NL2005524C2 - Method for transmitting data, network translator and measurement system. - Google Patents

Method for transmitting data, network translator and measurement system. Download PDF

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Publication number
NL2005524C2
NL2005524C2 NL2005524A NL2005524A NL2005524C2 NL 2005524 C2 NL2005524 C2 NL 2005524C2 NL 2005524 A NL2005524 A NL 2005524A NL 2005524 A NL2005524 A NL 2005524A NL 2005524 C2 NL2005524 C2 NL 2005524C2
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Prior art keywords
network
data
address
terminal
data network
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NL2005524A
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Dutch (nl)
Inventor
Frits Theodorus Maria Hilderink
Niels Willem-Jan Kolthoff
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Elbers Stevens Holding B V
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Publication of NL2005524C2 publication Critical patent/NL2005524C2/en

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L61/00—Network arrangements, protocols or services for addressing or naming
    • H04L61/09—Mapping addresses
    • H04L61/25—Mapping addresses of the same type
    • H04L61/2503—Translation of Internet protocol [IP] addresses
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00—Data switching networks
    • H04L12/28—Data switching networks characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]
    • H04L12/46—Interconnection of networks
    • H04L12/4604—LAN interconnection over a backbone network, e.g. Internet, Frame Relay
    • H04L12/462—LAN interconnection over a bridge based backbone
    • H04L12/4625—Single bridge functionality, e.g. connection of two networks over a single bridge
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L2101/00—Indexing scheme associated with group H04L61/00
    • H04L2101/60—Types of network addresses
    • H04L2101/618—Details of network addresses
    • H04L2101/622—Layer-2 addresses, e.g. medium access control [MAC] addresses
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L61/00—Network arrangements, protocols or services for addressing or naming
    • H04L61/09—Mapping addresses
    • H04L61/10—Mapping addresses of different types
    • H04L61/103—Mapping addresses of different types across network layers, e.g. resolution of network layer into physical layer addresses or address resolution protocol [ARP]

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

Description

P30419NL00/HSE
Title: Method for transmitting data, network translator and measurement system
The invention relates to a method for transmitting data from a source network terminal in a first data network to a destination network terminal in a second data network.
Furthermore, the invention relates to a network translator comprising a first network port for 5 connecting the network translator to a first data network, and a second network port for connecting the network translator to a second data network. Still further, the invention relates to a measurement system comprising such network translator.
Data networks are presently applied for many applications, including for example the distributed measurement of data. In such applications, a plurality of sensors is connected to 10 the data network. The sensors each provide measurement data, for example at periodic intervals, the measurement data being transmitted via the network to a remote computer, such as for example for data logging, for control, monitoring, or others.
In many applications, the sensors are connected to a network infrastructure that is also used for other purposes, such as one or more already existing data networks. Each 15 network is assigned a range of IP (internet protocol) addresses, that may be assigned to terminals (such as computers or sensors) in the network. The terminals may each be assigned an IP address (such as a private IP address or a global IP address) within that range. In each installation, different network conditions allow. When installing sensors in a network at a site, an administration would hence be required of the IP addresses that are 20 assigned to such sensors, so as to be able to retrieve a corresponding IP address in case of installation, service, repair replacement, etc. Thereby, this also complicates spare part delivery. In case a sensor would be defective, a replacement (spare part) sensor would need programming so as to provide it with its IP address within the IP address range available at that location.
25 The invention aims to provide a simple addressing scheme for terminals connected to a data network.
This problem is solved, according to an aspect of the invention, by a method for transmitting a data packet from a first network terminal in a first data network to a second network terminal in a second data network, the method comprising: 30 - transmitting the data packet from the first network terminal to a network translator that interconnects the first and second data networks, the data packet comprising a source IP address field comprising as entry therein a first data network IP address of the first network terminal that identifies the first network terminal in the first data network, and 2 a destination IP address field comprising as entry therein a first data network IP address of the second network terminal that identifies the second network terminal in the first data network, - translating, by the network translator, the first data network IP address of the second 5 network terminal into a second data network IP address of the second network terminal that identifies the second network terminal in the second data network and translating the first data network IP address of the first network terminal into a second data network IP address of the first network terminal that identifies the first network terminal in the second data network; - replacing (by the network translator), in the data packet, the first data network IP address of 10 the second network terminal by the second data network IP address of the second network terminal and the first data network IP address of the first network terminal by the second data network IP address of the first network terminal; and - sending (by the network translator) the data packet from the network translator via the second data network to the second network terminal.
15 Hence, the data network where the first network terminal (for example a sensor) is connected to may be separated by means of the network translator from the second data network to which the second network terminal is connected. The first data network may be assigned its own IP address range. Likewise, the second data network may be assigned its own IP address range. In accordance with an aspect of the invention, the first network 20 terminal (e.g. the source) may obtain its own IP address in the first network (within the first network IP address range), as well as its own IP address in the second network (within the second network IP address range). Likewise, the second network terminal (e.g. the destination) may obtain its own IP address in the first network (within the first network IP address range), as well as its own IP address in the second network (within the second 25 network IP address range). For data traffic that is passed from the one to the other network, the IP address is translated by the network translator. Thus, any terminal connected to the first network may be assigned an IP address within the first data network IP address range. This range may for example be a predetermined IP address range, hence allowing to use standard (e.g. factory programmed) IP addresses for the terminals in the first network and 30 performing an translation to translate the addresses into addresses in the IP address range of the second data network, by the network translator. Preferably, a bi-directional translation is provided so as to allow optimum transparence. As an alternative solution, a Virtual Private Network (VPN) may be used to access a subnet comprising the first and second network terminals, however in comparison to the invention, this may take more sophisticated 35 hardware and may place more burden on an end-user.
