HK1032275B - Integrated ip network - Google Patents

Description

Integrated IP network

Technical Field

The present invention relates to an integrated IP (internet protocol) network of an IP network for computer communication based on TCP/IP (transmission control protocol/internet protocol) technology.

Background

An IP network designed to transmit and receive digitized voice data according to the TCP/IP technology (hereinafter referred to as an "IP telephony network") uses a communication circuit speed of about 64Kbps to keep the voice data arrival time below, for example, 0.1 seconds. An IP telephone network (hereinafter referred to as an "IP video network") that transmits and receives television compressed video images according to the TCP/IP technology uses a communication circuit speed of, for example, 1.5Mbps, and allows a video data arrival time of several minutes.

The IP telephone network (hereinafter referred to as "IP electronic text network") that transmits electronic receipt text according to the TCP/IP technology has a communication circuit speed of about 128Kbps to keep the data arrival time below 1 second. In this case, since reliability is valued more than voice transmission and television video transmission, the communication error rate is kept lower than one percent of the IP telephone network and the IP video network.

Other IP telephony networks include: for example, an "IP data multicast network (IP data multicast network)" which transmits IP data such as electronic books and electronic news from one transmission source to a plurality of destinations, and an "IP-based television broadcast network", an IP audio-image network, which transmits (or broadcasts) television voice data and video data to a plurality of destinations using a multicast technique. These multicast type networks differ from the previously described IP telephony networks in that they do not use a one-to-one communication scheme.

As shown in fig. 1, in a conventional IP network 20 as represented by the internet, an IP packet 26-1 including IP telephone data, IP video data and IP electronic receipt text data is sent from a terminal 23-1 in the LAN 21, via a router 24-1 in the LAN 21 and routers 22-1 to 22-4 in the IP network 20, and via a router 24-2 in the LAN22 to a terminal 23-2 in the LAN 22. Although the internet cannot guarantee communication speed and other parameters in IP transmission, it is generally called a "best effort network (besteffort network)" in the sense that it makes the best effort for transmission. As in this example, IP telephone data, IP audio data and IP electronic receipt text data flow through the communication circuits in the IP network 20 in a mixed manner. That is, a plurality of independent IP networks having different characteristics, such as an IP telephone network, an IP video network, an IP electronic text network, a best effort network, an IP data multicast network, and an IP-based television broadcast network, are not included in the conventional IP network. For this reason and others, separately constituting an IP telephone network, an IP video network, an IP electronic text network, a best effort network, an IP data multicast network, and an IP-based television broadcast network, leads to a problem of increasing the overall cost of the entire IP network.

Referring to fig. 2, a multicast-type IP network 27-1 for transmitting data from an originating source to a plurality of destinations will be described. Reference numerals 27-2 to 27-9 denote routers, of which 27-2, 27-6, 27-7, 27-8 and 27-9 are in particular routers to which the subscriber IP terminals 28-1 to 28-9 can be connected by communication circuits, also referred to as network nodes. The routers 27-3, 27-4, 27-6, 27-7, 27-8 have a router multicast table that tells each router to send received IP packets to a plurality of communication circuits according to a multicast address included in the received IP packets. In this embodiment, the multicast address specifies "MA 1". IP terminal 28-1 sends IP packet 29-1 through router 27-2, which has a multicast address "MA 1". When the packet arrives at the router 27-3, the router 27-3 copies the IP packet 29-2, checks the router multicast table, and transmits the IP packet 29-3 and the IP packet 29-4 to the communication circuit. The router 27-4 copies the received IP packet 29-3 and transmits the IP packet 29-5 and the IP packet 29-6 to the communication circuit according to the router multicast table. The router 27-5 does not have a router multicast table so the IP packet 29-4 passes through the router 27-5 and is delivered to the router 27-8 as an IP packet 29-7. The router 27-6 copies the received IP packet 29-5, checks the router multicast table, and transmits the IP packet 29-8 to the IP terminal 28-2 and the IP packet 29-9 to the IP terminal 28-3. The router 27-7 copies the received IP packet 29-6, refers to the router multicast table, and transmits the IP packet 29-10 to the IP terminal 28-4 and transmits the IP packet 29-11 to the IP terminal 28-5. The router 27-8 copies the received IP packet 29-7, refers to the router multicast table, and transmits the IP packet 29-12 to the IP terminal 28-6, transmits the IP packet 29-13 to the IP terminal 28-7, and transmits the IP packet 29-14 to the IP terminal 28-8. When the source terminal 28-1 transmits electronic books and electronic news in the form of digital data to the IP network 27-1, the IP network 27-1 serves as an IP data multicast network for distributing the electronic books and electronic news, and IP terminals 28-2 to 28-8 are used to represent user IP terminals subscribing to the electronic books and electronic news. When the source terminal 28-1 is replaced with a television broadcast audio-image transmission apparatus and a television program (i.e., voice and video) is broadcast, the IP network functions as an IP-based television broadcast network, and IP terminals 28-2 to 28-8 are used to represent television viewer IP terminals having a television reception function.

Disclosure of Invention

The present invention has been achieved under the above circumstances, and an object of the present invention is to provide an integrated IP network which respectively includes a plurality of independent IP networks having different characteristics, for example, an IP telephone network, an IP video network, an IP electronic text network, a full power network, an IP data multicast network, an IP-based television broadcast network, and the like.

