JP6371321B2 - COMMUNICATION SYSTEM AND PACKET TRANSFER METHOD - Google Patents

Description

  The present invention relates to a technique for transferring a packet transmitted from a transmission source to a plurality of sites.

  In order to realize live distribution of concerts and sports, it is necessary to transmit video from one distribution source to many distribution destinations while making the encoder economical. In order to realize this, an example of performing IP multicast (MC) on the VPN using an IP-VPN that easily guarantees communication quality is widely seen.

  However, for telecommunications carriers, MC increases the system processing load and it is difficult to predict the demand. For this reason, additional charges are generally incurred when using MC. If the same operation as MC can be realized only by unicast (UC) in the VPN, further economy can be expected.

  On the other hand, in recent years, there has been a demand for realization of high processing performance sufficient to deliver Full HD live video (4810pps) to, for example, 48 prefectures. Conventional unicast technology cannot satisfy such performance conditions.

Naoto Fujii, "IP Multicast Technology," Internet Week 1999, December 15, 1999 Tim Stevenson, "Cisco Nexus 7000/7700 Switch Architecture," BRKARC-3470, pp. 47-57, CiscoLive 2015 San Diego, 2015 Takeshi Inoue, "Design and Implementation of a Multicast System Excellent for Phased Introduction by Flexcast," IEICE Transactions DI, Information and Systems, I-Information Processing, J88 (2): pp. 272-291, 2005 February 1 S. Tani and T. Miyazaki, and N. Takahashi, "Adaptive Stream Multicast Based on IP Unicast and Dynamic Commercial Attachment Mechanism: An Active Net-work Implementation," IWAN2001, pp.116-133, 2001.

  In order to transfer a single packet to multiple sites, it has been difficult to duplicate packets or rewrite header information flexibly because network devices were conventionally hardware-implemented from the viewpoint of performance. New protocol implementations such as protocols (Non-Patent Documents 1 and 2) and unicast copies (Non-Patent Documents 3 and 4) have been made and applied.

  However, for example, when using the IP multicast protocol, it is necessary to support the protocol of all network devices, and there are problems with the introduction of unicast copy, such as special terminal installation time and performance problems. there were. Specifically, it is as follows.

  In conventional multicast technology (Non-Patent Documents 1 and 2), a multicast tree from the distribution source to the distribution destination is autonomously configured, a special IP address is assigned to the packet, and the packet is transferred along the multicast tree. doing.

  In addition, in the conventional unicast copy technology (Non-Patent Documents 3 and 4), a multicast tree is manually / automatically configured using a tunneling protocol such as GRE, and packets are transferred along the multicast tree. . In this method, it is necessary to use VLAN technology such as VLAN / GRE in order to control the destination. As the MTU (Maximum Transmission Unit) is reduced and the header processing load is increased, the throughput decreases and the equipment cost increases. there is a possibility.

  The present invention has been made in view of the above points, and it is possible to transfer a packet transmitted from a transmission source to a plurality of bases without performing a special setting or the like for an existing device, which is necessary in the prior art. The purpose is to provide the technology.

According to an embodiment of the present invention, a communication system comprising a packet transfer device, a packet transfer control device, and a signal format checker connected to the packet transfer device,
The packet transfer control device sets a flow rule for the packet transfer device,
The packet forwarding device replicates the packet received from the packet transmitting device according to the flow rule, rewrites the destination address of each duplicated packet, and forwards each packet to each packet receiving device.
The signal format checker receives and monitors one of a plurality of packet flows transferred by the packet transfer device ;
The destination address is a destination IP address and a destination MAC address,
The packet transfer control device creates a flow rule having a destination IP address and a destination MAC address using a destination MAC address obtained by an ARP inquiry process based on a list of destination IP addresses, and transfers the flow rule to the packet transfer There is provided a communication system characterized by being set in an apparatus .