3
Comparing the invention with a commonly known router that interconnects two networks, when transmitting a data packet from the first network terminal in the first data network to the second network terminal in the second data network, the router would replace the source IP address which identifies the first network terminal in the first data network by 5 the IP address of the router that identifies the router in the second data network. Thus, instead of translating the source IP address into an address that still identifies the first network terminal (i.e. the source of the data packet), the source IP address is translated into an address that identifies the router. Hence, a less transparent solution is provided which may impede the application of such a router to interconnect the first and second data networks, 10 depending on the requirements of the application, first and second network terminals, etc. Also, as will be explained below, the known router translates a MAC address of the first network terminal (i.e. the source) into the MAC address of the router itself. Thereby, an identification of the first network terminal as the source of the data packet is hidden in the second data network, as in the second data network the MAC address if the router is applied 15 as the source MAC address.
Comparing the invention with a commonly known port forwarding technique that interconnects two networks (e.g. by means of a router), when transmitting a data packet from the first network terminal in the first data network to the second network terminal in the second data network, the router would replace the source IP address which identifies the first 20 network terminal in the first data network by the IP address of the router that identifies the router in the second data network. Also, the data packet transmitted by the first network terminal and received by the router, would not contain a destination IP address that identifies the second network terminal, but instead it would contain a destination IP address that identifies the router itself. Based on the port number received with the data packet, the router 25 would identify to which terminal in the second data network the data packet is meant to be sent. Again, a less transparent solution is provided when compared to the invention.
In contrast with the known router, when two different network terminals in the first data network transmit a data packet to a network terminal in the second data network, the router transmits the data packets onto the second data network whereby the IP address of the 30 router is used as the source address of both these data packets when transmitted by the router onto the second data network (thus using the same source address for both data packets although the data packets have a different origin), while in accordance with the invention, the IP addresses of the respective source terminals as assigned to the respective source terminals in the second data network, are used as the source addresses of the data 35 packets when transmitting the data packets in the second data network (thus using in the second data network unique source addresses that identify the origin of the datapacket). The 4 unique and transparent assignments allow the terminals in the first and second data network that transmit data to each other, to operate as if they would have sent the data packet to a network terminal in the same data network as the data network in which the sending network terminal is residing, thereby simplifying a configuration of the network terminals themselves 5 (taking away tasks related to the separation, routing, translation, etc between the first and second data networks form the network terminals themselves and offering the network terminals a relatively transparent environment.)
Furthermore, many different data may be transmitted over the network to which the sensors (or more generally speaking, the first network terminal) are connected, other than 10 data that is transmitted from or to the sensors. Such other data may have an adverse effect in for example real time applications, whereby it is desired that the measurement results that have been measured by the sensors, are transmitted in a time correct manner. This may be achieved conveniently in that a data packed having a destination IP address that is not known to the network translator - hence cannot be translated by it - is not passed through from the 15 first data network to the second data network and vice versa.
In an embodiment, the network translator maintains for the first and second data network: a MAC address of the first network terminal as a source MAC address, and a MAC address of the second network terminal as a destination MAC address. By 20 maintaining (i.e. not changing) the MAC address when transmitting the data via the network translator, from the first to the second network, and possibly vice versa, a transparency in the network may be achieved, as the communicating source and destination terminals do not know from each other that they communicate via the translator. A change of the MAC addresses, as commonly performed by a router, implies that different MAC address and IP 25 addresses would need to be tied together. Some applications, such as Programmable Logic Controllers (PLC’s) and Ethernet device servers, however require unique MAC addresses for identification of a terminal. Thereby, existing, supplied software tools can be used for management, configuration and remote firmware updates. Also, a so called port forwarding is not a solution here because the tools often require unique IP addresses per device. Further, 30 locations of the sources and destinations remain known and directly identifiable. Still further, a keeping trace of connection states, such as performed by a router, may be omitted. All in all, complex, hence time consuming translations and corresponding processing time that may provide a delay in the data transfer, and might provide a limit on data transfer rate, may be omitted at least in part.
35 In an embodiment, the method further comprises: prior to sending the data packet from the source network terminal in the first data network: 5 sending an ARP message from the source network terminal in the first data network to the network translator, the ARP message comprising the first data network destination IP address of the destination network terminal; replacing,, by the network translator, the first data network destination IP address by the 5 second data network destination IP address; transmitting by the network translator the translated ARP message onto the second data network; receiving via the second data network, an ARP reply message comprising the second data network destination IP address and the MAC address of the destination network terminal; 10 translating, by the network translator, the second data network destination IP address as received in the ARP reply message into the first data network destination IP address; and transmitting the translated ARP message to the source network terminal in the first data network.
Hence, the network translator provides a transparency, so that, in case a MAC address is 15 requested by means of an ARP (address resolution protocol) message, the MAC address of a destination in the other network, the network translator translates the IP addresses and transmits the ARP message onto the other network, hence allowing address resolution even of destinations in the other network.
