DEVICE FOR CONNECTION OF ATM TERMINALS AND/OR LAN TERMINALS TO AN ATM-BASED NETWORK

Abstract: The present invention relates to a device for making possible connection of and communication between ATM terminals and LAN terminals in an ATM-based business network. An adaption equipment is arranged in the ATM network and is arranged to receive information respective transmit information to the terminals. The adaption equipment is further arranged to manage control messages or LAN from the ATM terminals. Information exchange between LAN terminals, ATM terminals, or between LAN terminals and ATM terminals, is made possible via the adaption equipment in the ATM network.

Description: TITLE OF THE INVENTION Device for connection of ATM terminals and/or LAN terminals to an ATM-based network. TECHNICAL FIELD The present invention relates to ATM terminals and LAN terminals which are to be connected to a data network. The LAN terminals consist of conventional terminals intended to be connected to data network of today. The ATM terminals are intended for transmission of broad band information. The ATM terminals address each other with call numbers or the like which the network processes and effects setting up of necessary connection. The ATM terminals transfer information on broad band and address each other via address information in the information transmission. The tranferred information is further possible to receive in a multiple of receivers. STATE OF TECHNOLOGY Terminals of type LAN and ATM relate in to-day's data network to different types of networks. The different terminals are not possible to use in the other network's structure. The principles of addressing are basically- different. Accordingly the ATM terminals implies that the network receives information from a terminal and converts this information to identification of a receiver. The connection is after that made via connection devices between the transmitter and the receiver. The ATM terminals use broad band information transmission. The information channels in this case contain information of different kinds which is selectable at the receiver. Further the information can be transferred to one or more receivers at the same time. Addressing to the receivers are in this case included in the transferred information. DESCRIPTION OF THE INVENTION TECHNICAL PROBLEM At the introduction of new broad band networks, elder terminals originating from the LAN network will for a long time be existent in the network. At this a need exists that elder terminals of type LAN should be possible to use also in the future network. Further there is a need that LAN terminals shall be possible to use in communication with ATM terminals - respective networks. There also exists a wish that LAN terminals shall have the ability to communicate with each other over the ATM network. The possibility to use different types of terminals in the network shall further be made possible without modifications in the current terminals. The network or equipments in the network shall further be able to convert the information so it will be interpretable for respective terminals. Further the adressing functions shall be possible to translate between the different network systems. A further existing wish is that the system rapidly and efficently shall be able to establish connections when required. The present invention intends to solve the above mentioned problem. THE SOLUTION The present invention relates to a device for connection of ATM terminals and LAN terminals to an ATM based business network. The ATM terminals are arranged to establish contact with each other by means of call numbers which are sent out in the network. The network identifies the information and sets up connections over which the terminals can communicate. The LAN terminals adress each other in the information transmission as usual. The terminals select that amount of information which is addressed to them. The information is further possible to receive at a multiple of LAN teminals. An adaption equipment in the data network is arranged to receive information from, respective transmit information to, ATM terminals. In a further development of the invention the adaption equipment is arranged to convert information from the ATM terminals to information and addressing which is identifiable by the ATM terminals. The adaption equipment comprises a first register for local terminals and a second register for remote terminals. In the data network several adaption equipments can be connected. The adaption equipments are arranged to communicate with each other at which information exchange occurs and the first respective second register can be updated. The information from the ATM terminals terminates in the network which is arranged to send information to the receivers via ports and indentify the receiver. ADVANTAGES The present invention consequently has the advantage that the terminals which are in fact intended for different types of data networks can be connected to one and the same network, and that the mentioned terminals can be used for information transmission between themselves. The invention further allows that the information from the ATM network can be transmitted to the LAN network on the LAN network's conditions. The intelligence needed to be introduced into the terminals is with the invention minimal. This entails that the costs for terminals can be strongly reduced. By introducing intelligence to the network allowing connection of different types of terminals to the network, new future terminals can be connected without special measures with the terminals. Both technical and economical advantages are in this way achieved. DESCRIPTIONS OF FIGURES Figure 1 shows a general block picture