JP2004040348A - Packet control apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify settings of a router and a personal computer or the like when a new application such as the VoIP is going to be added to an existing LAN facility or the like. <P>SOLUTION: A network application adaptor 20 is interposed between an ADSL modem 2 and the router 4 or between the ADSLmodem 2 and the personal computer 8. The adaptor 20 principally passes supplied packets without applying any processing to them, but separately decodes in itself packets for the VoIP supplied via the ADSLmodem 2 and supplies a voice signal or a control signal to a telephone set 10. Further, the adaptor 20 generates packets for the VoIP wherein a MAC address of the router 4 or the personal computer 8 is used for a sender MAC address on the basis of the voice signal or the control signal from the telephone set 10 and transmits the packets via the ADSL modem 2. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a packet control device suitable for connecting various network devices.
[0002]
[Prior art]
2. Description of the Related Art In recent years, a technology called VoIP for realizing a voice call on an IP network has become widespread. As a result, the telephone network can be integrated with the data network, the operation rate of the line can be improved, and the communication cost can be reduced. Here, FIG. 1A shows a configuration example of a user-side device compatible with VoIP. In the figure, reference numeral 2 denotes an ADSL modem, which communicates with an Internet service provider (ISP) using a PPPoE (point to point protocol over Ethernet, "Ethernet" or "Ethernet" is a registered trademark) protocol.
[0003]
Are personal computers, 6 is a VoIP adapter, and a LAN (local area network) 5 is formed by these. Reference numeral 4 denotes a router, which extracts packets to be transmitted to the WAN side such as the Internet via the ADSL modem 2 from the packets in the LAN 5 and supplies the packets to the ADSL modem 2, and receives the packets from the WAN side received via the ADSL modem 2 Is supplied to the LAN 5. The VoIP adapter 6 converts a voice signal and a control signal received from the telephone 10 into IP packets and transmits these IP packets via the LAN 5, and converts the supplied IP packets into voice signals and control signals to the telephone 10. Supply.
[0004]
Also, another configuration example of the user-side device is shown in FIG. In the figure, an ADSL modem 2 and a VoIP adapter 6 are directly connected to one personal computer 8, and a telephone 10 is connected to the VoIP adapter 6. Of the IP packets supplied to the personal computer 8 via the ADSL modem 2, packets relating to VoIP are supplied to the VoIP adapter 6 and converted to voice signals or control signals via the VoIP adapter 6, and then these signals are transmitted to the telephone. 10 is supplied. The voice signal and the control signal supplied from the telephone 10 are converted into IP packets in the VoIP adapter 6, and the IP packets are transmitted to the ADSL modem 2 via the personal computer 8. The conversion into the IP packet may be executed by the personal computer 8 in some cases.
[0005]
[Problems to be solved by the invention]
By the way, assuming a configuration without the VoIP adapter 6 and the telephone 10 in FIGS. 1A and 1B, adding the VoIP adapter 6 and the like to these configurations is extremely complicated for the user as described below. Therefore, it is difficult for a user who does not have knowledge of the IP protocol to make settings.
[0006]
First, in the configuration of FIG. 1A, a technique called IP masquerade is frequently used in order to associate a plurality of local addresses in the LAN 5 with one global address on the WAN side. When IP masquerading is performed, a port number different from the port number in the LAN 5 is generally used on the WAN side. However, since the port number to be used for VoIP is defined in advance, it is necessary to set the router 4 so that the packet related to VoIP does not change the port number. In the configuration shown in FIG. 2B, new software corresponding to the VoIP adapter 6 needs to be installed in the personal computer 8, and new settings on the WAN side are also required.
[0007]
Such complicated setting is not limited to VoIP, but often occurs when a new application is added to the network. The present invention has been made in view of the above circumstances, and has as its object to provide a packet control device that can easily add necessary applications.
[0008]
[Means for Solving the Problems]
In order to solve the above problems, the present invention is characterized by having the following configuration. The contents in parentheses are examples.
