JP2009088962A - Communication adapter, communication device, and communication method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication device or the like capable of inexpensively executing a communication protocol processing at high speed, and facilitating a verification for algorithm update and guarantee of quality of TCP connection management. <P>SOLUTION: The communication adapter is equipped with: a TCP processing part 707 which is mounted on software for performing normal processing of a TCP; and a TCP information synchronization part which treats TCP connections with the same TOE part 402 to be mounted on a high speed communication adapter for performing high speed reception processing to a TCP packet and performing synchronization processing of TCP connection information in the TCP connections. The TCP information synchronization part uses a value calculated from transmission data length of TCP transmission as a condition for updating the TCP connection information from the TOE part to the TCP processing part 707 for software mounting, and in update processing, reception processing of the software mounted TCP processing part 707 is utilized to operate the TCP processing. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a communication technique when video data is received via a network, and more particularly to a communication adapter, a communication apparatus, and a communication method using TCP, which is a communication protocol.

As a conventional TCP packet communication device, a communication adapter for low-speed processing that executes only lower-layer communication protocol processing related to network transmission path control, and communication for high-speed processing that executes communication protocol processing including the upper layer at high speed A technique for mounting an adapter is disclosed (for example, see Patent Document 1). Here, the communication adapter for low-speed processing realizes TCP / IP processing by software on the host CPU, and the communication adapter for high-speed processing has a separate hardware in charge of TCP / IP processing mounted in the communication adapter. It takes a form.
JP-A-6-309251 (first page, FIG. 5, etc.)

  However, the conventional TCP packet communication apparatus mainly has the following three features.

  (A) In order to realize a communication adapter for high-speed processing, packet processing for TCP connection connection / disconnection is complicated in algorithm, and there is a high possibility that a new method will be proposed for the algorithm itself. Implementation by hardware is high risk in terms of interoperability including legacy issues. This corresponds to the case where only the high-speed communication adapter 1301 is hardwareized and no external memory 1302 is provided in FIG. 13 (see FIG. 15 for the communication sequence diagram in this case).

  (B) As a means for speeding up TCP / IP processing, there is a high risk due to hardware as described in (a) above, so a dedicated CPU is provided as the internal configuration of the communication adapter for high-speed processing. The form performed by software processing is realistic. This corresponds to the case where a high-speed communication adapter 1301 and an external memory 1302 are provided as shown in FIG. 13 (see FIG. 14 for a communication sequence diagram in this case).

  (C) As a network technology that has been used in the past, since the implementation under the powerful CPU in the PC architecture has been performed, the need for the approaches (a) and (b) described above was small. On the other hand, it is required to support transmission standards in the home centered on recent DLNA, the necessity of networking home appliances increases, and the limited CPU resources and cost constraints in conventional home appliances In particular, there is an increasing need to solve the trade-off with performance for handling high-definition and large-capacity video data.

  In mounting the communication adapter for high-speed processing in the conventional TCP packet communication device, there are the following two problems.

  (1) A communication adapter for high-speed processing requires a dedicated CPU, and at least a few MB for the processing and to absorb the difference between the maximum input packet rate and the maximum output packet rate (relative to the host CPU). External memory is required, resulting in higher costs.

  (2) Since there are a plurality of processing units that perform packet processing for connection management such as connection / disconnection for TCP connection in the host CPU and the communication adapter for high-speed processing, algorithm update and verification for quality assurance are possible. Have difficulty.

  The present invention has been made in view of the above problems, and provides a communication device that can easily perform TCP protocol management algorithm updates and verification for quality assurance while executing communication protocol processing at low cost and at high speed. The purpose is to do.

  In order to solve the above-described problems, a communication apparatus according to the present invention is particularly intended for application to a receiver such as a TV, and specializes in receiving high-capacity video data at high speed, and has a complicated algorithm. Only connection management processing for connection / disconnection and data transmission processing are performed by a communication adapter for low-speed processing (that is, TCP processing is performed by software operating on the host CPU), and packet transmission for receiving payload data including video data is received. Only processing is performed with a communication adapter for high-speed processing.

  With this configuration, a communication adapter for high-speed processing can be realized without an external memory (that is, at low cost).

