JP5125643B2

JP5125643B2 - Relay device, data transfer system, data transfer method, and data transfer program

Info

Publication number: JP5125643B2
Application number: JP2008067550A
Authority: JP
Inventors: 謙太郎本山
Original assignee: NEC Corp
Current assignee: NEC Corp
Priority date: 2008-03-17
Filing date: 2008-03-17
Publication date: 2013-01-23
Anticipated expiration: 2028-03-17
Also published as: JP2009225121A

Description

本発明は、データの転送中に帯域変更を行う中継装置及びデータ転送システムに関する。 The present invention relates to a relay apparatus and a data transfer system that change a band during data transfer.

従来、データ通信において送信データの伝送速度を変更したい場合、一旦送信出力を中断し、所望の帯域に切り替えた後、再び送信を開始するといったプロセスを採るのが一般的であった。
ところが、このような方法では、帯域の切り換えのために送信処理を中断しなければならず、送信停止による無駄時間が発生するとともに、送信の中断時及び再開時に必要なデータが欠落したり、無用な送信データが送出されたりするおそれもあった。 Conventionally, when it is desired to change the transmission rate of transmission data in data communication, it has been a common practice to temporarily stop transmission output, switch to a desired band, and then start transmission again.
However, in such a method, the transmission process must be interrupted to switch the bandwidth, and there is a waste of time due to the suspension of transmission. There is also a risk that the transmission data may be sent out.

そこで、これまで、例えば特許文献１には、送信側の２つのメモリに送信データを交互に格納し、伝送速度に応じて送出する送信データを切り替えることにより、送信を中断することなく、確実にデータ伝送速度の切り替えが可能なデータ伝送速度切替装置が提案されている。
また、特許文献２には、データ伝送量に応じて通信回線の通信容量を変更するとともに、この変更に合わせて必要な通信帯域を変更する通信帯域の動的割当て方法が提案されている。
さらに、特許文献３には、データパケットを用いた通信を行うために必要な帯域が確保できるか否かを判定するパケット通信方式が提案されている。 Therefore, for example, in Patent Document 1, for example, transmission data is alternately stored in two memories on the transmission side, and transmission data to be transmitted is switched according to the transmission speed, so that transmission can be reliably performed without interruption. A data transmission rate switching device capable of switching the data transmission rate has been proposed.
Patent Document 2 proposes a dynamic allocation method for communication bands in which the communication capacity of a communication line is changed according to the amount of data transmission and a necessary communication band is changed in accordance with the change.
Further, Patent Document 3 proposes a packet communication method for determining whether or not a bandwidth necessary for performing communication using data packets can be secured.

特開２００２−１７６４６１号公報JP 2002-176461 A 特開平０９−１３５２６３号公報JP 09-135263 A 特開２００１−２６８１１８号公報JP 2001-268118 A

しかしながら、特許文献１に提案されているデータ伝送速度切替装置は、送信側で送出データの切替え制御を行うというのみで、帯域確保や途中経路、データ受信側の状態等は特に考慮されていなかった。
このため、途中の中継ノードや受信側の状況により帯域が確保できない場合には、送出データの切替えを行っても十分な伝送速度が得られないことがあった。 However, the data transmission rate switching device proposed in Patent Document 1 merely performs transmission data switching control on the transmission side, and does not particularly take into consideration bandwidth reservation, a route on the way, the state on the data reception side, and the like. .
For this reason, when a band cannot be secured due to a relay node on the way or a situation on the receiving side, a sufficient transmission rate may not be obtained even if transmission data is switched.

一方、特許文献２に提案されている通信帯域の動的割当て方法では、タイマーやバッファ監視による帯域制御を行うことで、データ伝送量に応じて通信容量を動的に変更することが可能であった。
しかしながら、タイマーによる帯域制御は、同期を取るための高精度なタイマーを各装置に搭載する必要があり、装置の複雑化、高コスト化を招くという問題が生じた。また、バッファ制御による帯域制御は、監視負担が極めて大きくなり、実際には採用は困難であった。
さらに、この特許文献２記載の方法では、多重化装置が必須の構成要件となっているため、現実の適用範囲は極めて限定されたものとなり、利用性、汎用性に欠けるという問題もあった。 On the other hand, in the communication bandwidth dynamic allocation method proposed in Patent Document 2, it is possible to dynamically change the communication capacity according to the amount of data transmission by performing bandwidth control using a timer or buffer monitoring. It was.
However, bandwidth control using a timer requires that each device be equipped with a high-precision timer for synchronization, resulting in a problem that the device is complicated and expensive. Further, the bandwidth control by the buffer control has a very large monitoring burden, and is actually difficult to adopt.
Furthermore, in the method described in Patent Document 2, since the multiplexing device is an indispensable component, the actual application range is extremely limited, and there is a problem that the usability and versatility are lacking.

また、特許文献３に提案されているパケット通信方式は、通信に必要な帯域が確保できるか否かの判定は行われるものの、実際に帯域を変更する仕組み、構成については考慮されていなかった。
従って、通信に必要な帯域が確保できない場合には対処できず、実際には何ら問題の解決には至っていないという問題があった。 In addition, although the packet communication method proposed in Patent Document 3 determines whether or not a bandwidth necessary for communication can be secured, the mechanism and configuration for actually changing the bandwidth have not been considered.
Therefore, there is a problem that it is impossible to cope with a case where a bandwidth necessary for communication cannot be secured, and that the problem has not been solved in practice.

本発明の目的は、上述した課題である所望の帯域への変更に際しデータ転送の途中で通信が中断する問題を解決する中継装置、データ転送システム、データ転送方法及びデータ転送プログラムを提供することにある。 An object of the present invention is to provide a relay device, a data transfer system, a data transfer method, and a data transfer program that solve the above-described problem that communication is interrupted in the middle of data transfer when changing to a desired band. is there.

上記目的を達成するため、本発明の中継装置は、受信したデータを所定のバッファに保持し、前記バッファに保持したデータを転送する中継装置であって、前記受信したデータであって、新たな帯域での通信を予定するデータを、前記バッファとは異なる他のバッファに保持する手段と、前記新たな帯域が確保された後、前記他のバッファに保持されているデータを転送する手段と、を備えた構成としてある。 In order to achieve the above object, a relay apparatus according to the present invention is a relay apparatus that holds received data in a predetermined buffer and transfers the data held in the buffer. Means for holding data scheduled for communication in a band in another buffer different from the buffer; means for transferring the data held in the other buffer after the new band is secured; It is set as the structure provided with.