In the packet control device according to the first aspect, the packet is transmitted and received between a first packet transmission / reception device (LAN-side device) and a second packet transmission / reception device (WAN-side device). An information acquisition unit (SP302 to SP316) for observing a packet transmitted via the path and acquiring address information (MAC address) for specifying the first packet transmission / reception device; And a packet transmitting means (SP402 to SP416) for generating a packet using the obtained address information as a source address and transmitting the packet to the second packet transmitting / receiving apparatus (WAN-side device).
Further, according to the configuration of the second aspect, in the packet control apparatus of the first aspect, the packet is transmitted from one of the first and second packet transmitting / receiving apparatuses to the other in accordance with a result of the acquisition by the information acquiring means. It is characterized by further comprising blocking means (SP110, SP210) for blocking the packet as required.
Further, in the configuration according to the third aspect, in the packet control apparatus according to the first aspect, one of the first and second packet transmitting and receiving apparatuses is transmitted to the other according to an acquisition result of the information acquiring unit. It is characterized by further comprising modifying means (modification) for modifying the transmitted packet as necessary and transmitting the modified packet.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
1. Configuration of the embodiment
1.1. Configuration example of user device
Next, a configuration example of a user-side device using an application adapter according to an embodiment of the present invention will be described with reference to FIGS. 2A, a plurality of personal computers 8, 8,... And a router 4 are connected via a LAN 5, as in FIG. A network application adapter 20 is interposed between the ADSL modem 2 and the router 4, and the telephone 10 is connected to the adapter 20. In FIG. 2A, an example in which VoIP is newly introduced to the existing configuration originally including the ADSL modem 2, the router 4, and the personal computers 8, 8,. Example) is assumed.
[0010]
FIG. 2B shows an example in which VoIP is newly introduced while one personal computer 8 is connected to the WAN via the ADSL modem 2 (that is, the adapter 20 and the telephone 10 are added). Example) is assumed. Although the reason will be described later, in any of the examples, it is one of the features of the network application adapter 20 of the present embodiment that the router 4 or the like does not need to change the existing setting status at all.
[0011]
1.2. Hardware configuration of application adapter
Next, the hardware configuration of the network application adapter 20 will be described with reference to FIG. In the figure, reference numeral 220 denotes a CPU, which controls each unit in the adapter 20 via the bus 228 based on a control program stored in the flash memory 222. A RAM 224 is used as a work memory of the CPU 220. A display 226 displays various kinds of information under the control of the CPU 220. Reference numerals 202, 206, and 216 denote interface controllers connected to external devices. The interface controller 202 is connected to the WAN-side device (ADSL modem 2 in the example of FIGS. 2A and 2B), and transmits and receives packets to and from the WAN-side device.
[0012]
The interface controller 206 is connected to the LAN-side device (the router 4 or the personal computer 8 in the example of FIGS. 2A and 2B) and transmits and receives packets to and from the LAN-side device. The interface controller 216 is connected to the telephone 10 and transmits and receives a voice signal and a control signal to and from the telephone 10. That is, the interface controller 216 converts an analog signal (voice signal or control signal) received from the telephone 10 into a digital signal and outputs the digital signal via the bus 228, and converts the digital signal received via the bus 228 into an analog signal. It is supplied to the telephone 10.
[0013]
Incidentally, the packet transmitted in the LAN 5 in FIG. 2A is an IP packet. Here, a format of a TCP / IP packet will be described with reference to FIG. In the figure, an Ethernet header 110 is provided at the beginning of a TCP / IP packet, where a source MAC address MSA and a destination MAC address MDA are specified. Reference numeral 120 denotes an IP header, which specifies a transport layer protocol PROT, a source IP address ISA, and a destination IP address IDA in the OSI hierarchical model.
[0014]
In a TCP / IP packet, "TCP protocol" is specified in the protocol PROT. Reference numeral 130 denotes a TCP header, in which a source port number SRC_PORT and a destination port number DEST_PORT are specified. After the TCP header 130, a data section 140 to be transmitted is provided.
