JP2004282572A - Packet communication method and communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication method and a communication system which perform setting of the optical pathway of an optical network especially in advance of data communication, regarding an optical network which connects parts between a plurality of networks. <P>SOLUTION: When a first transfer instrument 1320 requests data, line setting request which requests setting of line in a line switching type network 1100 is transmitted via a packet-switched network 1200, the first transfer instrument 1320 and a second transfer instrument 1420 hold setting information on a line established based on the line setting request until data request from the first transfer instrument 1320 reaches the second transfer instrument 1420, and the second transfer instrument 1420 transmits the request data to the first transfer instrument 1320 via the line established based on the line setting request. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an optical network connecting a plurality of networks, and more particularly, to a communication method and a communication system for setting an optical path of an optical network.
[0002]
[Prior art]
In recent years, with the advent of content distribution services and global storage services, large-capacity, low-delay communication networks are required. Further, in order to respond to traffic demand, a communication device capable of processing packets in the terabit class is required. For this reason, a method has been proposed in which an optical network is provided in parallel with the Internet based on the conventional IP (Internet Protocol), and large-capacity data is transferred via this optical network. This optical network is composed of optical nodes and optical fibers, and can transmit terabits of packets per second over one link by using wavelength multiplexing technology (for example, see Non-Patent Document 1).
[0003]
Further, since the optical node is constituted by an optical switch, it is possible to freely set an optical path route through which a packet passes according to a command from the control unit. At present, as an optical node system, an optical cross connect device OXC (Optical Cross Connect) and an optical add / drop device OADM (Optical Add Drop Multiplexer) for manually setting an optical path are put into practical use, and the optical path is automatically set. An optical burst switch to be set is being studied.
[0004]
In the above-described conventional technique, it is necessary to determine a communication route (optical path) of the optical network before packet transfer. Therefore, the optical burst switch uses a control packet in advance to secure a communication path from the entrance to the exit of the optical network. Until the communication path is secured, the packet to be transferred is stored in the buffer to form a super packet, and after the communication path has been secured, the super packet is transferred along the communication path.
[0005]
Two-way and one-way methods have been proposed as methods for securing communication paths for control packets. The Two-Way method is a method for confirming reservation of an optical path. In addition, the One-Way method is a method that does not confirm reservation of an optical path, and a Tell-And-GO method and a Just-Enough-Time method are known (for example, Non-Patent Document 2).
[0006]
[Non-patent document 1]
"General Remarks-Creating a 21st Century Network and the Unlimited Impact", IEICE, May 2002
[Non-patent document 2]
"Optical Burst Switching", Journal of High Speed Networks, vol. 8, January 1999, p. 69-84
[0007]
[Problems to be solved by the invention]
However, in the above-described related art, there is a problem that it takes time to establish a communication path because an optical path is set after an IP packet arrives at a server. Establishing this communication path usually requires several milliseconds when an optical switch is used. IP packets are accumulated in the buffer unit of the OXC until the communication path is established. However, if it takes time to establish the communication path, there is a problem that the buffer overflows and the packet discard rate increases.
[0008]
[Means for Solving the Problems]
SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and sets an optical path of an optical network in advance before issuing a request from a client to a server. It is an object of the present invention to provide a communication system in which a communication path is established. When the client is connected to the Internet and the optical network at the same time, the client transmits an IP packet to the Internet, issues an optical path setting request to the optical network at the same time, and obtains a response from the server. An object of the present invention is to provide a high-speed, low-delay packet communication method, a packet communication method suitable for an application requiring communication quality, and a communication system by establishing a communication path of an optical network secured in advance.
[0009]
Further, the packet transfer device that realizes the above generates an IP packet and a control packet based on the header information of the input packet, and generates a token when a communication path is established, to change the state of the optical path of the optical network. It manages and executes arithmetic processing for controlling the flow of IP packets. Further, in order to guarantee communication quality, data from the server is transferred on an optical path in which a communication path is established in End-to-End.
[0010]
【The invention's effect】
According to the present invention, when data is transferred from the server to the client, the data transfer time can be significantly reduced because the communication path of the optical network has already been established. In particular, since data can be transferred using an optical path for which a communication path has been established in End-to-End, a highly reliable communication method can be provided. Furthermore, since data can be transferred via an optical network having a terabit-class transmission band, a large amount of data can be instantaneously moved to a remote site on the client side.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0012]
<First embodiment>
First, a communication system according to the first embodiment will be described. In the first embodiment, a client and a server are connected to one optical network.
[0013]
FIG. 1 is a network configuration diagram of the communication system according to the first embodiment.
[0014]
The site A 1300 and the site B 1400 are connected to the optical network 1000. The site A1300 includes a client 1310, a gateway router A1320A1320, and a terminal 1330. The client 1310 is a computer device that makes a request to the network on the server side, and is loaded with an OS (Operating Systems) and application software. The gateway router A 1320 is a router device that connects the IP network and the optical network and can exchange data with each other. The terminal 1330 is a terminal that inputs data to the client 1310 or the gateway router A 1320.
[0015]
The site B1400 includes a server 1410, a gateway router B1420, and a terminal 1430. The server 1410 is a computer device that transmits stored data in response to a request from a client. The gateway router B 1420 is a router device that connects the IP network and the optical network and exchanges data with each other. The terminal 1430 is an input device for performing various settings. Note that the gateway router A1320 and the transfer device A1500, and the gateway router B1420 and the transfer device D1500 are connected by a communication line using a protocol such as Ethernet (registered trademark together with Ethernet; the same applies hereinafter).
[0016]
The optical network 1000 is logically divided into a data plane 1100 and a control plane 1200. The data plane 1100 is an optical network mainly for transferring data, and is a circuit switching type network in which a line for transferring data needs to be set in advance. On the other hand, the control plane 1200 is an optical network for transferring a control signal (packet) between the transfer devices 1500, and is a packet transfer type network. The optical network 1000 includes transfer devices A, B, C, and D1500, and the transfer devices 1500 are interconnected using an optical fiber.
[0017]
A communication line between the transfer devices A, B, C, and D is applied with wavelength division multiplexing (WDM) technology, and a plurality of lines are formed by using a plurality of channels (wavelengths) in one optical fiber. Communication can be performed. In this embodiment, the plurality of channels are logically divided into a data channel 1610 and a control channel 1620. The data channel 1610 is a channel for transferring only data, and includes a default channel using the wavelength λ1 and a transfer channel using the wavelength λ2. The default channel λ1 is a channel connected between the transfer devices 1500 according to a preset route. Each transfer device 1500 uses the default channel to establish a line state or communication state with an adjacent transfer device 1500. Can be grasped. The transfer channel λ2 is a channel set so that a large amount of data can be transferred from the server to the client after setting the optical path.
[0018]
The control channel 1620 is a channel used when setting an optical path of the optical network, and includes a control channel using the wavelength λ3.
[0019]
FIG. 2 is a block diagram of the transfer device 1500 according to the first embodiment.
[0020]
The transfer device 1500 includes input line interfaces 1910 to 191n, WDM input line interfaces 2010 to 201n, a token generation unit 2100, a packet analysis unit 2110, a path control unit 2120, an optical path setting determination unit 2130, a management information unit 2140, and IP packet assembly. It comprises a unit 2150, a control packet generation unit 2160, a switch unit 2170, an optical switch control unit 2180, output line interfaces 2190 to 219n, and WDM output line interfaces 2200 to 220n.
[0021]
The input line interfaces 2010 to 201n receive the packet sent from the electric line and send it to the packet analysis unit 2120.