  In addition, the communication apparatus according to the present invention includes a TCP processing unit that handles TCP packets in both the host CPU and the communication adapter for high-speed processing. In order to share TCP connection information between these two TCP processing units. The TCP connection information managed by each is updated while notifying each other at a predetermined timing.

  Furthermore, the communication adapter according to the present invention notifies the TCP processing information to be managed to the TCP processing unit of the host CPU only when a TCP packet having a condition dynamically specified in advance is received, not every time a TCP packet is received. It has a function that can do.

  Furthermore, the TCP processing unit operating on the host CPU included in the communication apparatus according to the present invention has a function including a transmission data number (Ack) for requesting a TCP confirmation response as a notification condition of the communication adapter for high-speed processing. Also, a function of updating the reception order information (Seq) received by the communication adapter for high-speed processing as a pre-processing at the time of TCP transmission.

  With this configuration, it is possible to suppress host CPU processing resources necessary for updating TCP connection information.

  As a method for updating TCP connection information from a communication adapter for high-speed processing to a TCP processing unit operating on the host CPU, the communication adapter driver for high-speed processing generates a TCP packet and performs reception processing. Seq has a function of not setting an update value.

  With this configuration, it is possible to perform necessary related processing such as congestion control processing, retransmission control processing, and connection disconnection processing when updating the TCP connection information to the TCP processing unit operating on the host CPU.

  Furthermore, the communication adapter for high-speed processing of the TCP packet processing apparatus according to the present invention has two or more output paths for the payload data of the received TCP packet, for example, output by CPU access and output by a dedicated bus. Make it possible. Furthermore, by making it possible to designate these continuous output amounts, higher layer protocol analysis such as HTTP in TCP payload data, video data extraction, and output by a dedicated bus are possible.

  Further, the present invention is a communication method by a communication device that performs TCP communication with a communication partner, wherein a CPU provided in the communication device performs connection management in TCP communication and transmission processing to the communication partner, and the communication device The communication adapter attached to the device performs reception processing of a TCP packet sent from the communication partner.

  Furthermore, the present invention can be realized as an integrated circuit including characteristic constituent means in the communication adapter.

  According to the present invention, the following effects can be expected.

  (1) A low-cost TCP communication adapter for high-speed reception processing that does not require a dedicated CPU and external memory can be realized.

  (2) A processing unit that performs packet processing for connection management such as TCP connection connection / disconnection is integrated into software that operates on the host CPU, so that algorithm update and verification for quality assurance are facilitated.

  (3) Update the TCP connection information from the TCP communication adapter for high-speed reception processing to the TCP processing unit of the software that runs on the host CPU, the straight line for performing the TCP transmission processing, and until the confirmation response is completed Only the limited period can be set, and the load on the CPU processing resource can be suppressed.

  (4) With respect to the received TCP packet, HTTP, which is an upper layer thereof, can separate the HTTP header and video data and output the video data directly to the digital TV tuner.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings. In addition, although this invention is demonstrated using the following embodiment and attached drawing, this is for the purpose of illustration and this invention is not intended to be limited to these.

  FIG. 1 is a block diagram showing an example of the configuration of the network system according to the present embodiment. As shown in FIG. 1, the network system 100 includes a video server 101 and a DTV (Digital TV) 103, which are connected to each other via an IP network 102. Note that devices other than those described above may be connected to the IP network 102.

  The DTV 103 receives a digital broadcast by a broadcast wave and acquires a TCP packet including video data from the video server 101 via the IP network 102. In response to this, the video server 101 transmits a TCP packet including video data to the DTV 103 in response to a request from the DTV 103. More specifically, the protocol used in the network system 100 is HTTP, and the DTV 103 requests acquisition of video data by a GET command and receives a plurality of TCP packets from the video server 101 as HTTP responses.

  FIG. 2 is a block diagram illustrating an example of a hardware configuration of a general DTV. As shown in FIG. 2, the DTV 200 includes a main memory 201, a CPU 202, a digital RF 203, a digital TV tuner 204, and an AV decoder 205, which are connected to each other by a bus 206.