また、本発明のデータ転送システムは、送信装置と受信装置と一以上の中継装置とからなり、前記送信装置から送信されたデータを前記中継装置の所定のバッファに保持し、前記受信装置に転送するデータ転送システムであって、前記中継装置が、前記送信装置又は前記送信装置側に接続された中継装置から受信したデータであって、新たな帯域での通信を予定するデータを、前記バッファとは異なる他のバッファに保持する手段と、前記新たな帯域が確保された後、前記他のバッファに保持されているデータを前記受信装置又は前記受信装置側に接続された中継装置に転送する手段と、を備える構成としてある。 The data transfer system of the present invention comprises a transmitting device, a receiving device, and one or more relay devices, holds data transmitted from the transmitting device in a predetermined buffer of the relay device, and transfers the data to the receiving device. A data transfer system, wherein the relay device receives data that is received from the transmission device or a relay device connected to the transmission device, and that is scheduled to communicate in a new band, and the buffer. Means for holding in another different buffer, and means for transferring the data held in the other buffer to the receiving device or a relay device connected to the receiving device after the new bandwidth is secured And so on.

また、本発明のデータ転送方法は、受信したデータを所定のバッファに保持し、前記バッファに保持したデータを転送するデータ転送方法であって、前記受信したデータであって、新たな帯域での通信を予定するデータを、前記バッファとは異なる他のバッファに保持するとともに、前記新たな帯域が確保された後、前記他のバッファに保持されているデータを転送する方法としてある。 The data transfer method of the present invention is a data transfer method for holding received data in a predetermined buffer and transferring the data held in the buffer, wherein the received data is a new band. This is a method of holding data scheduled for communication in another buffer different from the buffer and transferring the data held in the other buffer after the new bandwidth is secured.

さらに、本発明のデータ転送プログラムは、受信したデータを所定のバッファに保持し、前記バッファに保持したデータを転送するデータ転送プログラムであって、前記中継装置を構成するコンピュータを、前記受信したデータであって、新たな帯域での通信を予定するデータを、前記バッファとは異なる他のバッファに保持する手段、前記新たな帯域が確保された後、前記他のバッファに保持されているデータを転送する手段、として機能させるためのプログラムとしてある。 Furthermore, the data transfer program of the present invention is a data transfer program for holding received data in a predetermined buffer and transferring the data held in the buffer, wherein the computer constituting the relay device is connected to the received data Means for holding data scheduled for communication in a new band in another buffer different from the buffer, and after the new band is secured, the data held in the other buffer It is a program for functioning as a transfer means.

本発明によれば、予め帯域の確保を行うことによって、データ転送の途中での帯域変更に際し、データ欠落や無駄なデータ送信等がなくなり、信頼性及び利便性に優れた中継装置、データ転送システムを提供することができる。 According to the present invention, by securing a bandwidth in advance, there is no data loss or useless data transmission when changing the bandwidth in the middle of data transfer, and the relay device and data transfer system are excellent in reliability and convenience. Can be provided.

以下、本発明の好ましい実施形態について図１〜図８を参照して説明する。
ここで、以下に示す本実施形態の中継装置を含むデータ転送システムは、プログラム（ソフトウェア）の命令によりコンピュータで実行される処理，手段，機能によって実現される。プログラムは、コンピュータの各構成要素に指令を送り、以下に示すような所定の処理・機能を行わせる。すなわち、本実施形態の中継装置における各処理・手段は、プログラムとコンピュータとが協働した具体的手段によって実現される。
なお、プログラムの全部又は一部は、例えば、磁気ディスク，光ディスク，半導体メモリ，その他任意のコンピュータで読取り可能な記録媒体により提供され、記録媒体から読み出されたプログラムがコンピュータにインストールされて実行される。また、プログラムは、記録媒体を介さず、通信回線を通じて直接にコンピュータにロードし実行することもできる。 A preferred embodiment of the present invention will be described below with reference to FIGS.
Here, the data transfer system including the relay device of the present embodiment described below is realized by processing, means, and functions executed by a computer in accordance with a program (software) instruction. The program sends a command to each component of the computer to perform predetermined processing and functions as shown below. That is, each process / means in the relay apparatus of this embodiment is implement | achieved by the specific means with which the program and the computer cooperated.
Note that all or part of the program is provided by, for example, a magnetic disk, optical disk, semiconductor memory, or any other computer-readable recording medium, and the program read from the recording medium is installed in the computer and executed. The The program can also be loaded and executed directly on a computer through a communication line without using a recording medium.

［第一実施形態］
図１は、本発明の第一実施形態に係るデータ転送システムの構成を示すシステム構成図である。
図１に示すとおり、本実施形態のデータ転送システム１は、送信側ホスト２、中継ノード３，４及び受信側ホスト５を備えている。 [First embodiment]
FIG. 1 is a system configuration diagram showing the configuration of the data transfer system according to the first embodiment of the present invention.
As shown in FIG. 1, the data transfer system 1 of this embodiment includes a transmission side host 2, relay nodes 3 and 4, and a reception side host 5.

送信側ホスト２は、受信側ホスト５に対し、所望のデータパケットを送信する送信側装置であり、受信側ホスト５は、送信側ホスト２から送信されたデータパケットを受信する受信側装置である。
また、中継ノード３，４は、送信側ホスト２から送信されたデータパケットを中継し、受信側ホスト５に転送する中継装置である。
なお、中継ノードは一以上であればよく、特に、数的な制限はない。 The transmission side host 2 is a transmission side device that transmits a desired data packet to the reception side host 5, and the reception side host 5 is a reception side device that receives a data packet transmitted from the transmission side host 2. .
The relay nodes 3 and 4 are relay devices that relay the data packet transmitted from the transmission side host 2 and forward it to the reception side host 5.
The number of relay nodes may be one or more, and there is no particular limitation.

ここで、送信側ホスト２の構成について図面を参照しながら説明する。
図２は、本実施形態に係るデータ転送システムの一部をなす送信側ホスト２の内部構成を示すブロック図である。
図２に示すとおり、本実施形態に係る送信側ホスト２は、ポート２１，シグナリング処理部２２，パケット送信部２３、マーカー送信部２４，制御部２５及びタイマー２６の各部を備えている。 Here, the configuration of the transmission side host 2 will be described with reference to the drawings.
FIG. 2 is a block diagram showing an internal configuration of the transmission side host 2 forming a part of the data transfer system according to the present embodiment.
As shown in FIG. 2, the transmission side host 2 according to the present embodiment includes each unit of a port 21, a signaling processing unit 22, a packet transmission unit 23, a marker transmission unit 24, a control unit 25, and a timer 26.

