JP2004120222A - Communication apparatus and communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication apparatus which calculates a packet delivery path whereby a communication delay and a total traffic volume can be reduced with a small calculation amount without the need for management by a server. <P>SOLUTION: Each of communication apparatuses A to G is provided with: a destination list storage section 1 for storing destination addresses of the other communication apparatuses in a form of a destination address list; an arrangement section 2 for rearranging contents of the destination address list on the basis of a prescribed procedure; a packet transmission section 3 for transmitting communication packets with the destination address list provided in them to a transmission destination address resulting from a top destination address of the destination address list rearranged by the rearrangement section 2; a packet reception section 4 for receiving communication packets from the other communication apparatuses; and a destination list edit section 5 for deleting its own address from the destination address list included in the communication packets. Since simple sorting is applied to the destination address list on the basis of a prefix of the IPv6 assigned to each communication apparatus to decide a succeeding destination, the communication delay and the total traffic volume are optimized with a simple processing procedure. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a communication device and a communication system that exchange communication packets with a plurality of other communication devices connected to a network.
[0002]
[Prior art]
The transition to IPv6 (Internet Protocol version 6), in which an IP (Internet Protocol) address is represented by 128 bits, is gradually progressing. With the introduction of IPv6, the communication form of the Internet has shifted to end-to-end communication, and the feasibility of one-to-many (multicast) communication in a wide area environment has been increased.
[0003]
As one method for realizing multicast communication, there is the following method (see Patent Documents 1 and 2). This method is a source routing type multicast protocol in which a transmitting node explicitly designates a plurality of nodes as communication destinations and delivers communication packets via the plurality of nodes.
[0004]
In the conventional multicast, it was necessary to separately prepare a router that manages a distribution tree for distributing communication packets. However, in this method, multicast communication can be realized only by the communication node, and high usability independent of the network environment is provided. Service can be realized.
[0005]
[Patent Document 1]
JP 2000-354063 A [Patent Document 2]
Japanese Patent Application Laid-Open No. 2001-168861
[Problems to be solved by the invention]
However, when using the source routing type packet delivery method, if the delivery order is specified without considering the topology information of the scattered communication destinations, useless traffic due to overlapping delivery routes may occur, or delivery with a large communication delay may occur. Could be in order.
[0007]
For this reason, it was necessary for the user to collect topology information by e-mail or chat, etc., and to manually derive the optimum communication path. There was a problem that artificial failure frequently occurred during collection.
[0008]
In the methods described in Patent Literatures 1 and 2, in order to cope with the above-described problem, a method of introducing a management server that calculates an optimal delivery route based on topology information of a communication destination has been proposed.
[0009]
However, even if the management server is introduced, if the management server does not have user management authority, it is difficult for end-to-end terminals to perform registration and deletion processing on these management servers. It may be low, and a single point of failure may occur.
[0010]
Further, when the members participating in the multicast communication change dynamically, the optimum route is recalculated every time, so that the calculation amount becomes enormous, and it may be difficult to guarantee the scalability of the server.
[0011]
The present invention has been made in view of such a point, and an object of the present invention is to obtain a packet delivery route capable of reducing a communication delay and a total traffic amount with a small amount of calculation without requiring server management. It is an object of the present invention to provide a communication device and a communication system that can perform the communication.
[0012]
[Means for Solving the Problems]
In order to solve the above-described problem, the present invention is directed to a communication device that transmits a communication packet via the network to a plurality of other communication devices connected to a network, the communication device comprising: Storage means for storing the destination address of each device as a destination address list; reordering means for reordering the destination address list based on a predetermined procedure; and the first destination of the destination address list reordered by the reordering means And transmitting means for transmitting the communication packet to which the destination address list is assigned, using an address as a destination address.
[0013]
According to the present invention, the transmission destination of the communication packet is determined based on the destination address list sorted in a predetermined procedure.
[0014]
The present invention is also a communication device that receives a communication packet transmitted from any of a plurality of other communication devices connected to a network, and transmits the received communication packet to a next destination. Receiving means for receiving the communication packet to which the destination address list including the address is added, destination address list editing means for deleting its own address from the destination address list, and new address edited by the destination address list editing means. Transmission means for adding the new destination address list to the communication packet and transmitting the packet to the next destination address based on the destination address list.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a communication device and a communication system according to the present invention will be specifically described with reference to the drawings.