  In the DTV 200, the digital broadcast wave received by the digital RF 203 is output to the digital TV tuner 204 and demodulated into a video signal or the like, and further, the video signal or the like demodulated by the AV decoder 205 is decoded. Further, in the DTV 200, each operation of the digital RF 203, the digital TV tuner 204, and the AV decoder 205 is controlled by software (control program) operating on the CPU 202. Note that the DTV 200 shown in FIG. 2 does not describe all necessary functions, but only describes the hardware configuration related to the present invention.

  The DTV 200 as described above does not have enough processing resources to perform a wideband video reception process using TCP / IP using a normal communication adapter (LAN controller). As a means for solving this problem, a high-speed communication adapter can be used.

  FIG. 3 is a block diagram showing a hardware configuration of a DTV obtained by adding a high-speed communication adapter to the DTV 200 shown in FIG.

  A high-speed communication adapter 301 shown in FIG. 3 is connected to the bus 206 and directly to the digital TV tuner 204 via a dedicated bus 207 for transmitting video data. That is, in the DTV 103, the video data received by the high-speed communication adapter 301 via the IP network 102 is directly input to the digital TV tuner 204 without being processed by protocol processing software operating on the CPU 202.

  In the DTV 103 as described above, the TCP processing unit implemented by software operating on the CPU 202 and the TCP processing unit of the high-speed communication adapter 301 implemented by hardware are operated in conjunction with the same TCP connection. It will be.

  FIG. 4 is a block diagram showing a functional configuration of the high-speed communication adapter 301 in FIG. The high-speed communication adapter 301 distributes the Ether frame received from the video server 101 via the general-purpose LAN control unit 401 having the conventional communication adapter function, the TOE unit 402 having the TCP offload function, and the IP network 102, and the general-purpose LAN. A control unit 401 and a sorting unit 403 for inputting to the TOE unit 402 are provided. For convenience of explanation, the Ether frame is illustrated, but the physical layer / MAC layer is not limited to the Ether. As for transmission / reception in the general-purpose LAN control unit 401 according to the present invention, only connection control and transmission processing of the same TCP connection as the TCP connection received by the TOE unit 402 will be described hereinafter.

  In the above high-speed communication adapter 301, the general LAN control unit 401 is responsible for connection control by the TCP processing unit (to be described later) and TCP packet transmission control realized by software operating on the CPU 202. It is assumed that the TOE unit 402 is in charge of the reception processing of the included TCP packet.

  In other words, TCP connection management establishment / disconnection and transmission of a video acquisition request as TCP transmission processing are performed by the general-purpose LAN control unit 401, and TCP processing is controlled by software operating on the CPU 202. On the other hand, reception processing of TCP packets including wideband video data is performed by the TOE unit 402, and transmission of TCP confirmation responses accompanying reception processing of TCP packets is also performed by the TOE unit 402.

  FIG. 5 is a block diagram showing a functional configuration of the TOE unit 402 in FIG. As shown in FIG. 5, the TOE unit 402 includes an interrupt control unit 601, a TCP information input / output unit 602, a TCP packet output control unit 603, a CPU access output control unit 604, a TCP packet reception processing unit 605, and a video data output control unit. 606.

  The interrupt control unit 601 is set with interrupt signal operation conditions from software operating on the CPU 202 (after CPU access). This condition includes conditions for an event in which a TCP packet is input to the TOE unit 402, an event in which the value of a TCP acknowledgment number (also referred to as “Ack”) included in the TCP packet is equal to or less than a set value, and the like. It is. Note that it is possible to switch the validity or invalidity of these conditions as a whole or individually.

  The TCP information input / output unit 602 performs setting of TCP information as an initial value for the TOE operation from software operating on the CPU 202 (after CPU access), and updating of TCP information changed by TCP transmission, Also, TCP information that has changed due to the reception of the TCP packet by the TCP packet reception processing unit 605 is acquired.

  The TCP packet output control unit 603 receives the TCP packet passed from the TCP packet reception processing unit 605 from the software operating on the CPU 202 (after the CPU access), by the CPU access output control unit 604 or the video data output control unit 606. A notification (or setting) about which to pass is received, and the TCP packet is processed according to the notification (setting).

  The CPU access output control unit 604 provides a function that allows the TCP packet passed from the TCP packet output control unit 603 to be read or written by CPU access from software operating on the CPU 202.

