JP2002026927A - Capsulating method and unit, and program recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a capsulating technology that improves data transfer efficiency in the case of adopting a configuration of capsulating the packets. SOLUTION: When the capsulating unit of this invention acts as a transmitter side, the capsulating unit collects and capsulates packets to be capsulated in the order of reception so as to be contained in a specified collection length and having the same transmission destination or a transmission form, and processes the transmission of capsulated packets and non-capsulated packets in the reception order. In the case of the capsulating unit acting as a receiver side, when receiving capsulated packets, the capsulating unit decodes the packets into a state that they are capsulated, extracts packets before the collection, and processes the transmission of the packets to the transmission destination under its control. Thus, by the processing that includes collecting packets, capsulating them and transmitting the capsulated packets the data transfer efficiency is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an encapsulation method and apparatus for encapsulating and transmitting a packet, an encapsulation apparatus for receiving the encapsulated packet, and a program used to realize the encapsulation apparatus. The present invention relates to a program recording medium, and more particularly, to a capsulating method and apparatus capable of improving data transfer efficiency, and a program recording medium on which a program used to realize the capsulating apparatus is recorded.

[0002] Routers and VPN devices (Virtual Private Net)
In a device such as a work device, a packet received from a subordinate terminal is encapsulated as data of another packet by processing (for example, encrypting) as necessary, and is transmitted to the device of the other party, and the encapsulation is performed. When receiving a garbled packet, restore the original packet,
The process of transmitting to the terminal under the control is executed.

[0003] When an apparatus for performing such processing is provided (hereinafter, referred to as a capsulating apparatus), it is necessary to construct a technology that does not reduce the data transfer efficiency.

[0004]

2. Description of the Related Art In a conventional encapsulation apparatus, when a packet to be encapsulated is received from a subordinate terminal, the packet is encapsulated one by one as it is and transmitted to the other encapsulation apparatus.

[0005] That is, in the conventional capsuling device,
As shown in FIG. 19, when a packet to be encapsulated is received from a subordinate terminal, the packet is encapsulated one by one as it is, and additional information such as a header added in the encapsulation process and the encapsulated packet are transmitted. , And processing is performed so that the packet is transmitted to the other party's encapsulating device.

[0006] When the encapsulated packet is received, the restoration-side encapsulation device restores the original packet and sends it to the terminal under the control of the original packet destination. are doing.

[0007]

However, according to such a conventional technique, since the packets to be encapsulated are encapsulated one by one, the encapsulating device on the transmitting side requires the encapsulation device from the subordinate terminal to perform the encapsulation. Each time a packet is received, the packet transmission process must be performed, and the encapsulating device on the receiving side must receive the encapsulated packet each time. There is a problem that the number of times increases.

[0008] Then, the packets to be encapsulated are encapsulated one by one, and additional information such as a header added in the encapsulation processing and a protocol header for transmitting the encapsulated packet are added thereto. Therefore, there is a problem in that the size of packets to be transmitted increases and the number of memory acquisition processes required to add them increases.

Furthermore, according to the prior art, there is a problem that the transmission line cannot be used efficiently.

For example, an MTU (maximum transfer unit) of a transmission path between a transmission-side capsulating apparatus and a terminal under the transmission-side capsulation apparatus is 1500 bytes, and a transmission path between a transmission-side capsulation apparatus and a reception-side capsulation apparatus. MTU of 4500
Assume that it is a byte.

In this case, the terminal under the transmission-side encapsulation device divides the packet according to 1500 bytes according to the fragment processing of the Internet protocol and sends the packet.
By encapsulating this 1500 byte order packet, an encapsulated packet slightly larger than 1500 bytes is normally generated and transmitted to the receiving-side encapsulation device.

As described above, in the prior art, the transmission path between the capsulating device on the transmitting side and the capsulating device on the receiving side is smaller than the MTU of the transmission line between the capsulating device on the transmitting side and the terminal under the capsulating device. Even if a device having a large MTU is prepared, actually, a process of transmitting only a packet of a length that does not use the capability of the large MTU (in this case, a length of less than half) is performed. Therefore, the transmission path cannot be used efficiently.

