JP2006279867A - Adsl communication apparatus, program and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent up link transmission delay of TCP/IP communication caused by an ADSL line and to also surely transmit data upwardly. <P>SOLUTION: An ACK rewrite processing section 27 scans a transmission queue 22 and searches for an ACK in which a transmission source IP address, a destination IP address, a transmission source port number and a destination port number coincide with those of an ACK delivered from an ACK monitoring section 26 and if such a matching ACK packet is not found out, the delivered ACK is linked to the tail of the transmission queue 22 as it is. If the matching ACK packet is found out and it is an ACK packet to which datagram are attached, its ACK flag is changed into "0", for example, and the ACK is linked to the tail of the transmission queue 22. If it is an ACK packet to which datagram are not attached, on the other hand, its ACK number is rewritten into an ACK number of the ACK packet delivered from the ACK monitoring section 26. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ADSL communication apparatus, program, and method, and in particular, in TCP / IP communication including UDP / IP, expectation from the communication speed in the downstream direction of the ADSL line due to the delay in the ACK transfer in the upstream direction of the ADSL line. The present invention relates to an ADSL communication apparatus, program, and method capable of preventing deterioration of data transfer efficiency in the downstream direction of the ADSL line.

  In the ADSL line, the frequency band used for downstream communication and the frequency band used for upstream communication are different.

  FIG. 5 is a block diagram showing an operational configuration of a commonly used ADSL router. The ADSL router 201 is connected to the LAN terminal 101 via a LAN (LAN 9 itself is, for example, 100 Mbps in both upstream and downstream directions), while being connected via an ADSL line 10 (for example, 40 Mbps in the downstream direction and 1 Mbps in the upstream direction). Connected to an external network such as the Internet, and has a function of relaying TCP / IP communication between the server 401 and the LAN terminal 101 belonging to the external network.

  FIG. 6 is a sequence chart showing an operation example of TCP / IP communication in the conventional ADSL router 2. In this description, it is assumed that the LAN terminal 101 has notified the server 401 of the window size for four data packets at the time of TCP connection. Here, the window size is the number of data packets that the server 401 can continuously transmit without receiving an ACK (acknowledgment) from the LAN terminal 101.

  In FIG. 6, data packets 1, 2, 3,..., 7 from the server 401 arrive at the ADSL router 201 sequentially, and the ADSL router 201 transfers them to the LAN terminal 1. The LAN terminal 101 sequentially transmits ACK (acknowledgement) packets for the received data packets 1, 2, 3,..., 7 to the ADSL router 201. The ADSL router 201 receives the received ACK (acknowledgement) packets 1, 2,. 3,..., 7 are transmitted to the server 401. When transmission data 1, transmission data 2, transmission data 3, and transmission data 4 are transmitted from the server 401, the transmission is temporarily stopped due to the window size limitation, and an ACK (acknowledgment response) from the LAN terminal 101 is awaited. When ACK1 arrives at the server 401, the server 401 can transmit one more data packet and transmits the data packet 5.

  When the transmission of ACK1 is completed, the ADSL router 201 receives ACK1, 2, 3 from the LAN terminal 1, and transmits ACK2 to the server 401 in order. The server 401 transmits the data packet 6 after receiving ACK2. Similarly, ADSL router 201 transmits ACK3 after transmission of ACK2 is completed, and server 401 transmits transmission data 7 after receiving ACK3.

  As described above, in the operation of the conventional ADSL router 201, ACK3 is received from the LAN terminal 101 when ACK1 is completely transmitted to the ADSL line, and the LAN terminal 101 can receive up to the data packet 7. First, the server 401 receives ACK2 and transmits only the transmission data 6.

  Thereafter, since the server 401 waits for an ACK before sending a data packet, there is an interval (time interval) for sending the data packet, and the data transfer rate expected from the downlink communication speed of the ADSL line is set. There was an inconvenience that it could not be obtained.

  Here, the ADSL line is a connection method in which the frequency band used for downlink communication and the frequency band used for uplink communication are different, and the uplink communication speed is higher than the downlink communication speed. Connections may be established in extremely low conditions. That is, when the downlink communication speed is extremely higher than the uplink communication speed, the transmission of the uplink ACK (acknowledgment) packet for the TCP data packet in the downlink cannot catch up with the TCP window size in the TCP communication. TCP data transmission from the server may be temporarily stopped, and TCP / IP communication efficiency may be reduced.