[0022]
The WDM input line interface separates the signal of each channel from the signal sent from the optical line using WDM, receives the separated packet of each channel, and sends the packet to the packet analysis unit via the token generation unit 2100. Send to 2110. The token generation unit 2100 generates a token indicating whether an optical path has been set.
[0023]
The packet analyzer 2110 determines the contents of the packet sent from each interface, and passes only necessary packets to the optical path setting determiner 2130 and thereafter. The optical path setting determination unit 2130 determines the contents of the packet. That is, if the packet is an optical path setting request packet, it instructs the control packet generator 2160 to generate a control packet, and sends the generated packet to the WDM output line interfaces 2200 to 220n via the switch 2170. If the packet is a packet other than the optical path setting request packet, the packet is passed to the IP packet assembling unit 2150, the header of the source and destination is changed, and the packet is transferred via the output line interfaces 2190 to 219n via the switch unit 2170. I do.
[0024]
The switch unit 2170 includes an electric switch 2171 and an optical switch 2172. The optical switch 2172 is configured by an optical switching device such as a MEMS (Micro Electro Mechanical Systems), and switches a communication channel according to a command from the optical switch control unit 2180.
[0025]
The route control unit 2120 holds a packet route table. The contents of this routing table are sequentially updated using an Internet standard protocol such as RIP (Routing Information Protocol) and OSPF (Open Shortest Path First).
[0026]
The management information unit 2140 monitors the WDM line input interfaces 2010 to 201n and the WDM line output interfaces 2190 to 219n, and holds a band management table. The bandwidth management table includes adjacent transfer device management information (number of adjacent transfer devices, control channel number), UNI (User Network Interface) management information (link number, number of channels, channel number, client address, use state), NNI ( Network Node Interface) management information (link number, input / output type, channel number, wavelength information), label management information (link number, label (wavelength number), idle / busy state), LSP (Label Switched Path) management information (LSP number) , Input link numbers, input channel numbers, output link numbers, output channel numbers, identification codes, recovery types, and link management information (local link numbers, remote link numbers, controller addresses), and the like. Note that these contents are updated as needed using LMP (Link Management Protocol) or the like.
[0027]
Next, the operation of the communication system according to the first embodiment configured as described above will be described.
[0028]
FIG. 3 is a sequence diagram illustrating a process of setting an optical path of an optical network prior to data transfer and transferring data via the set optical path in the first embodiment.
[0029]
First, a packet for requesting data is transmitted from the client 1310 to the gateway router A 1320. The gateway router A 1320 sets a light path by transmitting a request packet (described later in FIG. 4) for setting a light path to the gateway router B 1420 via the optical network 1000 using the wavelength λ3 according to the contents of the packet. Then, the gateway router B 1420 transfers the data of the server 1410 using the set optical path.
[0030]
The setting of the optical path by the optical path setting request packet is performed in the following procedure.
[0031]
First, the gateway router A 1320 generates an optical path setting request packet 1710 as a control packet for an optical path setting request, and transmits it to the optical network 1000.
[0032]
The optical path setting request packet 1710 includes information such as a band of a line used for transmitting data requested from the client to the server, a wavelength used by the line, and a capacity of data requested from the server.
[0033]
When the transfer device A1500 directly connected to the gateway router A1320 receives the optical path setting request packet 1710, the transfer device A1500 refers to the band management table held in the management information section 2140 to check the available wavelength or the available band. From the information such as the line bandwidth included in the setting request, an appropriate route for transferring data is selected, and a route for transferring the packet 1710 is determined. Here, a route to the transfer device A 1500 is determined, and as a result, the optical path setting request packet 1710 is transferred to the transfer device B 1500. Next, the transfer device B1500 to which the optical path setting request packet 1710 has been transferred refers to the bandwidth management table held in the management information section 2140 of the transfer device B1500, and either the transfer device C1500 or the transfer device D1500. Is selected, and a route for transferring the packet 1710 is determined. Here, the route to the transfer device D1500 is selected, and the optical path setting request packet 1710 is sent to the transfer device D1500. The transfer device D1500 transfers the control packet to the gateway router B1420.
[0034]
As a result, in the data plane 1100 of the optical network 1000, a transfer channel λ2 having the transfer device ABD 1500 as an optical path is set. This result is stored in the gateway router B 1420 as Token.
[0035]
Next, it is confirmed that an optical path is set in the two-way method. In this case, the optical path setting notification packet 1715 is also notified from the gateway router B 1420 to the gateway router A 1320 as confirmation (ACK) of the optical path setting request 1710 using the wavelength λ3. When the One-Way system is used, the setting of the optical path is not confirmed.
[0036]
Next, data is transferred between the server 1410 and the client 1310 using the data plane 1100. The gateway router A 1320 sends a file transfer request packet 1720 from the client 1310 to the gateway router B 1420 using the transfer channel λ2 set previously. Upon receiving the file transfer request packet 1720, the gateway router B 1420 searches for data from the server 1410 according to the contents of the packet, and sends the searched data 1725 to the gateway router A 1320 via the gateway router B 1420 using the same wavelength λ2. . The gateway router A 1320 sends the received data to the client 1310.
[0037]
Through the above processing, data transfer between the client and the server can be performed using a predetermined optical path.
[0038]
The set optical path is released when a certain time has elapsed after the data transfer is completed. When the gateway router A 1320 detects the elapse of a predetermined time (timeout) from the end of the data transfer, the optical path release request packet 1730 is transmitted via the optical path set in the control plane 1200 using the wavelength λ3. To the gateway router B. Each transfer device 1500 of the optical network 1000 releases the optical path in accordance with the optical path release request packet 1730, and the release of the optical path is completed. When the optical path release request packet 1730 reaches the gateway router B 1420, the gateway router B 1420 , Sends an optical path release notification packet 1735 to the gateway router A 1320 via the default channel.
[0039]
FIG. 4 is a format diagram of a packet transmitted from the client 1310 to the gateway router A 1320 according to the first embodiment.
[0040]
In the present embodiment, a case where the line is Ethernet, the network layer protocol is IP (Internet Protocol), and the transport layer protocol is TCP (Transmission Control Protocol) is exemplified.
[0041]
This packet includes an L2 header 1800 including header information of the second layer (data link layer), an L3 header 1810 including header information of the third layer (network layer), and an L3 header 1810 including header information of the third layer (network layer) in an OSI (Open Systems Interconnection) reference model. It is composed of L3 data 1820 including data. The L3 data 1820 includes an L4 header 1830 including header information of the fourth layer (transport layer) and L4 data 1840 including data of the fourth layer. Further, the L4 data 1840 includes an L7 header 1850 including header information of the seventh layer (application layer) and L7 data 1860 including data of the seventh layer.
[0042]
The format of the L2 header 1800 varies depending on the line type, but when the line is Ethernet as in the present embodiment, the L2 header 1800 includes a source MAC (Media Access Control) address, a destination MAC address, a packet length, and the like. Data is included.
[0043]
The L3 header 1810 includes information such as a source IP address (SIP (Source IP)) 1811 indicating the source terminal of the packet, a destination IP address (DIP (Destination IP)) 1812 indicating the destination terminal of the packet, and options 1813. . In this embodiment, when the client 1310 requests generation of a control packet to indicate that the request from the client 1310 to the gateway router A 1320 includes a generation request of a control packet for setting an optical path, the client 1310 A flag is set in a predetermined area of the option 1813 of the packet generated by the application software 1310. That is, if a flag is present in the option 1813, the request is an optical path setting request, and if there is no flag, the packet is another packet.