On the other hand, for example, the MTU of the transmission path between the capsulating device on the transmitting side and the terminal under its control is 1500 bytes, and the MTU of the transmission line between the capsulating device on the transmitting side and the capsulating device on the receiving side is 1500 bytes. Assume that it is 1500 bytes.

In this case, the terminal under the transmission-side encapsulation device divides the packet in accordance with 1500 bytes according to the fragment processing of the Internet protocol and sends the packet.
By encapsulating this 1500 byte order packet, usually, an encapsulated packet slightly larger than 1500 bytes is generated, and according to the fragmentation processing of the Internet protocol, this is converted into 1500 bytes and the remaining small length packet. And the data is transmitted to the capsulating device on the receiving side.

As described above, in the prior art, the transmission path between the transmitting-side capsulating apparatus and the receiving-side capsulating apparatus is the same as the MTU of the transmission path between the transmitting-side capsulating apparatus and the terminal under the same. Even when a packet having an MTU of a size is prepared, a process of transmitting a packet that is divided by exceeding the MTU in a packet that is very small compared to the capability of the MTU is performed. Therefore, the transmission path cannot be used efficiently.

The present invention has been made in view of such circumstances, and provides a new encapsulation method and apparatus capable of improving data transfer efficiency, and records a program used to realize the encapsulation apparatus. It is intended to provide a new program recording medium.

[0017]

In order to achieve this object, in the capsulating apparatus of the present invention, when operating as a transmitting side, while determining whether a received packet is to be encapsulated, Means for creating an order table for managing the order of reception of received packets, and one or a means for managing the order of reception of packets to be encapsulated having the same destination or transmission form from packets determined to be encapsulated. Means for creating a plurality of aggregation order tables, and according to the order table and the aggregation order table,
While encapsulating and encapsulating packets to be encapsulated that have the same destination or transmission form within the prescribed aggregation length, the first packet of the encapsulated packet and the non-encapsulated packet are arranged in the order of reception Means for transmitting an encapsulated packet and a non-encapsulated packet in a side by side format.

At this time, as the aggregation length, the maximum transfer unit (MT) of the transmission path to the restoration-side encapsulation device is set.
It is configured to use a value that is a natural number multiple of U).

On the other hand, in the encapsulating device of the present invention, when operating as a receiving side, means for determining whether or not an encapsulated packet has been received, and means for restoring the received encapsulated packet to a state before encapsulation. And a means for extracting each of a plurality of packets aggregated into the restored packet from the restored packet, and a means for transmitting the extracted packet to a destination.

In the capsulating apparatus of the present invention configured as described above, when operating as a transmitting side, packets to be encapsulated having the same transmission destination or transmission form are received in the order of reception so as to be within the prescribed aggregation length. Processes to transmit the encapsulated packet and the non-encapsulated packet in the order of reception while aggregating and encapsulating, and upon receiving this, when operating as a receiving side, when the encapsulated packet is received, it is pre-encapsulated. , The packets before aggregation are extracted from them, and the packets are transmitted to the subordinate destinations.

As described above, according to the present invention, since the packets to be encapsulated are aggregated and encapsulated, and the packet is transmitted, the number of times of the transmission processing and the number of reception processing of the encapsulating apparatus can be reduced. In addition to being able to use the additional information such as the header added in the encapsulation process and the protocol header for transmitting the encapsulated packet, it is possible to reduce the packet size and add them. Can be reduced in the number of memory acquisition processes required for performing

In the present invention, the packet to be encapsulated is contained within the aggregate length by using the aggregate length defined by a value which is a natural number multiple of the maximum transfer unit of the transmission path with the restoration side. Are aggregated and encapsulated, so that the transmission path can be used efficiently according to the fragment processing of the Internet protocol.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail according to embodiments.

As shown in FIG. 1, according to the present invention, a packet transmitted from a subordinate terminal (some packets may or may not be encapsulated) is received, and a packet to be encapsulated is received. It aggregates and encapsulates it, and processes it to send it to the other party.

In this encapsulation processing, for example, as shown in FIG. 2, packet data is encrypted and authentication data is added thereto.

Here, the IP header shown in FIG. 2 describes the IP address of the source terminal and the IP address of the destination terminal, and the new IP header added by encryption is
The IP address of the source encapsulation device and the IP address of the destination encapsulation device are described.