  Therefore, for example, in the “data terminal in the TCP network” disclosed in Patent Document 1, congestion (fullness) of the ACK queue is processed in the data terminal (LAN terminal) provided with the ACK queue (buffer). The Specifically, even if the ACK queue is congested (full), the oldest ACK packet in the queue is discarded without discarding new ACK packets after becoming congested (full), and the congestion ( The latest ACK packet after full) is stored in the queue.

  Further, in the “data communication method and data communication network” disclosed in Patent Document 2, an ACK packet transmitted from a reception destination (LAN terminal) having an ACK buffer (queue) to a data transmission destination (server) is discarded. It is hard to be done. Specifically, a high-priority buffer that preferentially transmits an ACK buffer and a low-priority buffer that transmits an ACK buffer with a lower priority are provided, and the capacity of the high-priority buffer is increased. For the X damage of the priority, a value indicating the priority is set in the TOS (type of service) field of the packet or the label field of IPv6.

  Furthermore, in the “TCP / IP communication relay device and TCP / IP communication relay method” disclosed in Patent Document 3, the data transfer of a system in which a wireless terminal receives data from a server via a wireless base station and the Internet Prevent delays. Here, the data transfer delay is caused by radio signal modulation / demodulation processing or error correction processing output from the radio base station. ACK (acknowledgment response) is a response signal sent back to the server by the wireless terminal in connection-type communication such as TCP / IP, and this system is not based on ADSL. Prevention of data transfer delay in this system is performed by the radio base station appropriately changing the contents of ACK (acknowledgment response) transmitted by the radio terminal. Specifically, the radio base station confirms the ACK number from the radio terminal, confirms the transmitted number from the server, acquires a difference (a result obtained by subtracting the ACK number from the transmitted number), The indicated data amount is added to the data request amount in the ACK from the wireless terminal. Moreover, you may transmit ACK which changed the ACK number into the transmitted number to a server. As a result, the data packet can be transmitted from the server at the transfer rate requested by the wireless terminal.

JP-A-10-126446 (FIG. 4, paragraph 0042) JP 2001-127830 A (FIG. 5, paragraph 0015) JP 2003-78550 A (FIG. 2, paragraph 0027)

By the way, TCP / IP is a connection-type protocol, and connection establishment processing must be performed before starting communication. On the other hand, UDP (user datagram protocol), which is the upper protocol of IP
Is a connectionless communication protocol and does not require connection setting / maintenance, so there is no guarantee that the data will surely reach the other party, but it is suitable for high-speed data transfer for live playback of moving images and audio.

  TCP / IP is a protocol that includes UDP / IP. The UDP / IP datagram is a system in which a communication path is dynamically set and delivered to a destination without establishing a connection. Therefore, if an ACK packet accompanies a datagram, the ACK packet must not be discarded.

  However, in Patent Documents 1 to 3, an ACK packet may be discarded regardless of whether or not a datagram is attached.

  Therefore, the present invention has an object to provide an ADSL communication apparatus, program, and method capable of preventing an upstream transmission delay of TCP / IP communication through an ADSL line and reliably transmitting a datagram in the upstream direction. To do.

  In the present invention, an ACK (acknowledgment) packet to be transmitted in the upstream direction of an ADSL line having a low communication speed is detected, and an ACK (acknowledgment response) having an old ACK number with the same connection as the ACK (acknowledgment) packet. When a packet is waiting to be transmitted, the transmission of the standby packet is canceled and discarded from the transmission queue, and an ACK (acknowledgment) packet having the latest ACK number is input to the transmission queue and transmitted. As a result, the ACK responses to be transmitted in a plurality of packets are aggregated and transmitted to the server, and the frequency at which the server side pauses transmission due to the window size limitation while waiting for the ACK response is reduced, thereby improving the efficiency of TCP / IP communication. It has a feature in that it is improved. If an ACK (acknowledgment) packet with the same ACK (acknowledgment) packet and having an old ACK number is waiting for transmission with a datagram attached, the waiting packet is held in the transmission queue. It has been continued.