[0044]
The L4 header 1830 includes information such as a source port number and a destination port number. Further, the content of the L7 header 1850 depends on the application that requests the data. For example, when the application uses http (Hyper Text Transport Protocol), information such as “GET URL version” is included.
[0045]
Next, the operation of the transfer device 1500 according to the first embodiment will be described.
[0046]
FIG. 5 is a flowchart illustrating a process of the optical path setting determination unit 2130 of the transfer device 1500.
[0047]
First, it is determined whether or not there is a flag in the option 1813 (see FIG. 4) area of the input packet (process 501). If it is determined that there is no flag, the packet is sent to IP packet assembling section 2150, and the packet is sent to the next transfer device 1500 using the default channel of the data plane (process 504).
[0048]
On the other hand, if it is determined that there is a flag, it is determined whether Token is present or ACK is received (process 502). If there is a token, the setting of the optical path is completed and the token is held between the gateway routers. If an ACK is received, the setting of the optical path is completed and the confirmation is being performed. Therefore, it can be seen that the setting of the optical path has already been completed. Then, the packet is sent to the next transfer device 1500 via the optical path already set (process 503).
[0049]
On the other hand, in the process 504, if there is no Token and no ACK is received, it is necessary to set the optical path requested to the optical network 1000, so a control packet for setting the optical path is generated ( Process 505), the control packet is transferred to the next transfer device 1500 using the control channel of the control plane (Process 506).
[0050]
Next, as a modified example of the data transfer procedure of the first embodiment, a case where an optical path setting request and a data transfer request are performed simultaneously will be described.
[0051]
FIG. 6 is a sequence diagram illustrating a flow of a process of transmitting a request for setting an optical path of an optical network simultaneously with a request for data transfer and transferring data via the set optical path in the first embodiment. FIG.
[0052]
Upon receiving the request from the client 1310, the gateway router A 1320 sends to the data plane 1100 a file transfer request packet 1740 for requesting a file transfer according to the contents of the request. The file transfer request packet 1740 is sent to the gateway router B 1420 via the gateway router A 1320 via the default channel of the wavelength λ1. At this time, the time required for the file transfer request packet 1740 to reach the gateway router B 1420 from the gateway router A 1320 is T7.
[0053]
On the other hand, the gateway router A 1320 sends the file transfer request packet 1740 and sends an optical path setting request packet 1750 as a control packet for requesting the setting of the optical path to the control plane 1200. The optical path setting request packet 1750 is sent from the gateway router A 1320 to the gateway router B 1420 via the default channel via the control channel λ 3 via the gateway router A 1320, and as a result, between the transfer devices A-C-D. An optical path is set. The setting of this optical path is performed in the same manner as in the sequence of FIG. At this time, the time required for the optical path setting request packet 1750 to reach the gateway router B 1420 from the gateway router A 1320 is T8. When the Two-Way method is used, the gateway router B 1420 sends an optical path setting notification packet 1755 to the gateway router A 1320 using the wavelength λ3 when the setting of the optical path is completed. Does not send the optical path setting notification packet.
[0054]
Here, the file transfer request packet 1740 is sent using the wavelength λ1 to the default channel of the data plane 1100, but the band of the wavelength λ1 is smaller than the wavelength λ2 or the wavelength λ3. The arrival time (T7) is longer than the arrival time (T8) of the optical path setting request packet 1750 (T8 <T7). Therefore, when the file transfer request 1740 reaches the gateway router B1420, the optical path has already been set in the data plane 1100, so that the gateway router B1420 passes through the set optical path between the transfer devices A-C-D. Then, the transfer of the file requested by the file transfer request 1740 can be started.
[0055]
The server 1410 transmits the data requested according to the file transfer request packet 1740 to the gateway router A 1420A using the wavelength λ2 from the gateway router B 1420 to the gateway router A 1320A using the optical path set in the transfer device DCA 1500. Transfer 1760 is performed.
[0056]
As described above, the optical path is set up with the gateway router B 1320 in response to the request from the gateway router A 1320, and the data transfer becomes possible.
[0057]
Note that, as described above with reference to FIG. 3, after a certain period of time, the optical path is released by the optical path release request packet 1770 and the optical path release notification packet 1775.
[0058]
In the communication system of the first embodiment configured as described above, when data is transferred via the optical network 1000, the optical path setting is performed prior to or together with the data transfer request. Since the request is sent and the data is transferred via the optical path set based on the setting request, the optical path is set before the data transfer starts. The time until a path is set can be reduced, and the throughput of data transfer can be improved.
[0059]
<Second embodiment>
Next, a communication system according to a second embodiment will be described.
[0060]
FIG. 7 is a network configuration diagram of the communication system according to the second embodiment.
[0061]
The second embodiment is different from the first embodiment in that a plurality of optical networks are connected in series between a site A 1300 and a site B 1400. Note that the same reference numerals are given to components performing the same operations as in the first embodiment, and description thereof will be omitted.
[0062]
The site A1300 and the site B1400 are connected via an optical network A2500 and an optical network B2600. The optical network 2500 includes transfer devices A, B, C, and D1500, and the optical network 2600 includes transfer devices D, E, F, and G1500. The transfer device D1500 belongs to both the optical network A2500 and the optical network B2600, and functions as a gateway device that connects the optical network A2500 and the optical network B2600.
[0063]
The wavelength channel 2910 provided in the optical network A 2500 and the wavelength channel 2920 provided in the optical network B 2600 are configured by a data plane including a wavelength λ1 (default channel) and a wavelength λ2 (transfer channel) and a control plane including a wavelength λ3. Have been. Note that, as in the first embodiment, the data plane is an optical network for mainly transferring data, and is a circuit-switching type network in which a line for transferring data needs to be set in advance. is there. On the other hand, the control plane is an optical network for transferring a control signal (packet) between transfer devices, and is a packet transfer type network. Although the data plane and the control plane are shown separately in FIG. 1, these are also shown together in FIG.
[0064]
Next, an operation when the communication system of the second embodiment transfers data will be described.
[0065]
FIG. 8 is a sequence diagram showing a flow of processing for setting an optical path of an optical network prior to data transfer and transferring data via the set optical path in the second embodiment.
[0066]
The client 1310 sends a packet for a data request to the gateway router A 1320. A flag is provided in the optional area 1813 (see FIG. 4) of the L3 header of this packet, and the L7 data 1860 includes a file transfer request (restore request to the server 1410). The gateway router A 1320 generates an optical path setting request packet 2710 according to the content of the received packet, sends an optical path setting request packet 2710 to the optical network A 2500 and the optical network B 2600 using the control channel λ3, and Set. The setting of this optical path is the same as the procedure described in FIG. If the file capacity required for the server 1410 is known, the bandwidth of the optical path can be designated in the optical path setting request 2710.
[0067]
When the optical path of the transfer device A-D-G 1500 is set by the optical path setting request 2710, the result is stored in the gateway router B 1420 as Token.
[0068]
Next, the gateway router A 1320 sends a file transfer request packet 2720 to the gateway router B 1420 using the wavelength λ1 via the set optical path. Next, the file transfer request packet 2720 arriving at the gateway router B 1420 is sent to the server 1410, and a necessary file is searched according to the contents of the file transfer request packet 2720, and the searched file is sent from the server 1410 to the set optical path. (Transfer device G-D-A1500) to the gateway router A 1320 using the transfer channel λ2. The gateway router A 1320 transfers the transmitted file to the client 1310. The optical path between the transfer device 1500A and the transfer device G is released by an optical path release request packet 2730 and an optical path release notification packet 2735 after a lapse of a predetermined time, as described in FIG.
[0069]
With the above procedure, the client 1310 can receive the file of the server 1410.