In an embodiment, the translating, by the network translator, the first data network 20 destination IP address into a second data network destination IP address and translating the first data network source IP address into a second data network source IP address comprises looking up the first data network destination IP address in an IP address translation table, and reading the second data network destination IP address as a translated IP address from the translation table. Thereby, a convenient translation mechanism is provided that may easily be 25 programmed into the network translator by a skilled technician.
In an embodiment, the data packet is blocked from being transferred by the network translator to the second data network in case the network translator is not able or not allowed to translate at least one of the first data network destination IP address and the first data network source IP address. As a result, data for or from other application that is not desired 30 on a particular data network (as it is not addressed to a destination IP address recognized and translatable by the network translator), may be kept away, hence avoiding additional data loading on the first or second data network, as the network translator does not allow the data to pass.
The concept described in this document may be applied to many applications, such as 35 the first data network is a wired sensor network, the source network terminal comprising a sensor. According to an aspect of the invention, a measurement system is provided that 6 comprises at least one sensor, a remote computer, a first data network connected to the at least one sensor, a second data network connected to the remote computer, and the network translator according to an aspect of the invention, whereby a connection between the first data network and the second data network is established by means of the network translator.
5 In this document, the term network is to be understood as to comprise any data communication facility that allows communication between two or more entities. The term terminal is to be understood as an entity, connected to the network, from which or to which data may be communicated via the network. The term sensor is to be understood so as to comprise any sensor, including but not being limited to pressure, humidity, temperature, 10 vibration, sound level, acceleration, position, velocity, gravity, magnetism, etc. The sensor may include a network interface that allows it to communicate the data via the network. The term data is to be understood so as to comprise any digital information. The term MAC address is to be understood so as to comprise any hardware address. In this document, the term data is to be understood so as to comprise any kind of digital data, comprising e.g. one 15 or more data packets. The term data packet is to be understood so as to comprise a content (e.g. information to be transmitted) and further data, such as related to the destination, source and/or format, etc. The data packet may have a fixed length or a variable length. In this document, both the phrasing “a network terminal in a data network” or similar wording and “a network terminal connected to a data network” or similar wording are used. It will be 20 understood by the skilled person that both phrasings are to be understood as being equivalent and interchangeable.
It will be understood that the same or similar advantages as described above with reference to the method according to the invention, also apply the network translator according to the invention. Also, the same or similar preferred embodiments may be provided 25 thereby achieving the same or similar effects.
Further advantages and features of the invention will become clear from the appended drawing and corresponding description, wherein a non limiting embodiment of the invention is shown, wherein:
Figure 1 depicts a highly schematic diagram of a network translator in accordance with 30 an embodiment of the invention;
Figure 2 depicts a highly schematic diagram of an application in which the network translator of fig. 1 may be applied;
Figure 3 depicts a transfer of a data packet between the first and second networks;
Figure 4 depicts a transfer of an ARP message and ARP reply message between the 35 first and second networks; and
Figure 5 depicts an IP address translation table.
7
Figure 1 depicts a network translator NT that is connected via a first network port FNP to a first data network FN and via a second network part SNP to a second data network SN. The first and second data network may each be formed by a wired or wireless data communication network. A first terminal FT is provided in the first data network. A second 5 terminal ST is provided in the second data network. The first terminal FT and second terminal ST may be formed by a respective network terminal, i.e. a device that is arranged to send and/or receive data in a data network. The network terminals may comprise any data communication device, such as a sensor, a data logger, a computer, etc. Further network terminals (not depicted in fig. 1) may be provided in each of the first and second data 10 networks. A practical embodiment is depicted in figure 2.
Figure 2 depicts a first data network FN to which a plurality of sensors SNS and a first control computers FCP are connected. The sensors SNS may measure any suitable quantity, such a temperature, humidity, irradiation, particle concentration, etc, and provide data representing a value of the measured quantity. The data may for example be provided 15 periodically by each of the sensors at a sampling rate. The sampling rate may be preset by the sensor or may be chosen so as to match an expected rate of change of the quantity to be measured. Also, a control action that is to be performed based in the obtained measurement data from one or more of the sensors, may require approaching a condition of real time data information, thereby requiring the sensor to provide the data at a high rate. Furthermore, it 20 may be desirable to obtain the information with as little as possible delay so as to provide time accurate measurement results and to approach real time conditions as good as possible.
A network translator NT connects the first data network to a second data network SN. In this embodiment, a second control computer SCP is connected to the second data network and is arranged to log the data as provided by one or more of the sensors, respectively to 25 control an operation of the sensors. Respective measurement data is transmitted by each one of the sensors to the first and second control computers FCP and SCP. Control data that e.g. controls an operation of the sensors, is sent from the first control computer FCP to one or more of the sensors. The first and second network are interconnected by network translator Nt. Hence, measurement data and control data is transferred between the networks via the 30 network translator. Control actions, more specifically actions that require a real-time response, may be provided by the first control computer that is connected to the first data network. As data traffic to and from the first control computer remains in the first data network FN, disturbance from other factors, such as from other data traffic may be omitted, as such other data traffic may be kept by the network translator in the second network. Non real-time 35 data, such as data logging may be exchanged via the network translator NT to the second data network SN. The network translator may thereby operate as a filter to suppress 8 broadcast messages and other unwanted network traffic generated on the second data network SN from entering the first data network FN and cannot protect against influences inside the same data network. Hence, if e.g. the second control computer SCP generates unwanted traffic all other members of the second data network SN may suffer from such data 5 traffic, but no members of the first data network FN. It is noted that the above configuration is an example only. Data logging and control may for example be performed by one and the same control computer (which may be connected to for example the first data network or the second data network). Alternatively, data logging may be performed by the first control computer connected to the first data network, and control may be performed by the second 10 control computer connected to the second data network.