  Specifically, in the present invention, in an ADSL communication apparatus that connects a client terminal and a server, an ACK monitoring unit that monitors ACK newly input from the client terminal described above, an ACK change unit that changes the ACK, And a transmission queue for storing the ACK. Then, when the ACK changing unit described above determines that the UDP signal newly input by the ACK monitoring unit described above is attached to the TCP packet, the ACK changing unit operates to send an ACK to the same destination already stored in the transmission queue described above. A TCP-UDP storage function for storing a TCP-UDP packet newly discarded and stored at the end of the transmission queue is provided (claim 1).

  Thereby, the time during which transmission is stopped after waiting for an ACK response is reduced, and the efficiency of TCP / IP communication can be improved.

  According to the present invention, in the ADSL communication apparatus that connects the client terminal and the server, an ACK monitoring unit that monitors an ACK newly input from the client terminal, an ACK changing unit that changes the ACK, and the ACK are stored. And a transmission queue. Then, the ACK changing unit described above operates when it is determined by the ACK monitoring unit that a newly input ACK is attached to the TCP packet, and discards the ACK to the same destination already stored in the transmission queue described above. A TCP-ACK storage function for storing the ACK flag of the newly input packet at the end of the transmission queue with the ACK flag set to “1”, and a UDP signal newly input by the ACK monitoring unit A TCP-UDP storage function that operates when it is determined by the ACK monitoring unit when attached and changes the ACK flag of a newly input packet to “0” and stores it at the end of the transmission queue described above; (Claim 2).

  Thus, the time during which transmission is stopped after waiting for an ACK response is effectively reduced, and the efficiency of TCP / IP communication can be reliably improved.

  Here, the ACK changing unit described above operates when the ACK flag is not “1” and has a function of storing a newly input ACK at the end of the transmission queue, and the ACK monitoring unit includes the ACK monitoring unit. A function that operates when the flag is “1” to determine whether or not the ACK is accompanied by a UDP packet, and the ACK changing unit is configured to determine that the ACK does not accompany a UDP packet. A function to operate and discard the ACK to the same destination already stored at the end of the transmission queue, and store this at the end of the transmission queue with the newly input ACK flag being set to “1” And the ACK changing unit operates when it is determined that the packet is accompanied by a UDP packet, changes the ACK flag to “0”, and changes this to the end of the transmission queue. A function of storing, the transmit queue may be configured to include a function of sequentially transmits the packet to the server (claim 3).

  In this case, the client terminal described above may be a LAN terminal connected to the LAN, and the ADSL communication apparatus described above may be an ADSL router connected to the LAN. The client terminal described above may be a stand-alone terminal, and the ADSL communication apparatus may be an ADSL modem.

  In the present invention, the following configuration is adopted as the ADSL communication program. That is, in order to connect the client terminal and the server to perform ADSL communication, the computer has a function as an ACK monitoring unit that monitors ACK newly input from the client terminal as an ACK changing unit that changes ACK. And a function as a transmission queue for storing ACKs, respectively, and the ACK changing unit described above operates when it is determined that a newly input ACK is accompanied by a TCP packet. The ACK change function described above has the function of discarding the ACK to the same destination already stored in and storing it at the end of the transmission queue while keeping the ACK flag of the newly input packet at “1”. Operates when the newly input ACK is accompanied by a UDP packet and changes the newly input ACK flag to “0”. Was the ability to store it at the end of the transmission queue as described above, and so as to implement respectively (claim 6).

  Here, when the above-described ACK flag is not “1” in the above-described computer, the ACK change unit has a function of storing the newly input ACK at the end of the above-described transmission queue. When “1”, the above-described ACK monitoring unit realizes the function of determining whether or not the above-described ACK is accompanied by a UDP packet, and further, the above-described ACK does not attach a UDP packet. In this case, the ACK changing unit described above discards the ACK to the same destination already stored at the end of the transmission queue and keeps the newly input ACK flag set to “1”. If the packet stored at the end or the above packet is accompanied by a UDP packet, the above ACK changing unit changes the ACK flag to “0”. Then, the above-described function of storing at the end of the transmission queue and the above-described transmission queue may be configured to realize the above-described function of sequentially transmitting the packets to the server. ).

