via the voice connection and from there to the control unit STE of the communication system PBX tet. The control unit STE of the communication system PBX then sets up a terminal connection between the second external terminal KE2 and the first internal terminal KE3.

Is there a possibility at the second external terminal KE2 that the second external terminal KE2 in the communication network KN To automatically transmit the assigned number, for example, as part of an ISDN connection (as part of the 'calling party number' feature) to the IGATE network coupling unit, the subscriber can initiate a connection setup based on the PBX communication system by entering a special 'teleworking' call number . The network coupling unit IGATE recognizes on the basis of the special 'teleworking' call number that a terminal connection is to be set up from the second external terminal KE2 to another terminal and does not accept the call of the second external terminal KE2. In a next step, based on the PBX communication system, a connection is established from the further fictitious connection port RP of the network coupling unit IGATE to the second external terminal KE2 in the communication network KN based on the call number of the second external terminal KE2 automatically transmitted in the context of the ISDN connection, so that for the Participants on the second external terminal KE2 for the terminal connection to be set up with the further terminal are not charged.

The control information sent by the second external terminal KE2 during a terminal connection existing between the second external terminal KE2 and a further terminal is transmitted to the network coupling unit IGATE in the form of DTMF signals via the terminal connection. The control information is identified on the network coupling unit IGATE by the DTMF recognition unit DTMF and forwarded to the teleworking computer TW-R. In the teleworking computer TW-R, the control data received are converted into terminal-oriented signaling information, for example using a list (not shown). This converted terminal-oriented signaling information is forwarded via the network coupling unit IGATE to the control unit STE of the communication system PBX. Can the control information transmitted by the second external terminal KE2 in the form of DTMF signals from the network coupling unit IGATE are not interpreted, the DTMF signals are forwarded to the other terminal.

After the end of the existing connection between the second external terminal KE2 and the other terminal connection, the further fictitious connection port RP of the network coupling unit IGATE is released by the teleworking computer TW-R and thus stands for a new connection between any terminal registered on the communication system PBX and another Terminal available. The fictitious connection port FP of the network coupling unit IGATE, however, remains assigned to the second external terminal KE2 and is only released after the second external terminal KE2 has been de-registered by the subscriber. After logging off, due to the deactivation of the call forwarding on the communication system PBX, the terminal-oriented signaling information to be transmitted from the control unit STE of the communication system PBX to the subscriber is sent to the connection port of the internal terminal assigned to the subscriber - for example to the connection port of the second internal

Terminal KE4 with the communication system internal call number 4711 - transmitted. When a further external terminal with the same internal telephone number or code number as the second external terminal KE2 registers, the fictitious connection port FP of the network coupling unit IGATE is assigned to the further external terminal.

A maximum of 256 fictitious connection ports can be configured on the IGATE network coupling unit. Furthermore, the network coupling unit IGATE in the form of PCM highways is connected to the switching network module KN of the communication system PBX via 128 user data channels. Since two user channels are required for each terminal connection between a registered terminal and another terminal, a maximum of 64 terminal connections can be established simultaneously via the IGATE network coupling unit. Since with a maximum of 64 terminal connections set up simultaneously, 64 further fictitious connection ports RP Network coupling unit IGATE are occupied by the terminal connections, 191 free fictitious connection ports FP of the network coupling unit IGATE are available for registering terminals with the communication system PBX.