According to an embodiment of the present invention, there is provided a packet transfer method in a communication system including a packet transfer device, a packet transfer control device, and a signal format checker connected to the packet transfer device,
The packet transfer control device sets a flow rule for the packet transfer device;
The packet forwarding device replicating the packet received from the packet transmitting device according to the flow rule, rewriting the destination address of each duplicated packet, and forwarding each packet to each packet receiving device;
The signal format checker receiving and monitoring one of a plurality of packet flows transferred by the packet transfer device ; and
The destination address is a destination IP address and a destination MAC address,
In the step of setting the flow rule, the packet transfer control device creates a flow rule having a destination IP address and a destination MAC address using a destination MAC address obtained by an ARP inquiry process based on a list of destination IP addresses. Then, a packet transfer method is provided in which the flow rule is set in the packet transfer apparatus .

  According to the embodiment of the present invention, there is provided a technique that enables a packet transmitted from a transmission source to be transferred to a plurality of locations without performing special settings for existing devices, which was necessary in the prior art. Is done.

1 is an overall configuration diagram of a communication system according to an embodiment of the present invention. 1 is a configuration diagram of an SDN switch 100. FIG. 2 is a configuration diagram of a switch control device 200. FIG. It is a figure for demonstrating the procedure of operation | movement of a communication system. It is a figure which shows the example of a description of the action part of a flow entry. FIG. 6 is a diagram for explaining a packet transfer operation example 1; FIG. 11 is a diagram for explaining a packet transfer operation example 2; It is a figure which shows the structural example in the case of providing a monitoring function.

  Embodiments of the present invention will be described below with reference to the drawings. The embodiment described below is merely an example, and the form to which the present invention can be applied is not limited to the following embodiment. For example, in the following example, a configuration in which an encoder for video distribution and a plurality of decoders are connected is described, but this is only an example. The present invention is also applicable to various applications other than video distribution.

(System configuration)
FIG. 1 shows the overall configuration of a communication system according to an embodiment of the present invention. As shown in FIG. 1, in the communication system according to the present embodiment, an SDN (Software Defined Networking) switch 100 is arranged, and an image encoder 300 and a plurality of decoders 400 are connected to the SDN switch 100 via a network. It has the structure made. In the example of FIG. 1, an L3SW (layer 3 switch) 500 is also connected to the SDN switch 100. In the example of FIG. 1, the IP segment is divided on the input side and the output side.

  The SDN switch 100 includes a flow table (may be called a flow rule) having a match field (match part) and an action field (action part), and includes information such as headers of input packets and information described in the match field. If the two match, the action described in the action field (eg, rewrite the header and output from the predetermined port) is executed. The SDN switch 100 may be referred to as a packet transfer device.

  Moreover, as shown in FIG. 1, a switch control device 200 is provided. The switch control device 200 executes ARP (Address Resolution Protocol) execution control, flow table setting, and the like for the SDN switch 100. Note that the switch control device 200 may be referred to as a packet transfer control device. Further, the encoder 300 may be referred to as a packet transmission device, and the decoder 400 may be referred to as a packet reception device.

  In the communication system, the SDN switch 100 receives a packet (encoded data) transmitted from the transmission side, and the SDN switch 100 transmits the packet to a plurality of reception sides by unicast copying. More specifically, it is as follows.

  The input video is encoded by the encoder 300, and a packet of encoded data (destination = 192.168.99.1: 60002) is transmitted from the encoder 300 to the SDN switch 100 by unicast. The SDN switch 100 receives the packet from the port 3. The SDN switch 100 copies (duplicates) a packet for transmission to a plurality of destinations, rewrites the destination IP address and destination MAC address of the packet in accordance with each destination, and transmits the packet to each decoder 400. Note that the source IP address and the source MAC address of the packet may be rewritten in order to further support the transfer to another IP segment by the L3SW 500 or the like on the output side.

  Here, when the encoder 300 on the video distribution side transmits a packet to 192.168.99.1, the MAC address of the destination is required, so the encoder 300 executes ARP inquiring about the MAC address of 192.168.99.1. The MAC address is acquired from the SDN switch 100. On the other hand, the SDN switch 100 has a function of returning a corresponding MAC address in response to an ARP inquiry addressed to 192.168.99.1.

  In this embodiment, since the output side transmits the packet by unicast, as described above, the SDN switch 100 rewrites the destination IP address and the destination MAC address of the output packet in accordance with the destination of the packet. . Here, the destination MAC address is obtained by the SDN switch 100 (or the switch control device 200) executing an ARP inquiry specifying the destination IP address.