An operation of the network translator as depicted in figure 1 and 2 will be described below with reference to figure 3.
In the first data network, all terminals, such as the first terminal depicted in fig. 1, are provided with an IP address within an IP address range of the first data network. In the 15 second data network, all terminals, such as the second terminal depicted in fig. 2, are provided with an IP address within an IP address range of the second data network. Commonly, the IP address ranges of the first and second data networks do not overlap, however a partial or full overlap may be possible. The terminals in the first data network are to communicate with some of the terminals in the second data network. Thereto, the terminals in 20 the second data network, that are to communicate with terminals in the first data network, are also assigned an IP address in the first data network. Similarly, the terminals in the first data network, that are to communicate with terminals in the second data network, are assigned an IP address in the second data network. In fig 3, the first terminal FT is provided in the first network with IP address IPFN-FT, while the second terminal ST is provided in the first 25 network with IP address IPFN-ST. In the second network, the first terminal FT is provided with the IP address IPSN-FT, and the second terminal is provided with the IP address IPSN-ST. Thus, some or all of the terminals in the first data network have been assigned two IP addresses, namely an IP address in the first data network IP address range and an IP address in the second data network IP address range. Referring to figure 3, when a data 30 packet PCKT is to be transferred from the first terminal to the second terminal, the first terminal transmits the data packet onto the first data network. The data packet comprises a source address SRC and a destination address DST. The first terminal (in the first data network) uses as source address of the data packet the IP address of the first terminal as assigned in the first data network IPFN-FT and as destination address of the data packet the 35 IP address of the second terminal IPFN-ST as assigned in the first data network. The data packet is received by the network translator NT, which then performs an IP address 9 translation: The network translator translates the IP address of the source, being the IP address of the first terminal IPFN-FT as assigned in the first data network into the IP address of the first terminal IPSN-FT as assigned in the second data network. Similarly, the network translator translates the IP address of the second terminal IPFN-ST as assigned in the first 5 data network into the IP address of the second terminal IPSN-ST as assigned in the second data network. The network translator then transmits the data packet onto the second data network, where it is received by the second terminal. Similarly, the second terminal transmits a data packet back to the first terminal. Thereby, the second terminal uses as source address of the data packet the IP address of the second terminal as assigned in the second data 10 network and as destination address of the data packet the IP address of the first terminal as assigned in the second data network. The data packet is received by the network translator, which then performs an IP address translation: The network translator translates the IP address of the source, being the IP address of the second terminal as assigned in the second data network into the IP address of the second terminal as assigned in the first data network.
15 Similarly, the network translator translates the IP address of the first terminal as assigned in the second data network into the IP address of the first terminal as assigned in the first data network. The network translator then transmits the data packet onto the first data network, where it is received by the first terminal. Hence, the first and the second terminal may communicate with each other in a transparent way. The network translator, in case a data 20 packet is received from one of the networks that is for a destination that does not have a corresponding IP address in the other one of the networks, blocks the data packet from transmission to the other data network, i.e. does not forward the data packet to the other data network. Hence, it may be prevented that data traffic that is not intended for the other data network, is transmitted via it, thus avoiding load on the other data network of data traffic that 25 is not intended to be received there. Furthermore, in case of an existing configuration of for example the second data network, and a plurality of network terminals are to be added (for example a plurality of networked sensors or otherwise) that need to communicate data to a terminal in the second data network, the to be added terminals (such as the sensors) may be assigned their own IP address range and provided in a separate network (in the examples 30 referred to as the first data network) to be connected to the second data network via the network translator. Thereby, it may be avoided that the terminals to be added all need to be assigned an IP address in the second data network address range, which may avoid a programming of such IP address in each of the to be added terminals. Instead, the terminals may apply their pre-programmed IP address, or addresses in a pre-programmed IP 35 addresses range, hence avoiding such reprogramming. The network translator translates the IP addresses in the first data network address range, into a second data network IP address 10 range, thus allowing the terminals in the first data network to communicate with terminals in the second data network in a transparent way, without requiring a reprogramming of the IP addresses of the terminals in the first data network.
Reverting to figure 2, the above effects may allow to transmit data from a plurality of 5 sensors to the data logging computer at a high data rate. Furthermore, the network translator provides a separation as it prevents that data packets on the second data network that are not destined for the sensors in the first data network, are transferred to the first data network. Thus, load on the first data network of data traffic not intended for the first data network, may be prevented. Thereby, the network facilities with which the sensors communicate to provide 10 their data, may be kept as clean as possible, so as to provide maximum capacity and minimum delay for the data packet transmission from the sensors.