  The TCP packet reception processing unit 605 performs reception processing of the TCP packet distributed by the distribution unit 403 and performs TCP confirmation response processing as necessary. In addition, the TCP information input / output unit 602 is instructed to acquire TCP connection information from the received TCP packet.

  The video data output control unit 606 outputs video data to the dedicated bus 207 so that the TCP packet passed from the TCP packet output control unit 603 is input to the digital TV tuner 204.

  FIG. 6 is a diagram illustrating an example of a functional configuration of software that operates on the CPU 202. In FIG. 6, only the parts necessary for the description of the present invention are shown, but in actuality, various other software function units are mounted.

  In FIG. 6, an application 701 is software for controlling processing related to screen data display processing and screen image acquisition processing from the video server 101 via the IP network 102 in the DTV 103.

  The protocol processing unit 702 is a part of an OS (operating system) that is basic software, and includes at least a TCP processing unit 707 and an IF processing unit 708. The TCP processing unit 707 includes an update condition notification unit 709 and a Seq update unit 710.

  The general-purpose LAN control unit driver 703 is software that controls the general-purpose LAN control unit 401 by being connected to the protocol processing unit 702 by the IF processing unit 708 in order to transmit and receive TCP packets controlled by the TCP processing unit 707.

  The TOE unit driver 704 is software that controls the TOE unit 402, and is connected to the TCP processing unit 707, IF processing unit 708, and application 701. Details of this connection will be described later. The TOE unit driver 704 includes a TCP information update unit 711, a TCP information management unit 712, and a TCP reception control unit 713.

  The digital TV tuner driver 705 is software that controls the digital TV tuner 204, and the AV decoder driver 706 is software that controls the AV decoder 205.

  The general-purpose LAN control unit driver 703 and the TOE unit driver 704 may be mounted as a single driver. In particular, such an arrangement is useful when the interrupt signals of the general-purpose LAN control unit 401 and the TOE unit 402 of the high-speed communication adapter 301 are shared and input to the CPU 202.

  Note that it is also possible to configure a TCP information synchronization unit in which the update condition notification unit 709, the Seq update unit 710, and the TOE unit driver 704 are combined. In this case, in the TCP processing unit 707, only a call for executing the update condition notification unit 709 and the Seq update unit 710 is performed, and the entity is implemented and called in the TOE unit driver 704. be able to.

  Next, the communication operation between the video servers 101 in the DTV 103 configured as described above will be described with reference to the drawings.

  FIG. 9 is a diagram showing how processing is shared in communication between the video server 101 and the DTV 103 according to the present embodiment. In FIG. 5, the direction from the top to the bottom indicates the passage of time. A specific example of the video server 101 is DVR (Digital Video Recorder).

  9 is a TCP process performed by the TOE unit 402, and a process located in “software” in FIG. 9 is a TCP process performed by software operating on the CPU 202. It is. In the example shown in FIG. 9, connection management by HTTP, video acquisition request, and video data transmission / reception are mainly performed. “HTTP GET” in FIG. 9 is a type of HTTP command, and is transmitted by the TCP of the DTV 103 software. The “HTTP GET” is composed of one or a plurality of TCP packets.

  In FIG. 9, the video server 101 that has received “HTTP GET”, which is a video acquisition request, transmits video data to the DTV 103 as an HTTP response. The video data as the HTTP response is composed of one or a plurality of TCP packets, and may be composed of 1000 or more TCP packets at a time. The reception of the TCP packet constituting the HTTP response is processed by hardware in the DTV 103, and the acknowledgment transmission (Ack transmission) corresponding to the reception of the TCP packet is also performed by the hardware.

  Note that after the video data acquisition is completed, the DTV 103 disconnects the TCP connection. Transmission / reception of a TCP packet necessary for disconnecting the TCP connection in the DTV 103 is processed by software. However, when a TCP packet (FIN or RST) for disconnecting the TCP connection is sent from the video server 101, the reception is unpredictable for the DTV 103, and is received at least once by the hardware. In this case, the TCP connection can be disconnected by processing the TCP packet with software.

  Hereinafter, a more detailed operation of the DTV 103 will be described.