(Device configuration)
FIG. 2 shows a configuration diagram of the SDN switch 100 in the present embodiment. As illustrated in FIG. 2, the SDN switch 100 includes a packet reception unit 101, a packet match processing unit 102, an address conversion unit 103, a packet transmission unit 104, a flow table holding unit 105, and a switch control unit 106.

  The switch control unit 106 sets a flow table in the flow table holding unit 105 (eg, addition, replacement, deletion, modification, etc. of a flow entry) based on an instruction from the switch control device 200. When the packet receiving unit 101 receives the packet, the packet match processing unit 102 compares the packet information (eg, destination / source address, destination / source port number, etc.) with the match part of the flow table, and matches If there is an entry to be copied, the packet is copied.

  Then, the address conversion unit 103 performs address conversion for each packet according to the contents of the action part of the flow table, and the packet transmission unit 104 transmits the packet from the designated port. The above processing is an example. For example, the packet receiving unit 101 may perform packet copying, or the address conversion unit 103 may perform packet copying.

  For example, the packet receiving unit 101 and the packet transmitting unit 104 include a function of receiving an ARP inquiry and performing an ARP response, and a function of transmitting an ARP inquiry and receiving an ARP response. For example, in order for the switch control device 200 to grasp the MAC address of the video distribution destination, the switch control device 200 sends an ARP execution instruction together with the list of destination IP addresses to the switch control unit 106 of the SDN switch 100 to control the switch. The unit 106 instructs the packet transmission unit 104 and the packet reception unit 101 to make an ARP inquiry for each destination IP address in the list. For example, when the packet receiving unit 101 acquires MAC addresses corresponding to each destination IP address, it notifies them to the switch control unit 106, and the switch control unit 106 transmits the MAC address to the switch control device 200.

  FIG. 3 shows a configuration diagram of the switch control device 200 according to the present embodiment. As illustrated in FIG. 3, the switch control device 200 includes a distribution source / distribution destination list registration unit 201, a data storage unit 202, an ARP control unit 203, a flow table generation unit 204, and a flow table setting unit 205.

  The distribution source / destination destination list registration unit 201 receives a list of distribution source and distribution destination IP addresses from an operator terminal or the like, and stores the list in the data storage unit 202. The data storage unit 202 stores various data.

  The ARP control unit 203 stores in the data storage unit 202 the MAC address for the destination IP address obtained by the ARP execution instruction or ARP response to the SDN switch 100. The flow table generation unit 204 generates a flow table using the distribution source / distribution destination list and the MAC address acquired by the ARP control unit 203. The flow table setting unit 205 transmits (sets) the flow table generated by the flow table generation unit 204 to the SDN switch 100.

  The switch control device 200 according to the present embodiment can be realized, for example, by causing one or a plurality of computers to execute a program describing the processing content described in the present embodiment. That is, the function of the switch control device 200 is realized by executing a program corresponding to the processing executed by the switch control device 200 using hardware resources such as a CPU and a memory built in the computer. Is possible. The above-mentioned program can be recorded on a computer-readable recording medium (portable memory or the like), stored, or distributed. It is also possible to provide the program through a network such as the Internet or electronic mail. Note that the above program may not include a function related to each database.

  The SDN switch 100 can also be realized by causing one or a plurality of computers to execute a program describing the processing contents described in this embodiment.

  Further, both the switch control device 200 and the SDN switch 100 can be realized by using a hardware circuit (integrated circuit) incorporating processing.

(Operation procedure)
Next, an example of an operation procedure of the communication system in the present embodiment will be described along the procedure shown in the flowchart of FIG.

  First, a list of IP addresses of encoders serving as video distribution sources and IP addresses of a plurality of decoders serving as distribution destinations is input to a distribution source / distribution destination list registration unit 201 of the switch control device 200 by an operator or the like. The list is stored in the data storage unit 202 by the distribution source / distribution destination list registration unit 201.