The present invention relates to an integrated IP network, and the above object of the present invention can be achieved by an integrated IP network comprising: a plurality of IP networks and a plurality of network node devices; wherein each of said network node devices is connected to one or more of said IP networks via a communication circuit and has their network node connected to an external terminal via a communication circuit; wherein, when one of the network node devices receives an IP packet from an external terminal, the following sequence of operations is performed: in a first case where a network node address of a network node through which a received IP packet passes is registered in an address management table as a virtual private line connection unspecified, comparing a destination terminal address and a port number registered in the address management table with a source terminal address, a destination terminal address, a source port number and a destination port number included in the IP packet to find a record containing a network identifier indicating to which destination IP network the IP packet is to be sent; in a second case where the network node address of the network node through which the received IP packet passes is registered in the address management table as specifying a virtual private line connection, detecting a record containing a network identifier indicating to which destination IP network the IP packet is to be sent; after the process of the first case or the second case is completed, generating one integrated IP network packet using the source network node address and the destination network node address contained in the detected record, and then transmitting it to the destination IP network; the integrated IP network packet reaches another network node device through an IP packet switching point and a destination IP network, in which a integrated IP network header is deleted from the integrated IP network packet to restore a source IP packet, and then transmitted to a destination IP terminal; wherein an address management table is referred to select a destination IP network to which an IP packet is to be transmitted and the IP packet is transmitted to the destination IP network, and the integrated IP network packet is transmitted through two or more IP networks of different carriers in the destination IP network and through an IP packet switching point.

The above object of the present invention can also be achieved by an integrated IP network comprising: a plurality of IP networks and a plurality of network node devices; wherein each of said network node devices is connected to one or more of said IP networks via a communication circuit and has their network node connected to an external terminal via a communication circuit; wherein each IP network comprises a plurality of dedicated domain name servers; each domain name server comprises a corresponding relation between an external terminal IP address and a terminal host name; upon receiving an IP packet targeting a domain name server from an external source terminal, one of the network node devices transmits the received IP packet to the destination domain name server; the destination domain name server extracting a destination terminal IP address corresponding to a destination terminal host name contained in the received IP packet and transmitting an IP packet containing the obtained destination terminal IP address back to the source terminal; the source terminal generating a new IP packet having the destination terminal IP address obtained from the domain name server and transmitting the generated new IP packet to one of the network node devices; the network node device compares a source terminal address, a destination terminal address and a port number registered in the address management table with a source terminal address, a destination terminal address and a port number included in the new IP packet to find a record designating a destination IP network to which the integrated IP packet is to be transmitted, generates an integrated IP network packet using the source network node address and the destination network node address included in the detected record, and transmits the generated integrated IP network packet to the destination IP network; the integrated IP network packet is transmitted to another network node device through the IP network and the IP packet switching point, where an integrated IP network header is deleted from the integrated IP network packet to restore the new IP packet, and then transmitted to a target IP terminal; wherein the address management table is referred to select a target IP network to which an IP packet is to be transmitted, and the IP packet is transmitted to the target IP network, and the integrated IP network packet is transmitted via two or more IP networks of different carriers in the target IP network and through the IP packet switching point.

Drawings

Fig. 1 is a conceptual diagram illustrating IP transmission according to a conventional internet;

fig. 2 is a conceptual diagram showing multicast-type IP transmission;

FIG. 3 is a block diagram illustrating a first embodiment of the present invention;

FIG. 3 is a schematic block diagram illustrating a first embodiment of the present invention;

fig. 4 is a flowchart showing an example of operations performed by the network node apparatus of the first embodiment of the present invention;

fig. 5 is an address management table used in the first embodiment of the present invention;

fig. 6 is a schematic diagram of one packet transmitted and received in the first embodiment of the present invention;

fig. 7 is a flowchart showing another example of operations performed by the network node apparatus of the first embodiment of the present invention;

fig. 8 is another example of an address management table used in the first embodiment of the present invention;

FIG. 9 is a block diagram showing a second embodiment of the present invention;

fig. 10 is a flowchart showing an example of operations performed by the network node apparatus of the second embodiment of the present invention;

fig. 11 is an example of an address management table used in the second embodiment of the present invention;

fig. 12 is a diagram of one packet transmitted and received in the second embodiment of the present invention;

fig. 13 is a flowchart showing another example of operations performed by the network node apparatus of the second embodiment of the present invention;

FIG. 14 is a schematic block diagram illustrating a third embodiment of the present invention;

fig. 15 shows an address management table used in the third embodiment;

fig. 16 is an example of "transmitted and received packet" used in the third embodiment;

fig. 17 is an example of "transmitted and received packet" used in the third embodiment;

fig. 18 is an example of "transmitted and received packet" used in the third embodiment;

fig. 19 is an example of "transmitted and received packet" used in the third embodiment;

fig. 20 is an example of "transmitted and received packet" used in the third embodiment;

fig. 21 is a flowchart showing an example of an operation performed by the network node apparatus of the third embodiment;

fig. 22 shows an IP packet used in the third embodiment;

fig. 23 is a flowchart showing another example of operations performed by the network node apparatus of the third embodiment;

fig. 24 is a timing chart showing another example of operations performed by the network node device of the third embodiment;

FIG. 25 is a block diagram showing a fourth embodiment of the present invention;

fig. 27 is a diagram showing how to transmit and receive IP packets used in the fourth embodiment;

fig. 26 is a timing chart showing how to transmit and receive an IP packet used in the fourth embodiment;

fig. 28 is a diagram showing how to transmit and receive IP packets used in the fourth embodiment;

fig. 29 is a diagram showing how to transmit and receive IP packets used in the fourth embodiment;

fig. 30 is a diagram showing how to transmit and receive IP packets used in the fourth embodiment.

Detailed Description

In the present invention, a plurality of IP networks having different characteristics, i.e., an IP telephone network, an IP video network, an IP electronic text network, a best effort network, an IP data multicast network, an IP-based television broadcast network, etc., are actually installed. An address management table is set in a network node device installed at an entry point through which the integrated IP network is accessed from the outside. A terminal address and a port number identifying an Application (AP) included in the terminal are registered in an address management table in advance. The address and port number written in the IP packet entering the integrated IP network are compared with the address and port number registered in the address management table to transmit the IP packet to an appropriate IP network within the integrated IP network. The port number may not be used and only the addresses may be compared.