(1) Connection establishment First, the application 701 instructs the protocol processing unit 702 to establish a TCP connection with the video server 101 in order to enable HTTP communication for obtaining video data from the video server 101. Instruct. The protocol processing unit 702 establishes a TCP connection by the TCP processing unit 707 in accordance with a normal protocol processing operation. Specifically, TCP packet transmission / reception called “3 Way-Handshake” of TCP is performed by the general-purpose LAN control unit 401 of the high-speed communication adapter 301 via the general-purpose LAN control unit driver 703.

(2) TOE Initial Setting When the above TCP connection is established, the application 701 sends the established TCP connection to the TCP reception control unit 713 of the TOE unit driver 704 as a TCP connection to be processed by the TOE unit 402. Notify that there is. As a result, the TCP reception control unit 713 instructs the TCP information management unit 712 to acquire the TCP connection information of the corresponding TCP connection and perform the initial setting to the TOE unit 402. Further, the TCP reception control unit 713 instructs the TCP packet output control unit 603 of the TOE unit 402 to set the output mode (CPU access mode) to the CPU access output control unit 604. The TCP information management unit 712 acquires the specified TCP connection information from the TCP processing unit 707, instructs the distribution unit 403 of the high-speed communication adapter 301 to distribute the TCP packet to the TOE unit 402, and further specifies the specified TCP connection information. The initial value of the TCP connection information of the TCP connection is set in the TCP information input / output unit 602 of the TOE unit 402.

(3) Transmission of Video Data Acquisition Request and TCP Connection Information Update Condition Setting Next, the application 701 instructs the protocol processing unit 702 to transmit an “HTTP GET” command that is a video data acquisition request. As a result, the TCP processing unit 707 in the protocol processing unit 702 calculates the confirmation response number used for the update condition from the TCP packet sequence number of the “HTTP GET” command and the TCP payload length, and the TCP of the TOE unit driver 704 is calculated. The information update unit 711 is notified.

  Further, the TCP processing unit 707 controls the general-purpose LAN control unit 401 of the high-speed communication adapter 301 to perform the TCP transmission processing via the general-purpose LAN control unit driver 703 in accordance with the normal protocol processing operation.

  The TCP information update unit 711 performs interrupt permission setting in the interrupt control unit 601 of the TOE unit 402 according to the notified update conditions. This “interrupt permission setting” means the confirmation response number as the notified update condition, and is larger than the confirmation response number of the TCP packet processed by the TCP packet reception processing unit 605 by the interrupt control unit 601. The TCP information update unit 711 receives a TCP packet from the CPU access output control unit 604 as a condition for outputting an interrupt signal in some cases, or simply as a condition when the TCP packet reception processing unit 605 performs a TCP packet reception process. It is possible to implement a configuration for determining by reading.

(4) TCP connection information update by video data reception preparation process and confirmation response As described above, when an HTTP response including video data composed of a plurality of TCP packets is transmitted from the video server 101, these TCP packets are The sorting unit 403 sorts the TOE unit 402. The TCP packet reception processing unit 605 of the TOE unit 402 performs TCP based on a predetermined condition, for example, a condition such as “send one TCP confirmation response for reception of two TCP packets at normal reception”. Send confirmation response. On the other hand, when the order change or the packet drop is detected, the TCP packet reception processing unit 605 transmits a TCP confirmation response even when this condition is not satisfied.

  Also, the TCP packet reception processing unit 605 extracts and sets the TCP connection information from the received TCP packet information in the TCP information input / output unit 602.

  The interrupt control unit 601 issues an interrupt signal according to the above interrupt permission setting. The TCP information input / output unit 602 updates TCP connection information managed by itself according to the TCP packet received by the TCP packet reception processing unit 605. The TCP packet processed by the TCP packet reception processing unit 605 is sent to the CPU access output control unit 604 because the TCP packet output control unit 603 is in the CPU access mode.

  The TCP information update unit 711 receives the interrupt signal and updates the TCP connection information to the TCP processing unit 807. At this time, if the TCP processing unit 707 has a TCP reception function, the TCP connection information to be generated and updated is stored, and the TCP connection information is stored by performing reception processing via the IF processing unit 708. In addition, necessary congestion control, retransmission control, and connection management processing can be executed simultaneously with the update.