[0015]
FIG. 10A illustrates an example of a TCP / IP packet. In a UDP / IP packet, the protocol PROT of the IP header 120 is set to “UDP”, and a UDP header is provided instead of the TCP header 130. become. In the UDP header, similarly to the TCP header 130, a source port number SRC_PORT and a destination port number DEST_PORT are provided.
[0016]
On the other hand, various protocols are used between the router 4 and the Internet service provider. Here, it is assumed that PPPoE is adopted. That is, in the router 4, the IP packet and the PPPoE packet are mutually converted. Therefore, all packets transmitted and received by the network application adapter 20 are PPPoE packets. Here, FIG. 10B shows an example in which the IP packet of FIG. 10A is converted into a PPPoE packet.
[0017]
In FIG. 10B, reference numeral 150 denotes an Ethernet header, in which a source MAC address MSA and a destination MAC address MDA are specified in the same manner as the Ethernet header 110. Next, reference numeral 160 denotes a PPPoE header, which designates a session ID that uniquely identifies a PPPoE session. Next, reference numeral 170 denotes a PPP header, and the data length after the PPP header 170 is specified here. Reference numeral 180 denotes an IP header, in which, similarly to the IP header 120, a protocol PROT of the transport layer, a source IP address ISA, and a destination IP address IDA are designated. However, the IP address specified in the IP header 180 is a global IP address.
[0018]
Reference numeral 190 denotes a TCP header, in which a source port number SRC_PORT and a destination port number DEST_PORT are specified as in the case of the TCP header 130. After the TCP header 190, a data section 200 to be transmitted is provided. Note that the UDP / IP protocol can be applied to the PPPoE packet for the IP header 180 and thereafter. In such a case, the protocol PROT is set to “UDP” in the IP header 180, and a UDP header is provided instead of the TCP header 190.
[0019]
1.3. Task configuration of network application adapter 20
Next, the task configuration of various tasks executed by the CPU 220 in the adapter 20 will be described with reference to FIG. In the figure, reference numeral 204 denotes a packet analysis / information extraction task, which mutually transmits and receives packets transmitted and received by the interface controllers 202 and 206, analyzes these packets, and extracts necessary information. Further, transmission of packets that should not be transmitted to each other between the interface controllers 202 and 206 is stopped, or packets generated inside the adapter 20 are transmitted via the interface controllers 202 and 206 as necessary.
[0020]
An information storage area 224 a is secured in a predetermined address range in the RAM 224 and stores various information extracted by the packet analysis / information extraction task 204. An input determination task 212 determines whether the signal received from the telephone 10 is a voice signal or a control signal according to the VoIP protocol or a signal for setting an internal state of the adapter 20. Since the network application adapter 20 of the present embodiment is not provided with any input operation element, the user can perform various settings for the adapter 20 by performing a predetermined operation on the telephone 10. The adapter 20 itself may be provided with a unit for inputting information, or the display 226 may be omitted by using a display of another device together.
[0021]
The input determination task 212 determines whether the signal supplied from the telephone 10 corresponds to the “predetermined operation”, and if so, notifies the setting operation task 210 of the content of the operation. In the setting operation task 210, the internal state of the adapter 20, that is, the storage content in the information storage area 224a is updated based on the notified operation content. On the other hand, signals other than the “predetermined operation” supplied from the telephone 10 are control signals or voice signals according to the VoIP protocol. In such a case, the signal is provided to the application control task 208.
[0022]
In the application control task 208, an IP packet (a PPPoE packet) for VoIP communication is generated based on these control signals or voice signals. Further, in the application control task 208, of the packets received via the interface controller 202, IP packets for VoIP communication are decomposed. As a result, a control signal or a voice signal from the communication partner is reproduced and supplied to the telephone 10 via the interface controller 216. A control task 218 controls other tasks based on a program described later.