[0016]
FIG. 1 is a schematic diagram of an embodiment of a communication system according to the present invention. As shown, three autonomous systems AS-1, AS-2, and AS-3 are connected to the network 10. The network 10 is, for example, the Internet using the next generation IP protocol, IPv6.
[0017]
The autonomous system AS-1 is provided with communication devices A, B, and C, and the communication devices B and C connect to the Internet via the same ISP (Internet Service Provider). The communication device D is provided in the autonomous system AS-2. The autonomous system AS-3 is provided with communication devices E, F, and G, and the communication devices F and G connect to the Internet via the same ISP.
[0018]
Each of the communication devices A to G in FIG. 1 can be a source node, a relay node, and a destination node of a communication packet. Each of the communication devices A to G transmits and receives communication packets using IPv6. The upper bit sequence (prefix) of IPv6 assigned to each of the communication devices A to G is, for example, as shown in FIG.
[0019]
FIG. 3 is a block diagram illustrating an example of the internal configuration of each of the communication devices A to G. As shown in FIG. 3, each of the communication devices A to G includes a destination list storage unit 1 that stores the destination address of each of the other communication devices as a destination address list, and a unit that rearranges the destination address list based on a predetermined procedure. A packet transmitting unit 3 that assigns a destination address list using the first destination address of the destination address list rearranged by the rearranging unit 2 as a transmission destination address and transmits a communication packet, and communication from another communication device. It has a packet receiving unit 4 for receiving a packet, and a destination list editing unit 5 for deleting its own address from a destination address list included in a communication packet.
[0020]
When each of the communication devices A to G is a transmission source, the destination list storage unit 1, the rearrangement unit 2, and the packet transmission unit 3 shown in FIG. 3 are used. The editing unit 5 and the packet transmission unit 3 are used.
[0021]
The communication system of FIG. 1 is characterized in that a communication packet delivery route capable of reducing the communication delay and the total traffic amount is obtained by a simple processing procedure.
[0022]
(First processing procedure)
Hereinafter, a first processing procedure of the communication system of FIG. 1 will be described. For example, when the communication device A in FIG. 1 is the transmission source, the destination addresses are simply sorted in ascending order based on the IPv6 prefix shown in FIG. The relay order of C → D → E → F → G is obtained. If communication packets are transmitted in this relay order, packet transmission with optimized communication delay and total traffic becomes possible.
[0023]
However, when the communication device F in FIG. 1 is the transmission source, the communication devices A, B, C, D, E, and G as transmission destinations are simply sorted in ascending order based on the IPv6 prefix shown in FIG. As shown in the destination address list of FIG. 5, the relay order of the communication devices A → B → C → D → E → G is obtained. FIG. 6 shows the relay order of the communication packets in this case by arrows.
[0024]
Although the relay order in FIG. 6 cannot optimize the communication delay and the total traffic amount for the communication device A as the first destination, the relay order for the communication devices B, C, D, E, and G as the second and subsequent destinations cannot be optimized. On the other hand, communication delay and total traffic volume can be optimized.
[0025]
FIG. 7 is a flowchart showing a first processing procedure, and shows a processing procedure of each communication device of a transmission source, a relay node, and a final destination. First, the communication device of the transmission source acquires a destination list from the destination list storage unit 1 (step S1). Next, each destination registered in the destination list is simply sorted in ascending order or descending order in prefix order (step S2). Next, a destination IP address of the communication packet is set (step S3). Here, the communication device registered at the head of the destination list is the transmission destination. Next, a communication packet is transmitted with the destination list added to the destination IP address (step S4).
[0026]
Upon receiving the communication packet (step S11), the communication device of the relay node performs a procedure for accepting the contents of the communication packet and extracts a destination list (step S12). Next, a destination IP address of the communication packet is set (step S13). Here, the next communication device registered in the destination list is the destination. Next, a packet is transmitted (step S14).
Upon receiving the communication packet (step S21), the communication device at the final destination performs a procedure for accepting the contents of the communication packet (step S22).
[0027]
As described above, in the first processing procedure, simple sorting is performed based on the IPv6 prefix assigned to each communication device registered in the destination list to determine the next destination. Can optimize communication delay and total traffic volume.
[0028]
(Second processing procedure)
In the second processing procedure, after simple sorting based on the destination list, IPv6 prefixes assigned to the respective communication devices are compared, and the destination address is determined based on the comparison result.
[0029]
FIG. 8 is a flowchart showing the second processing procedure, and shows the processing procedure of each of the communication devices of the transmission source, the relay node, and the final destination. The communication device of the transmission source acquires the destination list (step S31), performs simple sorting in the ascending order or the descending order in the prefix order (step S32), and compares the prefix of its own IPv6 with the prefix of the communication device of each destination. (Step S33). Here, the upper 64 bits of the IPv6 IP address are compared as a prefix.