  An example of the format of a TCP packet generated by the above-mentioned TOE unit driver 704 is shown in FIG. As shown in FIG. 7, the TCP packet 800 includes a MAC header 801, an IP header 802, and a TCP header 803, but the TCP packet 800 does not have payload data 804. The TCP header 803 includes a sequence number 80301, an acknowledgment number 80302, and a reception window size 80303 other than values that are managed in advance by default settings. These are received by the TCP information management unit 712 from the TCP information input / output unit 602. Obtain and store.

  Note that “source port number” and “destination port number” in the TCP header 803 are values uniquely determined for each TCP connection, and “Offset” is fixed to “5” (data length: 20 bytes). The “urgent pointer” may be fixed to “0”. Further, “Flag” in the TCP header 803 may be set according to the received packet as long as “Ack” is “1”. Further, “Checksum” in the TCP header 803 is calculated and stored from the above TCP header 803 and the source IP address and destination IP address uniquely determined for each TCP connection. This storage method is based on a general TCP checksum calculation method.

  Note that the update value of the reception sequence number (Seq) is not stored in the TCP packet for update, but the value before update is stored. This is because the TCP packet 800 does not have the payload data 804 and stores the updated value of “Seq” and causes the TCP processing unit 707 to perform reception processing, which is not normally processed. The update for “Seq” that is not updated will be described later.

(5) Video Data Reception Processing After transmitting the “GET command”, the application 701 makes a read request by CPU access to the TCP reception control unit 713 by specifying the read amount (reception amount). Accordingly, the TCP reception control unit 713 receives the interrupt signal, reads the specified amount from the CPU access output control unit 604, and responds to the application 701.

  Note that the application 701 controls the read amount so as not to exceed the start position of the video data.

  If the start position of the video data does not fit in the first TCP packet in the HTTP response and starts from a TCP packet after being divided, if the corresponding TCP packet has not arrived, the TCP reception control unit 713 enters a wait state. Since the application 701 waits for the process, the wait process can be interrupted. This is performed by an instruction to the TCP reception control unit 713.

  When the TCP permission updating unit 711 determines and controls the interrupt permission setting, this determination is performed by reading the TCP header from the CPU access output control unit 604.

  The application 701 obtains the start position of the video data and the continuous amount thereof by analyzing the received HTTP header, and outputs to the TCP reception control unit 713 the output to the dedicated bus 207, the start position, and the continuous output. Instruct the competence. Accordingly, the TCP reception control unit 713 instructs the TCP packet output control unit 603 to switch to a mode (video data output mode) in which output to the video data output control unit 606 is performed. Note that the TCP reception control unit 713 sends the video data output mode to the TCP packet output control unit 603 when the data reception of the continuous output amount, which is the data amount to be continuously output, is completed or an interruption occurs. To switch to the CPU access mode.

  In addition, the TCP reception control unit 713 designates the video data output control unit 606 with the start position and the continuous output amount of the video data. As a result, the TCP packet is transferred to the video data output control unit 606, the video data is output to the dedicated bus 207, and the video data is transferred to the digital TV tuner 204.

  Note that the output of the application 701 can be interrupted before the output of the continuous output amount specified in the video data output mode is completed. This is realized by instructing the TCP reception control unit 713 to suspend and the TCP reception control unit 713 instructing the video data output control unit 606 (see FIG. 8).

(6) Transmission of continuation request When the application 701 completes the acquisition of the first designated video data, the application 701 may subsequently transmit a video data acquisition request. In this case, the application 701 instructs the protocol processing unit 702 to transmit an “HTTP GET” command in the same manner as described above. Here, the difference from the first operation is that the TCP processing unit 707 performs a pre-processing of the transmission processing by the Seq update unit 710 from the TCP information management unit 712 to receive order number (one of TCP connection information). Seq) is acquired, and the table managed by itself is updated. This makes it possible to update Seq that is not updated by generating and receiving the above TCP packet.

  FIG. 10 is a diagram illustrating an image of an operation in which the processing of the software described above is limited to the TOE unit driver 704 and the TCP processing unit 807. The update condition notification unit 809 and the Seq update unit 810 are executed as pre-processing in the transmission process. Also, the TCP packet generated to update the TCP connection information from the TOE unit driver 704 is received by the reception I / F of the TCP processing unit 807, and is operated in the same manner as normal reception processing, and the related congestion is performed. Processing such as control and retransmission control is performed to update the TCP connection information.