FIG. 3 shows an embodiment of the present invention. In the figure, reference numeral 1 denotes a transmitting-side encapsulating device equipped with the present invention, and 2 denotes a receiving-side encapsulating device equipped with the present invention.

As shown in FIG. 1, a transmitting-side encapsulating apparatus 1 of the present invention receives a packet to be transmitted from a subordinate terminal, and processes the packet received by the receiving processing unit 10 as a processing target. , Setting information table 1
2, an aggregated packet management unit 11 that creates an order table 13 and an aggregation order table 14, a received packet management unit 15 that manages packets received by the reception processing unit 10, an order table 13 and an aggregation order table 14
, An aggregate packet processing unit 16 that aggregates the packets to be encapsulated, and a capsule processing unit 17 that encapsulates the packets aggregated by the aggregate packet processing unit 16
And a transmission processing unit 18 that transmits the encapsulated packet and the packet not to be encapsulated to the reception-side encapsulation device 2.

On the other hand, the receiving-side capsulating device 2 of the present invention
Is a reception processing unit 20 that receives a packet transmitted from the transmission-side encapsulation device 1 of the present invention;
Received packet management unit 2 that manages received packets of 0
1, a capsule processing unit 22 for restoring an encapsulated packet among the packets received by the reception processing unit 20 to a state before encapsulation, and extracting a packet before aggregation from the aggregated packet restored by the capsule processing unit 22 And a transmission processing unit 24 that transmits a packet extracted by the aggregation packet processing unit 23 or a received packet that is not to be encapsulated to a terminal under its control.

Here, the functions of the transmission-side encapsulation device 1 of the present invention and the reception-side encapsulation device 2 of the present invention are specifically realized by programs, and these programs are readable by a computer. It can be stored in an appropriate recording medium such as a semiconductor memory.

The setting information table 12 provided in the transmission-side encapsulation apparatus 1 of the present invention is used to determine whether a packet received from a subordinate terminal is to be encapsulated.

FIGS. 4 to 6 show an embodiment of the setting information table 12. FIG.

As shown in FIG. 7, the I "1.1.1.50"
Under the capsulating device A having the P address, "1.1.
Terminal A1 having an IP address of “1.1” and “1.1.1.
Terminal A2 having an IP address of "2"
A terminal B1 having an IP address of "2.1.1.1" and a terminal B2 having an IP address of "2.1.1.2" exist under the encapsulation device B having an IP address of "2.1.1.50". The terminal C1 having the IP address “3.1.1.1” and the I-terminal “3.1.1.2” under the encapsulation device C having the IP address “.1.50”.
It is assumed that there is a terminal C2 having a P address.

In the setting information table 12 shown in FIG. 4, the terminals A1, A2 (1.1.0.0) to the terminals B1, B2 (2.1.0.0)
Transmitted to the terminal A1, A2 (1.1.0.0)
Packets transmitted from the terminal C1 to the terminals C1 and C2 (3.1.0.0) are packets belonging to the same group and to be encapsulated.

Similarly, packets to be encapsulated are defined for the encapsulating devices B and C. However, each encapsulating device A, B and C does not hold all the information in the setting information table 12, Thus, only the information used by the own device may be held.

On the other hand, in the setting information table 12 shown in FIG. 5, packets transmitted from the terminal A1 to the terminal B1 are packets to be encapsulated belonging to the same group,
The packet transmitted from the terminal A1 to the terminal B2 is a packet to be encapsulated belonging to the same group, and the packet transmitted from the terminal A2 to the terminal B1 is a packet to be encapsulated belonging to the same group.
Transmitted from the terminal A1 to the terminal B2 are packets to be encapsulated belonging to the same group, packets transmitted from the terminal A1 to the terminal C1 are packets to be encapsulated belonging to the same group, and Packets transmitted to C2 are packets to be encapsulated belonging to the same group, and are transmitted from terminal A2 to terminal C1.
Are packets to be encapsulated belonging to the same group, and packets transmitted from the terminal A2 to the terminal C2 are packets to be encapsulated belonging to the same group.

Similarly, packets to be encapsulated are defined for the encapsulation devices B and C. However, each of the encapsulation devices A, B, and C does not hold all the information in the setting information table 12. Thus, only the information used by the own device may be held.