  In step S102, the ARP control unit 203 transmits a list of distribution destination IP addresses to the SDN switch 100, thereby causing the SDN switch 100 to execute an ARP inquiry specifying each IP address of the distribution destination. The SDN switch 100 acquires the MAC address of each delivery destination decoder, and the MAC address is returned to the ARP control unit 203 of the switch control device 200. The ARP control unit 203 stores the MAC address in the data storage unit 202 in association with the destination IP address.

  In addition, when the source MAC address is also referred to at the time of the match processing at the time of rewriting the packet destination address, which will be described later, the ARP control unit 203 designates the distribution source IP address and instructs the SDN switch 100 to perform an ARP instruction. The source MAC address can be acquired.

  In the above example, the switch control apparatus 200 issues an ARP execution instruction to the SDN switch 100, and the SDN switch 100 executes ARP. Instead, the switch control apparatus 200 itself performs the distribution source encoder. / ARP for the destination decoder may be executed.

  Next, in step S103, the flow table generation unit 204 of the switch control device 200 uses the list of distribution source / destination IP addresses stored in the data storage unit 202 and the MAC address acquired in step S102. To create a flow table.

  FIG. 5 is a diagram illustrating an example of the action part of the flow table generated in step S103. Here, for example, assuming the example of FIG. 1, the matching part of the flow table is information including “source IP address: 192.168.99.10, destination IP address: 192.168.99.1, input port = port 3”. This means that when the source IP address of the packet input from the port 3 is 192.168.99.10 and the destination IP address is 192.168.99.1, the process described in the action part is executed. Note that the port number is also subject to the matching process and the address conversion process, but in this embodiment, the port number description is omitted for easy understanding of the process.

  The example of the action part shown in FIG. 5 shows an example in which a packet is distributed to two decoders by unicast copying. Specifically, the action unit copies “the packet for the packet matched with the match unit, and for the first packet (addressed to 192.168.0.101), the destination MAC address corresponding to 192.168.0.101 is 00: Rewrite to 00: 00: 00: 00: 01, rewrite the destination IP address to 192.168.0.101, output the rewritten packet from port 1, and for the second packet (addressed to 192.168.0.102) "The MAC address is rewritten to 00: 00: 00: 00: 00: 02 corresponding to 192.168.0.102, the destination IP address is rewritten to 192.168.0.102, and the rewritten packet is output from port 2." .

  The above is an example when there are two distribution destinations. If the distribution destination is N, N action parts as described above are set. In the present embodiment, the flow table generation unit 204 automatically generates a flow table, but an operator or the like may manually generate the flow table and input it to the switch control device 200.

  In step S104 of FIG. 4, the flow table setting unit 205 transmits the flow table generated in step S103 to the SDN switch 100. The switch control unit 106 of the SDN switch 100 receives the flow table and stores the flow table in the flow table holding unit 105.

  In step S105, packet transfer processing with reference to the flow table is started. That is, when the SDN switch 100 receives a packet transmitted from the encoder 300, the SDN switch 100 copies the packet for the number of distribution destinations, and rewrites the destination address for each packet as described in each entry of the flow table. And output from the specified output port.

(About packet transfer operation)
The packet transfer operation of the SDN switch 100 in the present embodiment includes packet sequential processing (packet sequential processing) and packet parallel processing (packet parallel processing). Hereinafter, these will be described as a packet transfer operation example 1 and a packet transfer operation example 2.

  FIG. 6 is a diagram for explaining a packet transfer operation example 1 (packet sequential processing). As shown in FIG. 6, in packet transfer operation example 1, packet copying, address rewriting, and packet output are executed sequentially. That is, for example, when there are three delivery destination decoders, decoder A, decoder B, and decoder C, the SDN switch 100 first copies a packet to be transferred to the decoder A in accordance with the flow table. The destination address is rewritten and output, then the packet to be transferred to the decoder B is copied, the destination address is rewritten and output, and then the packet to be transferred to the decoder C is copied and the destination address is rewritten, Output. Such a process is executed every time a packet is received from the encoder 300.