[0070]
The above processing procedure may be such that the optical path setting notification and the file transfer request are sent simultaneously, as shown in FIG. At this time, the file transfer request packet 2720 is sent using the wavelength λ1 on the default channel of the data plane, but the bandwidth of the wavelength λ1 is smaller than the wavelength λ2 or λ3, and as a result, the file transfer request packet 1740 arrives. The time (T23) is longer (T21 <T23) than the time (T21) in which the optical path setting request packet 2710 arrives. Therefore, when the file transfer request 2720 reaches the gateway router B 1420, an optical path has already been set in the data plane.
[0071]
In the communication system according to the second embodiment configured as described above, when data is transferred via the plurality of optical networks 2500 and 2600, prior to the data transfer request or together with the data transfer request. , An optical path setting request is sent, and the data is transferred via the optical path set based on the setting request. Therefore, as in the first embodiment, the optical path is set before the data transfer is started. Is set, the time from when data is requested to when an optical path is set can be reduced, and the throughput of data transfer can be improved.
[0072]
<Third embodiment>
Next, a communication system according to a third embodiment will be described.
[0073]
FIG. 9 is a network configuration diagram of the communication system according to the third embodiment.
[0074]
In the third embodiment, as compared with the first or second embodiment, a plurality of optical networks 2500 and 2600 are connected in series between a site A 1300 and a site B 1400, and further, the optical networks 2500 and The difference is that a network (for example, the Internet 3000) using electrical signals is connected between the 2600s. Note that the same reference numerals are given to components that perform the same operations as in the first or second embodiment, and description thereof will be omitted.
[0075]
The site A1300 is connected to the site B1400 via the optical network A2500, the Internet 3000, and the optical network B2600. The optical network A2500 includes transfer devices A, B, C, and D1500, and the optical network B2600 includes transfer devices E, F, G, and H1500.
[0076]
The Internet 3000 is a network configured from a public IP network or the like, and includes core routers A, B, and C3010. The core router A3010 is connected to the transfer device D of the optical network A2500, and the transfer device D functions as a gateway device connecting the optical network A2500 and the Internet 3000. The core router C3010 is connected to the transfer device E of the optical network B2600, and the transfer device E functions as a gateway device that connects the optical network B2600 and the Internet 3000.
[0077]
In the third embodiment, as in the first embodiment, the optical network A 2500 and the optical network B 2600 include a data plane including a wavelength λ1 (default channel) and a wavelength λ2 (transfer channel), and a wavelength λ3. And a control plane composed of The data plane is an optical network for mainly transferring data, and is a circuit switching type network in which a line for transferring data needs to be set in advance. On the other hand, the control plane is an optical network for transferring a control signal (packet) between transfer devices, and is a packet transfer type network.
[0078]
Next, an operation when the communication system of the third embodiment transfers data will be described.
[0079]
The setting of the optical path and the data transfer from the site A1300 to the optical network A2500 and from the optical network B2600 to the site B1400 are similar to those of the first and second embodiments. The file is transferred via the optical path set by the transfer request.
[0080]
In the area of the Internet 3000 between the transfer device D1500 and the transfer device E1500, a file is transferred by specifying a path between core routers by applying a label technology such as MPLS (Multi-Protocol Label Switch).
[0081]
The optical path setting request packet transmitted from the gateway router A to the gateway router B 1420 first sets an optical path from the transfer device A 1500 to the transfer device D 1500 in the optical network A 2500. When the optical path of the optical network A 2500 is set, the transfer device D 1500 adds an MPLS label to the optical path setting request packet and sends the packet to the Internet 3000. The core router A 3010 of the Internet 3000 transfers the received optical path setting request to the core router B or C 3010, and the core router B 3010 transfers the received optical path setting request to the core router C 3010. The core router C3010 sends the received optical path setting request to the optical network B2600. The transfer device E1500 of the optical network B2600 changes the received packet to an optical path setting request packet again, and sets an optical path from the transfer device E1500 to the transfer device H1500 according to the contents of the optical path setting request packet.
[0082]
At this time, the content of Token set in the gateway router B1420 includes information indicating each of the path of the optical path of the optical network A2500, the path of the optical path of the optical network B2600, and the path of the Internet 3000. Note that the route information of the Internet 3000 is not always necessary.
[0083]
In the third embodiment, similarly to the above-described embodiment, the optical path setting notification and the file transfer request can be transmitted simultaneously or the optical path setting notification can be sent prior to the file transfer request.
[0084]
In the communication system according to the third embodiment configured as described above, when data is transferred via a plurality of optical networks 2500 and 2600 and a public IP network such as the Internet, a data transfer request is issued. Or an optical path setting request is sent together with the data transfer request, and the data is transferred via the optical path set based on the setting request, so that the data is transferred in the same manner as in the first or second embodiment. Since the optical path is set before the transfer is started, the time from when data is requested to when the optical path is set can be reduced, and the throughput of data transfer can be improved.
[0085]
<Fourth embodiment>
Next, a communication system according to a fourth embodiment will be described.
[0086]
FIG. 10 is a network configuration diagram of the communication system according to the fourth embodiment.
[0087]
In the fourth embodiment, a client and a server are directly connected in parallel by an optical network and an electrical communication network (for example, the Internet), a request from the client to the server is transmitted via the Internet, and a request from the server to the client is transmitted. The transmission of data is configured to take place over an optical network. Note that the same reference numerals are given to components that perform the same operations as those in the first to third embodiments, and descriptions thereof are omitted.
[0088]
The client 10 is connected to the server 20 via the Internet 100 and the optical network 200. The Internet 100 is configured by a public IP network or the like, and includes an edge router A110, an edge router B110, and a core router 120.
[0089]
The optical network 200 includes a plurality of optical cross-connects OXC A, B, C, and D210. The OXCs 210 are connected to each other by optical fibers, and can be used by dividing one optical fiber into a plurality of channels by WDM. The OXC 210 includes a wavelength management control unit (control plane) and a data transfer unit (data plane). The wavelength management control unit analyzes the received control packet, transmits a control signal to the WDM in-band, and sets a mutual optical path among the OXCs A, B, C, and D210.
[0090]
The client 10 and the edge router A110 are connected using a connection line 150, and the server 20 and the edge router B110 are connected using a connection line 155. As the protocol of the connection lines 150 and 155, Ethernet which is an L2 protocol is used.
[0091]
Further, the client 10 and the OXC A 210 are connected via a connection line 160, and the server 20 and the OXC D 210 are connected via a connection line 165. As the protocol of the connection lines 160 and 165, Ethernet or SDH / SONET (Synchronous Digital Hierarchy / Synchronous Optical Network) which is an L2 protocol is used.
[0092]
The client 10 includes an OS and application software, and generates an IP packet for the edge router 110 and a control packet for the OXCA 210 by the application software. For example, when the server 20 is a web server, the client 10 generates a request packet including an http request. Further, the client 10 generates a control packet in which information such as the physical address, link ID, and channel ID of the OXC 210 is embedded, and sends the control packet to the edge router A110 and the OCX A210, respectively.
[0093]
When the server 20 is a storage device, the client 10 transmits a packet including a protocol (for example, a SCSI command or an application-specific command) for requesting a backup or a restore to the edge router 110.
[0094]
In the fourth embodiment, as in the first embodiment, the optical network 200 includes a data plane including a wavelength λ1 (default channel) and a wavelength λ2 (transfer channel) and a control plane including a wavelength λ3. And is constituted by. The data plane is an optical network for mainly transferring data, and is a circuit switching type network in which a line for transferring data needs to be set in advance. On the other hand, the control plane is an optical network for transferring a control signal (packet) between the OXCs 210, and is a packet transfer type network. The Internet 100 is also an electrical communication network for transferring control signals (packets) between the client 10 and the server 20, and functions as a packet transfer type network.