On the other hand, in the setting information table 12 shown in FIG. 6, the packets transmitted from the terminals A1 and A2 (1.1.0.0) to the terminal B1 are the packets to be encapsulated belonging to the same group, and the terminals A1 and A2 (1.1.0.0) to terminal B
2 are packets to be encapsulated belonging to the same group, and are transmitted to the terminals A1 and A2 (1.1.0.
0) to the terminal C1 are packets to be encapsulated belonging to the same group,
It is defined that the packets transmitted from 1, A2 (1.1.0.0) to terminal C2 are packets to be encapsulated belonging to the same group.

Similarly, packets to be encapsulated are defined for the capsulating apparatuses B and C. However, each of the encapsulating apparatuses A, B and C does not hold all the information in the setting information table 12. Thus, only the information used by the own device may be held.

Hereinafter, for convenience of explanation, it is assumed that the setting information table 12 shown in FIG. 4 is prepared.

The order table 13 provided in the transmission-side encapsulation apparatus 1 of the present invention manages the order of reception of packets received by the reception processing unit 10. On the other hand, the aggregation order table 14 included in the transmission-side encapsulation device 1 of the present invention includes a group of packets to be encapsulated (the setting information table 1) defined as the same group in the setting information table 12.
2), and manages the reception order of the packets belonging to that group.

For example, first, a packet A not to be encapsulated is received, a packet B to be encapsulated is subsequently received, a packet C not to be encapsulated is subsequently received, and When the packet D to be encapsulated is received, and subsequently, the packet E to be encapsulated is received, the order table 13
Manages the reception of packets in the order of “packet A, packet B, packet C, packet D, packet E” as shown in FIG.
Manages the reception of packets to be encapsulated in the order of “packet B, packet D, packet E” as shown in FIG. 8B.

FIGS. 9 to 11 show an embodiment of a processing flow executed by the aggregated packet management unit 11 provided in the transmission-side encapsulation apparatus 1 of the present invention.
One embodiment of the processing flow executed by the aggregated packet processing unit 16 included in the transmission-side encapsulation device 1 of the present invention. FIG. 14 illustrates the processing flow executed by the aggregated packet processing unit 23 included in the reception-side encapsulation device 2 of the present invention. 1 illustrates an example of an embodiment.

Next, the present invention will be described in detail according to these processing flows.

When the aggregated packet management unit 11 included in the transmission-side encapsulation apparatus 1 according to the present invention is activated, first, as shown in the processing flow of FIGS. Receive the received packet.

Although not described above, the reception processing unit 10 is constituted by hardware, receives a packet transmitted from a terminal under its control, responds to a request from the aggregated packet management unit 11, and To the aggregated packet management unit 11,
The aggregated packet management unit 11
These packets are received by issuing a request to receive the received packets.

Subsequently, in step 2, it is determined whether or not selection of all packets received from the reception processing unit 10 has been completed. If it is determined that selection of all packets has not been completed, the process proceeds to step 2. Proceeding to No. 4, one packet is selected from the unselected received packets according to the reception order received by the reception processing unit 10.

Subsequently, in step 5, variables used in the subsequent processing are cleared, and in step 6, the variable X points to the head of the setting information array managed by the setting information table 12, thereby determining the processing target. Is selected (the aggregation order table 14). That is, in the case of the capsulating device A, the setting information table 1 shown in FIG.
The head setting information array among the two setting information arrays assigned to the encapsulation device A of the second is selected as a processing target.

Subsequently, at step 7, the source IP address / destination IP address of the selected packet, and the local terminal (IP) address / other terminal (IP) address of the selected setting information array When it is determined whether or not the values match, and when it is determined that they do not match, the process proceeds to step 8, where the variable X points to the next setting information array managed by the setting information table 12.

Subsequently, at step 9, the variable X is set to NULL.
When it is determined whether or not the variable X points to NULL, the process returns to step 7. That is, when it is determined that the last setting information array managed by the setting information table 12 has not been reached, the process returns to step 7.

On the other hand, when it is determined in step 9 that the variable X points to NULL, that is, the source IP address / destination IP address of the selected packet is not registered in the setting information table 12. Then, when it is determined that the packet is not the object of encapsulation, the processing of steps 10 to 15 described below is executed to perform an addition processing to the order table 13.