In any of the depicted and/or described embodiments, in contrast to a router, the network translator behaves transparent to the MAC addresses in both the first and second data network. Thus, in the first data network as well as in the second data network, the same 15 MAC address is assigned to communication with a terminal, namely the MAC address of that terminal. This in contrast to the router, where the MAC address of the router is applied in the data network other than the network in which the terminal is physically connected. Thus, for the first terminal, in the first data network, the IP address of the first terminal in the first data network address range and the MAC address of the first terminal are used, while in the 20 second data network, the IP address of the first terminal in the second data network address range and the MAC address of the first terminal are used. For the second terminal, in the first data network, the IP address of the second terminal in the first data network address range and the MAC address of the second terminal are used, while in the second data network, the IP address of the second terminal in the second data network address range and the MAC 25 address of the second terminal are used.
By maintaining (i.e. not changing) the MAC address when transmitting the data via the network translator, from the first to the second network, and possibly vice versa, a transparency in the network may be achieved, as the communicating source and destination terminals do not know from each other that they communicate via the translator. A change of 30 the MAC addresses, as commonly performed by a router, implies that different MAC address and IP addresses would need to be tied together. Some applications however require unique MAC addresses for identification of a terminal. Further, locations of the sources and destinations remain known and directly identifiable. Still further, a keeping trace of connection states, such as performed by a router, may be omitted. All in all, complex, hence time 35 consuming translations and corresponding processing time that may provide a delay in the data transfer, and might provide a limit on data transfer rate, may be omitted at least in part.
11
Further referring to fig. 4, in case a MAC address is to be retrieved, an ARP message is sent by the terminal, for example by the first terminal in the first data network, in order to retrieve the MAC address of a the second terminal in the second data network. Thereto, the first terminal in the first data network sends an ARP message ARP onto the first data network, 5 which ARP message is received by the network translator. The ARP message comprises the IP address of the second terminal IPFN-ST as assigned in the first data network. The network translator replaces the IP address of the second terminal IPFN-ST as assigned in the first data network by the IP address of the second terminal IPSN-ST as assigned in the second data network. The network translator then transmits the translated ARP message (i.e. the 10 ARP message with the translated IP address) onto the second data network. The second terminal (or another terminal in for example the second data network) which knows the IP address of the second terminal, receives the translated ARP message, and generates an ARP reply message ARP-R comprising the IP address of the second terminal APSN-ST as assigned in the second data network and the MAC address of the second terminal MAC-ST. 15 The ARP reply message is then transmitted onto the second data network where it is received by the network translator NT. The network translator translates the IP address of the second terminal as assigned in the second data network and as received in the ARP reply message, into the IP address of the second terminal IPFN-ST as assigned in the first data network. The translated ARP reply message ARP-R is then transmitted to the first network 20 terminal in the first data network. Again, full transparency is provided via the network translator, as the first terminal receives the MAC address of the second terminal, using the IP address as valid in the first data network, thus for the first terminal it appears that the second terminal is identified by the IP address of the second terminal as assigned to it in the first data network, and the MAC address. Thus, to the first terminal, is seems that the second terminal 25 is present in the same, i.e. the first data network.
A simple, effective and fast means of translation may be provided by means of an IP address translation table TT as depicted in fig. 5. The translation table TT that comprises as corresponding entries in the table the IP addresses of the terminal as valid in the first data network FN and in the second data network SN. In order to translate the IP address, the IP 30 address of a terminal for one of the data networks is looked up in this table and the IP address of that terminal for the other one of the data networks is read as a translated IP address from the translation table. For example, to translate IPFN-FT, this entry is looked up in the translation table. The corresponding value IPSN-FT is read from the other column in the table. The table may be stored as a digital data table in a memory of the network 35 translator.
12
As a further feature, terminals connected to the network may be identified automatically by the network translator. Thereto, terminals in for example the first data network may scanned by the network translator. The network translator requests available information from the terminal that is scanned such as supplier, type, mode, etc. The 5 information as obtained may be stored in a database memory of the network translator. Using for example the MAC address, information about a terminal may then be obtained from the network translator. A simplified configuration of the translation table may be provided thereby, as additional information of the network terminals (such as sensors) may be provided, the additional information for example containing information regarding supplier, type, mode, etc.
10 An operator who configures the network translator may thereby more easily establish a link between the configuration data and the physical elements represented by the configuration data, information regarding a manufacturer of a sensor may for example help to link the configuration data to particular sensors or other network terminals.
As another feature, replacement of a defective terminal may be performed (semi) 15 automatically. When a replacement terminal is connected to the network, the replacement terminal makes itself known by transmitting a message onto the network to which it is connected. The network translator receives the message, and stores information regarding the replacement terminal. In a service application of the network translator (such as configuration and maintenance program), the replacement terminal may be selected as a 20 replacement of the defective terminal, so that the translation that was previously performed for the defective terminal is now performed for the replacement terminal. Thus, service and maintenance costs may be reduced, as a reconfiguration in case of a replacement of a terminal may relatively easily be performed by a selection, for example in a service and maintenance software application so as to assign the replacement terminal as a replacement 25 of the removed or defective terminal.
As a still further feature network loops may be detected. A loop may for example be formed as a result of a network connection that connects the first data network to the second data network, the network connection being outside the network translator. As a result of such a connection, a loop may be formed, for example from the first data network, via the network 30 translator to the second data network, and then from the second data network via the connection back to the first data network or vice versa. The network translator may monitor the data traffic for terminals that appear to be present in both the first data network and the second data network. If the same terminal appears to be present in both networks, a detection message may be generated by the network separator, and for example presented 35 to a user service and maintenance software application.