  Furthermore, in the present invention, the following configuration is adopted as the ADSL communication method. That is, in an ADSL communication method in which a client terminal and a server are connected to perform ADSL communication, a step (in which the ACK monitoring unit) determines whether or not a newly input ACK accompanies a TCP packet; It operates when it is determined that a packet is attached (the ACK changing unit) discards the ACK to the same destination already stored in the transmission queue and sets the ACK flag of the newly input packet to “1”. And storing at the end of the transmission queue as it is, determining whether or not the newly input ACK is accompanied by a UDP packet (by the ACK monitoring unit), and determining that the ACK is accompanied by a UDP packet The ACK flag is changed to “0” and stored at the end of the transmission queue. It and a-up (Claim 8).

  Here, when the above-described ACK flag is not “1”, the above-described ACK monitoring unit stores the newly input ACK at the end of the above-described transmission queue, and the ACK flag is “1”. In some cases, the ACK monitoring unit described above determines whether or not the ACK accompanies a UDP packet, and operates when the ACK does not accompany a UDP packet. Discarding the ACK to the same destination already stored at the end of the packet and storing it at the tail of the transmission queue with the newly input ACK flag set to “1”; And the ACK changing unit that operates when ancillary is included, and changes the ACK flag to “0” and stores it at the end of the transmission queue. Configuration and then, the transmission queue, and to include a step of sequentially transmits the packet to the server as described above (claim 9).

  This also reduces the time during which transmission is stopped after waiting for an ACK response, as in the above-described inventions, and the efficiency of TCP / IP communication can be improved.

  According to the present invention, it is possible to effectively prevent an upstream transmission delay of TCP / IP communication through an ADSL line, and to achieve an excellent effect that can be reliably transmitted in the upstream direction.

  An embodiment of the present invention will be described below with reference to FIGS. In the embodiment shown in FIG. 1 to FIG. 4, in a router device connected to an ADSL line and relaying communication between the Internet and a LAN, TCP / IP caused by the conventional asymmetrical speed of uplink / downlink of ADSL. It is possible to effectively suppress deterioration in data transfer efficiency of communication (including UDP / IP).

[ADSL communication apparatus of this embodiment]
FIG. 1 shows a block diagram of an ADSL communication apparatus (ADSL router) of this embodiment.
In FIG. 1, an ADSL router 12 is connected to a LAN terminal 11 via a LAN port (LAN 9 is, for example, 100 Mbps for both directions), while an ADSL line 10 (for example, a downlink 40 Mbps, an uplink 1 Mbps). It is connected to an external network such as the Internet 13 via the network, and relays TCP / IP communication (including UDP / IP communication) between the server 14 belonging to the external network and the LAN terminal 11.

  Here, the ADSL router 12 changes the ACK flag depending on whether or not the data packet transmitted from the LAN terminal is a datagram, and TCP / IP communication using the ADSL line is performed by changing the ACK flag. Thus, the datagram is also reliably transmitted in the upstream direction.

  Specifically, the ADSL router 12 controls data transmission / reception between the LAN transmission / reception control unit 21 that controls data transmission / reception with the LAN terminal 11 and the ADSL line, and temporarily holds a transmission packet to the ADSL line. And an ADSL transmission / reception control unit 24 having an ADSL transmission unit 23 for transmitting data along the transmission synchronization signal of the ADSL line. The ADSL router 12 further includes a routing control unit 25 that controls the direction of a bidirectional data packet that travels between the LAN side and the ADSL side, and a TCP ACK transmitted from the routing control unit 25 to the ADSL line side. And an ACK changing unit 27 that updates the contents of an ACK (acknowledgment) packet waiting in the transmission queue 22 in accordance with an instruction from the ACK monitoring unit 26.

  When the ADSL transmission / reception control unit 24 receives a packet from the ADSL line 10, the ADSL router 12 passes the packet to the routing control unit 25. The routing control unit 25 makes a route determination with reference to the destination IP address of the passed packet, and when it is addressed to the LAN side address, it passes it to the LAN transmission / reception control unit 21 and receives it, and receives the LAN transmission / reception control unit 21 described above. Sends a packet to the LAN terminal 11.

  On the other hand, a packet transmitted from the LAN terminal 11 is received by the LAN transmission / reception control unit 21 and passed to the routing control unit 25. The routing control unit 25 makes a route determination with reference to the destination IP address of the passed packet, and passes the packet to the ACK monitoring unit 26 if the packet is addressed to an external network such as the Internet 13. The ACK monitoring unit 26 checks whether the passed packet is an ACK (acknowledgment) packet. Here, the ACK (acknowledgment response) packet refers to a packet having only a header and no payload and having an ACK flag set to 1.