  In the example shown in FIG. 6, address rewriting is performed after the packet is copied. This process is realized, for example, by a process in which the packet receiving unit 101 shown in FIG. 2 temporarily stores received packets in a buffer, sequentially copies the packets, and passes the copy packets to the packet matching processing unit 102. The Alternatively, the packet matching processing unit 102 may temporarily store a packet in a buffer for a packet that matches the matching unit, copy the packet, and pass the copy packet to the address conversion unit 103.

  Further, in the packet match processing unit 102, for the packet matched with the match unit, the address conversion unit 103 may store the packet in a buffer and simultaneously perform packet copy and address rewriting.

  FIG. 7 is a diagram for explaining a packet transfer operation example 2 (packet parallel processing). As shown in FIG. 7, in the packet transfer operation example 2, packet copying, address rewriting, and packet output are executed in parallel. That is, for example, when there are three delivery destination decoders, decoder A, decoder B, and decoder C, the SDN switch 100 copies the input packet into three packets, and the packet to be transferred to the decoder A The destination address rewriting / output, the destination address rewriting / output of the packet transferred to the decoder B, and the destination address rewriting / output of the packet transferred to the decoder C are executed in parallel. Such a process is executed every time a packet is received from the encoder 300.

  In the example shown in FIG. 7, address rewriting is performed after the packet is copied. This process is realized, for example, by a process in which the packet receiving unit 101 shown in FIG. 2 copies a received packet and passes a plurality of copy packets to the packet match processing unit 102. Alternatively, the packet matching processing unit 102 may copy the packet for the packet that matches the matching unit and pass the multiple copy packet to the address conversion unit 103.

  Further, the packet matching processing unit 102 may perform a process in which the address conversion unit 103 simultaneously performs packet copying and address rewriting for a packet that matches the matching unit.

  In the case of supporting parallel processing, for example, the packet match processing unit 102 and the address conversion unit 103 illustrated in FIG. 2 are configured to be capable of parallel processing in hardware. More specifically, for example, a plurality of CPUs corresponding to the packet match processing unit 102 and the address conversion unit 103 are provided in parallel.

(About the monitoring function)
As shown in FIG. 8, a signal format checker 250 may be connected to the SDN switch 100. Here, for example, in the SDN switch 100, the signal format checker 250 captures one of a plurality of packet flows copied and rewritten according to the flow table on the network, and the packet reachability and format normality are captured. Confirm. Further, in the flow table, a flow addressed to the signal format checker 250 may be added, and the signal format checker 250 may receive the flow to check the reachability of the signal and the format normality.

(Summary of embodiment)
As described above, according to the present embodiment, a communication system including a packet transfer device and a packet transfer control device, wherein the packet transfer control device sets a flow rule for the packet transfer device, The packet transfer device duplicates a packet received from a packet transmission device according to the flow rule, rewrites the destination address of each duplicated packet, and forwards the packet to each packet reception device. A communication system is provided.

  The destination address is, for example, a destination IP address and a destination MAC address. The destination address may be only the destination IP address.

  The packet transfer control device creates a flow rule having a destination IP address and a destination MAC address using a destination MAC address obtained by an ARP inquiry process based on a list of destination IP addresses, and transfers the flow rule to the packet transfer It is good also as setting to an apparatus.

  The packet transfer apparatus may sequentially execute rewriting processing of the destination address of each copied packet, or may execute rewriting processing of the destination address of each copied packet in parallel.

  Further, according to the present embodiment, the packet transfer control device in a communication system including a packet transfer device and a packet transfer control device, using a destination MAC address obtained by ARP inquiry processing based on a list of destination IP addresses Means for creating a flow rule having a destination IP address and a destination MAC address, and means for setting the flow rule in the packet transfer device. In the packet transfer device, from the packet transmission device according to the flow rule A packet transfer control device is provided, in which a received packet is duplicated, a destination address of each duplicated packet is rewritten, and each packet is transferred to each packet receiving device.

  As described above, in this embodiment, by using the flexible packet control function by the SDN technology, the problems in the conventional multicast technology and the conventional unicast copy technology are solved, and economical efficiency and high processing performance are achieved. It is possible to realize compatible multi-point distribution.