13
In another feature, network monitoring may be provided by the network translator. For example, the network translator, as it transfers all data traffic between the first and second data network, may monitor the data traffic transferred by it, for example in a form of a periodic report. Also, overload may be signaled in case the traffic exceeds a predetermined data traffic 5 rate. Also, an origin of the traffic may be monitored by the network translator, so that a terminal responsible for a high or excessive load on the network may easily be identified.
Also, a data transmission delay may be monitored by the network translator so as to identify if data packets can be transmitted from the first data network to the second data network with a sufficiently low delay to keep it within criteria preset by a real time application that receives 10 the data packets.

Claims (13)

1. Werkwijze voor het verzenden van een datapakket vanaf een eerste netwerkterminal in een eerste datanetwerk naar een tweede netwerkterminal in een tweede datanetwerk, waarbij de werkwijze omvat: - het verzenden van het datapakket vanaf de eerste netwerkterminal naar een 5 netwerkvertaalinrichting die het eerste en het tweede datanetwerk verbindt, waarbij het datapakket omvat: een bron IP-adresveld omvattende als invoer daarin een eerste datanetwerk IP-adres van de eerste netwerkterminal die de eerste netwerkterminal identificeert in het eerste datanetwerk, en een bestemming IP-adresveld omvattende als invoer daarin een eerste 10 datanetwerk IP-adres van de tweede netwerkterminal die de tweede netwerkterminal identificeert in het eerste datanetwerk, - het vertalen, door de netwerkvertaalinrichting, van het eerste datanetwerk IP-adres van de tweede netwerkterminal in een tweede datanetwerk IP-adres van de tweede netwerkterminal die de tweede netwerkterminal identificeert in het tweede datanetwerk en het vertalen van 15 het eerste datanetwerk IP-adres van de eerste netwerkterminal in een tweede datanetwerk IP-adres van de eerste netwerkterminal die de eerste netwerkterminal identificeert in het tweede datanetwerk, - het vervangen in het datapakket van het eerste datanetwerk IP-adres van de tweede netwerkterminal door het tweede datanetwerk IP-adres van de tweede netwerkterminal en 20 het eerste datanetwerk IP-adres van de eerste netwerkterminal door het tweede datanetwerk IP-adres van de eerste netwerkterminal; en - het verzenden van het datapakket van de netwerkvertaalinrichting via het tweede datanetwerk naar de tweede netwerkterminal.A method for sending a data packet from a first network terminal in a first data network to a second network terminal in a second data network, the method comprising: - sending the data packet from the first network terminal to a network translation device comprising the first and the first connects a second data network, the data packet comprising: a source IP address field comprising as input therein a first data network IP address of the first network terminal identifying the first network terminal in the first data network, and a destination IP address field comprising as input a first Data network IP address of the second network terminal that identifies the second network terminal in the first data network, - translation, by the network translation device, of the first data network IP address of the second network terminal into a second data network IP address of the second network terminal which the second network terminal identifies in the two the data network and translating the first data network IP address of the first network terminal into a second data network IP address of the first network terminal identifying the first network terminal in the second data network, - replacing the data packet of the first data network IP address of the second network terminal by the second data network IP address of the second network terminal and the first data network IP address of the first network terminal by the second data network IP address of the first network terminal; and - sending the data packet from the network translation device via the second data network to the second network terminal. 2. Werkwijze volgens conclusie 1, waarbij de netwerkvertaalinrichting voor het eerste en tweede datanetwerk behoudt: een MAC-adres van de eerste netwerkterminal als een bron MAC-adres, en een MAC-adres van de tweede netwerkterminal als een bestemming MAC-adres.The method of claim 1, wherein the network translation device for the first and second data network retains: a MAC address of the first network terminal as a source MAC address, and a MAC address of the second network terminal as a destination MAC address. 3. Werkwijze volgens conclusie 2, verder omvattende: voorafgaand aan het zenden van het datapakket vanaf de eerste netwerkterminal: het zenden van een ARP-bericht vanaf de eerste netwerkterminal naar de netwerkvertaalinrichting waarbij het ARP-bericht het eerste datanetwerk IP-adres van de tweede netwerkterminal omvat; het vervangen door het netwerkvertaalinrichting van het eerste datanetwerk IP-adres van de tweede netwerkterminal door het tweede datanetwerk IP-adres van de tweede netwerkterminal; het verzenden door de netwerkvertaalinrichting van het vertaalde ARP-bericht op het 5 tweede datanetwerk; het ontvangen via het tweede datanetwerk van een ARP-antwoordbericht omvattende het tweede datanetwerk IP-adres van de tweede netwerkterminal en het MAC-adres van de tweede netwerkterminal; het vertalen door de netwerkvertaalinrichting van het tweede datanetwerk IP-adres van de 10 tweede netwerkterminal zoals ontvangen in het ARP-antwoordbericht in het eerst datanetwerk IP-adres van de tweede netwerkterminal; het verzenden van het vertaalde ARP-antwoordbericht naar de eerste netwerkterminal.The method of claim 2, further comprising: prior to sending the data packet from the first network terminal: sending an ARP message from the first network terminal to the network translation device wherein the ARP message the first data network IP address of the second network terminal; replacing the network translation device of the first data network IP address of the second network terminal with the second data network IP address of the second network terminal; transmitting by the network translation device of the translated ARP message on the second data network; receiving via the second data network an ARP response message comprising the second data network IP address of the second network terminal and the MAC address of the second network terminal; translating by the network translation device the second data network IP address of the second network terminal as received in the ARP response message in the first data network IP address of the second network terminal; sending the translated ARP response message to the first network terminal. 