That is, the process proceeds to step 10 (the processing flow of FIG. 10), where the variable M is used to point to the leading information of the order table 13, and in the subsequent step 11, the variable N is used to indicate the next information of the order table 13 indicated by the variable M. Point. Subsequently, in step 12, it is determined whether or not the variable N points to NULL. When it is determined that the variable N does not point to NULL, the process proceeds to step 13, where the variable N
Is set to the variable M, and the process returns to step 11.

By repeating the processing from step 11 to step 13, the end of the order table 13 is reached, and in step 12, the variable N is set to NULL.
If it is determined that L points to L, the process proceeds to step 14, where a new table is created and a link (registering the next information / previous information shown in FIG. 8) with the order table 13 is established, A new table is added to the end of the order table 13, and in step 15, the memory address of the selected packet is set in the new table, and the process returns to step 2.

As described above, when the source IP address / destination IP address of the selected packet is not registered in the setting information table 12 and it is determined that the packet is not to be encapsulated, step 10 is executed. Executing the processing from step 15 to the processing of adding the memory address of the selected packet to the end of the order table 13 is performed.

On the other hand, in step 7, when the source IP address / destination IP address of the selected packet is registered in the setting information table 12 to determine that the packet is to be encapsulated, Proceeding to step 16 (the processing flow in FIG. 11),
0 to step 15, the memory address of the selected packet is stored in the order table 13
Register at the end of.

Subsequently, at step 17, the variable X
Points to the leading information of the aggregation order table 14 indicated by
In the following step 18, the variable n points to the next information of the aggregation order table 14 indicated by the variable m. Subsequently, in step 19, it is determined whether or not the variable n points to NULL. When it is determined that the variable n does not point to NULL, the process proceeds to step 20, and the variable n is set to the variable m. Then, the process returns to step 18.

By repeating the processing from step 18 to step 20, the end of the aggregation order table 14 is reached.
If it is determined that it points to the UL, the process proceeds to step 21 where a new table is created and the aggregation order table 14
A new table is added to the end of the aggregation order table 14 by establishing a link (next information shown in FIG.

Subsequently, in step 22, the memory address of the selected packet is set in the new table, and the aggregation table 14 is added to the new table added to the end of the order table 13 according to the processing in step 16.
After setting the start address, the process returns to step 2.

When the source IP address / destination IP address of the selected packet is registered in the setting information table 12 to determine that the packet is to be encapsulated, By executing the processing from step 16 to step 22, the memory address of the selected packet is additionally registered at the end of the order table 13, and the memory address of the selected packet is set at the end of the aggregation order table 14. Processing is performed so that additional registration is performed.

When it is determined in step 2 that the selection of all the packets received from the reception processing unit 10 has been completed, the process proceeds to step 3 where the aggregation packet processing unit 1
6 is started.

As described above, the aggregated packet management unit 11 included in the transmission-side encapsulation device 1 of the present invention performs the processing of the sequence having the data structure as shown in FIG. In addition to creating the table 13, the aggregation order table 14 having a data structure as shown in FIG.
6 is started.

When activated in this way, the aggregated packet processing unit 1 included in the transmission-side encapsulation device 1 of the present invention.
6, as shown in the processing flows of FIGS. 12 and 13, first, in Step 1, an aggregated packet area is created and variables to be used are cleared, and in Step 2, a variable I is used in the order table. 13 points to the top information.

Subsequently, in step 3, it is determined whether or not the start address of the aggregation order table 14 is set in the entry area of the order table 13 indicated by the variable I, and the start address of the aggregation order table 14 is set. When it is determined that the packet is to be encapsulated, that is, when it is determined that the packet registered in the entry area of the order table 13 indicated by the variable I is the packet to be encapsulated, the process proceeds to step 4. Points to the top information of the aggregation order table 14.

Subsequently, in step 5, the received packet of the aggregation order table 14 indicated by the variable J is added to the aggregated packet area, and the received packet length is added to the variable L. Subsequently, in step 6, the aggregation order table 14 indicated by the variable J
In order to delete the received packet from the order table 13, the link of the order table is changed, and the received packet is deleted from the order table 13 in the subsequent step 7.