[0023]
2. Operation of the embodiment
2.1. Packet reception from LAN side
Next, an operation when various events occur in the present embodiment will be described. First, when a certain packet (here, a PPPoE packet) is supplied from the LAN device to the network application adapter 20, the control task 218 starts the LAN packet reception event processing routine shown in FIG. In the figure, when the processing proceeds to step SP102, a necessary information extraction processing subroutine (FIG. 7) for extracting various information from the packet is called. In FIG. 7, when the process proceeds to step SP302, the Ethernet header 150 of the PPPoE packet is analyzed, and the source MAC address MSA and the destination MAC address MDA are obtained.
[0024]
Here, the source MAC address MSA is the MAC address of the device on the LAN side, and the destination MAC address MDA is the MAC address of a broadcast address or a BAS (Broadband Access Server, not shown) on the Internet service provider (ISP) side. . Next, when the process proceeds to step SP304, the PPPoE header 160 is analyzed and a session ID is obtained. Next, when the process proceeds to step SP306, the PPP header 170 or the IP header 180 is analyzed, whereby the IP addresses (the source global IP address and the destination global IP address) included in the PPPoE packet are obtained.
[0025]
Next, when the process proceeds to step SP308, it is determined whether or not each of the information obtained in steps SP302 to 306 matches the information stored in the information storage area 224a. If “NO” is determined here, the process proceeds to step SP310, and it is determined whether or not the information stored in the information storage area 224a is locked (whether or not updating is prohibited). For example, when the session ID or global IP address used for VoIP is fixed in advance, the information is forcibly set by the user (by manual operation via the telephone 10). In some cases. In such a case, if such information is updated based on the packet supplied to the network application adapter 20, communication cannot be performed, so that the information needs to be locked.
[0026]
If the information is not locked, “NO” is determined in the step SP310, and the process proceeds to a step SP312. Here, the information acquired in steps SP302 to SP306 is written to the information storage area 224a instead of the currently stored information. If "NO" is determined in the step SP308 or the step SP10, the step SP312 is not executed, and the information stored up to that point is stored in the information storage area 224a as it is.
[0027]
Next, when the process proceeds to step SP314, it is determined whether or not the information obtained in steps SP302 to SP306 is to be displayed on the display 226. Note that whether to display such information is set in advance by the user. If “YES” is determined in step SP314, the process proceeds to step SP316, and the acquired information is displayed on display 226. With the above steps, the necessary information extraction processing subroutine (FIG. 7) ends, and the process returns to the LAN-side packet reception event processing routine (FIG. 5).
[0028]
In FIG. 5, when the process proceeds to step SP104, the destination port number DEST_PORT in the TCP header 190 (or a UDP header instead thereof) is analyzed. Then, it is determined whether or not the port number is in a range other than the TCP or UDP number 5060 or the UDP numbers 5004 to 5015. Here, these port numbers will be briefly described. In VoIP, two protocols, "SIP" for call setting control and "RTP" for voice signal transmission, are adopted. TCP or UDP No. 5060 is allocated for SIP, and UDP Nos. 5004 to 5015 are allocated to RTP.
[0029]
By the way, if "YES" is determined in step SP104, that is, if the packet received from the LAN-side device is a packet not related to VoIP, the process proceeds to step SP106, and the packet is transmitted to the WAN side as it is. . As a result, the packet transmitted to the WAN-side device is exactly the same as when no network application adapter 20 is inserted.
[0030]
On the other hand, if the packet received from the LAN-side device is a packet related to VoIP, “NO” is determined in the step SP104, and the process proceeds to a step SP108. Here, it is determined whether the use of SIP or RTP is permitted in the LAN-side device. Note that the use of SIP or RTP in the LAN-side device is not permitted in a default state, but it is also possible for the user to set in advance in the adapter 20 in order to enable the use.