Now, an embodiment of the present invention will be described by referring to the drawings.

1. A first embodiment of selecting an IP network based on IP address and port number:

in fig. 3, for example, a source terminal 8-1 in LAN 1 sends an IP packet PK01 to a destination IP terminal 8-2 in LAN2 via the integrated IP network 1. The connection points of the communication circuits 6-X1 and 6-X2 to the network node device 5-X are referred to as "network nodes". The network node (5-X) of the communication circuit 6-X1 is given a network node address "G100" for use in the integrated IP network 1; the network node (5-X) of the communication circuit 6-X2 is assigned a network node address "G110" and the network node (5-Y) of the communication circuit 6-Y is assigned a network node address "G200". The IP packet PK01 includes address "a 100" of the source terminal 8-1, address "a 200" of the destination terminal 8-2, source port number "4300" (SP) identifying the Application (AP) in the source terminal 8-1, destination port number "300" (DP) identifying the application in the destination terminal 8-2, and data used by the application.

The application programs include a voice telephone transmission/reception program, a video transmission/reception program, an electronic receipt transmission/reception program, a WWW (world wide web) data transmission/reception program based on HTTP (hypertext transfer protocol). The voice telephone transmission/reception program means a telephone transmission/reception program for an IP telephone using digital technology. In this embodiment, the terminal address represents an IP address, and the port number represents a port number set in a TCP (transmission control protocol) type block or a UDP (user datagram protocol) type block. In the present invention, a record in an address management table specifies a row in the table and includes a plurality of data items.

In fig. 3, reference 2 is an IP video network comprising an IP video network 2-X of carrier X and an IP video network 2-Y of carrier Y connected simultaneously to an IP packet switching point 2-1. The label 3 is an IP general network comprising an IP general network 3-X of a communication company X and an IP general network 3-Y of a communication company Y both connected to the IP packet switching point 3-1. Reference numeral 4 is an IP telephone network including an IP telephone network 4-X of a carrier X and an IP telephone network 4-Y of a carrier Y connected to the IP packet switching point 4-1 at the same time. The integrated IP network 1 comprises an IP video network 2, an IP general network 3 and an IP telephony network 4. Further, the network node device 5-X is connected to the address management table rewriting device 11-1, and the network node device 5-Y is connected to the address management table rewriting device 11-2. The address management table rewriting devices 11-1 and 11-2 can write addresses and port numbers into the address management tables in the network node devices 5-X and 5-Y.

In this structure, the operation of the network will be described with reference to the flowchart of fig. 4. Fig. 4 is a flowchart showing an example of the operation of the network node device 5-X. First, the IP packet PK01 enters the network from the communication circuit 6-X1 via the network node assigned a network node address "G100". Upon receiving the IP packet PK01 (step S100), the network node device 5-X searches the address management table of fig. 5 included in the device for the "source network node address" column to see whether there is a registered record with the network node address "G100" and checks whether the request identification value of the record is "3" (step S101). In this embodiment the request identification value is not 3, which means that the packet does not specify a so-called virtual private line connection (case 1). Then, the network node device 5-X reads the address "a 100" (SA) of the source terminal 8-1, the address "a 100" (DA) of the destination terminal 8-2, the source port number "4300" (SP) identifying the application in the source terminal 8-1, and the destination port number "300" (DP) identifying the application in the destination terminal 8-2 from the IP packet PK01 (step S102). Then, the network node device 5-X searches the address management table set in the device for a record whose address matches the source terminal address "a 100" (SA) and the destination terminal address "a 200" (DA) of the packet (step S103). It should be noted that there are typically two or more records that meet this condition.

Next, since, among the extracted records, there is one record having the source port number "4300" (SP) or the destination port number "300" (DP), it is searched for and identified (step S104). In this embodiment, the record is found on the first line from the top in the address management table of fig. 5, and has "SA — a100, DA — a200, P — 300, N-SA — G100, N-DA — G200, and network identifier NWa (video net)". From the record, the apparatus extracts the source network node address "G100" and the destination network node address "G200", and the procedure proceeds to step S106. The network node address may use an IP address as described above. That is, an address applied to the third layer of OSI (open systems interconnection) may be used, or an address applied to the second layer of OSI, for example, one used in FR (frame relay) switching and ATM (asynchronous transfer mode) switching (for example, a telephone number according to the e.164 specification) may be used.

In the above-described step S100, if another IP packet PK05 enters the network from the communication unit 6-X2 via the network node specified by one network node address "G100", the network node apparatus 5-X receives the IP packet PK05, searches the address management table in the apparatus to see whether or not there is a record having the network node address "G110" in the column of "source network node address" in the table, and checks whether or not the "request identification" value of the record is "3" (step S101). In this embodiment the record has a "request identification value" of "3" (on the second row from above in the address management table), which means that the packet specifies a so-called virtual private line connection (case 2). Therefore, the routine proceeds to step S105. Then, before proceeding to step S106, the apparatus extracts the source network node address "G110" and the destination network node address "G210" registered in the specific record.

Next, the apparatus adds an integrated IP network header as shown in fig. 6 to the packet to generate an integrated IP network packet PK11 (step S106). This step uses the source network node address "G100" or "G110" (N-SA) and the destination network node address "G200" or "G210" (N-DA) obtained in step S104 or step S105. Next, the integrated IP network packet PK11 generated through the above-described process is transmitted to the communication circuit 7-1 according to the designated network identifier "NWa" (IP video network) (step S107). The communication circuit 7-1 is connected to an IP video network 2-X operated by a communication company X in the IP video network 2.