  If the packet passed to the ACK monitoring unit 26 is not an ACK (acknowledgment) packet, the ACK monitoring unit 26 connects the packet to the transmission queue 22. This ACK (acknowledgment response) process will be described separately for cases where a datagram is not attached to an ACK (acknowledgement) packet and cases where the datagram is attached.

[When processing an ACK without a datagram]
When the packet delivered to the ACK monitoring unit 26 described above is an ACK (acknowledgment) packet not accompanied by a datagram, the packet is delivered to the ACK changing unit 27. The ACK changing unit 27 scans the transmission queue 22, and the received ACK (acknowledgment response) packet matches the source IP address, destination IP address, source TCP port number, and destination TCP port number ACK (confirmation). Response) packet is searched, and if a matching ACK (acknowledgment) packet is found, the ACK (acknowledgment) packet is taken out of the transmission queue 22 and discarded, and ACK (acknowledgment) passed from the ACK monitoring unit 26 instead. Response) The packet is linked to the end of the transmission queue 22. In other words, when a matching ACK packet is found, the ACK number of the ACK packet is rewritten to the ACK number of the ACK packet passed from the ACK monitoring unit 5. At the same time, the TCP checksum necessary in this case is also recalculated. The packets connected to the transmission queue 22 are taken out by the ADSL transmission unit 23 and sequentially transmitted toward the ADSL line 10.

  FIG. 2 shows a sequence chart for processing an ACK not accompanying a datagram (attaching a TCP packet). Here, it is assumed that the LAN terminal 11 notifies the server 14 of the window size for four packets at the time of TCP connection.

  Transmission data 1, 2, 3,..., 9 from the server 14 arrives at the ADSL router 12 sequentially, and the ADSL router 12 transfers them to the LAN terminal 11. The LAN terminal 11 sequentially transmits ACK packets 1, 2, 3,..., 7 for the received data packets 1, 2, 3,..., 9 to the ADSL router 12, and the ADSL router 12 transmits the received ACK packets to the server. 14 is transmitted. When transmission data 1, transmission data 2, transmission data 3, and transmission data 4 are transmitted from the server 14, the transmission is temporarily stopped due to the window size limitation, and the window size is updated by the ACK packet from the LAN terminal 11. Wait for. When ACK1 arrives, the server 14 can further transmit one packet and transmits transmission data 5.

  The ADSL router 12 receives ACK2 and ACK3 while ACK1 is completely transmitted. However, in this embodiment, since ACK2 is discarded when ACK3 arrives, ACK3 is transferred to server 14 after ACK1. The server 14 can transmit the transmission data 5 and the transmission data 6 by receiving ACK3. Since the ADSL router 12 has received up to ACK 5 when transmission of ACK 3 is completed, ACK 5 is then passed to the server 14.

  The times when the ADSL router 12 receives ACK1, ACK2, ACK3, ACK4, and ACK5 from the LAN terminal 11 are t1, t2, t3, t4, and t5, respectively, and the operation of the ACK changing unit 27 and the state of the transmission queue 22 at each time And the state of the ADSL transmitter 23 are summarized in the table shown in FIG.

  At time t1, the ACK changing unit 27 transfers ACK1 to the transmission queue 22, the transmission queue 22 transfers ACK1 to the ADSL transmission unit 23 and becomes empty, and the ADSL transmission unit 23 starts transmitting ACK1. Next, at time t2, the ACK changing unit 27 transfers ACK2 to the transmission queue 22 and waits for ACK2, while the ADSL transmitting unit 23 is transmitting ACK1. Next, at time t3, the ACK changing unit 27 discards ACK2 and transfers ACK3 to the transmission queue 22, so that ACK3 is waiting in the transmission queue 22, while the ADSL transmission unit 23 is transmitting ACK1. In the middle.

  Next, at time t4, the ACK changing unit 27 transfers ACK4 to the transmission queue 22, so that ACK4 is waiting in the transmission queue 22, while the ADSL transmission unit 23 completes transmission of ACK1 and is transmitting ACL3. is there.