ポート２１は、中継ノード３に対してデータパケットの送受信を行うための通信インタフェースである。
シグナリング処理部２２は、シグナリングプロトコルの処理全般を行うものであり、特に、本実施形態においては、タイマー２６及び制御部２５による制御のもと、中継ノード３に対し、帯域を確保するための帯域要求信号を送信するようになっている。このシグナリング処理部２２が本発明に係る帯域要求信号送信手段として機能する。
具体的には、シグナリング処理部２２は、例えば図８に示すように、ＲＳＶＰ（Resource Reservation Protocol）におけるＰＡＴＨメッセージやＲＥＳＶメッセージを送受信することにより、帯域確保のための資源予約の制御を行う。 The port 21 is a communication interface for transmitting / receiving data packets to / from the relay node 3.
The signaling processing unit 22 performs the entire processing of the signaling protocol. In particular, in this embodiment, a band for securing a band for the relay node 3 under the control of the timer 26 and the control unit 25. A request signal is transmitted. The signaling processing unit 22 functions as a band request signal transmission unit according to the present invention.
Specifically, as shown in FIG. 8, for example, the signaling processing unit 22 transmits and receives a PATH message and a RESV message in RSVP (Resource Reservation Protocol) to control resource reservation for securing a bandwidth.

パケット送信部２３は、利用者の所望のデータをパケット化した後、ポート２１を介して送信させるものであり、本発明に係るデータ送信手段として機能する。
マーカー送信部２４は、タイマー２６の設定によって、予め決められた時刻になると帯域変更を指示するためのマーカーパケット（マーカー信号）を発生させ、ポート２１を介して送信させるようになっており、本発明のマーカー送信手段として機能する。
制御部２５は、タイマー２６との連携により予め定められた時刻になるとマーカー送信部２４に対しマーカーパケットを送信するよう命令を行う（本発明のマーカー送信制御手段）とともに、シグナリング処理部２２へ新たに帯域を確保するよう命令を行う（本発明の帯域要求制御手段）。
タイマー２６は、常に時刻を管理しており、管理者より設定された時刻になると制御部２５に対し所定の制御信号を送信するようになっている。 The packet transmission unit 23 packetizes user-desired data and then transmits it through the port 21 and functions as a data transmission unit according to the present invention.
The marker transmission unit 24 generates a marker packet (marker signal) for instructing a band change at a predetermined time according to the setting of the timer 26, and transmits the marker packet via the port 21. It functions as a marker transmitting means of the invention.
The control unit 25 instructs the marker transmission unit 24 to transmit a marker packet at a predetermined time in cooperation with the timer 26 (marker transmission control means of the present invention), and sends a new signal to the signaling processing unit 22. Is instructed to secure the bandwidth (bandwidth request control means of the present invention).
The timer 26 always manages the time, and transmits a predetermined control signal to the control unit 25 when the time set by the administrator is reached.

次に、中継ノード３，４の構成について図面を参照しながら説明する。
図３は、本実施形態に係るデータ転送システムの一部をなす中継ノード３，４の構成を示すブロック図である。
図３に示すとおり、本実施形態に係る中継ノード３，４は、入力側ポート３１，出力側ポート３２，分岐部３３、集約部３４，バッファ３５，３６及びシグナリング処理部３７によって構成される。 Next, the configuration of the relay nodes 3 and 4 will be described with reference to the drawings.
FIG. 3 is a block diagram showing the configuration of the relay nodes 3 and 4 that form part of the data transfer system according to the present embodiment.
As shown in FIG. 3, the relay nodes 3 and 4 according to the present embodiment include an input side port 31, an output side port 32, a branching unit 33, an aggregation unit 34, buffers 35 and 36, and a signaling processing unit 37.

入力側ポート３１は、他の装置（他の中継ノード含む）から送られたデータを受信する。具体的には、入力側ポート３１は、送信側の装置からマーカーパケットを受信し（本発明のマーカー受信手段）、また、送信側の装置から帯域要求信号を受信し（本発明の帯域要求信号受信手段）、さらに、受信側の装置から帯域確保信号を受信する（本発明の帯域確保信号受信手段）。
出力側ポート３２は、各種データを他の装置（他の中継ノード含む）に送信する。具体的には、出力側ポート３２は、所定のマーカーパケットを受信側の中継ノードに転送し（本発明のマーカー転送手段）、また、所定の帯域要求信号を受信側の装置に送信し（本発明の帯域要求信号送信手段）、さらに、所定の帯域確保信号を送信側の装置に送信する（本発明の帯域確保信号送信手段）。 The input port 31 receives data sent from other devices (including other relay nodes). Specifically, the input side port 31 receives a marker packet from the transmission side device (marker receiving means of the present invention), and receives a band request signal from the transmission side device (the band request signal of the present invention). Receiving means), and further, a band securing signal is received from the receiving apparatus (band securing signal receiving means of the present invention).
The output side port 32 transmits various data to other devices (including other relay nodes). Specifically, the output side port 32 transfers a predetermined marker packet to the receiving side relay node (marker transfer means of the present invention), and transmits a predetermined band request signal to the receiving side device (this (Band Request Signal Transmitting Unit of Invention), and further, a predetermined band securing signal is transmitted to the transmission side device (band securing signal transmitting unit of the present invention).

分岐部３３は、入力側ポート３１が受信したデータパケットをバッファ３５又はバッファ３６へ転送する。
また、分岐部３３は、入力側ポート３１で受信したデータがマーカーパケットである場合、そのマーカーパケットのコピーを集約部３４へ転送する。
さらに、分岐部３３は、入力側ポート３１で受信したデータパケットが、帯域を変更するためのシグナリングプロトコルに関するパケットである場合、シグナリング処理部３７へ転送する。 The branching unit 33 transfers the data packet received by the input side port 31 to the buffer 35 or the buffer 36.
Further, when the data received at the input side port 31 is a marker packet, the branching unit 33 transfers a copy of the marker packet to the aggregation unit 34.
Further, the branching unit 33 transfers the data packet received at the input side port 31 to the signaling processing unit 37 when the packet is related to the signaling protocol for changing the band.

集約部３４は、バッファ３５又はバッファ３６からデータパケットを抽出し出力側ポート３２を介して受信側へ転送するものであり、本発明のデータ転送手段を構成している。
ただし、分岐部３３からマーカーパケットのコピーが転送されてきた場合、そのパケットを優先して出力側ポート３２へ転送する。
また、シグナリング処理部３７より帯域変更制御パケットが送信されてきた場合は、そのパケットを優先して出力側ポート３２へ転送する。 The aggregating unit 34 extracts a data packet from the buffer 35 or 36 and transfers it to the receiving side via the output side port 32, and constitutes a data transfer means of the present invention.
However, when a copy of the marker packet is transferred from the branching unit 33, the packet is transferred to the output port 32 with priority.
When a bandwidth change control packet is transmitted from the signaling processing unit 37, the packet is preferentially transferred to the output side port 32.