4. Werkwijze volgens een van de voorgaande conclusies, waarbij het vertalen door de 15 netwerkvertaalinrichting het opzoeken omvat van de IP-adressen in een IP-adres vertaaltabel en het lezen van de vertaalde IP-adressen uit de vertaaltabel.4. Method as claimed in any of the foregoing claims, wherein the translation by the network translation device comprises searching the IP addresses in an IP address translation table and reading the translated IP addresses from the translation table. 5 IP adres van de eerste netwerk terminal dat de eerste netwerkterminal in het tweede datanetwerk identificeert; - het vervangen in het datapakket van het eerste datanetwerk IP-adres van de tweede netwerkterminal door het tweede datanetwerk IP-adres van de tweede netwerkterminal en het eerste datanetwerk IP-adres van de eerste netwerkterminal door het tweede 10 datanetwerk IP-adres van de eerste netwerk terminal; en - het zenden van het datapakket van de netwerkvertaalinrichting via het tweede datanetwerk naar de tweede netwerkterminal.IP address of the first network terminal that identifies the first network terminal in the second data network; - replacing in the data packet of the first data network IP address of the second network terminal by the second data network IP address of the second network terminal and the first data network IP address of the first network terminal by the second data network IP address of the first network terminal; and - sending the data packet from the network translation device via the second data network to the second network terminal. 5. Werkwijze volgens een van de voorgaande conclusies, waarbij het datapakket wordt geblokkeerd voor overbrengen daarvan door de netwerkvertaalinrichting naar het tweede 20 datanetwerk in het geval dat de netwerkvertaalinrichting niet in staat is of het daaraan niet toegestaan is om tenminste een van het IP-adres in het bestemming IP-adresveld en het IP-adres in het bron IP-adresveld te vertalen.5. Method as claimed in any of the foregoing claims, wherein the data packet is blocked for transfer thereof by the network translation device to the second data network in the event that the network translation device is unable to or at least one of the IP address is allowed thereto translate in the destination IP address field and the IP address in the source IP address field. 6. Werkwijze volgens een van de voorgaande conclusies, waarbij het eerste 25 datanetwerk een bedraad datanetwerk is.6. Method according to any of the preceding claims, wherein the first data network is a wired data network. 7. Netwerkvertaalinrichting omvattende een eerste netwerkpoort voor verbinden van de netwerkvertaalinrichting met een eerste datanetwerk, en een tweede netwerkpoort voor het verbinding van de netwerkvertaalinrichting met een tweede datanetwerk, waarbij de netwerk 30 vertaalinrichting is ingericht voor: - het ontvangen aan de eerste netwerkpoort van een datapakket van een eerste netwerkterminal in het eerste datanetwerk, waarbij het datapakket omvat een bron IP-adresveld omvattende als invoeren daarin een eerste datanetwerk IP-adres van de eerste netwerkterminal die de eerste netwerkterminal identificeert in het eerste 35 datanetwerk, en een bestemming IP-adresveld omvattende als invoer daarin een eerste datanetwerk IP-adres van een tweede netwerkterminal dat een tweede netwerkterminal in het eerste datanetwerk identificeert, - het vertalen door de netwerkvertaalinrichting van het eerste datanetwerk IP-adres van de tweede netwerkterminal in een tweede datanetwerk IP-adres van de tweede netwerkterminal die de tweede netwerkterminal identificeert in het tweede datanetwerk en het vertalen van het eerste datanetwerk IP-adres van de eerste netwerkterminal in een tweede data netwerk7. Network translation device comprising a first network port for connecting the network translation device to a first data network, and a second network port for connecting the network translation device to a second data network, the network translation device being arranged for: - receiving at the first network port a data packet of a first network terminal in the first data network, the data packet comprising a source IP address field including as entries therein a first data network IP address of the first network terminal identifying the first network terminal in the first data network, and a destination IP address field comprising as input therein a first data network IP address of a second network terminal that identifies a second network terminal in the first data network, - the translation by the network translation device of the first data network IP address of the second network terminal into a second data network IP address of the tweed the network terminal identifying the second network terminal in the second data network and translating the first data network IP address of the first network terminal into a second data network 8. Netwerkvertaalinrichting volgens conclusie 7, waarbij de netwerkvertaalinrichting is 15 ingericht voor het behouden van het eerste en tweede datanetwerk van: een MAC-adres van de eerste netwerkterminal als een bron MAC-adres, en een MAC-adres van de tweede netwerkterminal als een bestemming MAC-adres.8. Network translation device according to claim 7, wherein the network translation device is adapted to retain the first and second data network of: a MAC address of the first network terminal as a source MAC address, and a MAC address of the second network terminal as a destination MAC address. 