[0031]
If the use of SIP or RTP in the LAN device is not permitted, “NO” is determined in the step SP108, and the process proceeds to a step SP110, where the packet is discarded. That is, in such a state, VoIP can be executed only by the telephone 10 connected to the adapter 20, and even if another VoIP adapter or the like is connected to the LAN side device, it is impossible to use it. Will be possible.
[0032]
On the other hand, when the use of SIP or RTP in the LAN-side device is permitted, “YES” is determined in step SP108, and the process proceeds to step SP106. As a result, the packet related to VoIP generated in the LAN device is transmitted to the WAN device via the adapter 20 as it is. When the above steps are completed, the event processing when a packet is received from the LAN device ends.
[0033]
2.2. Packet reception from WAN side
Next, an operation when a PPPoE packet is supplied from the WAN device to the network application adapter 20 will be described. When a packet is supplied from the WAN-side device, the WAN-side packet reception event processing routine shown in FIG. In the figure, when the processing proceeds to step SP202, the necessary information extraction processing subroutine (FIG. 7) is called as in step SP102 described above, and the source MAC address MSA, destination MAC address MDA, session ID, source global The IP address and the destination global IP address are extracted.
[0034]
However, in the packet received from the WAN device, the source MAC address MSA and the source global IP address are the addresses of the BAS on the Internet service provider (ISP) side, and the destination MAC address MDA and the destination global IP address are This is the address of the LAN device. Next, when the process proceeds to step SP204, it is determined whether or not the extracted packet is a packet of the SIP or RTP protocol.
[0035]
Here, if the packet is not a packet of the SIP or RTP protocol, it is determined as “NO”, the process proceeds to step SP212, and the packet is transmitted to the LAN side device as it is. That is, when the packet received from the WAN device is a packet not related to VoIP, the packet transmitted to the LAN device is exactly the same as when the network application adapter 20 is not inserted.
[0036]
On the other hand, if the packet received from the WAN-side device is a packet related to VoIP, “YES” is determined in the step SP204, and the process proceeds to a step SP206. Here, it is determined whether the network application adapter 20 is communicating using SIP or RTP. If "YES" is determined here, the process proceeds to step SP210, and a process according to the SIP or RTP protocol is executed in the adapter 20 (in particular, in the application control task 208). As a result, the communication process being executed in the adapter 20 is continued for the newly received packet.
[0037]
If the adapter 20 is not communicating using SIP or RTP, "NO" is determined in the step SP206, and the process proceeds to a step SP208. Here, it is determined whether the use of SIP or RTP in the LAN device is permitted. If “YES” is determined here, the process proceeds to step SP212 described above, and the received packet is transmitted to the LAN-side device as it is. As a result, processing related to SIP or RTP is processed in the LAN-side device.
[0038]
If “NO” is determined in step SP208, the process proceeds to step SP210 described above. That is, when the use of SIP or RTP in the LAN-side device is not permitted and the adapter 20 receives a packet related to the SIP or RTP protocol in a state where the adapter 20 is not communicating using SIP or RTP, Usually, it is a case where a new call setting request is received from the outside. Therefore, in such a case, in the application control task 208, a call setting process or the like according to the protocol is performed on the packet. When the above steps are completed, the event processing when a packet is received from the WAN side device ends.
[0039]
2.3. Packet transmission processing
In the application control task 208, when a control signal or a voice signal is supplied from the telephone set 10 via the input discrimination task 212, the TCP header 190 of the PPPoE packet for VoIP (or a UDP header instead of this) is based on this. And the data section 200 are sequentially generated. When the data section 200 and the like are generated, a packet transmission request is supplied to the control task 218, and the control task 218 starts a packet transmission processing routine shown in FIG.
[0040]
In the figure, when the processing proceeds to step SP402, it is determined whether or not the use of SIP or RTP in the LAN-side device is not permitted and whether the SIP or RTP is usable on the adapter 20 side. . If "NO" is determined here, the present routine ends immediately. On the other hand, if “YES” is determined in the step SP402, the process proceeds to a step SP404, and it is determined whether or not information necessary for forming a packet is already stored in the information storage area 224a.