of the invention. Figure 2 shows the conception of the register. PREFERRED EMBODIMENT In the following the invention is described on the basis of the figures with references to the indications therein. The invention relates to a device which can be connected to an ATM network. The ATM network is used for transmission of information in a public data network. The LAN network is used for information transmission in local networks. The LAN network can be connected to the ATM network via connection links or the like. Adaption is at that arranged between the two networks at which adaption equipments effects that convertion of signals and other information to for each network processable information is made. Terminals which are connected in respective network can not normally be used in the other network. The reason for this is that the different networks have basically different functions which the equipment cannot use in respective network. To solve this problem the present invention specifies that a special function shall be possible to introduce in the network. The device according to Figure 1 comprises a protocol agent, PA, which has the task of converting PC specific messages sent over CLC channels to network specific control messages and vice versa. A register function, DA, keeps in order and maintains address tables which have inputs to the adresses of the destination users and corresponding VCI values for the connections. The protocol agent effects a call control (CC) which establishes a control connection between the ports of the two users. In the case when the destination terminal is not local, its port address is given by a connectionless service access agent (CLS-AA) in the destination area. The user communicate with CLS-AA over the connectionless service channel. CLS-AA sends and receives unique signals for each channel. The signals shall be related to respective switching port on which the messages are received. This is necessary for making PA able to identify the port and the address of the calling terminal. On the user side coded messages are sent in PC protocol. Other connectionless service address agents on the receiver side receive these messages and introduce them. A search message (SEARCH-CHN) from the local user is received by the protocol agent which checks the destination address of the wished destination. If the destination address is a group address, the protocol agent allocates one out of eight program channels by transmitting an identification message with program channel identification to the enquiring user. The allocated program channel is released after a given period of time. If the destination address is not a group address, the protocol agent will check whether the enquiring user already is a PC-destination in the local address. If that is the case, a table value will be sent to the enquiring user by transmitting a verification message. If not, the protocol agent will first ask DA for the address of the user. The protocol agent will for this purpose send a message to DA for finding the address with indicated parameters and start a time search. At reception of a set address from DA, the protocol agent will initiate a call. If the waiting for the set address from DA becomes too long, the protocol agent will instead use the broadcast channel until the address of the receiver becomes known. The protocol agent will also maintain a list over user/connections to which such a message has been sent. If a timer function for the PC is triggered, the protocol agent will initiate a resetting message to the user and start a new timer function and then wait for validation of the resetting. If the value indicated in the resetting message is equal to zero, the user shall set all inputs to zero. When a validation of resetting is received from the user, the protocol agent shall first start and wait for a signal before the PC- connection is broken. The connection is broken by transmission of a releasing message to the call control. If the resetting time is exceeded, the protocol agent will in a corresponding way send a releasing message to release the PC. The protocol agent initiates the establishing of partial connection by sending an inquiry to the call control indicating specified parameters. The protocol agent after that uses the received local addressed from DA for setting up a partial connection through the network. The receiver of an established call signal with a result parameter indicates success for the protocol agent which stores the obtained value together with the local address in corresponding table and establishes a received value to the enquiring user who uses a found-channel message. At the reception of an established control indication message from the call control with indication of completed connection, the protocol agent will update corresponding tables with new, established partial connections and send back a received call answer message to the call control. To establish necessary tables, the protocol agent will also initiate a message to DA where the local address is given and the register address is unknown. At reception of established call indication the protocol agent will also check whether a found-channel message has recently been issued between the same source and the destination user. If that is the case, the protocol agent will first release the previously found channel message and initiate a new connection message to the channel user. When the program channel is broken the protocol agent shall initiate a new direct channel between the source and the destination user by initiating a found channel message. When an establishing call indication indicating error is received, the protocol agent will send a received call answer with the same