Subsequently, in step 8, it is determined whether or not the next information is set in the aggregation order table 14 indicated by the variable J. When it is determined that the next information is set, the process proceeds to step 9. Then, the next information is set to a variable N, and in the subsequent step 10, the length of the reception packet indicated by the variable N (that is, the reception packet set to the next information) is set to a variable L1.

Subsequently, in step 11 (the processing flow of FIG. 13), the added value of the variable L and the variable L1 is calculated. In the following step 12, it is determined whether or not the calculated added value is larger than the optimum aggregation length. Judge. Here, as the aggregation optimum length, the MTU (maximum transfer unit) of the transmission path with the receiving-side encapsulation device 2 is multiplied by a natural number (for example, twice).
A value obtained by subtracting the packet increase that is increased by encapsulation from the data obtained by the encapsulation is set.

When it is determined that the added value of the variable L and the variable L1 does not become larger than the optimal aggregation length by this determination processing, it is determined that the received packets up to that point can be aggregated. In order to check whether or not it is possible to aggregate up to
The process proceeds to step 3, where the received packet registered in the entry area of the aggregation order table 14 indicated by the variable J is deleted, the variable N is set to the variable J, and the process returns to step 5.

On the other hand, in step 12, the variable L and the variable L1
When it is determined that the added value of the sum is larger than the optimal aggregation length, the process proceeds to step 14, where the received packet registered in the entry area of the aggregation order table 14 indicated by the variable J is deleted.

Subsequently, in step 15, the capsule processing unit 17 is activated by designating the received packets stored in the aggregated packet area as an aggregation target, and in response to this activation, the capsule processing unit 17 After encapsulation while aggregating, in subsequent step 16, the transmission processing unit 18
Is activated, the encapsulated packet created by the capsule processing unit 17 is transmitted to the reception-side encapsulation device 2.

When the sequence table 13 becomes empty, the process is terminated, and when the sequence table 13 is not empty, the process is repeated from step 1 again.

On the other hand, when it is determined in step 8 that the next information is not set in the aggregation order table 14 indicated by the variable J, that is, when it is determined that the information reaches the end of the aggregation order table 14, Step 1
The process proceeds to step 4 to execute the processing of steps 14 to 16 to create an encapsulated packet and transmit it to the receiving-side encapsulation device 2.

When the sequence table 13 becomes empty, the process is terminated, and when the sequence table 13 is not empty, the process is repeated from step 1 again.

On the other hand, when it is determined in step 3 that the start address of the aggregation order table 14 is not set in the entry area of the order table 13 indicated by the variable I, that is, when the entry area of the order table 13 indicated by the variable I is determined. When it is determined that the packet registered in the packet is not a packet to be encapsulated, the process immediately proceeds to step 16, and the packet not to be encapsulated is transmitted to the receiving-side encapsulation device 2 as it is.

When the sequence table 13 becomes empty, the process is terminated, and when the sequence table 13 is not empty, the process is repeated from step 1 again.

As described above, the aggregated packet processing unit 16 included in the transmission-side encapsulation device 1 of the present invention
As shown in FIG. 16, while encapsulating and encapsulating the packets to be encapsulated in the order in which they are received within the optimal aggregation length, as shown in FIG. 16, the encapsulated packets and the non-encapsulated packets are transmitted in the order in which they are received. It is processed to go.

In FIG. 16, when packets a to j are received in alphabetical order, packets a and d are not to be encapsulated, and packets b, f and g are not to be encapsulated. , J are packets to be encapsulated belonging to the same group, and packets c, e, h, i are packets to be encapsulated belonging to another same group.

In this case, according to the processing of the aggregated packet processing unit 16, first, the packet a is transmitted, subsequently, the encapsulated encapsulated packet of the packets b and f is transmitted, and subsequently, the packet c is transmitted. , E is transmitted, followed by packet d, followed by the aggregated encapsulated packets of packets g, j, followed by packets h, i. As a result, the first packet of the encapsulated packet and the non-encapsulated packet are transmitted in the order in which they are received.

Upon receiving the transmission of the encapsulated packet,
The aggregated packet processing unit 23 included in the reception-side encapsulation device 2 of the present invention performs a process of extracting a packet before aggregation from the aggregated packet restored by the capsule processing unit 22 according to the processing flow of FIG.