[0041]
Here, the “necessary information” is the global IP address of the LAN device, the session ID of the PPPoE session, the MAC address of the LAN device, and the MAC address of the WAN device. If "NO" is determined in the step SP404, the process of this routine also ends immediately.
[0042]
That is, if “NO” is determined in the step SP402 or SP404, the data part 200 generated in the application control task 208 is discarded without being actually transmitted as an IP packet. On the other hand, if “YES” is determined in both of these steps, the process proceeds to step SP406, in which the global IP address of the LAN device extracted in the necessary information extraction processing subroutine (FIG. 7) is replaced by the source IP address. An ISA IP header 180 is formed.
[0043]
Next, when the process proceeds to step SP408, the PPP header 170 is configured based on the data length of the data section 200 and the like. Next, when the process proceeds to step SP410, the PPPoE header 160 is configured based on the session ID of the PPPoE session. Next, when the process proceeds to step SP412, the MAC address of the LAN-side device is set as the source MAC address MSA, the MAC address of the WAN-side device is set as the destination MAC address MDA, and the Ethernet header 150 is formed.
[0044]
By the above steps, the PPPoE packet (FIG. 10B) is completed. Therefore, when the process proceeds to step SP414, the PPPoE packet is transmitted to the WAN side device. Next, when the process proceeds to step SP416, the application control task 208 clears the packet transmission request related to the PPPoE packet.
[0045]
2.4. Phone operation detection processing
When the telephone 10 is off-hook and the telephone 10 is off-hook and any operation is performed on the numeric keypad, a telephone operation processing routine (FIG. 9) shown in FIG. In the figure, when the process proceeds to step SP502, it is determined whether or not the operation is an instruction to start a VoIP connection. For example, an operation of inputting a normal telephone number or the like on the numeric keypad is an operation of instructing a start of VoIP connection.
[0046]
If "YES" is determined here, the process proceeds to step SP504, and it is determined whether or not the destination number is displayed. Whether or not to display the destination number is set by the user in the adapter 20 in advance. If “YES” is determined in step SP504, the process proceeds to step SP506, and the destination number is displayed on display 226. Next, when the process proceeds to step SP508, the input telephone number is notified to the application control task 208, and the application control task 208 executes a protocol process such as a call control process on the telephone number. .
[0047]
On the other hand, if “NO” is determined in step SP502, the process proceeds to step SP510. Here, it is determined whether or not the operation content corresponds to a “predetermined operation” for performing various settings for the adapter 20. If "YES" is determined here, the contents of the parameters and the like stored in the information storage area 224a are updated based on the manual operation of the numeric keyboard of the telephone 10 by the user. On the other hand, if “NO” is determined in step SP510, the processing is completed without performing substantial processing in this routine.
[0048]
3. Modified example
The present invention is not limited to the embodiments described above, and various modifications are possible, for example, as follows.
(1) The network application adapter 20 of the above embodiment is connected to the LAN-side device, and is premised on providing the VoIP service using the MAC address of the LAN-side device. That is, in step SP302 (FIG. 7), the MAC address of the LAN-side device is acquired based on the PPPoE packet sent by the LAN-side device such as the router 4, and the acquired MAC address is sent to the PPPoE sent by the network application adapter 20. Used as the source MAC address MSA of the packet.
[0049]
However, the network application adapter 20 may be used even when the LAN device is not operating. Specifically, when a PPPoE packet is not supplied from the LAN-side device interface controller 206 for a predetermined period of time, the adapter 20 uses its own MAC address to establish a PPPoE session with the WAN-side device (first PPPoE session). Session) to provide a VoIP service via the session.
[0050]
When the operation of the LAN-side device is started after the adapter 20 establishes the PPPoE session, the adapter 20 simulates the BAS of the WAN-side device, and establishes a PPPoE session (first session) between the adapter 20 and the LAN-side device. 2), and communication between the LAN-side device and the WAN-side device may be enabled by mediating the first and second sessions.