[0095]
Next, an operation when the communication system of the fourth embodiment transfers data will be described.
[0096]
FIG. 11 is a sequence diagram showing a process of transmitting a request 40 for setting an optical path of an optical network simultaneously with a request for data transfer and transferring 50 data via the set optical path in the fourth embodiment. It is. The left side of the figure shows the flow of processing in the Internet 100, and the right side shows the flow of processing in the optical network 200.
[0097]
First, the client 10 sends a file transfer request packet 30 encapsulating a file transfer request to the server 20 to the edge router A110. The edge router A 110 sends the file transfer request packet 30 to the core router 120 according to the route table included in the request packet 30. The core router 120 similarly sends the file transfer request packet 30 to the edge router B110, and the edge router B110 sends the file transfer request packet 30 to the server 20. The time at which the IP packet is transferred from the client 10 to the server 20 at this time is T14.
[0098]
On the other hand, the client 10 sends the file transfer request packet 30 to the server 20 and also transfers the optical path setting request packet 40 to the OXC A 210 as a control packet. The optical path setting request packet 40 includes a Path message. The Path message includes information such as a request source, a request destination, and a necessary line bandwidth. Each OCX 210 receives the optical path setting request packet 40 and determines a wavelength and a route to be used according to the content of the Path message included in the optical path setting request packet 40, so that an optical path from OXC A to D 210 is set. When the optical path setting request packet 40 arrives at the server 20, the setting of the path of the optical path in the optical network 200 is completed. The time at which the optical path setting request packet 40 is transferred from the client 10 to the server 20 at this time is T15.
[0099]
Next, in the case of T15 <= T14, since the optical path has already been set, the server 20 transfers the file requested by the request packet 30 via the optical path set in the optical network 200. Start. If T15> T14, the optical path has not yet been set when the file transfer request packet 30 reaches the server 20, so the request is made after the elapse of T15 (after the setting of the optical path is confirmed). The transfer of the file requested by the packet 30 is started.
[0100]
In the sequence of FIG. 11, the procedure has been described using an example using the One-Way scheme. However, in the case of using the Two-Way scheme, the optical path setting from the server 20 to the client 10 is completed when the optical path setting is completed. A notification packet is sent.
[0101]
After the file transfer is completed, a predetermined timeout period is provided, and when this period elapses, the client 10 transmits the optical path release packet 60 to the server 20 and releases the set optical path. .
[0102]
According to the above procedure, the data of the server 20 can be transferred in response to a request from the client 10.
[0103]
In the fourth embodiment, similarly to the above-described embodiment, an optical path setting notification can be sent prior to a file transfer request.
[0104]
In the communication system according to the fourth embodiment configured as described above, when a client and a server transfer data via a network directly connected to the optical network 200 and the Internet 100 in parallel. At the same time, a data transfer request is sent to the Internet 100 or, prior to sending a data transfer request to the Internet 100, an optical path setting request is sent to the optical network, and the setting is performed based on the setting request. Since the data is transferred via the optical path, the optical path is set before the data transfer is started, as in the first to third embodiments. The time until the optical path is set can be reduced, and the data transfer throughput can be improved.
[0105]
For example, when the connection lines 150 and 155 are connected by 100 Mbit / sec Ethernet and the connection lines 160 and 165 are connected by 10 Gbit / sec SDH / SONET, T14 is approximately 50 milliseconds, and T15 is About 10 milliseconds. Here, when transferring a 10-Mbyte file from the server 20 to the client 10, T16 is about 8 milliseconds, so T14 + T16 is about 58 milliseconds. Comparing this with the conventional case in which file transfer is performed via the Internet or the like without using the optical network 200, since T17 is about 800 milliseconds, the time from when the client 10 issues a file transfer request to when a file is received is received. T14 + T17 is about 850 milliseconds, and the data transfer throughput can be improved.
[0106]
<Fifth embodiment>
Next, a communication system according to a fifth embodiment will be described.
[0107]
FIG. 12 is a network configuration diagram of the communication system according to the fifth embodiment.
[0108]
In the fifth embodiment, a site A 1300 and a site B 1400 are connected in parallel by an optical network 200 and an electrical communication network (for example, the Internet 100). Note that components that perform the same operations as those in the first to fourth embodiments are given the same reference numerals, and descriptions thereof will be omitted.
[0109]
The site A 1300 and the site B 1400 are connected via the Internet 100 and the optical network 200.
[0110]
The site A1300 includes a client 1310, a gateway router A320, and a terminal 1330. The gateway router A320 is a router device that connects the IP network and the optical network and exchanges data with each other.
[0111]
The site B1400 includes a server 1410, a gateway router B420, and a terminal 1430. Like the gateway router A320, the gateway router B1420 is a router device that connects the IP network and the optical network and exchanges data with each other.
[0112]
The gateway router A320 and the edge router A110 are connected using a connection line 150, and the gateway router B420 and the edge router B110 are connected using a connection line 155. As the protocol of the connection lines 150 and 155, Ethernet which is an L2 protocol is used.
[0113]
The gateway router A320 and the OXC A210 are connected via the connection line 160, and the gateway router B420 and the OXC D210 are connected via the connection line 165. As the protocol of the connection lines 160 and 165, Ethernet or SDH / SONET (Synchronous Digital Hierarchy / Synchronous Optical Network) which is an L2 protocol is used.
[0114]
In the fifth embodiment, as in the first embodiment, the optical network 200 includes a data plane including a wavelength λ1 (default channel) and a wavelength λ2 (transfer channel), and a control plane including a wavelength λ3. And is constituted by. The data plane is an optical network for mainly transferring data, and is a circuit switching type network in which a line for transferring data needs to be set in advance. On the other hand, the control plane is an optical network for transferring a control signal (packet) between transfer devices, and is a packet transfer type network. The Internet 100 is also an electrical communication network for transferring control signals (packets) between the gateway router A 320 and the gateway router B 420, and functions as a packet transfer type network.
[0115]
FIG. 13 is a block diagram illustrating gateway routers A320 and B420 according to the fifth embodiment.
[0116]
The gateway routers A320 and B420 include input line interfaces 510 to 51n, WDM input line interfaces 520 to 52n, a token generation unit 530, a packet analysis unit 540, a route control unit 550, an optical path setting determination unit 560, a management information unit 570, and an IP. It comprises a packet assembling section 580, a control packet generating section 590, a frame converting section 600, a switch section 610, output line interfaces 620-62n, WDM output line interfaces 630-63n, 640-64n.
[0117]
The token generation unit 530 generates a token indicating whether an optical path has been set. The packet analysis unit 540 analyzes the header of each layer of L2, L3, L4, and L7 defined in the OSI reference model. The route control unit 550 determines the route of the packet based on the route table of the received packet. The optical path setting determination unit 560 determines whether to send the packet to the Internet 100 or to send the packet to the Internet 100 and generate a control packet to send to the optical network 200.
[0118]
The management information unit 570 holds management information of each OXC 210 provided in the optical network 200. This management table includes adjacent OXC management information, link management information, label management information, and the like.
[0119]
The IP packet assembling unit 580 replaces the L3 header in order to transfer the received packet. Further, the control packet generator 580 generates a control packet to be sent to the optical network 200 described above. The frame conversion unit 600 performs frame conversion (for example, frame conversion from IP / Ethernet to IP / SONET) according to the connection line type.