  FIG. 11 shows the state of this update in time series. It can be understood that most of the video reception sections occupying a lot of time are non-updated sections and the update frequency is low.

  In the present embodiment, the number of TCP connections handled by the TOE unit 402 has been described as being easy to understand. However, it goes without saying that the above-described operation can be applied to a plurality of TCP connections.

  As described above, according to the present invention, by using a low-cost TCP communication adapter for high-speed reception processing that does not require a dedicated CPU and an external memory, broadband video data by TCP is received via an IP network. A low-cost DTV capable of acquiring video data can be realized (see FIG. 12).

  The communication adapter and the communication device according to the present invention are useful as a DTV terminal that receives broadband video data and outputs video. Further, the present invention can be applied to uses such as a high-speed receiving apparatus using TCP.

It is a block diagram which shows an example of a structure of the network system which concerns on embodiment of this invention. It is a block diagram which shows an example of the hardware constitutions of general DTV. It is a block diagram which shows the hardware constitutions of DTV which concerns on embodiment of this invention. It is a block diagram which shows the function structure of the high-speed communication adapter which concerns on embodiment of this invention. It is a block diagram which shows the function structure of the TOE part in the high-speed communication adapter which concerns on embodiment of this invention. It is a block diagram which shows the function structure of the software which operate | moves on DTV which concerns on embodiment of this invention. It is a figure which shows an example of the format of the TCP packet which the driver for TOE parts which concerns on embodiment of this invention produces | generates. It is a figure for demonstrating the interruption function with which the TCP packet output control part which concerns on embodiment of this invention is provided. It is an image figure which shows a mode that the communication procedure in DTV which concerns on embodiment of this invention is switched with a high-speed communication adapter (hardware) and host CPU (software). It is an image figure which shows the mode of the connection operation | movement between the driver for TOE parts and the TCP process part in the function structure of the software which concerns on embodiment of this invention. It is the image figure which showed the mode of the connection operation | movement in the said FIG. 10 based on embodiment of this invention in time series. It is a figure for demonstrating the effect at the time of providing the high-speed communication adapter 301 which concerns on embodiment of this invention. It is a block diagram which shows an example of the hardware constitutions of the conventional DTV. It is a communication sequence diagram which shows a mode that a communication procedure is controlled only by software in the conventional DTV. It is a communication sequence diagram which shows a mode that a communication procedure is controlled only by hardware in the conventional DTV.

Explanation of symbols

101 Video server 102 IP network 103 DTV
201 Main memory 202 Host CPU
203 Digital RF
204 Digital TV tuner 205 AV decoder 206 Bus 207 Dedicated bus 301 High-speed communication adapter 401 General-purpose LAN control unit 402 TOE unit 403 Distribution unit 601 Interrupt control unit 602 TCP information input / output unit 603 TCP packet output control unit 604 CPU access output control unit 605 TCP packet reception processing unit 606 Video data output control unit 701 Application 702 Protocol processing unit 703 General-purpose LAN control unit driver 704 TOE unit driver 705 Digital TV tuner driver 706 AV decoder driver 707 TCP processing unit 708 IF processing unit 709 Update Condition notification unit 710 Seq update unit 711 TCP information update unit 712 TCP information management unit 713 TCP reception control unit 800 TCP packet 80 MAC header 802 IP header 803 TCP header 804 payload data (in fact is not included)
80301 Sequence number (Seq)
80302 Acknowledgment number (Ack)
80303 Reception window size (RWin)

Claims (16)