result parameters to the call control. When an establishing call message indicating error is received, the protocol agent will send a found channel message to the inquiring user. When the protocol agent receives a release indication message indicating success from the user control, the protocol agent will set the corresponding inputs from releveant parts of the table to zero, and send a release message answer back to the call control. When the call control sends a release call validation message indicating success, the protocol agent will set the corresponding inputs from corresponding table to zero. The catalogue function (DA) has as its main task to convert LAN-addresses to ATM-addresses. A connectionless user communicates with DA through the protocol agent. DA uses a multicast agent to reach the DAs. The catalogue function (DA) communicates with three different units, namely local user, protocol agent and other catalogue functions. The fundamental structure of the catalogue function is evident from Figure 2. The catalogue function keeps in order the addresses of the catalogue functions and corresponding local addresses for both local and remote terminals. For this reason two different address tables are supplied, namely the local table (LT) for local connected terminals, and the remote table (RT) for connected remote terminals. With this solution the following advantages are obtained: keeping the size of the address terminals small and at that obtaining short access times. most of the communication gets a tendency to be local. the catalogue function starts at a request coming from the protocol agent at the request from other register functions. Messages are exchanged between the catalogue functions and the protocol agents and messages are exchanged between the catalogue functions. When a message is received from the protocol agent regarding the register address for an ATM-adress, a local and a remote address table will answer with a message. When a received address message is received from the protocol agent, the register protocol unit (DAPE) will first consult its local address table, and if no entry is found, a check with the remote address table is performed. If still entry is lacking, the DAPE will first initiate a search address for all local connected users (multicast) and start the timer. If DAPE receives a found-address message from its local users, the local time clock will stop. The corresponding ATM- address will be obtained from the search table. The obtained address information will then be put in a local address table. DAPE will finally send an answer to the protocol agent with an address message. If the local time is exceeded, the DAPE will perform a register search to other registers and start a time function. If answer is not obtained within the prescribed time, DAPE will reject the message. Searching for local and remote connected terminals may be done parallelly. At reception of a register search message, DAPE will search in its local address and if an entry is found in the local address, a register-found message will be sent to the other DAPE and it updates the contents of its remote table register. If DAPE receives a register-found message for which it previously has registered a register search, it will first update the contents of the remote address table and then quite simply send a transmitted address message to the protocol agent. If DAPE receives a register-found message for which it has not initiated a register search, it will quite simply ignore the message. When a found address is received, DAPE will first stop the timer and update its local address table and then initiate a register-found message to all other DAPEs in the system. If no answer is obtained within the prescribed time, DAPE will throw away the register search message. The register and the local address of the transmitter is included in each inquiry which is sent to other registers. This information may be written in the remote register. The answers of inquiries sent over the network are sent to all registers, but only the register which initiated the inquiry will store the received answer. The others will quite simply ignore the register-found signal. To keep the size of the local address table manageable, the entries of the timers which have been exceeded are set to zero. There are eight preconfigured multicasts through program channels in each connection area, which makes a total of 16 program channels in LACE. The multicast agent (MA) maintains a list over program channels which is already assigned to the users. The progam channels which are allocated for group addressing are released after a predetermined time period if the allocated program channels are not finding a destination address which follows the same procedure as have previously been described for zero-setting of a direct channel. The number of preconfigured multicasts through program channels can of course be of a different number than what is mentioned above. Between the DAs there are one or more preconnected multicast channels. In PA there is a statistical table including the relation between ATM-addresses and port numbers. The switches will always convert data from the received port number to PA. Consequently DA can receive the local address by looking at the port numbers. PA maintans and manages control channels allocated to the users. The total number of control channnels is given for each connection area, and has a number of control channels. These control channels are preconfigured. Existing local network (LAN) differs radically from ATM in several important aspects. Services supplied by today's LAN are connectionless, whereas ATM is based on connection oriented technology. In connectionless mode no connection is