[0120]
Next, an operation when the communication system of the fifth embodiment performs data transfer will be described.
[0121]
FIG. 14 is a sequence diagram showing a process of transmitting a request for setting an optical path of an optical network simultaneously with a request for data transfer and transferring data via the set optical path in the fifth embodiment. . As in FIG. 11, the left side of the figure shows the flow of processing in the Internet 100, and the right side shows the flow of processing in the optical network 200.
[0122]
The client A1310 sends a request packet encapsulating the file transfer request to the gateway router A320. Upon receiving this request packet, the gateway router A 320 sends a file transfer request packet 70 for requesting a file transfer to the gateway router B 420 according to the contents of the request packet. This file transfer request packet 70 is sent to the gateway router B420 via the edge router A110, the core router 120, and the edge router B110. The time at which the file transfer request packet 70 is transferred from the gateway router A320 to the gateway router B420 at this time is T14.
[0123]
On the other hand, the gateway router A 320 sends the file transfer request packet 70 to the edge router 110 and also sends an optical path setting request packet 80 as a control packet for requesting the OXC 210A to set an optical path. In each of the OXCs A, B, C, and D210, as described above with reference to FIG. 11, the wavelength and the route to be used are determined according to the content of the Path message included in the optical path setting request packet 80, and the optical path from the OXC A to the D210 is determined. Is set. When the optical path setting request packet 80 is sent to the gateway router B420, the gateway router B420 generates Token. At this time, the time during which the optical path setting request packet 80 is transferred from the gateway router A 1320 to the gateway router B 420 is T15.
[0124]
Next, as in FIG. 11, in the case of T15 <= T14, since the optical path has already been set, the server 20 sends the request by the request packet 30 via the optical path set in the optical network 200. Transfer of the specified file is started. If T15> T14, the optical path has not yet been set when the file transfer request packet 30 reaches the server 20, so the request is made after the elapse of T15 (after the setting of the optical path is confirmed). The transfer of the file requested by the packet 30 is started.
[0125]
As in the case of FIG. 11, the procedure of FIG. 14 has been described using an example in which the One-Way system is used. However, in the case of using the Two-Way system, when the setting of the optical path is completed, the server 20 sends the client 10 Is notified of the optical path setting.
[0126]
Next, the operation of the gateway router will be described.
[0127]
FIG. 15 is a flowchart illustrating a process of the optical path setting determination unit 560 of the gateway routers 320 and 420 according to the fifth embodiment.
[0128]
First, it is determined whether or not there is a flag in the option 1813 (see FIG. 4) area of the L3 header of the input packet (processing 1501). If it is determined that there is no flag, the packet is sent to the IP packet assembling unit 580 and sent to the Internet 100 via the output interface (process 1504).
[0129]
On the other hand, when it is determined that there is a flag, it is determined whether or not there is a token. If there is a token, the setting of the optical path is completed and the token is being held between the gateway routers, and it can be seen that the setting of the optical path has already been completed. Then, the packet is sent to the optical network 200 (process 1503).
[0130]
On the other hand, if there is no token in process 1504, it is necessary to set the optical path requested to the optical network 200, so the control packet generator 590 generates a control packet for setting the optical path (process 1505). ), And sends this control packet to the optical network 200 (process 1506).
[0131]
In the fifth embodiment, similarly to the above-described embodiment, an optical path setting notification can be sent prior to a file transfer request.
[0132]
In the communication system according to the fifth embodiment configured as described above, when data is transferred in a network constituted by the optical network 200 and a public IP network such as the Internet, a data transfer request is sent to the Internet 100. Before transmitting the data to the Internet 100, the optical path setting request is transmitted to the optical network, and the data is transmitted via the optical path set based on the setting request. Therefore, similarly to the first to fourth embodiments, since the optical path is set before the data transfer is started, the time from when the data is requested to when the optical path is set can be reduced. , Can improve data transfer throughput
<Sixth embodiment>
Next, a communication system according to a sixth embodiment will be described.
[0133]
FIG. 16 is a network configuration diagram of the communication system according to the sixth embodiment.
[0134]
In the sixth embodiment, the site A1300 and the site B1400 are connected in parallel by the optical network 200 and the electrical communication network (for example, the Internet 100) as in the fifth embodiment. The difference is that A2320 and B2420 are not directly connected to the optical network 200. Note that the same reference numerals are given to components that perform the same operations as those in the first to fifth embodiments, and description thereof will be omitted.
[0135]
Site A 1300 and site B 1400 are connected via the Internet 100 and the optical network 200.
[0136]
The site A1300 includes a client 1310, a gateway router A2320, and a terminal 1330. The gateway router A2320 is a router device that is connected to the IP network and exchanges data with each other.
[0137]
The site B1400 includes a server 1410, a gateway router B2420, and a terminal 1430. Like the gateway router A2320, the gateway router is connected to and connected to the IP network and exchanges data with each other.
[0138]
The Internet 100 includes an edge router A 130, a core router 120, and an edge router B 130.
[0139]
The gateway router A2320 and the edge router A130 are connected using a connection line 150, and the gateway router B2420 and the edge router B130 are connected using a connection line 155. As the protocol of the connection lines 150 and 155, Ethernet which is an L2 protocol is used.
[0140]
Further, the edge router A 130 and the OXC A 210 are connected via a connection line 160, and the edge router B 130 and the OXC D 210 are connected via a connection line 165. As the protocol of the connection lines 160 and 165, Ethernet or SDH / SONET, which is an L2 protocol, is used.
[0141]
In the sixth embodiment, as in the first embodiment, the optical network 200 includes a data plane including a wavelength λ1 (default channel) and a wavelength λ2 (transfer channel) and a control plane including a wavelength λ3. And is constituted by. The data plane is an optical network for mainly transferring data, and is a circuit switching type network in which a line for transferring data needs to be set in advance. On the other hand, the control plane is an optical network for transferring a control signal (packet) between transfer devices, and is a packet transfer type network. The Internet 100 is also an electrical communication network for transferring control signals (packets) between the gateway router A 2320 and the gateway router B 2420, and functions as a packet transfer type network.
[0142]
Next, an operation when the communication system of the sixth embodiment performs data transfer will be described.
[0143]
In the present embodiment, the client 1310 sends a packet encapsulating the file transfer request to the gateway router 2320A, and the gateway router 3A220 that has received this packet sends the packet to the edge router A130 according to the contents of the packet.
[0144]
The edge router A130 analyzes the received packet, sends a file request packet to the core router 120, and sends a control packet including an optical path setting request to the OXC A210. This process is the same as the process described above with reference to FIG. 15, and a description thereof will be omitted. Also, the flow of processing for transferring a file by a file transfer request packet and setting an optical path by an optical path setting request packet is the same as the trend of the processing described above with reference to FIG.
[0145]
Also in the sixth embodiment, similarly to the above-described embodiment, the optical path setting notification and the file transfer request can be sent simultaneously, or the optical path setting notification can be sent prior to the file transfer request.
[0146]
In the communication system according to the sixth embodiment configured as described above, similarly to the fifth embodiment, the communication system includes the optical network 200 and the public IP network such as the Internet, and performs data transfer in the network. At this time, a data transfer request is sent to the Internet 100 or an optical path setting request is sent to the optical network prior to sending a data transfer ball to the Internet 100, and based on the setting request, Since the data transfer is performed via the optical path set by the user, the optical path is set before the data transfer starts, so the time from when the data is requested to when the optical path is set is reduced. Thus, the data transfer throughput can be improved.
[0147]
<Seventh embodiment>
Next, a communication system according to a seventh embodiment will be described.