The above step S105 switches between the IP telephone network and the IP general network according to whether the received IP packet PK01 designates "NWc" (IP telephone network) or "NWb" (IP general network) as the network identifier.

The integrated IP network packet PK11 is then sent to the network node device 5-Y via the IP video network 2-X, through the IP packet switching point 2-1 and through the IP video network 2-Y of carrier Y. As shown in the flowchart of fig. 7, the network node apparatus 5-Y, first receives the integrated IP network packet PK11 (step S120), deletes the IP network header from the received integrated IP network packet to recover the IP packet addressed to the local area network (step S121), and transmits the recovered IP packet to the terminal 8-2 through the communication circuit 6-Y (step S122).

When the terminal 8-2 in the LAN2 issues another IP packet PK02 in the direction opposite to the transmission direction of the IP packet PK11, the address and port number in the IP packet are made opposite to those of the previous IP packet in order. That is, the IP packet has a source terminal address "a 200", a destination terminal address "a 100", a source port number "300" identifying an application in the source terminal, and a destination port number "4300" identifying an application in the destination terminal. In this case, the address management table shown in fig. 8 is used, and the port selection explanation is reversed.

The IP packet switching point 2-1 measures the number of IP packets passing through the point and the time it takes for the IP packets to pass through the point. The carrier managing the IP video network 2-X and the carrier Y managing the IP video network 2-Y can measure the number and time of passing IP packets and serve as data for calculating the charge for communication to the IP packet sender and receiver. This embodiment may also be implemented so that there is no IP video network 2-Y and no IP packet switching point 2-1 of carrier Y, i.e. the IP video network 2 comprises only the IP video network 2-X of carrier Y. In this case, the communication company running the IP video network 2 is a company "X". Similarly, IP telephone network 4 may comprise only IP telephone network 4-X of carrier X.

Next, a case will be described where the terminal is a video transmitting/receiving device or an IP telephone, and the communication circuit of the logical terminal connected to the network node device is connected to the IP video network 2-X or the IP telephone network 4-Y alone. In fig. 3, reference numeral 9-1 is a video transmitting/receiving device which is connected to the network node device 9-3 via the communication circuit 9-2 and further connected to the IP video network 2-X via the communication circuit 9-4. Reference numeral 10-1 is an IP telephone which is connected to the network node apparatus 10-3 via the communication circuit 10-2 and further connected to the IP telephone network 4-Y via the communication circuit 10-4. Carrier X runs network node device 9-3 and carrier Y runs network node device 10-3. Address management tables prepared according to the same principle as fig. 5 or fig. 8 are set in the network node devices 9-3 and 10-3.

In this configuration, the IP packet including the video information transmitted from the video transmission/reception device 9-1 as digital information can exchange video data information with the video transmission/reception program in the terminal 8-2 via the network node device 9-3, the IP video network 2-X, IP packet switching point 2-1, the IP video network 2-Y, the network node device 5-Y, and the communication circuit 6-Y, for example. Similarly, an IP packet including voice information transmitted from the IP telephone 10-1 as digital data can exchange voice digital information with the telephone transmission/reception program in the terminal 8-1 via the network node device 10-3, the IP telephone network 4-Y, IP packet switching point 4-1, the IP telephone network 4-X, the network node device 5-X and the communication circuit 6-X1.

In the first embodiment described above, the IP network has been described as including an IP telephone network and an IP video network. It is also possible to separately provide a dedicated IP network for different purposes, such as an IP facsimile network dedicated to facsimile, an IP electronic receipt network dedicated to processing electronic receipts, and an IP outside exchange network dedicated to processing outside exchange.

2. A second embodiment in which the IP network is selected based only on the IP address;

similar to fig. 3, as shown in fig. 9, the network node of the communication circuit 6-X1 is given a network node address "G105" for use in the integrated IP network; the network nodes of the communication circuit 6-X2 are assigned a network node address "G115". For example, one source terminal 8-3 in LAN 3 sends an IP packet PK03 to one destination terminal in LAN 4. The IP packet PK03 includes the address "a 105" of the source terminal 8-3, the address "a 205" of the destination terminal 8-4 and the transmission data. The transmission data is a receipt processed by a voice telephone transmission/reception program, a video transmission/reception program, an electronic receipt transmission/reception program, and a WWW data transmission/reception program based on a known HTTP protocol. The voice telephone transmission/reception program means a telephone transmission/reception program for an IP telephone using digital technology.

In this structure, the operation of the network will be described with reference to the flowchart of fig. 10. First, the IP packet PK03 enters the network from the communication circuit 6-X1 via the network node specifying the network node address "G105". The network node device 5-X receives the IP packet PK03 (step S200), searches the address management table in the device to see whether there is a registered record with the network node address "G105" in the "source terminal node address" column, and checks whether the request identification value of the record is "3" (step S201). In this embodiment, the request identification value is not "3", meaning that the packet does not specify a virtual private line connection (case 1). Then, the network node device 5-X reads the address "a 105" of the source terminal 8-3 and the address "a 205" (DA) of the destination terminal 8-4 from the IP packet PK03 (step S202), and searches the address management table set in the device and illustrated in fig. 11 to find a record whose address matches the source terminal address "a 105" (SA) and the destination terminal address "a 205" (DA) of the packet (step S203). In this embodiment, this record is found on the first line from the top in the address management table of fig. 11, and has "SA ═ a105, DA ═ a205, N-SA ═ G105, N-DA ═ G205", and "network identifier Nwa (video network)". From the record, the apparatus extracts the source network node address "G105" and the destination network node address "G205", and the process proceeds to step S206. The network node address may use an IP address as described above. That is, an address applied to the OSI layer three can be used, or an address applied to the OSI layer two can be used, for example, an address used in FR switching and ATM switching (for example, a telephone number according to the e.164 specification).