[0051]
(2) In the above-described embodiment, an example has been described in which the LAN-side device and the WAN-side device communicate using the PPPoE protocol. However, the protocol between the LAN-side device and the WAN-side device is not limited to PPPoE. Needless to say, various protocols may be used. In this case, depending on the type of the protocol, an ascending serial number may be assigned to each packet to be transmitted.
[0052]
In such a case, if the LAN-side device and the network application adapter 20 independently transmit packets to the WAN-side device, duplicate serial numbers will be assigned to a plurality of packets to be transmitted. In such a case, in the adapter 20, a part of the packet (serial number in the above example) transmitted and received between the LAN-side device and the WAN-side device may be modified and transmitted.
[0053]
(3) In the above embodiment, the network application adapter 20 provides the VoIP service. However, the application provided by the adapter 20 is not limited to the VoIP service. Alternatively, the present invention can be applied to various applications using a specific port number.
[0054]
【The invention's effect】
As described above, according to the present invention, a packet transmitted / received between the first packet transmitting / receiving apparatus and the second packet transmitting / receiving apparatus is observed, and address information for specifying the first packet transmitting / receiving apparatus is obtained. At the same time, a packet having the obtained address information as the source address is generated and transmitted to the second packet transmitting / receiving apparatus, so that a new application can be executed without changing the settings of the first and second packet transmitting / receiving apparatuses. Can be easily added. Further, in the present invention, since address information can be obtained by observing a packet, setting operations by a user can be greatly reduced.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration example of a conventional user device using VoIP.
FIG. 2 is a block diagram illustrating a configuration example of a user-side device using a network application adapter 20 according to an embodiment of the present invention.
FIG. 3 is a hardware block diagram of the network application adapter 20 of the embodiment.
FIG. 4 is a block diagram of a task of the network application adapter 20 according to the embodiment.
FIG. 5 is a flowchart of a LAN-side packet reception event processing routine.
FIG. 6 is a flowchart of a WAN-side packet reception event processing routine.
FIG. 7 is a flowchart of a necessary information extraction processing subroutine.
FIG. 8 is a flowchart of a packet transmission processing routine.
FIG. 9 is a flowchart of a telephone operation processing routine.
FIG. 10 is a diagram showing the configuration of an IP packet and a PPPoE packet.
[Explanation of symbols]
2 ADSL modem, 4 router, 5 LAN, 6 VoIP adapter, 10 telephone, 20 network application adapter, 8, 8, ... personal computer, 110 Ethernet header, 120 IP header, 130 TCP header, 140 data part, 150 Ethernet header, 160 PPPoE header, 170 PPP header, 180 IP header, 190 TCP header, 200 data part, 204 packet analysis / information extraction task, 208 application Control task, 210: Setting operation task, 212: Input determination task, 218: Control task, 220: CPU, 222: Flash memory, 224: RAM, 224a: Information storage area, 226: Display, 228: Bus, 202, 206 , 21 ... interface controller.

Claims (3)

A packet control device inserted in a path for transmitting a packet transmitted / received between a first packet transmitting / receiving device and a second packet transmitting / receiving device,
Information acquiring means for observing a packet transmitted via the path and acquiring address information for specifying the first packet transmitting / receiving apparatus;
A packet control unit, comprising: a packet transmission unit that generates a packet using the acquired address information as a transmission source address and transmits the packet to the second packet transmission / reception device. 2. The apparatus according to claim 1, further comprising a blocking unit configured to block a packet transmitted from one of the first and second packet transmission / reception devices to the other as necessary according to an acquisition result of the information acquisition unit. 2. The packet control device according to 1. According to another feature of the present invention, the information processing apparatus further includes a modification unit configured to modify a packet transmitted from one of the first and second packet transmission / reception devices to the other as necessary and transmit the packet according to an acquisition result of the information acquisition unit. The packet control device according to claim 1.

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