[0148]
FIG. 17 is a network configuration diagram of the communication system according to the seventh embodiment.
[0149]
In the seventh embodiment, the site A 1300 and the site B 1400 are connected in parallel by the optical network 200 and the electrical communication network (for example, the Internet 100) as in the sixth embodiment. The difference is that the router 130 and the OXC 210 are provided with an integrated packet transfer device 170. Note that the same reference numerals are given to components that perform the same operations as those in the first to sixth embodiments, and description thereof will be omitted.
[0150]
The Internet 100 and the optical network 200 are provided with a packet transfer device 170A in which an edge router 130A and an OXC A210 are integrated, and a packet transfer device 170B in which an edge router 130B and an OXC D210 are integrated.
[0151]
The site A 1300, the site B 1400, the Internet 100, and the optical network 200 are connected via packet transfer devices 170A and 170B having the functions of the edge router 130 and the OXC 210. The gateway router A2320 and the packet transfer device 170A are connected by a connection line 150, and the gateway router B2420 and the packet transfer device 170B are connected by a connection line 155. For the connection lines 150 and 155, Ethernet, SDH / SONET, or the like is used.
[0152]
In the seventh embodiment, as in the first embodiment, the optical network 200 includes a data plane including a wavelength λ1 (default channel) and a wavelength λ2 (transfer channel), and a control plane including a wavelength λ3. And is constituted by. The data plane is an optical network for mainly transferring data, and is a circuit switching type network in which a line for transferring data needs to be set in advance. On the other hand, the control plane is an optical network for transferring a control signal (packet) between transfer devices, and is a packet transfer type network. The Internet 100 is also an electrical communication network for transferring control signals (packets) between the gateway router A 2320 and the gateway router B 2420, and functions as a packet transfer type network.
[0153]
FIG. 18 is a block diagram of a packet transfer device 170 according to the seventh embodiment.
[0154]
The packet transfer device 170 includes an input line interface 910-91n, a WDM input line interface 920-92n, a token generation unit 930, a packet analysis unit 940, a path control unit 950, an optical path setting determination unit 960, a management information unit 970, and an IP packet. It comprises an assembling unit 980, a control packet generation unit 990, a frame conversion unit 1001, a switch unit 1010, an optical switch control unit 1020, output line interfaces 1030 to 103n, WDM output line interfaces 1040 to 104n, and 1050 to 105n. The switch unit 1010 includes an electric switch 1011 and an optical switch 1012. The optical switch 1012 is configured by an optical device such as a MEMS, and switches an optical line (channel) according to an instruction from the optical switch control unit 1020.
[0155]
Next, the operation of the communication system including the packet transfer device 170 will be described.
[0156]
The client 1310 transfers the packet encapsulating the file transfer request to the gateway router A2320, and the gateway router A2320 that has received the packet further sends an IP packet to the packet transfer device A170.
[0157]
The packet transfer device A 170 analyzes the received packet, generates an optical path setting request packet as a control packet when the received packet includes an optical path setting request, and sends it to the OXCB or C210. The optical path is set by reserving the wavelength of the optical line from the packet transfer apparatus A 170 to the packet transfer apparatus B 170 by the optical path setting request packet. When the setting of the optical path is completed, the token is stored between the packet transfer apparatuses A and B170.
[0158]
On the other hand, the packet transfer device A 170 sends an optical path setting request packet and sends a file transfer request packet including a message requesting file transfer to the core router 120. This file transfer request packet is sent to the server 1410 via the core router 120, the packet transfer device B170, and the gateway router B2420 according to the route table included in the packet. The server 1410 sends the requested file to the gateway router B2420 according to the contents of the file transfer request packet, and the gateway router B2420 sends this file to the packet transfer device B170. The packet transfer apparatus B 170 confirms the token and checks whether an optical path is set, and sends the file to the packet transfer apparatus A 170 via the set optical path. The packet transfer device A170 sends the received file to the client 1310 via the gateway router A2320.
[0159]
According to the above procedure, a file from the server 1410 can be obtained in response to a request from the client 1310.
[0160]
Also in the seventh embodiment, similarly to the above-described embodiment, the optical path setting notification and the file transfer request can be sent simultaneously or the optical path setting notification can be sent prior to the file transfer request.
[0161]
In the communication system of the seventh embodiment configured as described above, similarly to the sixth embodiment, the communication system is configured by the optical network 200 and a public IP network such as the Internet, and transfers data in the network. At this time, a data transfer request is sent to the Internet 100 or, prior to sending a data transfer request to the Internet 100, an optical path setting request is sent to the optical network, and based on the setting request, Since the data transfer is performed via the optical path set by the user, the optical path is set before the data transfer starts, so the time from when the data is requested to when the optical path is set is reduced. Can be reduced and the data transfer throughput can be improved.
In particular, since the Internet 100 and the optical network 200 are connected by the packet transfer device 170, the optical network and the existing Internet can be comprehensively controlled.
[0162]
In the first to seventh embodiments described above, the description has been made using Ethernet and SDH / SONET as connection lines. However, the present invention is not limited to these protocols. Protocols such as a high-speed serial interface that will be put into practical use in the future can be applied.
[Brief description of the drawings]
FIG. 1 is a network configuration diagram of a communication system according to a first embodiment of this invention.
FIG. 2 is a block diagram of a transfer device 1500 according to the first embodiment.
FIG. 3 is a sequence diagram illustrating a data transfer process according to the first embodiment.
FIG. 4 is a format diagram of a packet transmitted from a client 1310 to a gateway router A 1320 according to the first embodiment.
FIG. 5 is a flowchart illustrating a process of an optical path setting determination unit 2130 of the transfer device 1500 according to the first embodiment.
FIG. 6 is a sequence diagram illustrating a data transfer process according to the first embodiment.
FIG. 7 is a network configuration diagram of a communication system according to a second embodiment of this invention.
FIG. 8 is a sequence diagram illustrating a data transfer process according to the second embodiment.
FIG. 9 is a network configuration diagram of a communication system according to a third embodiment of this invention.
FIG. 10 is a network configuration diagram of a communication system according to a fourth embodiment of the present invention.
FIG. 11 is a sequence diagram illustrating a data transfer process according to the fourth embodiment.
FIG. 12 is a network configuration diagram of a communication system according to a fifth embodiment of the present invention.
FIG. 13 is a block diagram of gateway routers A320 and B420 according to the fifth embodiment.
FIG. 14 is a sequence diagram illustrating a data transfer process according to the fifth embodiment.
FIG. 15 is a flowchart illustrating a process of the optical path setting determination unit 560 of the gateway router 320 according to the fifth embodiment.
FIG. 16 is a network configuration diagram of a communication system according to a sixth embodiment of the present invention.
FIG. 17 is a network configuration diagram of a communication system according to a seventh exemplary embodiment of the present invention.
FIG. 18 is a block diagram illustrating a packet transfer device 170 according to the seventh embodiment.