In the above-described step S200, if another IP packet PK15 enters the network from the communication circuit 6-X2 via the network node specified by a network node address "G115", the network node apparatus 5-X receives the IP packet PK15, searches the address management table in the apparatus to see whether or not there is a record having the network node address "G115" in the "source network node address" column of the table, and checks whether or not the request identification value of the record is "3" (step S201). In this embodiment, the record has a "request identification value" of "3" (on the second row from the top of the address management table), which means that the packet specifies a virtual private line connection (case 2). Therefore, the process proceeds to step S205. Then, before proceeding to step S206, the apparatus extracts the source network node address "G115" and the destination network node address "G215" registered in the specific record.

Next, the apparatus adds an integrated IP network header as shown in fig. 12 to the packet to generate an integrated IP network packet PK11 (step S206). This step uses the source network node address "G105" or "G115" (N-SA) and the destination network node address "G205" or "G215" (N-DA) obtained by step S203 or step S205. Next, the integrated IP network packet PK11 generated through the above-described procedure is transmitted to the communication circuit 7-1 according to the designated network identifier "NWa" (IP video network) (step S207). The communication circuit 7-1 is connected to an IP video network 2-X operated by a communication company X among the IP video networks 2. The above step S105 switches between the IP video network and the IP general network depending on whether the received IP packet PK03 designates "NWc" (IP telephone network) or "NWb" (IP general network) as the network identifier.

The integrated IP network packet PK13 is then transmitted to the network node apparatus 5-Y via the IP video network 2-X, through the IP packet switching point 2-1, and via the IP video network 2-Y of the communication company Y. As shown in the flowchart of fig. 13, the network node apparatus 5-Y receives the integrated IP network packet PK11 (step S220), deletes the IP network header from the received integrated IP network packet to recover the IP packet addressed to the local area network (step S221), and transmits the recovered IP packet to the terminal 8-4 through the communication circuit 6-Y (step S222). The IP packet switching point 2-1 measures the number of IP packets passing through the point and the length of time it takes for the IP packets to pass through the point. The carrier managing the IP video network 2-X and the carrier Y managing the IP video network 2-Y can measure the number and time of passing IP packets and use as data for calculating the charge for communication to the IP packet sender and receiver.

The second embodiment may also be implemented so that there is no IP video network 2-Y and no IP packet switching point 2-1 of carrier Y, i.e. the IP video network 2 comprises only the IP video network 2-X of carrier X. In this case, the communication company running the IP video network 2 is a company "X". Similarly, IP telephone network 4 may comprise only IP telephone network 4-X of carrier X.

3. A third embodiment using a separate domain name server:

as shown in fig. 14, the integrated IP network 31 has an IP audio-video network 32, an IP data network 33, an IP telephone network 34, and a best effort network 35. The IP audio-visual 32 is an IP network similar to the IP video network but simultaneously transmitting video and its associated sound, such as movie and television broadcast video and its sound. The IP data network 33 has a function similar to an IP electronic text network, and can transmit data such as compressed still image data in addition to electronic text data composed of characters. Although the full force network 35 has a function of performing IP telephone communication, IP audio-image communication, and IP data communication, and is an IP network used by a user who knows that if traffic congestion occurs in IP transmission, a communication delay will occur or the number of discarded IP packets will increase. A typical example of an IP-based network is the internet.

In the integrated IP network 31, network node devices 35-1, 35-2, 35-3, 35-4, 35-5, and 35-6 are connected to one of the IP networks 31 (an IP audio-visual network 32, an IP data network 33, an IP telephone network 34, and an all-purpose network 35) through communication circuits 37-1 to 37-20. The network nodes of the network node devices are connected to the external terminals 42-1, 43-1, 44-1, 42-2, 43-2, 44-2 and the internal terminals of the LAN 31, the LAN 32, the LAN 33 and the LAN 34 of the integrated IP network 31 via one of the communication circuits 36-1, 36-2, 36-3, 36-4, 36-5, 36-6, 36-7, 36-8, 36-9, 36-10. Each network node device has an address management table in which the IP address of a registered terminal and a port number identifying an application of the terminal are written.

The IP network 31(IP audio-visual network 32, IP data network 33, IP telephony network 34 and best effort network 35) comprises dedicated domain name servers 45-1, 45-3, 45-4, 45-5, 45-6, 45-7, 45-8 used in these networks. These domain name servers have a one-to-one correspondence between host names assigned to the external terminals 42-1 to 44-2 and their IP addresses.

A network node address "G361" is given to the network node of the communication circuit 36-1 for use in the IP network 31. Which represents the logical boundary between the network node devices 35-1 to 35-6 and the external communication circuits of the integrated IP network 31. Each network node is assigned a network node address. Further, a network node address "G362" is assigned to the network node of the communication circuit 36-2, a network node address "G366" is assigned to the network node of the communication circuit 36-6, a network node address "G367" is assigned to the network node of the communication circuit 36-7, a network node address "G368" is assigned to the network node of the communication circuit 36-8, and a network node address "G3610" is assigned to the network node of the communication circuit 36-10.

Fig. 15 shows an example of an address management table in the network node device 35-1. The domain name server is assigned a network node address and an IP address, which is used as an address for sending and receiving IP packets.

Next, a communication method from IP telephone 38-1 in LAN 31 to IP telephone 40-1 in LAN 33, for example, will be described with reference to fig. 15 to 23. The IP phone 38-1 has an IP address "A381", and the IP phone 40-1 has a phone number "T401" corresponding to the host name and IP address "A401" of the terminal. The domain name server 45-3 dedicated to the IP telephony network 34 has an IP address "a 453" and a network node address "G453".