[0030]
FIG. 9 is a diagram showing the comparison result of step S33, and shows an example where the communication device F is the transmission source and the destination list is as shown in FIG. In FIG. 9, the bit whose comparison result matches is represented by “0”, and the bit whose comparison result does not match is represented by “1”.
[0031]
Next, based on the comparison result of the prefixes, the destination lists are rearranged in descending order of the degree of matching with the own prefix (step S34). The destination list in FIG. 5 is rearranged as shown in FIG.
[0032]
Next, after setting the destination IP address of the communication packet based on the rearranged destination list (step S35), the packet is transmitted (step S36).
[0033]
The processing procedure of the relay node and the communication device of the final destination is the same as that of FIG.
[0034]
For example, when the processing of the flowchart in FIG. 8 is performed with the communication source set to the communication device F, the communication packet is transmitted in the direction indicated by the arrow in FIG. In FIG. 6, the communication packet is sent from the communication device F to the communication device A having a large communication delay, but in FIG. 9, the communication packet is sent from the communication device F to the communication device A via the communication G and E.
[0035]
As described above, in the second processing procedure, not only the destination list is simply sorted, but also the destination list is rearranged in consideration of the degree of coincidence of the IPv6 prefix, so that the communication delay and the total traffic amount are more optimal. Can be
[0036]
(Third processing procedure)
In the third processing procedure, the communication device of the relay node performs the same sort processing as the communication device of the transmission destination.
[0037]
FIG. 12 is a flowchart illustrating the third processing procedure, and illustrates the processing procedure of each communication device of the transmission source, the relay node, and the final destination. The source communication device obtains the destination list (step S41), sorts the prefixes in ascending or descending order (step S42), compares the prefix with the prefix of each destination, and compares the prefix with the prefix of the destination. The communication device having the prefix with the highest matching degree is selected (step S43).
[0038]
Next, it is determined in step S43 whether a plurality of communication devices have been selected (step S44). If a plurality of communication devices have been selected, the prefixes of the plurality of communication devices are simply sorted in ascending or descending order. Then, a destination communication device is selected (step S45).
[0039]
Next, based on the communication device selected in step S43 or S45, a destination IP address of the communication packet is set (step S46), and the communication packet is transmitted (step S47).
[0040]
The communication device of the relay node receives the communication packet transmitted from the communication device of the transmission source (Step S51), and performs a receiving procedure of the received communication packet (Step S52).
[0041]
Thereafter, the communication device of the relay node performs the same process (steps S52 to S58) as the process performed by the communication device of the transmission source (steps S41 to S47).
[0042]
For example, when the processing of the flowchart in FIG. 12 is performed with the transmission source being the communication device F, the communication packet is transmitted in the direction indicated by the arrow in FIG. In the case of FIG. 13, a communication packet is transmitted from the communication device F to the communication device G. The communication device G, which is a relay node, performs the processing of steps S51 to S58 in FIG. In this case, the comparison result between the prefix of the communication device G itself and the prefixes of the other communication devices A, B, C, D, and E is as shown in FIG. It can be seen that the communication device E has the highest matching degree. Therefore, the communication device G determines the communication device E as the next destination and transmits the communication packet.
[0043]
The communication device E that has received the communication packet performs the processing of steps S51 to S58 in FIG. In this case, the comparison result between the prefix of the communication device E itself and the prefixes of the other communication devices A, B, C, and D is as shown in FIG. It can be seen that the communication device A has the highest matching degree. Therefore, the communication device E determines the communication device A as the next destination and transmits the communication packet.
[0044]
As described above, in the third processing procedure, since both the transmission source and the communication device of the relay node select the communication device having the prefix with the highest degree of matching with the prefix of the own communication device as the destination, The node can also transmit a communication packet to a destination where the communication delay and the total traffic amount are minimized. In particular, the third processing procedure is advantageous in an environment where the relay communication device is frequently replaced.
[0045]
In the embodiment described above, an example in which the IPv6 protocol is used has been described. However, the type of communication protocol is not limited to IPv6, and another communication protocol (for example, IPv4) may be used. The number of bits of the prefix to be compared may be changed according to the communication protocol used.