9. Netwerkvertaalinrichting volgens conclusie 8, voorts ingericht voor: 20 het ontvangen van een ARP-bericht van de eerste netwerkterminal, waarbij het ARP-bericht het eerste datanetwerk IP-adres van de tweede netwerkterminal omvat; het vervangen door de netwerkvertaalinrichting van het eerste datanetwerk IP-adres van de tweede netwerkterminal door het tweede datanetwerk IP-adres van de tweede netwerkterminal; 25 het verzenden door de netwerkvertaalinrichting van het vertaalde ARP-bericht op het tweede datanetwerk; het ontvangen via het tweede datanetwerk van een ARP-antwoordbericht omvattende het tweede datanetwerk IP-adres van de tweede netwerk terminal en het MAC-adres van de tweede netwerkterminal; 30 het vertalen door de netwerkvertaalinrichting van het tweede datanetwerk IP-adres van de tweede netwerkterminal zoals ontvangen in het ARP-antwoordbericht in het eerste datanetwerk IP-adres van de tweede netwerkterminal; en heet verzenden van het vertaalde ARP-antwoordbericht naar de eerste netwerkterminal.9. Network translation device according to claim 8, further adapted to: receive an ARP message from the first network terminal, the ARP message comprising the first data network IP address of the second network terminal; replacing the network translation device of the first data network IP address of the second network terminal with the second data network IP address of the second network terminal; Sending the translated ARP message on the second data network by the network translation device; receiving via the second data network an ARP response message comprising the second data network IP address of the second network terminal and the MAC address of the second network terminal; 30 translating by the network translation device of the second data network IP address of the second network terminal as received in the ARP response message in the first data network IP address of the second network terminal; and is called sending the translated ARP response message to the first network terminal. 10. Netwerkvertaalinrichting volgens een van conclusies 7-9, verder omvattende een IP adres vertaaltabel, waarbij de netwerkvertaalinrichting zodanig is ingericht dat het vertalen door de netwerk vertaalinrichting het opzoeken omvat van het IP-adres in een IP-adres vertaaltabel en het lezen van het vertaalde IP-adres uit de vertaaltabel.The network translation device according to any of claims 7-9, further comprising an IP address translation table, wherein the network translation device is arranged such that the translation by the network translation device comprises looking up the IP address in an IP address translation table and reading the translated IP address from the translation table. 11. Netwerkvertaalinrichting volgens een van conclusies 7-10, ingericht voor het 5 blokkeren van het datapakket om door de netwerkvertaalinrichting naar het tweede datanetwerk te worden verzonden in geval dat de netwerkvertaalinrichting niet in staat is of het daaraan niet toegestaan is om ten minste een van het IP-adres in het bestemming IP-adresveld en het IP-adres in het bron IP-adresveld te vertalen.11. Network translation device as claimed in any of claims 7-10, arranged for blocking the data packet from being transmitted by the network translation device to the second data network in the event that the network translation device is not capable of at least one of the translate the IP address into the destination IP address field and the IP address into the source IP address field. 12. Netwerkvertaalinrichting volgens een van de conclusies 7-11, waarbij de eerste netwerkpoort voor het eerste datanetwerk een bedrade netwerkpoort is voor verbinding met een bedraad datanetwerk.A network translation device according to any of claims 7-11, wherein the first network port for the first data network is a wired network port for connection to a wired data network. 13. Meetsysteem omvattende ten minste een sensor, een computer op afstand, een 15 eerste datanetwerk verbonden met de ten minste ene sensor, een tweede datanetwerk verbonden met de computer op afstand, en de netwerk vertaalinrichting volgens een van conclusies 7-12, waarbij een verbinding tussen het eerste datanetwerk en het tweede datanetwerk wordt bewerkstelligd door middel van de netwerkvertaalinrichting.13. Measuring system comprising at least one sensor, a remote computer, a first data network connected to the at least one sensor, a second data network connected to the remote computer, and the network translation device according to any of claims 7-12, wherein a connection between the first data network and the second data network is established by means of the network translation device.
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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002103547A1 (en) * 2001-06-15 2002-12-27 Advanced Network Technology Laboratories Pte Ltd. Computer networks
WO2003049445A2 (en) * 2001-11-30 2003-06-12 Scientific-Atlanta, Inc. Integrated internet protocol (ip) gateway services in an rf cable network

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002103547A1 (en) * 2001-06-15 2002-12-27 Advanced Network Technology Laboratories Pte Ltd. Computer networks
WO2003049445A2 (en) * 2001-11-30 2003-06-12 Scientific-Atlanta, Inc. Integrated internet protocol (ip) gateway services in an rf cable network

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
SRISURESH M HOLDREGE LUCENT TECHNOLOGIES P: "IP Network Address Translator (NAT) Terminology and Considerations; rfc2663.txt", IETF STANDARD, INTERNET ENGINEERING TASK FORCE, IETF, CH, 1 August 1999 (1999-08-01), XP015008446, ISSN: 0000-0003 *
TEO S W YEOW R SINGH NATIONAL UNIVERSITY OF SINGAPORE W T: "IP Relocation through twice Network Address Translators (RAT); draft-ietf-nat-rnat-00.txt", IETF STANDARD-WORKING-DRAFT, INTERNET ENGINEERING TASK FORCE, IETF, CH, 1 February 1999 (1999-02-01), XP015024064, ISSN: 0000-0004 *

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