The IP telephone 38-1 first transmits an IP packet PK30 including the telephone number "T401" of the destination terminal or the destination IP telephone 40-1 to the network node device 35-1 (step S401). The network node device 35-1 reads the address "a 381" (SA) of the source IP telephone 38-1, the IP address "a 453" (DA) of the destination domain name server 45-3, and the port number "25" from the received IP packet PK30, and then searches the address management table (fig. 15) set in the network node device 35-1 to find a record whose address and port number match the address "a 381" (SA) of the source IP telephone 38-1, the address "a 453" (DA) of the destination domain name server 45-3, and the port number "25" (step S402). In this example, the record is found on the first line from the top in the address management table of fig. 15, and has "SA-a 381, DA-a 453, N-SA-G361, and N-DA-G453". From the record, the apparatus extracts the source network node address "G361" and the destination network node address "G453", adds the integrated IP network header to the packet to generate one IP packet PK31, and transmits PK31 to the domain name server 45-3 (step S403).

The domain name server 45-3 receives the IP packet PK31, searches the internal database and sends back the IP address "a 401" corresponding one-to-one to the telephone number "T401" of the destination IP telephone 40-1. Network node device 35-1 sends IP packet 32 back to IP phone 38-1 (step S405). Using the above-described procedure, the IP telephone 38-1 acquires the IP address "a 401" having a one-to-one correspondence with the destination telephone number "T401".

Next, IP telephone 38-1 generates a "terminal-to-terminal IP packet PK 33" comprising IP address "a 381" of source IP telephone 38-1, IP address "a 401" of the destination telephone, and voice digitized and stored in the IP packet payload portion (data field). IP telephone 38-1 transmits the packet over communication circuit 36-1 (step S406). Upon receiving the IP packet PK33, the network node device 35-1 reads from the packet the address "a 381" (SA) of the source IP telephone 38-1, the address "a 401" (DA) of the destination IP telephone 40-1 and the port number "4000", and then searches the address management table (fig. 15) set in the device to find a record whose address and port number match the address "a 381" (SA) of the source IP telephone 38-1, the destination terminal address "a 401" (DA) of the destination IP telephone 40-1 and the port number "4000" (step S407). In this example, the record is found on the second line from the top in the address management table of fig. 15, and has "SA ═ a381, DA ═ a401, port number ═ 4000, N-SA ═ G361, and N-DA ═ G366". Based on the record, the apparatus extracts the source network node address "G361" and the destination network node address "G366", adds an integrated IP network header to the packet to generate an integrated IP network packet PK34, and transmits PK34 to the IP telephone network 34-X (step S408).

The packet PK34 passes through the packet switching point 34-1 and the IP telephony network 34-Y. The network node apparatus 35-4 receives the IP packet PK34 (step S421), deletes the header from the received packet PK34 to recover the IP packet PK33 (step S422), and transmits the IP packet PK33 to the telephone 40-1 (step S423). In step S407, comparison is performed using two IP addresses and port numbers. However, some records in the address management table have no port number written to them. In this case, it is possible to check only two kinds of IP addresses without comparing port numbers.

As described above, the network node address may be implemented as an IP address applied to the OSI layer three. Moreover, it can be implemented as an address applied to the OSI layer two, such as an address used in FR switching and ATM switching (e.g., a telephone number according to the e.164 specification), or it can be implemented using a two-layer protocol based on WDM technology. When the address applied to the second layer is used, the "integrated IP network header" as shown in fig. 22 uses a header based on two-layer communication protocols such as ATM and WDM.

Next, further explanation will be made with reference to the time chart of fig. 24. In fig. 24, reference numerals 49-1 and 49-2 denote various types of terminals installed outside the integrated IP network 31. An IP packet is sent from the terminal 49-1 to the network node device 35-1 (step S401), from which it is transferred to the domain name server 45-3 dedicated to the IP telephony network 34 (step S403). Then, the packet is returned from the domain name server (steps S404 and S405). The terminal 49-1 transmits the IP packet to the network node device 35-1 (step S406) and transmits it to the integrated IP packet network by the network node device 35-1 (step S408). The packet passes through the packet switching point 34-1 of the IP telephone network 34 and is received by another network node device 35-4 (step S421), and the node device 35-4 in turn transmits the IP packet to the terminal 49-2 (step S423). The terminal 49-2 may send the IP packet back to the terminal 49-1 (step S425).

The steps of transmitting and receiving IP packets, i.e., from step S431 to step S455 shown in fig. 24, may be implemented by using the IP data network 33. That is, data may be communicated between terminal 49-1 and terminal 49-2 via a domain name server 45-2 dedicated to the IP data network 33 and a packet switching point 33-1 in the IP data network. Also, the steps of IP packet transmission, i.e., from step S461 to step 485 shown in fig. 24, can be realized by using the IP audio-image network 32. That is, data can be transmitted and received between the terminal 49-1 and the terminal 49-2 via the domain name server 45-1 dedicated to the IP audio-visual network 32 and the packet switching point 32-1 in the IP audio-visual network 32.

In the above description, the embodiment can be implemented so that there are no IP audio-visual network 32-Y and IP packet switching point 32-1 of carrier Y, i.e., the IP audio-visual network 32 includes only the IP audio-visual network 32-X of carrier X. In this case, the communication company running the IP audio-visual network 32 is a company "X". Similarly, IP data network 33 may comprise only IP data network 33-X for carrier X and IP telephone network 34 may comprise only IP telephone network 34-X for carrier X. Moreover, although full force network 35 may include only IP telephone network 35-X of carrier X.

In fig. 14, reference numerals 46-1, 46-2, 46-3 and 46-4 denote ATM switching networks, 47-1 and 47-2 denote FR communication networks, and 48-1 and 48-2 denote optical communication networks. They can be used as high-speed trunk networks in IP networks to transport IP packets. For example, these networks may use technologies commonly referred to as "IP transport over FR networks" (FR-based IP), "IP transport over ATM networks" (ATM-based IP), and "IP transport over optical communications networks" (WDM-based IP).