バッファ３５及びバッファ３６は、入力側ポート３１で受信したデータパケットを出力側ポート３２から送信するために一旦保持させるものであり、本発明のデータ保持手段を構成する。
特に、本実施形態の中継装置については、帯域変更のための手段としてバッファリングを利用することを特徴としている。
具体的には、一のバッファ（本実施形態ではバッファ３５）に現行の帯域に係るデータパケットを格納し、所定のタイミングを基準として、他のバッファ（本実施形態ではバッファ３６）に帯域変更後のデータパケットを格納するようにしている。従って、本実施形態では、バッファ３６が本発明に係る「他のバッファ」を構成している。
このように複数のバッファを使用することにより、データ転送を中断することなく円滑に帯域変更ができるようになっている。なお、本実施形態では、２つのバッファ３５，３６を備えているが、バッファの数は２つに限られず、３つ以上のバッファを備えることもできる。 The buffer 35 and the buffer 36 temporarily hold the data packet received at the input side port 31 for transmission from the output side port 32, and constitute the data holding means of the present invention.
In particular, the relay apparatus according to the present embodiment is characterized by using buffering as a means for changing a band.
Specifically, a data packet relating to the current bandwidth is stored in one buffer (buffer 35 in the present embodiment), and the bandwidth is changed to another buffer (buffer 36 in the present embodiment) with a predetermined timing as a reference. The data packet is stored. Therefore, in this embodiment, the buffer 36 constitutes “another buffer” according to the present invention.
By using a plurality of buffers in this way, the band can be changed smoothly without interrupting data transfer. In the present embodiment, the two buffers 35 and 36 are provided, but the number of buffers is not limited to two, and three or more buffers may be provided.

シグナリング処理部３７は、シグナリングプロトコルに関する処理全般を行うものである。
基本的には、送信側ホスト２に搭載されるシグナリング処理部２２と同様であり、隣接する他の装置に対し、帯域の確保を求める帯域要求信号やその応答である帯域確保信号の送受信を行うものである。 The signaling processing unit 37 performs all processing related to the signaling protocol.
Basically, it is the same as the signaling processing unit 22 mounted on the transmission side host 2, and transmits / receives a band request signal for requesting band reservation and a band reservation signal as a response to the other adjacent apparatus. Is.

受信側ホスト５は、特に図示しないが、中継ノード４から帯域要求信号を受信し（帯域要求信号受信手段）、受信した帯域要求信号の応答信号である帯域確保信号を返信し（帯域確保信号返信手段）、さらに、中継ノード４から転送されたデータパケットを受信する（データ受信手段）ようになっている。 Although not shown in particular, the receiving-side host 5 receives a band request signal from the relay node 4 (band request signal receiving means), and returns a band securing signal that is a response signal of the received band request signal (band securing signal reply). Further, the data packet transferred from the relay node 4 is received (data receiving means).

次に、本実施形態に係るデータ転送システムの動作手順について図面を参照しながら説明する。
図４は、本実施形態に係るデータ転送システムの動作手順を説明するためのフローチャートである。
前提として、送信側ホスト２においては、タイマー２６が、時刻を管理しており、管理者が予め設定した時刻になったかどうかを常時監視している（Ｓ１１）。
そのうえで、所定の設定時刻になったときには（Ｓ１１：ＹＥＳ）、次のステップＳ１２に移行するが、設定時刻でなければその時刻になるまでタイマー２６が監視を続ける（Ｓ１１：ＮＯ）。 Next, an operation procedure of the data transfer system according to the present embodiment will be described with reference to the drawings.
FIG. 4 is a flowchart for explaining an operation procedure of the data transfer system according to the present embodiment.
As a premise, in the transmission side host 2, the timer 26 manages the time, and constantly monitors whether the time set in advance by the administrator has come (S11).
In addition, when the predetermined set time is reached (S11: YES), the process proceeds to the next step S12, but if it is not the set time, the timer 26 continues monitoring until that time is reached (S11: NO).

送信側ホスト２において、タイマー２６が設定時刻になったことを感知すると、これに応じて制御部２５は、マーカー送信部２４に対しマーカーパケットを送信するよう指示を行う。
指示を受けたマーカー送信部２４は、ポート２１に対してマーカーパケットを送信し、ポート２１から中継ノード３へマーカーパケットが送信される（Ｓ１２）。
同時に、シグナリング処理部２２が、新たな帯域を確保するための帯域要求信号（例えば、ＰＡＴＨメッセージ等）を中継ノード３に対し一定間隔で送信する。 When the transmission side host 2 senses that the timer 26 has reached the set time, the control unit 25 instructs the marker transmission unit 24 to transmit a marker packet.
Upon receiving the instruction, the marker transmission unit 24 transmits a marker packet to the port 21, and the marker packet is transmitted from the port 21 to the relay node 3 (S12).
At the same time, the signaling processing unit 22 transmits a bandwidth request signal (for example, a PATH message) for securing a new bandwidth to the relay node 3 at regular intervals.

中継ノード３は、送信側ホスト２から送信されたマーカーパケットを受信すると、分岐部３３を介し、集約部３４へマーカーパケットのコピーを転送する（Ｓ１３）。
一方、分岐部３３は、それまでデータパケットを格納していたバッファ３５へマーカーパケットを転送し、新たな帯域での通信を予定するデータパケットをバッファ３５からバッファ３６に切り替えて格納する。（Ｓ１４）。
これにより、マーカーパケットの受信以降に送信側ホスト２から送信されてきたデータパケットは、バッファ３６で保持されることとなる。 When the relay node 3 receives the marker packet transmitted from the transmission side host 2, the relay node 3 transfers a copy of the marker packet to the aggregation unit 34 via the branching unit 33 (S13).
On the other hand, the branching unit 33 transfers the marker packet to the buffer 35 that has previously stored the data packet, and switches and stores the data packet scheduled for communication in the new band from the buffer 35 to the buffer 36. (S14).
As a result, the data packet transmitted from the transmission side host 2 after receiving the marker packet is held in the buffer 36.

ここで、中継ノードにおいては、次のデータ送信先（接続先）が受信側ホストか否かによって以降の処理が異なる（Ｓ１５）。
次のデータ送信先が、受信側ホスト５であれば（Ｓ１５：ＹＥＳ）、ステップＳ１７に進み、受信側ホスト５でなければ、すなわち、他の中継ノードであれば（Ｓ１５：ＮＯ）、ステップＳ１６に進む。
中継ノード３の場合、次のデータ送信先は、中継ノード４であるため、ステップＳ１６に進む。 Here, in the relay node, the subsequent processing differs depending on whether or not the next data transmission destination (connection destination) is the receiving host (S15).
If the next data transmission destination is the reception side host 5 (S15: YES), the process proceeds to step S17, and if it is not the reception side host 5, that is, if it is another relay node (S15: NO), step S16. Proceed to
In the case of the relay node 3, since the next data transmission destination is the relay node 4, the process proceeds to step S16.