  Then, at time t5, the ACK changing unit 27 discards ACK4 and transfers ACK5 to the transmission queue 22, so that ACK5 is waiting in the transmission queue 22, while the ADSL transmission unit 23 transmits ACK3. Is in the middle of Thus, at time t3 and t5, the old ACK (acknowledgment response) is discarded.

  By the above operation, when a plurality of ACK packets are waiting for transmission in the uplink direction of the ADSL line, the transmission source waits for an ACK response and stops transmission by degenerating the ACK number notification in a batch. Time can be reduced and the efficiency of TCP / IP communication can be improved.

  As described above, when processing an ACK not accompanied by a datagram, the server 4 connected via the ADSL line 10 reduces the time during which the server 4 waits for an ACK response and stops transmission, thereby reducing TCP / The efficiency of IP communication can be improved. In addition, since ACK passing through the upstream communication band of the ADSL line 10 having a low communication speed is reduced, the transmission band can be used for transmission of other communications.

[When processing an ACK accompanying a datagram (UDP packet)]
The ACK monitoring unit 26 also detects ACKs having datagrams. When ACK is detected by the ACK monitoring unit 26, the ACK is rewritten to the ACK rewrite processing unit 27. The ACK rewrite processing unit 27 scans the transmission queue 22 for an ACK that matches the source IP address, the destination IP address, the source port number, and the destination port number, and no matching ACK packet is found. If it is, it is connected to the tail of the transmission queue 22 as it is.

  On the other hand, if a matching ACK packet is found, the packet already stored at the end of the transmission queue 22 is not discarded, and the ACK flag newly passed from the ACK monitoring unit 26 is lowered (“ 1 ”is changed to“ 0 ”), and the checksum is recalculated and connected to the tail of the transmission queue 22.

  Thus, the datagram can be reliably transmitted from the server 14 to the LAN terminal 11 by reliably sending the ACK accompanying the datagram to the server 14 without discarding it.

[ADSL communication program in this embodiment]
The ADSL communication program according to this embodiment monitors the computer for connecting the client terminal 11 and the server 14 and monitors whether or not the ACK flag of the packet newly input from the client is “1”. Function as an ACK change unit for changing the ACK flag, and function as a transmission queue for storing the packet. When the ACK flag is not “1”, the packet is used as the ACK change unit. Function to store at the end of the transmission queue.

  Further, the ADSL communication program causes the computer to function as the ACK monitoring unit to determine whether or not the packet is accompanied by a datagram when the ACK flag is “1”. When the datagram is not attached (attached to the TCP packet), the ACK changing unit discards the ACK already stored at the tail end of the transmission queue and also sets the flag “1” of the newly input ACK packet. ”Is stored at the end of the transmission queue, and when the packet accompanies a datagram (attaches a UDP packet), the ACK changing unit changes the ACK flag to“ 0 ”. Function to store at the end of the transmission queue, and further, the ACK packet as the transmission queue. And it is realized by function to transmit to the next said server.

  Thereby, the time during which transmission is stopped after waiting for an ACK response is reduced, and the efficiency of TCP / IP communication can be improved.

[ADSL communication method in this embodiment]
The ADSL communication method according to this embodiment is an ADSL communication method in which a client terminal and a server are connected to perform ADSL communication. The ACK monitoring unit 26 determines whether or not a newly input ACK is accompanied by a TCP packet. And when the ACK is determined to accompany the TCP packet, the ACK changing unit 27 discards the ACK to the same destination already stored in the transmission queue and the newly input packet The step of storing the ACK flag at the end of the transmission queue while keeping the flag “1”, the step of the ACK monitoring unit 26 determining whether or not the newly input ACK is accompanied by the UDP packet, and the ACK is the UDP packet The ACK changing unit 27 sets the newly input ACK flag to “0”. Additional to and a step of storing at the end of the transmission queue 22.

  Further, in the present embodiment, in the ADSL communication method, when the ACK flag is not “1”, the ACK monitoring unit 26 stores the newly input ACK at the end of the transmission queue 22. And when the ACK flag is “1”, the ACK monitoring unit 26 determines whether or not the ACK accompanies the UDP packet, and when the ACK does not accompany the UDP packet. The ACK changing unit 27 discards the ACK to the same destination already stored at the end of the transmission queue 22 and keeps the newly input ACK flag set to “1”. And the ACK changing unit 27 sets the ACK flag to “when the packet is accompanied by a UDP packet”. And a step of storing by changing the end of the transmission queue 22 to the "transmit queue described above were to include a step of sequentially transmits the packet to the server 14 described above.