4. A fourth embodiment of selecting a domain name server:

as shown in fig. 25, the integrated IP network 131 includes an IP audio-video network 132, an IP data network 133, an IP telephone network 134, and a best effort network 135. Reference numerals 136-1, 136-2, 136-3, 136-4, 136-5, 136-6, 136-7, and 136-8 represent network node devices. The network node devices 136-1 through 136-8 are connected to one or more IP networks via communication circuits. The network nodes of the network node devices are connected to external terminals 151, 152, 153, 154 of the integrated IP network 131 and internal terminals of the LAN 160 and the LAN 170 via communication circuits 140, 141, 142, 143, 144, 145. The network node device has an address management table including IP addresses assigned to external terminals and port numbers.

The integrated IP network 131 includes domain name servers 112-1, 112-2 dedicated to the IP audio-visual network 132, domain name servers 113-1, 113-2 dedicated to the IP data network 133, domain name servers 114-1, 114-2 dedicated to the IP telephone network 134, and domain name servers 115-1, 115-2 dedicated to the best effort network 135. These domain name servers have a one-to-one correspondence of the IP address of an external terminal and the host name of the terminal. Block 101-1, which is connected to network node device 136-6, is a DNS select server having the function of selecting one of domain name servers 112-1, 113-1, 114-1, 115-1. 101-2, which is connected to network node device 136-2, is a "DNS select server" having the function of selecting one of domain name servers 112-2, 113-2, 114-2, 115-2. 137-1 in integrated IP network 131 indicates the range of IP networks managed by carrier X, and 137-2 in integrated IP network 131 indicates the range of IP networks managed by carrier Y. IP network 137-1 includes DNS selection server 101-1 and domain name servers 112-1, 113-1, 114-1, 115-1, and IP network 137-2 includes DNS selection server 101-2 and domain name servers 112-1, 113-2, 114-2, 115-2.

Next, the operation of these devices will be explained with reference to fig. 26 to 30.

Reference numerals 160-T and 170-T in fig. 26 denote terminals inside the LAN 160 and the LAN 170. First, the audio-image terminal 161 transmits an IP packet 181 to the network node device 136-6 (step S601); network node device 136-6 sends IP packet 181 to DNS selection server 101-1 (step S602); the DNS selecting server 101-1 finds the IP network designation code contained in "aa.bb.cc.audio-visual.jp" of the data part of the IP packet, in this case, "audio-visual", and thus transmits the IP packet 181 of fig. 27 to the domain name server 112-1 for the IP audio-visual network (step S603). The domain name server 112-1 returns an IP packet containing an IP address having a one-to-one correspondence with the host name "aa.bb.cc.audio-visual.jp" to the terminal 161 (step S605). Then, the terminal 161 transmits an IP packet to the terminal 171, and the terminal 171 is located on the IP address matching "aa.bb.cc.audio-visual.jp" obtained in the above-described step (steps S606 and S607). Upon receiving the IP packet, the terminal 171 generates an IP packet for response and sends it back to the terminal 161 (step S608).

When the terminal 162 for IP data communication transmits one IP packet to the network node device 136-6 (step S611), the operation performed is similar to the above-described operation. The difference from the above operation is that the DNS selecting server 101-1 finds the IP network specifying code, in this case, "data", contained in "aa.bb.cc.data.jp" of the data part of the IP packet 182 of fig. 28, and therefore, transmits the IP packet to the domain name server 113-1 for the IP data network (step S613). The domain name server 113-1 returns an IP address having a one-to-one correspondence relationship with the host name "aa.bb.cc.data.jp" to the terminal 162 (step S615). Next, the terminal 162 transmits the IP packet to the terminal 172, and the terminal 172 is located at the IP address corresponding one-to-one to "aa.bb.cc.audio-visual.jp" obtained in the above-described step (steps S616 and S617). Upon receiving the IP packet, the terminal 172 generates an IP packet for response and returns it to the terminal 162 (step S618).

When IP telephone 163 transmits IP packet 183 of fig. 29 to network node apparatus 136-6 (step S621), the operation performed is similar to the above-described operation. The difference from the above operation is that the DNS selecting server 101-1 finds an IP network specifying code, in this case "telephone", included in "aa.bb.cc.telephone.jp" of the data part of the IP packet 183, and thus transmits the IP packet 183 to the domain name server 114-1 for the IP telephone network (step S623). Domain name server 114-1 returns an IP address to IP phone 163 that corresponds one-to-one to the host name "aa.bb.cc.telephone.jp" (step S625). Next, phone 163 transmits an IP packet to IP phone 173, and IP phone 173 is located at an IP address one-to-one corresponding to "aa.bb.cc.telephone.jp" obtained in the above step (steps S626, S627). Upon receiving the IP packet, the IP telephone 173 generates an IP packet for response and returns it to the IP telephone 163 (step S628)

When the data portion of the IP packet 184 of fig. 30 from the terminal 164 does not contain any code specifying an IP audio-visual network, an IP data network, or an IP telephony network, the DNS selection server 101-1 selects the domain name server 115-1 for the best effort network 135. Terminal 164 then establishes IP communication with terminal 174 using best effort network 135. In this way, IP communication between two terminals may use an IP audio-visual network, an IP data network, an IP telephone network, or a full-force network.

As described above, the present invention can be used without using an expensive dedicated line, and can constitute a large-scale communication system at a low cost without using the internet which does not provide a high-speed communication circuit required for transmitting television and other video data, for which no one is responsible for planning the expansion of its communication circuit device. Furthermore, since a plurality of independent IP networks having different characteristics, such as an IP telephone network, an IP video network, an IP electronic text network, a best effort network, an IP data multicast network, and an IP-based television broadcast network, are included in the integrated IP network, the total cost can be low.