ステップＳ１６では、上述したように、入力側ポート３１、分岐部２４及び集約部３４を経て得たデータパケットを、出力側ポート３２を介して次の中継ノード（本実施形態の場合、中継ノード４）へ転送する。
また、送信側ホスト２から受信したマーカーパケットについても次の中継ノードへ転送する。
その後は、ステップＳ１３からの処理を再度行うこととなるが、一般的には、ステップＳ１５において次のデータ転送先が受信側ホストになるまで、ステップＳ１３乃至ステップＳ１６の処理を繰り返し行うこととなる。 In step S16, as described above, the data packet obtained through the input side port 31, the branch unit 24, and the aggregation unit 34 is transferred to the next relay node (in the present embodiment, the relay node 4). ).
Further, the marker packet received from the transmission side host 2 is also transferred to the next relay node.
Thereafter, the processing from step S13 is performed again. In general, the processing from step S13 to step S16 is repeatedly performed until the next data transfer destination becomes the receiving host in step S15. .

一方、ステップＳ１７では、バッファ３５において保持されていたデータパケットの後に付されていたマーカーパケットが集約部３４へ転送されると、バッファ３５で保持されていたデータパケットがすべて受信側に転送されたものと判断し、受信側ホスト５に対し、新たな帯域を確保するための帯域要求信号を送信する。
なお、バッファ３５で保持されていたデータパケットをすべて受信側に転送するまでは、帯域要求信号を受信していたとしても送信側にエラー信号を返すようにしても良い（本発明のエラー通知手段、エラー転送手段）。 On the other hand, in step S17, when the marker packet attached after the data packet held in the buffer 35 is transferred to the aggregation unit 34, all the data packets held in the buffer 35 are transferred to the receiving side. It is determined that the bandwidth request signal for securing a new bandwidth is transmitted to the receiving host 5.
Note that until all data packets held in the buffer 35 are transferred to the receiving side, an error signal may be returned to the transmitting side even if the bandwidth request signal is received (the error notification means of the present invention). Error transfer means).

そして、受信側ホスト５が帯域要求信号を受信すると、受信側ホスト５から中継ノード４に対し、応答信号（帯域確保信号）が送信される。
さらに、中継ノード４は、この帯域確保信号を受信すると、同様の帯域確保信号を中継ノード３に送信し、これを受けた中継ノード３は帯域確保信号を送信側ホスト２に送信する。
このように、送信側ホスト２は、確保された帯域を維持するため帯域要求信号を継続して送信し、各中継ノードでは、その応答信号である帯域確保信号を受信している間、バッファ３６に保持されているデータパケットは受信側へ転送され、これにより新たな帯域でのデータ転送が行われる。
以上の手順により、無中断で帯域を変更することができるようになる。 When the receiving host 5 receives the band request signal, a response signal (band securing signal) is transmitted from the receiving host 5 to the relay node 4.
Further, when receiving the band securing signal, the relay node 4 transmits a similar band securing signal to the relay node 3, and the relay node 3 receiving this transmits the band securing signal to the transmission side host 2.
In this way, the transmission side host 2 continuously transmits the band request signal to maintain the reserved band, and each relay node receives the band reservation signal as the response signal while receiving the band reservation signal. Are transferred to the receiving side, whereby data transfer in a new band is performed.
With the above procedure, the bandwidth can be changed without interruption.

以上説明したように、本実施形態のデータ転送システム１によれば、送信側ホスト２から送信されるデータを、中継ノード３，４を介して受信側ホスト５に転送するようにしており、特に、データ転送の途中に帯域幅を変更する場合には、予め各中継ノードにおける帯域を確保したうえで、その後のデータ転送を行うこととしている。
これにより、データ転送を中断することなく、帯域の切り替えや変更ができるようにしている。 As described above, according to the data transfer system 1 of the present embodiment, data transmitted from the transmission side host 2 is transferred to the reception side host 5 via the relay nodes 3 and 4. When changing the bandwidth in the middle of data transfer, the bandwidth in each relay node is secured in advance and the subsequent data transfer is performed.
As a result, the band can be switched or changed without interrupting the data transfer.

具体的には、送信側ホスト２にはタイマー２６を搭載しており、このタイマー制御により、予め設定した時刻になると所定のマーカーパケットを受信側に送信し、受信側ホスト５や中継ノードに対して帯域変更指示を行うようにしている。
これを受け、中継ノード３，４は、マーカーパケットを入力側ポート３１で受信すると、それまでデータパケットをバッファ３５によって保持させていたのを、バッファ３６に切り替えるようにし、その後の伝送データを、帯域割当てが変更されるまでの間、バッファ３６を用いて待機させるようにする。
そして、受信側ホスト５に対して新たな帯域を確保するための信号を送信し、受信側ホスト５からその応答信号を受信するとバッファ３６に保持されていたデータを順次転送するようにしている。 Specifically, the transmission side host 2 is equipped with a timer 26, and by this timer control, a predetermined marker packet is transmitted to the reception side at a preset time, and the reception side host 5 and the relay node are transmitted. To change the bandwidth.
In response to this, when receiving the marker packet at the input side port 31, the relay nodes 3 and 4 switch the data packet held by the buffer 35 to the buffer 36 until then, and transfer the transmission data thereafter. Until the bandwidth allocation is changed, the buffer 36 is used for waiting.
Then, a signal for securing a new band is transmitted to the receiving host 5, and when the response signal is received from the receiving host 5, the data held in the buffer 36 is sequentially transferred.

このため、データ転送の途中で、帯域を変更する場合、従来のように、一旦、通信を中断し、再度帯域の割当てを行った後にデータ転送を再開するといった手間を省くことができる。
また、データ転送量が多い時間帯や少ない時間帯に合わせたタイマー制御を行うことによって、円滑なデータ転送が可能となる。
このように本実施形態に係る中継ノード等によれば、利便性に優れ、かつ、転送データの欠落や重複のない合理的なデータ転送システムを実現し、提供することが可能である。 For this reason, when changing the band in the middle of the data transfer, it is possible to save the trouble of temporarily suspending the communication and re-allocating the data after allocating the band again as in the prior art.
In addition, smooth data transfer is possible by performing timer control according to a time zone with a large amount of data transfer or a time zone with a small amount of data transfer.
As described above, according to the relay node and the like according to the present embodiment, it is possible to realize and provide a rational data transfer system that is excellent in convenience and has no missing or duplicated transfer data.

［第二実施形態］
次に、本発明の第二実施形態に係るデータ転送システムについて図５乃至図７を参照しつつ説明する。
図５は、本実施形態に係るデータ転送システムの一部をなす送信側ホスト２のブロック図であり、図６は、中継ノード３，４のブロック図である。
これらの図に示すように、本実施形態に係る送信側ホスト２は、第一実施形態と異なり、マーカー送信部が搭載されておらず、一方、中継ノードには、制御部３８及びタイマー３９が搭載されている。 [Second Embodiment]
Next, a data transfer system according to a second embodiment of the present invention will be described with reference to FIGS.
FIG. 5 is a block diagram of the transmission side host 2 forming a part of the data transfer system according to the present embodiment, and FIG. 6 is a block diagram of the relay nodes 3 and 4.
As shown in these drawings, unlike the first embodiment, the transmission side host 2 according to the present embodiment is not equipped with a marker transmission unit, while the relay node includes a control unit 38 and a timer 39. It is installed.