The following items are disclosed in the specification.
(Section 1)
A communication system comprising a packet transfer device and a packet transfer control device,
The packet transfer control device sets a flow rule for the packet transfer device,
The packet forwarding device duplicates the packet received from the packet sending device according to the flow rule, rewrites the destination address of each duplicated packet, and forwards the packet to each packet receiving device.
A communication system characterized by the above.
(Section 2)
The destination address is a destination IP address and a destination MAC address
The communication system according to item 1, characterized in that:
(Section 3)
The packet transfer control device creates a flow rule having a destination IP address and a destination MAC address using a destination MAC address obtained by an ARP inquiry process based on a list of destination IP addresses, and transfers the flow rule to the packet transfer Set to device
The communication system according to item 2, characterized in that:
(Section 4)
The packet transfer apparatus sequentially executes rewriting processing of the destination address of each copied packet
The communication system according to any one of claims 1 to 3, characterized in that:
(Section 5)
The packet transfer apparatus executes rewriting processing of the destination address of each copied packet in parallel
The communication system according to any one of claims 1 to 3, characterized in that:
(Section 6)
A packet transfer method in a communication system comprising a packet transfer device and a packet transfer control device,
The packet transfer control device sets a flow rule for the packet transfer device;
The packet forwarding device replicating the packet received from the packet sending device according to the flow rule, rewriting the destination address of each duplicated packet, and forwarding each packet to each packet receiving device;
A packet transfer method comprising:
(Section 7)
The packet transfer control device in a communication system comprising a packet transfer device and a packet transfer control device,
Means for creating a flow rule having a destination IP address and a destination MAC address using a destination MAC address obtained by ARP inquiry processing based on a list of destination IP addresses;
Means for setting the flow rule in the packet transfer device,
In the packet transfer device, processing is performed in which the packet received from the packet transmission device is copied according to the flow rule, the destination address of each copied packet is rewritten, and each packet is transferred to each packet reception device.
A packet transfer control device.
(Section 8)
A program for causing a computer to function as each means in the packet transfer control device according to item 7.
The present invention is not limited to the above-described embodiments, and various modifications and applications are possible within the scope of the claims.

100 SDN switch 102 packet match processing unit 103 address conversion unit 104 packet transmission unit 105 flow table holding unit 106 switch control unit 200 switch control device 201 distribution source / destination list registration unit 202 data storage unit 203 ARP control unit 204 flow table generation Unit 205 flow table setting unit 250 signal format checker 300 encoder 400 decoder 500 L3SW

Claims (4)

A communication system comprising a packet transfer device, a packet transfer control device, and a signal format checker connected to the packet transfer device,
The packet transfer control device sets a flow rule for the packet transfer device,
The packet forwarding device replicates the packet received from the packet transmitting device according to the flow rule, rewrites the destination address of each duplicated packet, and forwards each packet to each packet receiving device.
The signal format checker receives and monitors one of a plurality of packet flows transferred by the packet transfer device ;
The destination address is a destination IP address and a destination MAC address,
The packet transfer control device creates a flow rule having a destination IP address and a destination MAC address using a destination MAC address obtained by an ARP inquiry process based on a list of destination IP addresses, and transfers the flow rule to the packet transfer A communication system characterized by being set in an apparatus . The communication system according to claim 1 , wherein the packet transfer apparatus sequentially executes a rewrite process of a destination address of each copied packet. 2. The communication system according to claim 1 , wherein the packet transfer device executes rewriting processing of a destination address of each copied packet in parallel. A packet transfer method in a communication system comprising a packet transfer device, a packet transfer control device, and a signal format checker connected to the packet transfer device,
The packet transfer control device sets a flow rule for the packet transfer device;
The packet forwarding device replicating the packet received from the packet transmitting device according to the flow rule, rewriting the destination address of each duplicated packet, and forwarding each packet to each packet receiving device;
The signal format checker receiving and monitoring one of a plurality of packet flows transferred by the packet transfer device ; and
The destination address is a destination IP address and a destination MAC address,
In the step of setting the flow rule, the packet transfer control device creates a flow rule having a destination IP address and a destination MAC address using a destination MAC address obtained by an ARP inquiry process based on a list of destination IP addresses. And the flow rule is set in the packet transfer apparatus .

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