  FIG. 4 shows a flowchart for specifically executing the ADSL communication method in the present embodiment. In FIG. 4, first, in step S <b> 1, an ACK packet is newly input from the LAN terminal 11 to the ADSL router 12. Next, in step S2, it is determined whether or not the ACK flag of the newly input ACK packet is “1”.

  If it is determined in step S 2 that the ACK flag of the new packet is not “1”, the process proceeds to step S 6, and the newly input ACK packet is stored in the transmission queue 22. On the other hand, if it is determined in step S2 that the ACK flag of the newly input ACK packet is “1”, the process proceeds to step S3, and whether or not the ACK is accompanied by a datagram (attached UDP packet). Is determined.

  If it is determined in step S3 that the ACK does not accompany the datagram, the process proceeds to S17, the last ACK in the transmission queue 22 is discarded, and then the process proceeds to step S7, where it is newly input in step S1 described above. ACK is stored at the end of the transmission queue 22. Subsequent to step S7, the process proceeds to step S8 described later.

  On the other hand, if it is determined in step S3 that the ACK is accompanied by a datagram, the process proceeds to step S4, the ACK flag newly input in step S1 described above is changed to “0”, and then the process proceeds to step S6. The newly input ACK packet is stored at the end of the transmission queue 22. Subsequent to step S6, the process proceeds to step S8 described later. In step S8, the ACK packets in the transmission queue are sequentially transmitted to the server 14.

  As a result, the ACK responses to be transmitted in a plurality of packets are aggregated and transmitted to the server, and the frequency at which the server side pauses transmission due to the window size limitation while waiting for the ACK response is reduced, thereby improving the efficiency of TCP / IP communication. It has a feature in that it is improved.

Other Embodiment
In the above embodiment, a stand-alone terminal may be used instead of the LAN terminal 11 described above, an ADSL modem may be used instead of the ADSL router, and a stand-alone terminal transmission / reception control unit may be used instead of the LAN transmission / reception control unit 21. Even if it does in this way, the effect can obtain the thing equivalent to embodiment mentioned above.

  The present invention relates to a TCP / IP communication (including UDP / IP communication) system using an ADSL line, and a TCP / IP communication (including UDP / IP communication) for connecting a stand-alone terminal not connected to a LAN to an ADSL modem. Can be used in the system.

It is a block diagram which shows one Embodiment of this invention. 2 is a sequence chart illustrating an example of processing an ACK [acknowledgment response] not accompanied by a datagram in the embodiment illustrated in FIG. 1. In the embodiment shown in FIG. 1, it is a table | surface which shows the state of each part of an ADSL router in the case of processing ACK (acknowledgment response) accompanying a datagram. It is a flowchart which shows the internal example of the ACK processing method in embodiment shown in FIG. It is a block diagram which shows the ADSL communication system in a prior art example. It is a sequence chart which shows the example of the ACK (acknowledgment response) process in a prior art example.

Explanation of symbols

9 LAN
DESCRIPTION OF SYMBOLS 10 ADSL circuit 11 LAN terminal 12 ADSL router 13 Internet 14 Server 21 LAN transmission / reception control part 22 Transmission queue 23 ADSL transmission part 24 ADSL transmission / reception control part 25 Routing control part 26 ACK monitoring part 27 ACK packet change part

Claims (9)