具体的には、送信側ホスト２から中継ノードに対してマーカーパケットは送信されず、中継ノードに搭載される制御部３８がタイマー３９との連携によって、所定時刻になるとマーカーパケットを分岐部３３に向けて発信するようにしている（本発明のマーカー信号発生手段）。
つまり、発信側ホスト２では、マーカー送信部を必要としないため構成を簡略化できるメリットを有している。
なお、他の構成部については同様であるため詳細な説明は割愛する。 Specifically, the marker packet is not transmitted from the transmission side host 2 to the relay node, and the control unit 38 mounted on the relay node cooperates with the timer 39 to send the marker packet to the branch unit 33 at a predetermined time. The signal is transmitted toward (marker signal generating means of the present invention).
That is, the originating host 2 has the advantage that the configuration can be simplified because it does not require a marker transmitter.
Since the other components are the same, detailed description thereof is omitted.

次に、本実施形態に係るデータ転送システムの動作手順について図７を参照しながら説明を行う。
図７は、本実施形態に係るデータ転送システムの動作手順を示すフローチャートである。
前提として、送信側ホスト２及び中継ノード３、４においては、タイマー２６及びタイマー３９が、時刻を管理しており、管理者が予め設定した時刻になったかどうかを常時監視している（Ｓ２１）。
そのうえで、所定の設定時刻になったときには（Ｓ２１：ＹＥＳ）、次のステップＳ２２に移行するが、設定時刻でなければその時刻になるまでタイマー２６及びタイマー３９が監視を続ける（Ｓ２１：ＮＯ）。 Next, the operation procedure of the data transfer system according to the present embodiment will be described with reference to FIG.
FIG. 7 is a flowchart showing an operation procedure of the data transfer system according to the present embodiment.
As a premise, in the transmission side host 2 and the relay nodes 3 and 4, the timer 26 and the timer 39 manage the time, and always monitor whether or not the time set in advance by the administrator is reached (S21). .
In addition, when the predetermined set time is reached (S21: YES), the process proceeds to the next step S22. However, if it is not the set time, the timer 26 and the timer 39 continue to monitor until the time is reached (S21: NO).

送信側ホスト２において、タイマー２６が設定時刻になったことを感知すると、これに応じて制御部２５は、シグナリング処理部２２に対し新たな帯域を確保するためのメッセージを送信するよう指示を行う。
一方、中継ノード３、４において、タイマー３９が設定時刻になったことを感知すると、これに応じて制御部３８は、分岐部３３に対してマーカーパケットを送信する（Ｓ２２）。 When the transmitting host 2 senses that the timer 26 has reached the set time, the control unit 25 instructs the signaling processing unit 22 to transmit a message for securing a new band. .
On the other hand, when it is detected at the relay nodes 3 and 4 that the timer 39 has reached the set time, the control unit 38 transmits a marker packet to the branching unit 33 accordingly (S22).

中継ノード３、４において、制御部３８から送信されたマーカーパケットを分岐部３３が受信すると、それまでデータパケットを格納していたバッファ３５へマーカーパケットを送信するとともに、集約部３４へマーカーパケットのコピーを転送する（Ｓ２３）。
次に、中継ノード３、４の分岐部３３では、それまでデータパケットを格納していたバッファ３５をバッファ３６に切り替え、それ以降に送信側ホスト２から送信されてきたデータパケットはバッファ３６によって保持されるようになる（Ｓ２４）。 When the branching unit 33 receives the marker packet transmitted from the control unit 38 in the relay nodes 3 and 4, the branching unit 33 transmits the marker packet to the buffer 35 that has previously stored the data packet, and also transmits the marker packet to the aggregation unit 34. The copy is transferred (S23).
Next, in the branching unit 33 of the relay nodes 3 and 4, the buffer 35 that has previously stored the data packet is switched to the buffer 36, and the data packet transmitted from the transmission side host 2 thereafter is held by the buffer 36. (S24).

そして、バッファ３５において保持されていたデータパケットの後に付されていたマーカーパケットが集約部３４へ転送されると、バッファ３５で保持されていたデータパケットがすべて受信側に転送されたものと判断し、受信側ホスト５に対し、新たな帯域を確保するための帯域要求信号を送信する。
次に、受信側ホスト５が係る帯域要求信号を受信すると、受信側ホスト５から中継ノード４に対し、応答信号（帯域確保信号）が送信される。
さらに、中継ノード４は、この帯域確保信号を受信すると、同様の帯域確保信号を中継ノード３に送信し、これを受けた中継ノード３は帯域確保信号を送信側ホスト２に送信する。
このように、送信側ホスト２は、確保された帯域を維持するため帯域要求信号を継続して送信し、各中継ノードでは、その応答信号である帯域確保信号を受信している間、バッファ３６に保持されているデータパケットは受信側へ転送され、これにより新たな帯域でのデータ転送が実現化される。 When the marker packet attached after the data packet held in the buffer 35 is transferred to the aggregation unit 34, it is determined that all the data packets held in the buffer 35 have been transferred to the receiving side. Then, a bandwidth request signal for securing a new bandwidth is transmitted to the receiving host 5.
Next, when the receiving host 5 receives the band request signal, a response signal (band securing signal) is transmitted from the receiving host 5 to the relay node 4.
Further, when receiving the band securing signal, the relay node 4 transmits a similar band securing signal to the relay node 3, and the relay node 3 receiving this transmits the band securing signal to the transmission side host 2.
In this way, the transmission side host 2 continuously transmits the band request signal to maintain the reserved band, and each relay node receives the band reservation signal as the response signal while receiving the band reservation signal. The data packet held in is transferred to the receiving side, thereby realizing data transfer in a new band.

以上説明したように、本実施形態のデータ転送システム１によれば、第一実施形態と同様の効果が発揮されるだけでなく、送信側ホスト２にはマーカー送信部を備えず、中継ノード３、４にマーカー送信機能を備えた構成としてあるので、送信側ホスト２の構成を簡易なものにすることができる。
また、システムのバリエーションが拡がり、ユーザの求めるシステムを構築し、提供することが可能となる。 As described above, according to the data transfer system 1 of the present embodiment, not only the same effect as the first embodiment is exhibited, but the transmission side host 2 does not include a marker transmission unit, and the relay node 3 4 has a marker transmission function, the configuration of the transmission side host 2 can be simplified.
Moreover, the variation of a system spreads and it becomes possible to construct and provide the system which a user demands.