A communication adapter that is attached to a communication device and functions as a communication interface,
A TCP reception processing unit for receiving a TCP packet sent from a communication partner;
A TCP information input / output unit that relays the exchange of TCP connection information, which is information related to a TCP connection, between the communication device and the TCP reception processing unit;
The TCP information input / output unit receives TCP connection information passed from the communication device and passes it to the TCP reception processing unit,
The TCP reception processing unit uses the TCP connection information passed from the TCP information input / output unit to perform reception of a TCP packet sent from a communication partner and TCP confirmation response processing corresponding to the received TCP packet. And notifying the TCP information input / output unit of the TCP connection information changed with the reception of the TCP packet,
The TCP information input / output unit outputs TCP connection information notified from the TCP reception processing unit to the communication device. The communication adapter further compares the value notified from the communication device with a reception confirmation response number included in the TCP packet received by the TCP reception processing unit, and based on the comparison result, the communication device The communication adapter according to claim 1, further comprising an interrupt control unit that generates an interrupt signal. A communication device that performs TCP communication with a communication partner,
A TCP processing unit that performs connection management in TCP communication and transmission processing to the communication partner;
The communication adapter according to claim 1, which receives a TCP packet sent from the communication partner;
A communication apparatus comprising: the TCP processing unit and a TCP information synchronization unit that performs processing for synchronizing TCP connection information in the communication adapter. When the TCP connection information managed by the communication adapter is changed, the TCP information synchronization unit reflects the connection information in the TCP processing unit when the changed connection information satisfies a predetermined condition. The communication apparatus according to claim 3, wherein synchronization processing is performed. The communication apparatus according to claim 4, wherein the TCP processing unit includes an interface processing unit having a reception function of receiving a TCP packet transmitted from the communication partner. The communication apparatus according to claim 5, wherein the TCP information synchronization unit reflects the connection information in the TCP processing unit using the reception function of the interface processing unit. The communication apparatus according to claim 6, wherein the TCP information synchronization unit reflects the connection information in the TCP processing unit, except for a reception sequence number managed by the communication adapter when the reception function is used. . The TCP processing unit sends a request to the TCP information synchronization unit as a pre-processing of the TCP transmission processing to obtain a reception order number managed by the communication adapter,
In response to the request from the TCP processing unit, the TCP information synchronization unit acquires a reception sequence number managed by the communication adapter, and responds to the TCP processing unit with the acquired reception sequence number.
The communication apparatus according to claim 7, wherein the TCP processing unit updates a value of a reception order number in response to a response from the TCP information synchronization unit. The TCP information synchronization unit compares the first value given in advance with the second value calculated from the reception confirmation response number included in the TCP packet received by the communication adapter, thereby changing the connection after the change. The communication apparatus according to claim 4, wherein it is determined whether or not the information satisfies a predetermined condition. When performing the TCP transmission process, the TCP processing unit notifies the TCP information synchronization unit of the last sequence number of the transmission data in the TCP transmission process,
The communication apparatus according to claim 9, wherein the TCP information synchronization unit performs the comparison using a value calculated from a sequence number notified from the TCP processing unit as the first value. The communication device according to claim 3, further comprising: a distribution unit that outputs the received TCP packet to two different output destinations according to the reception status of the TCP packet. The communication device further includes a CPU and a video processing unit for processing video data,
The distribution unit sends the TCP packet as two different output destinations to a first bus that connects the communication adapter and the CPU, and a second bus that connects the communication adapter and the video processing unit. The communication device according to claim 11, wherein the communication device outputs. The communication adapter further receives an output destination of the received TCP packet from the communication device and a designation of a continuous output amount that is a data amount continuously outputted to the output destination, and outputs the TCP packet according to the accepted designation. The communication apparatus according to claim 12, further comprising a TCP packet output control unit. The communication device according to claim 13, wherein the TCP packet output control unit has a function of interrupting the output before the output of the continuous output amount designated by the communication device is completed. A communication method by a communication device that performs TCP communication with a communication partner,
The CPU provided in the communication device performs connection management in TCP communication and transmission processing to the communication partner,
A communication method, wherein a communication adapter attached to the communication device performs a process of receiving a TCP packet sent from the communication partner. An integrated circuit functioning as a communication interface attached to a communication device,
A TCP reception processing unit for receiving a TCP packet sent from a communication partner;
A TCP information input / output unit that relays the exchange of TCP connection information, which is information related to a TCP connection, between the communication device and the TCP reception processing unit;
The TCP information input / output unit receives TCP connection information passed from the communication device and passes it to the TCP reception processing unit,
The TCP reception processing unit uses the TCP connection information passed from the TCP information input / output unit to perform reception of a TCP packet sent from a communication partner and TCP confirmation response processing corresponding to the received TCP packet. And notifying the TCP information input / output unit of the TCP connection information changed with the reception of the TCP packet,
The integrated circuit according to claim 1, wherein the TCP information input / output unit outputs TCP connection information notified from the TCP reception processing unit to the communication device.

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