In an ADSL communication apparatus that connects a client terminal and a server,
An ACK monitoring unit that monitors ACK newly input from the client terminal, an ACK changing unit that changes the ACK, and a transmission queue that stores the ACK,
The ACK changing unit operates when it is determined that a UDP signal newly input by the ACK monitoring unit is attached to a TCP packet, and discards an ACK to the same destination already stored in the transmission queue and A TCP / UDP storage function for storing a TCP-UDP packet input to the end of the transmission queue. In an ADSL communication apparatus that connects a client terminal and a server,
An ACK monitoring unit that monitors ACK newly input from the client terminal, an ACK changing unit that changes the ACK, and a transmission queue that stores the ACK,
The ACK changing unit operates when it is determined by the ACK monitoring unit that a newly input ACK is attached to a TCP packet, discards an ACK to the same destination already stored in the transmission queue, and A TCP-ACK storage function that stores the ACK flag of the packet input to “1” at the end of the transmission queue with the ACK flag set to “1”, and a UDP signal newly input by the ACK monitoring unit is attached to the TCP packet. Then, it has a TCP-UDP storage function that operates when it is determined by the ACK monitoring unit and changes the ACK flag of the newly input packet to “0” and stores it at the end of the transmission queue. ADSL communication device characterized by the above. The ADSL communication apparatus according to claim 2, wherein
The ACK changing unit has a function of operating when the ACK flag is not “1” and storing the newly input ACK at the tail of the transmission queue,
The ACK monitoring unit has a function of operating when the ACK flag is “1” and determining whether the ACK is accompanied by a UDP packet;
The ACK changing unit operates when it is determined that the ACK does not accompany a UDP packet, discards the ACK to the same destination already stored at the end of the transmission queue, and is newly input. The ACK flag is set to “1” and stored at the end of the transmission queue.
The ACK changing unit operates when it is determined that the packet is accompanied by a UDP packet, and has a function of changing the ACK flag to “0” and storing this at the end of the transmission queue,
The ADSL communication apparatus, wherein the transmission queue has a function of sequentially transmitting the packets to the server. The client terminal is a LAN terminal connected to a LAN;
The ADSL communication apparatus according to claim 1, 2, or 3, wherein the ADSL communication apparatus is an ADSL router connected to the LAN. The client terminal is a stand-alone terminal;
The ADSL communication apparatus according to claim 1, wherein the ADSL communication apparatus is the ADSL modem. In order to perform ADSL communication by connecting a client terminal and a server, the computer has a function as an ACK monitoring unit that monitors an ACK newly input from the client terminal as an ACK changing unit that changes the ACK. A function as a transmission queue for storing the ACK,
The ACK changing unit operates when it is determined that a newly input ACK is associated with a TCP packet, discards an ACK to the same destination already stored in the transmission queue, and is newly input The function of storing this at the end of the transmission queue while keeping the ACK flag of the packet “1”,
The ACK changing unit operates when a newly input ACK is accompanied by a UDP packet, changes the newly input ACK flag to “0”, and stores this at the end of the transmission queue. Function,
ADSL communication program characterized by realizing each. In the ADSL communication program according to claim 6,
When the ACK flag is not “1”, the ACK changing unit stores the newly input ACK at the end of the transmission queue,
When the ACK flag is “1”, the ACK monitoring unit determines whether or not the ACK is accompanied by a UDP packet.
If the ACK does not accompany a UDP packet, the ACK changing unit discards the ACK to the same destination already stored at the end of the transmission queue and sets the newly input ACK flag to “1”. The function to store at the end of the transmission queue as it is,
When the packet accompanies a UDP packet, the ACK changing unit has a function of changing the ACK flag to “0” and storing it at the end of the transmission queue,
The transmission queue has a function of sequentially transmitting the packets to the server.
An ADSL communication program characterized by being realized by a computer. In an ADSL communication method for performing ADSL communication by connecting a client terminal and a server,
Determining whether or not the newly input ACK is accompanied by a TCP packet (by the ACK monitoring unit), and operating when it is determined that the ACK is accompanied by a TCP packet (the ACK changing unit) Discarding the ACK to the same destination already stored in the transmission queue and storing the ACK flag of the newly input packet at the end of the transmission queue with the ACK flag set to “1”;
A step of determining whether the newly input ACK is accompanied by a UDP packet (when the ACK monitoring unit) determines that the ACK is accompanied by a UDP packet; And a step of changing the inputted ACK flag to “0” and storing it at the end of the transmission queue. The ADSL communication method according to claim 8, wherein
When the ACK flag is not “1”, the ACK monitoring unit stores the newly input ACK at the tail of the transmission queue;
When the ACK flag is “1”, the ACK monitoring unit determines whether the ACK is accompanied by a UDP packet;
When the ACK does not accompany a UDP packet, the ACK changing unit discards the ACK to the same destination already stored at the end of the transmission queue and sets the newly input ACK flag to “1”. And storing at the end of the transmission queue as it is, and when the packet accompanies a UDP packet, the ACK changing unit changes the ACK flag to “0” at the end of the transmission queue. Storing, and
The transmission queue includes a step of sequentially transmitting the packets to the server.

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