That is, when the aggregated packet processing unit 23 receives the aggregated packet restored by the capsule processing unit 22, first, in step 1, the aggregated packet processing unit 23 clears variables to be used, as shown in the processing flow of FIG. In the subsequent step 2, the aggregated packet length set in the memory management header of the restored aggregated packet is set in a variable L2.

Subsequently, in step 3, the variable P is used to point to the head of the restored aggregated packet.
Then, the packet length is obtained from the protocol header indicated by the variable P and set to the variable Lx.

Subsequently, in step 5, the value of the variable Lx is added to the variable L3. In the following step 6, the packet pointed to by the variable P is cut out by the size set in the variable Lx, and the transmission processing unit 24 is started. Thus, the cut-out packet is transmitted to the destination terminal.

Subsequently, in step 7, it is determined whether or not the value of the variable L2 is still larger than the value of the variable L3. When it is determined that the value is still larger, the process proceeds to step 8,
After adding the value of the variable P by the value of the variable Lx, the process returns to step 4, and when it is determined that the value of the variable L3 has become larger, the process ends.

As described above, upon receiving the aggregated packet restored by the capsule processing unit 22, the aggregated packet processing unit 23 included in the receiving-side encapsulation device 2 of the present invention, as shown in FIG. Processing is performed so that the aggregated packets are cut out and transmitted to the terminal under the control.

As described above, in the transmission-side encapsulation device 1 of the present invention, the packet increase increased by encapsulation is subtracted from the value obtained by multiplying the MTU of the transmission path with the reception-side encapsulation device 2 by a natural number. Is set as the optimal aggregation length, and within the optimal aggregation length,
Processing is performed such that packets to be encapsulated are encapsulated while being aggregated.

On the other hand, the transmission-side encapsulation device 1 of the present invention
Will transmit packets using the Internet protocol, so that the packets encapsulated in this way will have the MTU of the transmission path with the receiving-side encapsulation device 2 in accordance with the fragment processing of the Internet protocol. It will be divided and transmitted so as not to exceed.

At the time of this division, the transmission-side encapsulation apparatus 1 of the present invention generates an encapsulated packet so as not to exceed the above-mentioned optimal aggregation length, so that the transmission path can be used efficiently.

That is, for example, if the MTU of the transmission path between the transmission-side encapsulation device 1 and the terminal under its control is 150
If the MTU of the transmission path between the transmission-side encapsulation device 1 and the reception-side encapsulation device 2 is 4500 bytes, the terminal under the transmission-side encapsulation device 1 will be able to perform 1500 bytes in accordance with the Internet protocol fragment processing. The packet will be sent in accordance with
Since the encapsulated packets are generated while being aggregated in a natural number multiple of 4500 bytes, the transmission path can be used efficiently.

Also, for example, the transmission-side encapsulation device 1
If the MTU of the transmission path between the transmission side capsulating apparatus 1 and the receiving side capsulation apparatus 2 is 1500 bytes and the MTU of the transmission path between the transmission side encapsulation apparatus 1 and the reception side encapsulation apparatus 2 is 1500 bytes, Under the terminal, according to the fragment processing of the Internet protocol,
The packet is divided and sent according to 1500 bytes.
As shown in (1), since the encapsulated packets are generated while being aggregated so as to be a natural number multiple of 1500 bytes, the transmission path can be used efficiently.

[0089]

As described above, according to the present invention, the packets to be encapsulated are aggregated and encapsulated, and the packet is processed so as to be transmitted. Can be reduced, and the packet size can be reduced by sharing additional information such as a header added in the encapsulation process and a protocol header for transmitting the encapsulated packet. , It is possible to reduce the number of memory acquisition processes required to perform these additions.

In the present invention, the packet to be encapsulated is contained within the aggregate length by using the aggregate length defined by a value which is a natural number multiple of the maximum transfer unit of the transmission path with the restoration side. Are aggregated and encapsulated, so that the transmission path can be used efficiently according to the fragment processing of the Internet protocol.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of the present invention.

FIG. 2 is an example of an encapsulation process.

FIG. 3 is an embodiment of the present invention.

FIG. 4 is an example of an embodiment of a setting information table.