coupled for data transmission. Further, programs and multicasts are transmitted in shared media in LAN. The address formats for LAN and ATM are further different. In LAN so called LAC addresses are used, which cannot be used in ATM. Between . the network and the users a number of channels are reserved. The channels are of three types and can be labelled, (1) the control channel; it is used for exchanging necessary information for operations acccording to the so called PC-method, (2) channels used for direct communication between terminals. The difference between the direct and the control channels can only be observed by the network. A terminal can not decide whether a channel is a control channel or not. The PCs are virtual channel connections established by units residing in the network where a PC-agent is arranged. All traffic directed to a terminal is connected via a destination switch to the mentioned terminal. To obtain the PC-address a transmitter is arranged to communicate via PC's control channel with the PC-agent to get an ATM channel number via which it can reach the receiver. The PC-agent scans its connection table to check whether PC exist between the terminals and the return address. If there are no connection, one will be arranged and an address enquiry is sent back by the terminal, and if the other terminal is not known by the agent, an address search is initiated. The other terminal answers to the search and the PC-agent can establish a new PC and again send the adress. For further communication from the first terminal to the second terminal the PC-agent will store the address together with a MAC-address until a time-out or enquiry of disconnection is received. The address appointment and the storing procedures are parts which must be maintained. As addition to the simple communication described above an Ethernet emulation to offer multicast and broadcast has been arranged. Multicast is implemented by transmitting frames to all terminals with filtering in the terminals. For distribution of multicast frames a number of multipoint connections are arranged in the network at the time of initiation. Each one of these multipoint connections is uniquely identified. Cells transmitted to these multipoint connections are distributed to ports in the Ethernet emulation. At each point of time only one terminal can use a multipoint connection for transmission. For avoiding conflicts access to these connections are controlled by the PC-agent. The meaning of VCI in the PC-method is the same as for virtual channel connections. A PC is also defined between the users, but the main difference is that the PCs terminates in the access switch and not in the terminals. A recollection machine is allocated to a given channel only as long as cells are received and released at the end of a frame or after a time-out. The invention is not confined to the below specified patent claims but may be subject to modifications within the frame of the idea of invention.

Claims: PATENT CLAIMS 1. Device for connection of ATM-terminals and/or LAN- terminals to an ATM-based network, where the ATM- terminals are arranged to establish connection with each other over a LAN-network, and the information transmission between the LAN terminals in the LAN network is receiveable at a plurality of the LAN terminals, c h a r a c t e r i z e d in that an adaption equipment in the ATM-network is arranged to receive information from, respective transmit information to, the terminals, and that the adaption equipment is arranged to process control information from ATM/LAN terminals at which both ATM and LAN-terminals are connectable to the ATM network. 2. Device according to patent claim 1, c h a r a c t e r i z e d in that the adaption equipment is arranged to establish information exchange between ATM-terminals LAN-terminals ATM- and LAN-terminals. 3. Device according to any of the previous patent claims c h a r a c t e r i z e d in that the adaption equipment comprises mechanisms for address solution and catalogue function for both local and remote connected terminals. 4. Device according to patent claim 2, c h a r a c t e r i z e d in that the adaption equipment is arranged to convert address information from the LAN- terminals to for the ATM-terminals indentifiable information. 5. Device according to any of the previous patent claims c h a r a c t e r i z e d in that the adaption equipment comprises a first register over locally connected terminals. 6. Device according to any of the previous patent claims c h a r a c t e r i z e d in that the adaption equipment comprises a second register for remote connected terminals. 7. Device according to any of the previous patent claims c h a r a c t e r i z e d in that the ATM network is allowed to comprise many adaption equipments, e.g. a multicast function, or the catalogue function. 8. Device according to any of the previous patent claims c h a r a c t e r i z e d in that the adaption equipments are arranged to communicate with each other. 9. Device according to any of the previous patent claims c h a r a c t e r i z e d in that the adaption equipments are arranged to exchange information with each other at which the first respective second register can be updated. 10. Device according to patent claim 1, c h a r a c t e r i z e d in that the adaption equipment emulates, makes more efficent, the behaviour of the LAN network in the ATM network. 11. Device according to patent claim 10 c h a r a c t e r i z e d in that the information from an ATM and/or LAN terminal is receivable at a plurality of ATM-/LAN terminals.

Inventors: KAVAK NAIL, KAVAK, NAIL
Applicants: KAVAK NAIL, TELIA AB, KAVAK, NAIL
Application year: 1995
Main classification: H04L12
IPC codes: H04L12, H04Q11