[0046]
【The invention's effect】
As described in detail above, according to the present invention, when transmitting a communication packet to a destination communication device by sequentially relaying a plurality of communication devices, the communication packet is determined based on a destination address list rearranged in a predetermined procedure. , The communication delay and the total traffic volume can be reduced.
[0047]
Further, since the destination of the communication packet can be determined by a simple processing procedure, a management server is not required when determining the destination.
[0048]
Further, even in an environment where communication devices that relay communication packets are frequently replaced, it is possible to quickly and accurately determine a destination of a communication packet without requiring an enormous amount of calculation.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of an embodiment of a communication system according to the present invention.
FIG. 2 is a diagram showing an IPv6 prefix assigned to each communication device.
FIG. 3 is a block diagram showing an example of the internal configuration of each communication device.
FIG. 4 is a diagram showing an example in which a destination address list when a transmission source is a communication device A is simply sorted.
FIG. 5 is a diagram showing an example in which a destination address list in the case where a transmission source is a communication device F is simply sorted.
FIG. 6 is a diagram showing a relay order corresponding to FIG. 5;
FIG. 7 is a flowchart showing a first processing procedure.
FIG. 8 is a flowchart showing a second processing procedure.
FIG. 9 is a view showing a comparison result of step S33.
FIG. 10 is a diagram illustrating an example in which rearrangement is performed based on a comparison result between prefixes.
FIG. 11 is a diagram showing a relay order corresponding to FIG. 10;
FIG. 12 is a flowchart showing a third processing procedure.
FIG. 13 is a diagram showing a relay order indicating a processing result of FIG. 12;
FIG. 14 is a diagram showing a destination address list in the communication device G.
FIG. 15 is a diagram showing a destination address list in the communication device E.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 destination list storage unit 2 reordering unit 3 packet transmitting unit 4 packet receiving unit 5 destination list editing unit 10 network

Claims (9)

A communication device that transmits a communication packet via the network, with a plurality of other communication devices connected to the network as destinations,
Storage means for storing the destination address of each of the plurality of other communication devices as a destination address list,
Reordering means for reordering the destination address list based on a predetermined procedure;
A communication unit for transmitting the communication packet to which the destination address list is added, using the destination address at the head of the destination address list rearranged by the rearranging unit as a transmission destination address. . The predetermined procedure includes:
2. The communication apparatus according to claim 1, further comprising a step of rearranging the destination addresses in the destination address list stored in the storage unit based on a degree of association with the own address. The predetermined procedure includes:
2. The communication apparatus according to claim 1, wherein the destination address list stored in the storage unit is simply sorted in ascending or descending order of addresses. The predetermined procedure includes:
2. The communication apparatus according to claim 1, further comprising a step of rearranging the destination address list stored in the storage unit based on a higher-order bit string of each destination address. A communication device that receives a communication packet transmitted from any of a plurality of other communication devices connected to a network, and transmits the received communication packet to a next destination,
Receiving means for receiving the communication packet to which a destination address list including a plurality of destination addresses is provided;
Destination address list editing means for deleting its own address from the destination address list,
Transmitting means for adding the new destination address list to the communication packet and transmitting the packet to the next destination address based on the new destination address list edited by the destination address list editing means. Communication device. The destination address list editing means,
6. The communication device according to claim 5, wherein after deleting its own address, the destination address to be transmitted next is rearranged based on a predetermined procedure. The predetermined procedure includes:
7. The communication apparatus according to claim 6, wherein the destination address list after deleting its own address is simply sorted in ascending or descending order of addresses. The predetermined procedure includes:
7. The communication apparatus according to claim 6, wherein the destination address list after deleting its own address is rearranged on the basis of a higher-order bit string of each destination address. A source communication device that transmits a communication packet via the network, with a plurality of other communication devices connected to the network as destinations,
A relay communication device that receives a communication packet transmitted from any one of a plurality of other communication devices connected to the network, and transmits the received communication packet to a next destination,
The source communication device,
Storage means for storing the destination address of each of the plurality of other communication devices as a destination address list,
Reordering means for reordering the destination address list based on a predetermined procedure;
A first transmitting unit that transmits the communication packet to which the destination address list is added, with the destination address at the head of the destination address list rearranged by the rearranging unit as a transmission destination address,
The relay communication device,
Receiving means for receiving the communication packet to which a destination address list including a plurality of destination addresses is provided;
Destination address list editing means for deleting its own address from the destination address list,
A second transmission unit that adds the new destination address list to the communication packet and transmits the communication packet to a next destination address based on the new destination address list edited by the destination address list editing unit. A communication system comprising:

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