以上、本発明のデータ転送システムについて、好ましい実施形態を示して説明したが、本発明にかかるデータ転送システムは、上述した実施形態にのみ限定されるものではなく、本発明の範囲で種々の変更実施が可能であることは言うまでもない。
例えば、本発明の送信装置及び受信装置は、コンピュータに限らず、携帯電話端末やＰＤＡ等の通信端末であってもよく、これによりシステムのバリエーションをさらに広げることができる。 The data transfer system according to the present invention has been described with reference to the preferred embodiment. However, the data transfer system according to the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention. It goes without saying that implementation is possible.
For example, the transmission device and the reception device of the present invention are not limited to computers, and may be communication terminals such as a mobile phone terminal and a PDA, thereby further expanding the variations of the system.

本発明は、インターネット等のネットワーク環境で使用されるバッファリング機能を備えた中継装置に好適に利用することができる。 The present invention can be suitably used for a relay device having a buffering function used in a network environment such as the Internet.

本発明の第一実施形態に係るデータ転送システムの構成を示すシステム構成図である。It is a system configuration figure showing the composition of the data transfer system concerning a first embodiment of the present invention. 本発明の第一実施形態に係るデータ転送システムの一部をなす送信側ホストの内部構成を示すブロック図である。It is a block diagram which shows the internal structure of the transmission side host which makes a part of data transfer system which concerns on 1st embodiment of this invention. 本発明の第一実施形態に係るデータ転送システムの一部をなす中継ノードの構成を示すブロック図である。It is a block diagram which shows the structure of the relay node which makes a part of data transfer system which concerns on 1st embodiment of this invention. 本発明の第一実施形態に係るデータ転送システムの動作手順を説明するためのフローチャートである。It is a flowchart for demonstrating the operation | movement procedure of the data transfer system which concerns on 1st embodiment of this invention. 本発明の第二実施形態に係るデータ転送システムの一部をなす送信側ホストのブロック図である。It is a block diagram of the transmission side host which makes a part of data transfer system concerning a second embodiment of the present invention. 本発明の第二実施形態に係るデータ転送システムの一部をなす中継ノードのブロック図である。It is a block diagram of the relay node which makes a part of data transfer system concerning a second embodiment of the present invention. 本発明の第二実施形態に係るデータ転送システムの動作手順を説明するためのフローチャートである。It is a flowchart for demonstrating the operation | movement procedure of the data transfer system which concerns on 2nd embodiment of this invention. ＲＳＶＰ（Resource Reservation Protocol）の制御手順を示したシーケンス図である。It is the sequence diagram which showed the control procedure of RSVP (Resource Reservation Protocol).

Explanation of symbols

１データ転送システム
２送信側ホスト
３中継ノード
４中継ノード
５受信側ホスト 1 Data Transfer System 2 Sending Host 3 Relay Node 4 Relay Node 5 Receiver Host

Claims

A relay device that holds received data in one buffer and transfers the data held in the one buffer,
Marker receiving means for receiving a predetermined marker signal from a transmission device or a relay device connected to the transmission device side;
Band request signal receiving means for receiving a predetermined band request signal from the transmitting device or a relay device connected to the transmitting device side;
Data holding means for holding data received from the transmission device or a relay device connected to the transmission device side in another buffer different from the one buffer in response to reception of the marker signal;
Marker transfer means for transferring the received marker signal to a relay device connected to the receiving device side;
Band request signal transmitting means for transmitting a predetermined band request signal to the receiving apparatus or a relay apparatus connected to the receiving side in response to reception of the band request signal;
Band securing signal receiving means for receiving a predetermined band securing signal from the receiving device or a relay device connected to the receiving side;
Band securing signal transmitting means for transmitting a predetermined band securing signal to the transmitting device or a relay device connected to the transmitting device in response to reception of the bandwidth securing signal;
And a data transfer means for transferring data held in the other buffer to the receiving device or a relay device connected to the receiving side in response to reception of the band securing signal .

A relay device that holds received data in one buffer and transfers the data held in the one buffer,
Band request signal receiving means for receiving a predetermined band request signal from the transmission device or a relay device connected to the transmission device side;
Marker signal generating means for generating a predetermined marker signal;
Marker receiving means for receiving a predetermined marker signal from a relay device connected to the transmitting device side;
Data holding means for holding the data received from the transmission device or the relay device connected to the transmission device side after generation of the marker signal or received in another buffer different from the one buffer;
Marker transfer means for transferring the marker signal to a receiving device or a relay device connected to the receiving device side;
Band request signal transmitting means for transmitting a predetermined band request signal to the receiving device or a relay device connected to the receiving device in response to reception of the band request signal;
Band securing signal receiving means for receiving a predetermined band securing signal from the receiving device or a relay device connected to the receiving device side;
Band securing signal transmitting means for transmitting a predetermined band securing signal to the transmitting device or a relay device connected to the transmitting device in response to reception of the bandwidth securing signal;
Data transfer means for transferring data held in the other buffer to the receiving device or a relay device connected to the receiving device in response to reception of the band securing signal.
A relay device characterized by that .

The band request signal transmission means includes:
In response to the reception of the band request signal, only when all of the data held in the one buffer is transferred to the receiving apparatus or a relay apparatus connected to the receiving apparatus side, the predetermined band request signal is The relay apparatus according to claim 1, wherein the relay apparatus transmits to a receiving apparatus or a relay apparatus connected to the receiving apparatus side .

In response to reception of the band request signal, a predetermined error notification signal is sent to the transmitter until all of the data held in the one buffer is transferred to the receiver or a relay device connected to the receiver. Or error notification means for transmitting to the relay device connected to the transmission device side;
The relay apparatus according to claim 1, further comprising: an error transfer unit configured to transfer the received error notification signal to the transmission apparatus or a relay apparatus connected to the transmission apparatus side .

The bandwidth request signal is a PATH message in RSVP;
The relay apparatus according to any one of claims 1 to 4, wherein the band securing signal is a RESV message in RSVP .

The transmission device includes a transmission device, a reception device, and one or more relay devices. The relay device holds data transmitted from the transmission device in one buffer, and transfers the data held in the one buffer to the reception device. A data transfer system,
  The transmitting device is
Marker transmitting means for transmitting a predetermined marker signal to the relay device;
  Band request signal transmitting means for transmitting a predetermined band request signal to the relay device;
  Data transmission means for transmitting data to the relay device,
  The relay device is
  Band request signal receiving means for receiving the band request signal from the transmitter or a relay device connected to the transmitter side;
  Marker receiving means for receiving the marker signal from the transmitting device or a relay device connected to the transmitting device side;
  Data holding means for holding data received from the transmission device or a relay device connected to the transmission device side in another buffer different from the one buffer in response to reception of the marker signal;
  Marker transfer means for transferring the received marker signal to a relay device connected to the receiving device side;
  Band request signal transmitting means for transmitting a predetermined band request signal to the receiving device or a relay device connected to the receiving device in response to reception of the band request signal;
  Band securing signal receiving means for receiving a predetermined band securing signal from the receiving device or a relay device connected to the receiving device side;
  Band securing signal transmitting means for transmitting a predetermined band securing signal to the transmitting device or a relay device connected to the transmitting device in response to reception of the bandwidth securing signal;
  A data transfer means for transferring the data held in the other buffer to the receiving device or a relay device connected to the receiving device in response to the reception of the band securing signal;
  The receiving device is
  Band request signal receiving means for receiving the band request signal from the relay device;
  In response to reception of the band request signal, band ensuring signal return means for returning a predetermined band ensuring signal to the relay device;
  Data receiving means for receiving data transferred from the relay device
  A data transfer system characterized by that.