Claims (15)

1. An integrated IP network comprising:

a plurality of IP networks; and

a plurality of network node devices;

wherein each of said network node devices is connected to one or more of said IP networks via a communication circuit and has their network node connected to an external terminal via a communication circuit;

wherein, when one of the network node devices receives an IP packet from the external terminal, the following sequence of operations is performed: in a first case where a network node address of a network node through which a received IP packet passes is registered in an address management table as a virtual private line connection unspecified, comparing a destination terminal address and a port number registered in the address management table with a source terminal address, a destination terminal address, a source port number and a destination port number included in the IP packet to find a record containing a network identifier indicating to which destination IP network the IP packet is to be sent; in a second case where the network node address of the network node through which the received IP packet passes is registered in the address management table as specifying a virtual private line connection, detecting a record containing a network identifier indicating to which destination IP network the IP packet is to be sent; after the process of the first case or the second case is completed, generating one integrated IP network packet using the source network node address and the destination network node address contained in the detected record, and then transmitting it to the destination IP network; the integrated IP network packet reaches another network node device through an IP packet switching point and a destination IP network, where an integrated IP network header is deleted from the integrated IP network packet to recover the received IP packet, and then transmitted to a destination IP terminal;

wherein an address management table is referred to select a destination IP network to which an IP packet is transmitted and the IP packet is transmitted to the destination IP network, and an integrated IP network packet is transmitted through two or more IP networks of different carriers in the destination IP network and through an IP packet switching point.

2. An integrated IP network according to claim 1, in the first case a source terminal address and a destination terminal address registered in the address management table are compared with a source terminal address and a destination terminal address contained in the IP packet to find a record containing a network identifier indicating to which destination IP network the IP packet is to be sent, characterized in that the port numbers are not compared.

3. An integrated IP network according to claim 1, comprising a single IP network managed by one carrier, said integrated IP network packets passing within said IP network, characterized in that the integrated IP packets neither pass through two or more IP networks of different carriers nor through any IP packet switching point.

4. An integrated IP network according to claim 1, wherein at least one of the network node devices is connected to an IP video network within the IP network and is connected to an IP video device outside the IP network via a network node of the network node device.

5. An integrated IP network according to claim 1, wherein at least one of the network node devices is connected to an IP telephone network within the IP network and is connected to an IP telephone outside the IP network through a network node of the network node device.

6. An integrated IP network comprising:

a plurality of IP networks; and

a plurality of network node devices;

wherein each of said network node devices is connected to one or more of said IP networks via a communication circuit and has their network node connected to an external terminal via a communication circuit;

wherein each IP network comprises a plurality of dedicated domain name servers; each domain name server has a correspondence between an IP address of an external terminal and a host name of the terminal; upon receiving an IP packet destined to a domain name server from an external source terminal, one of the network node devices transmits the received IP packet to the destination domain name server; the destination domain name server extracts a destination terminal IP address corresponding to a destination terminal host name included in the received IP packet, and transmits the IP packet including the obtained destination terminal IP address to an external source terminal; the source terminal generating a new IP packet having the destination terminal IP address obtained from the domain name server and transmitting the generated new IP packet to one of the network node devices; the network node device compares a source terminal address, a destination terminal address and a port number registered in the address management table with a source terminal address, a destination terminal address and a port number included in the new IP packet to find a record designating to which destination IP network the integrated IP packet is to be sent, generates an integrated IP network packet using the source network node address and the destination network node address included in the detected record, and sends the generated integrated IP network packet to the destination IP network; the integrated IP network packet is sent to another network node device through an IP network and an IP packet switching point, an integrated IP network header is deleted from the integrated IP network packet on the network node device to recover the new IP packet, and then the new IP packet is sent to a destination IP terminal;

wherein an address management table is referred to select a destination IP network to which an IP packet is to be transmitted and the IP packet is transmitted to the destination IP network, and the integrated IP network packet is transmitted through two or more IP networks of different carriers in the destination IP network and through an IP packet switching point.

7. An integrated IP network according to claim 6, wherein a source terminal address and a destination terminal address registered in the address management table are compared with a source terminal address and a destination terminal address contained in the IP packet to find a record containing a network identifier indicating to which destination IP network the IP packet is to be sent, characterized in that the port numbers are not compared.

8. An integrated IP network according to claim 6, comprising a single IP network managed by one carrier, said integrated IP network packets passing within said IP network, characterized in that the integrated IP packets neither pass through two or more IP networks of different carriers nor through any IP packet switching point.

9. An integrated IP network according to claim 6 wherein at least one of the network node devices is connected to the IP audio-visual network inside the IP network and is connected to one of the IP audio-visual devices outside the IP network through a network node of the network node devices.

10. An integrated IP network according to claim 6, wherein at least one of the network node devices is connected to an IP telephone network within the IP network and to an IP audio-visual device through a network node of one of the network node devices.

11. An integrated IP network according to claim 6, wherein at least one of the network node devices is connected to the best effort network within the IP network and is connected to an IP terminal, IP telephone or audio-visual device through a network node of one of the network node devices.

12. An integrated IP network according to claim 6, wherein at least one of the network node devices is connected to the IP data multicast network within the IP network and to an IP terminal, IP telephone or audio-visual device via a network node of the network node device.

13. An integrated IP network according to claim 6, wherein at least one of the network node devices is connected to an IP-based television broadcast network within the IP network and to an IP terminal, IP telephone or audio-visual device via a network node of one of the network node devices.

14. An integrated IP network according to claim 6 wherein the IP network comprises an ATM network, an FR network or a WDM network having a function of transporting IP packets.

15. An integrated IP network according to claim 6 wherein a DNS selection server having the capability of selecting a dedicated domain name server is included in the IP network.