Claims

claims 1. network coupling unit (IGATE) for a communication system (PBX), - with at least one, a data network interface (LANS) for connection to a local data network (LAN) having data network connection unit (LAN-AE), - With a signaling unit (SE) for connection to a control unit (STE) of the communication system (PBX), - With at least one, a bidirectional time-division-oriented PCM interface (PCMS) for connection to an switching matrix module (KN) of the communication system (PBX) having PCM connection unit (PCM-AE), the Has an assembly switching matrix module (BG-KN) for coupling user data connections via the PCM interface (PCMS), has a DTMF recognition unit (DTMF) for identifying and analyzing control information received via the user data connections in the form of DTMF signals, - With a conversion unit (MH), which is connected to the data network unit (LAN-AE), the signaling unit (SE) and the PCM unit (PCM-AE), and - an evaluation unit (BW-R) for Has routing information, Has a switching unit (VM-R) for transmitting data packets as a function of the evaluation result, and - has a conversion unit (KV-R) for converting the data packets in accordance with the protocol. 2nd Arrangement according to claim 1, characterized in that the network coupling unit (IGATE) is designed as a subscriber line module of the communication system (PBX). 3. Arrangement according to claim 1 or 2, d a d u r c h g e k e n n z e i c h e t that the switching unit (VM-R) means for transmitting the Data packets - between internal communication terminals (KE3, KE4) connected to the communication system (PBX) and the local area network (LAN), and - Between external terminals that are connected to other, interconnected, communication networks (KN) forming communication systems (KE1, KE2) and have the local area network (LAN). 4. Arrangement according to one of the preceding claims, d a d u r c h g e k e n n z e i c h e t that the communication network (KN) is a digital or an analog communication network. 5. Arrangement according to claim 4, d a d u r c h g e k e n n z e i c h e t that the communication network (KN) is a wired and / or a radio communication network. 6. Arrangement according to one of the preceding claims, characterized in that in a on the network coupling unit (IGATE) arranged non-volatile memory (PROM) for identifying the data network interface (LANS) within the local data network (LAN) serving LAN identifier information (mac) is stored in a first partial area (SP1) of a memory (SPF) arranged on the network coupling unit (IGATE), a logical network identifier information (ipag) for identifying the data network interface (LANS) and on the local data network (LAN) ) connected communication terminals is stored, and that communication network identifier information (rnw) for identifying the network coupling unit (IGATE) is stored in the communication network (KN) in a second sub-area (SP2) of the memory (SPF). 7. Arrangement according to claim 6, d a d u r c h g e k e n n z e i c h e t that the LAN identifier information (mac) is an interface-related, standardized LAN address, that the logical network identifier information (ipag) is a standard Internet protocol address that the communication network identifier information (rnw) is a communication network number. 8. Arrangement according to claim 6 or 7, characterized in that m a third partial area (SP3) of the memory (SPF) further, logical network identifier information (ipel, ..., ipek) of further local data networks are stored, and that m a fourth Sub-area (SP4) of the memory (SPF) further communication network identifier information (rnl, ..., rnk) are stored, with further logical network identifier information (ipel, ..., ipek) and further logical communication network identifier information ( rnl, ..., rnk) are assigned to each other. 9. Arrangement according to claim 8, characterized in that the network coupling unit (IGATE) for the transmission of data packets via the communication network (KN) has a further conversion unit (KNK-R) for converting the logical network identifier information (ipel, ..., ipek) m has communication network identifier information (rnl, ..., rnk). 10. Arrangement according to one of the preceding claims, characterized in that the network coupling unit (IGATE) has a security unit (FWALL) for checking the routing information transmitted to the network coupling unit (IGATE) with regard to an admissibility for a communication connection between the origin and identified by a routmg formation in question Has target device. 11. Arrangement according to one of the preceding claims, that the network coupling unit (IGATE) has a protocol unit (PROT) for the secure and / or transmission protocol-compliant transmission of data packets as a function of a selected transmission protocol. 12. The arrangement according to claim 3 to 11, characterized in that the network coupling unit (IGATE) has an output unit (S-AE) for the transmission of stored messages to em external terminal (KE2), and that the messages in the form of an announcement and / or one optical display on the external terminal (KEl). 13. Arrangement according to one of the preceding claims, characterized in that the network coupling unit (IGATE) has at least one fictitious connection port (FP), in the context of a 'teleworking' registration of an external terminal (KEl), in the sense of a takeover of an internal terminal ( KE4), for call directed to the internal terminal (KE4), a diversion to the fictitious connection port (FP) is set up. 14. Arrangement according to claim 13, characterized in that the network coupling unit (IGATE) has at least one further fictitious connection port (RP), in the context of one of the external terminal (KEl) with another terminal or from the further terminal with the external terminal (KEl) initiated call, a connection between the external terminal (KEl) and the further fictitious connection port (RP) is provided. 15. Arrangement according to claim 13 or 14, so that the further terminal is an internal terminal or an external terminal.