FIG. 5 is an example of an embodiment of a setting information table.

FIG. 6 is an example of an embodiment of a setting information table.

FIG. 7 is an example of a system to which the present invention is applied.

FIG. 8 is an explanatory diagram of management data of an order table and an aggregation order table.

FIG. 9 is an embodiment of a processing flow executed by an aggregated packet management unit.

FIG. 10 is an embodiment of a processing flow executed by an aggregated packet management unit.

FIG. 11 is an embodiment of a processing flow executed by an aggregated packet management unit.

FIG. 12 is an embodiment of a processing flow executed by an aggregated packet processing unit.

FIG. 13 is an embodiment of a processing flow executed by an aggregated packet processing unit.

FIG. 14 is an embodiment of a processing flow executed by an aggregated packet processing unit.

FIG. 15 is an explanatory diagram of a packet encapsulation process.

FIG. 16 is an explanatory diagram of a packet transmission order.

FIG. 17 is an explanatory diagram of a disassembly process of an aggregated packet.

FIG. 18 is an explanatory diagram of the present invention.

FIG. 19 is an explanatory diagram of a conventional technique.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 transmitting-side capsulating device 2 receiving-side capsulating device 10 reception processing unit 11 aggregated packet management unit 12 setting information table 13 order table 14 aggregation order table 15 received packet management unit 16 aggregated packet processing unit 17 capsule processing unit 18 transmission processing unit 20 reception Processing unit 21 received packet management unit 22 capsule processing unit 23 aggregated packet processing unit 24 transmission processing unit

Claims (6)

[Claims] 1. A capsulating method for encapsulating a received packet and transmitting the encapsulated packet, wherein the packets to be encapsulated having the same destination or transmission form are encapsulated in the order of reception so as to fit within a prescribed aggregation length. And processing to transmit the encapsulated packet and the non-encapsulated packet in the order of reception. 2. An encapsulation apparatus for encapsulating and transmitting a received packet, wherein an order table for managing a reception order of the received packet while determining whether or not the received packet is to be encapsulated is created. Means for creating, from packets determined to be encapsulated, one or more aggregation order tables for managing the reception order of packets to be encapsulated having the same destination or transmission form; According to the table and the above aggregation order table,
While encapsulating and encapsulating packets to be encapsulated having the same transmission destination or transmission form within the prescribed aggregation length, the first packet of the encapsulated packet and the non-encapsulated packet are received. Means for transmitting the encapsulated packet and the non-encapsulated packet in a format arranged in order. 3. The encapsulation device according to claim 2, wherein the aggregation length is configured to use a value that is a natural number times a maximum transfer unit of a transmission path to the restoration-side encapsulation device. Characterized encapsulation device. 4. A capsulating device for receiving an encapsulated packet and a non-encapsulated packet, means for determining whether or not the encapsulated packet has been received, and restoring the received encapsulated packet to a state before the encapsulation. Means, means for extracting each of a plurality of packets aggregated in the restored packet from the restored packet, and means for transmitting the extracted packet to a destination. Encapsulation device. 5. A program recording medium on which a program used for realizing an encapsulation device for encapsulating and transmitting a received packet is recorded, and it is determined whether or not the received packet is an object to be encapsulated. A process of creating an order table for managing the order of reception of received packets, and managing the order of reception of packets to be encapsulated having the same destination or transmission form from packets determined to be encapsulated. Processing to create one or more aggregation order tables, according to the order table and the aggregation order table,
While encapsulating and encapsulating packets to be encapsulated having the same transmission destination or transmission form within the prescribed aggregation length, the first packet of the encapsulated packet and the non-encapsulated packet are received. A program recording medium characterized by recording a program for causing a computer to execute the process of transmitting the encapsulated packet and the process of transmitting the non-encapsulated packet in a format arranged in order. 6. A program recording medium on which a program used for realizing an encapsulation device for receiving an encapsulated packet and a non-encapsulated packet is recorded, and a process of judging whether or not the encapsulated packet has been received, A process of restoring the received encapsulated packet to a state before encapsulation, a process of extracting each of a plurality of packets aggregated into the packet from the restored packet, and a process of extracting the extracted packet. A program recording medium, wherein a program for causing a computer to execute a process of transmitting to a transmission destination is recorded.