[Explanation of symbols]
10, 1310 Client
20, 1410 server
100 Internet
110A, 110B, 130A, 130B Edge router
120 core router
170 Packet transfer device
200, 1000, 2500, 2600 Optical network
210 Optical Cross Connect
320, 1320, 2320 Gateway router A
420, 1420, 2420 Gateway router B
1330, 1430 Terminal
1500 transfer device

Claims (22)

A communication method performed between a first transfer device and a second transfer device connected by a packet-switched network for performing packet communication and a circuit-switched network that requires line setting prior to data communication. hand,
When the first transfer device requests data, transmits a line setting request for setting a line in the circuit-switched network via the packet-switched network;
The first transfer device and the second transfer device hold line setting information set based on the line setting request until a data request from the first transfer device reaches the second transfer device. ,
The communication method, wherein the second transfer device transmits the requested data to the first transfer device via a line set based on the line setting request. 2. The first transfer device and the second transfer device hold the setting information when a data request from the first transfer device reaches the second transfer device. Communication method described in. The first transfer device and the second transfer device are connected by an optical multiplex transmission network,
A control plane of the optical multiplex transmission network functions as the packet-switched network;
The communication method according to claim 1, wherein a data plane of the optical multiplex transmission network functions as the circuit-switched network. 2. The communication method according to claim 1, wherein, after receiving the response to the data request, the first transfer device transmits a line release request requesting release of a line set by the line setting request. . The communication method according to claim 4, wherein the first transfer device transmits the line opening / release request when data is not transmitted from the second transfer device for a predetermined time. The communication according to claim 1, wherein the first transfer device transmits the line setting request via the packet-switched network before requesting data to the second transfer device. Method. The packet-switched network is capable of transferring control packets at a higher speed than the circuit-switched network before the line for data transmission is set, and the first transfer device performs the second transfer. 2. The communication method according to claim 1, further comprising transmitting the line setting request via the packet switching network together with a data request to the device. The first transfer device and the second transfer device are connected via a plurality of serially connected optical multiplex transmission networks,
The optical multiplex transmission network uses a network configured by a data plane that functions as a circuit-switched network that requires line setting prior to data communication, and a control plane that functions as a packet-switched network. A communication method performed between a first transfer device and the second transfer device,
When the first transfer device requests data, transmits a line setting request for setting a line in the circuit-switched network via the packet-switched network;
The first transfer device and the second transfer device hold line setting information set based on the line setting request until a data request from the first transfer device reaches the second transfer device. ,
The communication method, wherein the second transfer device transmits the requested data to the first transfer device via a line set based on the line setting request. The first transfer device and the second transfer device are connected via a network in which a first optical multiplex transmission network, a packet communication network, and a second optical multiplex transmission network are serially connected;
The optical multiplex transmission network uses a network configured by a data plane that functions as a circuit-switched network that requires line setting prior to data communication, and a control plane that functions as a packet-switched network. A communication method performed between a first transfer device and the second transfer device,
When the first transfer device requests data, transmits a line setting request for setting a line in the circuit-switched network via the packet-switched network;
The first transfer device and the second transfer device hold line setting information set based on the line setting request until a data request from the first transfer device reaches the second transfer device. ,
The communication method, wherein the second transfer device transmits the requested data to the first transfer device via a line set based on the line setting request. A first computer and a second computer connected by an optical multiplex transmission network and a first packet-switched network;
The optical multiplex transmission network used a network constituted by a data plane functioning as a circuit-switched network requiring a line setting before data communication, and a control plane functioning as a second packet-switched network. , A communication method performed between the first computer and the second computer,
The first computer comprises:
Via the second packet-switched network, transmitting a line setting request for setting a line in the circuit-switched network;
And requesting the second computer to transmit data via the first packet-switched network;
The second computer comprises:
A communication method, wherein the requested data is transmitted to the first computer via a line set based on the line setting request. A first transfer device and a second transfer device connected by an optical multiplex transmission network and a first packet-switched network;
The optical multiplex transmission network used a network constituted by a data plane functioning as a circuit-switched network requiring a line setting before data communication, and a control plane functioning as a second packet-switched network. , A communication method performed between the first transfer device and the second transfer device,
The first transfer device includes:
Via the second packet-switched network, transmitting a line setting request for setting a line in the circuit-switched network;
And requesting the second transfer device to transmit data via the first packet-switched network;
The second transfer device includes:
A communication method, wherein the requested data is transmitted to the first transfer device via a line set based on the line setting request. A first transfer device and a second transfer device are connected by a first packet-switched network;
In the first packet-switched network, at least two connection devices are connected by an optical multiplex transmission network,
The optical multiplex transmission network used a network constituted by a data plane functioning as a circuit-switched network requiring a line setting before data communication, and a control plane functioning as a second packet-switched network. , A communication method performed between the first transfer device and the second transfer device,
The first transfer device includes:
Via the second packet-switched network, transmitting a line setting request for setting a line in the circuit-switched network;
And requesting the second transfer device to transmit data via the first packet-switched network;
The second transfer device includes:
A communication method, wherein the requested data is transmitted to the first transfer device via a line set based on the line setting request. A first transfer device and a second transfer device are connected by a network via a connection device;
The connection devices are connected by an optical multiplex transmission network and a first packet switching network,
The optical multiplex transmission network used a network constituted by a data plane functioning as a circuit-switched network requiring a line setting before data communication, and a control plane functioning as a second packet-switched network. , A communication method performed between the first transfer device and the second transfer device,
The first transfer device includes:
Via the second packet-switched network, transmitting a line setting request for setting a line in the circuit-switched network;
And requesting the second transfer device to transmit data via the first packet-switched network;
The second transfer device includes:
A communication method, wherein the requested data is transmitted to the first transfer device via a line set based on the line setting request. At least a communication method performed between a first transfer device and a second transfer device connected by a circuit-switched network requiring a line setting prior to data communication,
When the first transfer device requests data through the circuit-switched network, the first transfer device uses a line controlled by a different transfer control method to request a line setting request for setting a line in the circuit-switched network. A communication method characterized by transmitting. A data communication system comprising a first transfer device and a second transfer device connected by a packet-switched network for performing packet communication and a circuit-switched network that requires line setting prior to data communication. hand,
The first transfer device includes:
When requesting data, via the packet-switched network, a line setting request transmitting means for transmitting a line setting request for requesting a line setting in the circuit-switched network,
Setting information holding means for holding the setting information of the line set based on the line setting request,
The second transfer device includes:
Setting information holding means for holding line setting information set based on the line setting request until a data request from the first transfer device reaches the second transfer device;
Data transmission means for transmitting data requested by the first transfer device to the first transfer device via a line set based on the line setting request. Data communication system. The setting information holding means, wherein when the data request from the first transfer device reaches the second transfer device, the first transfer device and the second transfer device hold the setting information. The data communication system according to claim 15, wherein: The first transfer device and the second transfer device are connected by an optical multiplex transmission network,
A control plane of the optical multiplex transmission network functions as the packet-switched network;
The data communication system according to claim 15, wherein a data plane of the optical multiplex transmission network functions as the circuit-switched network. The first transfer device further comprises a line release request unit that transmits a line release request for requesting release of the line set by the line setting request after receiving the response to the data request. 16. The data communication system according to 15. 19. The data communication system according to claim 18, wherein said circuit release requesting means transmits said circuit release request when data is not transmitted from said second transfer device for a predetermined time. 16. The data communication according to claim 15, wherein the line setting request unit transmits the line setting request via the packet switching network before requesting data to the second transfer device. system. The packet-switched network can transfer a control packet at a higher speed than the circuit-switched network before the line for data transmission is set. 16. The data communication system according to claim 15, wherein the line setting request is transmitted via the packet-switched network together with a data request to the network. A data transfer device for connecting a computer device for transmitting and receiving data and an optical multiplex transmission network,
The optical multiplex transmission network is configured by a data plane that functions as a circuit-switched network that requires line setting prior to data communication, and a control plane that functions as a packet-switched network,
A control packet generator for generating a request for setting a line in the circuit-switched network;
Having a line setting information holding unit that generates setting information of the line set based on the generated line setting request,
A data transfer device for transferring data via the set line with reference to the line setting information holding unit.

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