The transmission device includes a transmission device, a reception device, and one or more relay devices. The relay device holds data transmitted from the transmission device in one buffer, and transfers the data held in the one buffer to the reception device. A data transfer system,
The transmitting device is
Band request signal transmitting means for transmitting a predetermined band request signal to the relay device;
Data transmission means for transmitting data to the relay device,
The relay device is
Band request signal receiving means for receiving a predetermined band request signal from the transmitting device or a relay device connected to the transmitting device side;
Marker signal generating means for generating a predetermined marker signal;
Marker receiving means for receiving a predetermined marker signal from a relay device connected to the transmitting device side;
Data holding means for holding the data received from the transmission device or the relay device connected to the transmission device side after generation of the marker signal or received in another buffer different from the one buffer;
Marker transfer means for transferring the marker signal to the receiving device or a relay device connected to the receiving device side;
Band request signal transmitting means for transmitting a predetermined band request signal to the receiving device or a relay device connected to the receiving device in response to reception of the band request signal;
Band securing signal receiving means for receiving a predetermined band securing signal from the receiving device or a relay device connected to the receiving device side;
Band securing signal transmitting means for transmitting a predetermined band securing signal to the transmitting device or a relay device connected to the transmitting device in response to reception of the bandwidth securing signal;
A data transfer means for transferring the data held in the other buffer to the receiving device or a relay device connected to the receiving device in response to the reception of the band securing signal;
The receiving device is
Band request signal receiving means for receiving the band request signal from the relay device;
In response to reception of the band request signal, band ensuring signal return means for returning a predetermined band ensuring signal to the relay device;
Data receiving means for receiving data transferred from the relay device
A data transfer system characterized by that .

The transmitting device is
8. The data transfer system according to claim 7, further comprising bandwidth request control means for transmitting a predetermined bandwidth request signal to the relay device when the timer measures a predetermined time .

A data transfer method for holding received data in one buffer and transferring the data held in the one buffer,
  Receiving a predetermined marker signal from a transmission device or a relay device connected to the transmission device side;
  Receiving a predetermined bandwidth request signal from the transmission device or a relay device connected to the transmission device side;
  In response to receiving the marker signal, thereafter, holding the data received from the transmission device or a relay device connected to the transmission device side in another buffer different from the one buffer;
  Transferring the received marker signal to a relay device connected to the receiving device;
  Transmitting a predetermined bandwidth request signal to the receiving device or a relay device connected to the receiving device in response to receiving the bandwidth request signal;
  Receiving a predetermined band securing signal from the receiving device or a relay device connected to the receiving device side;
  In response to receiving the band securing signal, transmitting a predetermined band securing signal to the transmitting apparatus or a relay apparatus connected to the transmitting apparatus side;
  In response to receiving the band securing signal, transferring the data held in the other buffer to the receiving device or a relay device connected to the receiving device side.
  A data transfer method characterized by the above.

  A data transfer method for holding received data in one buffer and transferring the data held in the one buffer,
  Receiving a predetermined bandwidth request signal from a transmission device that transmits data or a relay device connected to the transmission device side;
  Generating a predetermined marker signal;
  Receiving a predetermined marker signal from a relay device connected to the transmitter side;
  Holding the data received from the transmission apparatus or the relay apparatus connected to the transmission apparatus side after generation of the marker signal or after reception in another buffer different from the one buffer;
  Transferring the marker signal to a receiving device or a relay device connected to the receiving device;
  Transmitting a predetermined bandwidth request signal to the receiving device or a relay device connected to the receiving device in response to receiving the bandwidth request signal;
  Receiving a predetermined band securing signal from the receiving device or a relay device connected to the receiving device side;
  In response to receiving the band securing signal, transmitting a predetermined band securing signal to the transmitting apparatus or a relay apparatus connected to the transmitting apparatus side;
  Transferring the data held in the other buffer to the receiving device or a relay device connected to the receiving device in response to receiving the band securing signal;
  Have
  A data transfer method characterized by the above.

A data transfer program for holding received data in one buffer and transferring the data held in the one buffer,
  A computer constituting the relay device;
  Marker receiving means for receiving a predetermined marker signal from a transmission device or a relay device connected to the transmission device side,
  Band request signal receiving means for receiving a predetermined band request signal from the transmission device or a relay device connected to the transmission device side,
  Data holding means for holding data received from the transmission device or a relay device connected to the transmission device side in another buffer different from the one buffer in response to reception of the marker signal;
  Marker transfer means for transferring the received marker signal to a relay device connected to the receiving device side,
  Band request signal transmission means for transmitting a predetermined band request signal to the receiving device or a relay device connected to the receiving device in response to reception of the band request signal;
  Band securing signal receiving means for receiving a predetermined band securing signal from the receiving device or a relay device connected to the receiving device side,
  Band securing signal transmission means for transmitting a predetermined band securing signal to the transmitting device or a relay device connected to the transmitting device in response to reception of the bandwidth securing signal;
  In response to the reception of the band securing signal, it functions as data transfer means for transferring the data held in the other buffer to the receiving device or a relay device connected to the receiving device.
  A data transfer program characterized by that.

  A data transfer program for holding received data in one buffer and transferring the data held in the one buffer,
  A computer constituting the relay device;
  Band request signal receiving means for receiving a predetermined band request signal from a transmission device or a relay device connected to the transmission device side;
  Marker signal generating means for generating a predetermined marker signal;
  Marker receiving means for receiving a predetermined marker signal from a relay device connected to the transmitting device side,
  Data holding means for holding data received from the transmission device or a relay device connected to the transmission device side after generation of the marker signal or received in another buffer different from the one buffer,
  Marker transfer means for transferring the marker signal to a receiving device or a relay device connected to the receiving device side,
  Band request signal transmitting means for transmitting a predetermined band request signal to a receiving device or a relay device connected to the receiving device in response to reception of the band request signal;
  Band securing signal receiving means for receiving a predetermined band securing signal from the receiving device or a relay device connected to the receiving device side,
  Band securing signal transmission means for transmitting a predetermined band securing signal to the transmitting device or a relay device connected to the transmitting device in response to reception of the bandwidth securing signal;
  Data transfer means for transferring the data held in the other buffer to the receiving device or a relay device connected to the receiving device in response to receiving the band securing signal;
  To act as
  A data transfer program characterized by that.