JP2002124979A - Method for controlling communication path and its device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication path control method and device capable of applying the control of the same path control table to a plurality of IP address groups continuing in a specific digit area. SOLUTION: When a multi-cast address IP packet arrives at a path controller, the IP packet is temporarily stored in a register. When a destination address and a transmission origin address are expressed in binary numbers, those addresses are compared only when the values of digits corresponding to a bit mask in a path control table constituted of the transmission origin address, a bit mask, a multi-cast address, and an entry having interfaces are specific. The two addresses are judged to match regardless of the values of those addresses in the other case. When any entry matching both the transmission origin address and multi-cast address of the arriving IP packet is present in the path control table, the IP packet is outputted to all the interfaces on the entry. When any matching entry is not present, the IP packet is abandoned.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a communication path control method and apparatus, and more particularly, to a communication path control method and apparatus for multicast communication in an IP network.

[0002]

2. Description of the Related Art A conventional typical IP multicast route control device will be described.

FIG. 7 shows a configuration of a conventional IP multicast route control device.

In FIG. 1, a route selector 1 for controlling the transmission of an arriving IP packet and an arriving IP
A register 2 for temporarily holding a packet;
The comparison operation unit 3 that compares the address of the P packet with the stored entry of the routing control table, the packet transmission controller 7 that controls the transmission of the IP packet according to the result of the comparison operation, and the routing control table 80 A storage device 8 for holding the data and interfaces 9, 10, and 11 for inputting and outputting IP packets are provided.

In order to operate the route control device having the configuration shown in FIG. 1, first, a route control table 80 is constructed. The contents of the routing control table 80 are logically composed of a plurality of entries having the following configuration.

[0006] In this configuration, the interface is set to 0 depending on the situation.
It has more than one value. Also, the source address is
Values indicating "any" are allowed. The configuration of the routing control table 80 is performed before the routing controller starts the IP packet transfer operation.

In this state, when an IP packet having a multicast address as a destination address arrives at an arbitrary interface, for example, the interface 9, the IP packet is temporarily stored in the register 2, and each address of the destination and the source address is stored. Is the routing control table 8
Each entry at 0 is compared in the comparison operator 3.

This comparison operation is performed by, for example, an apparatus having a configuration as shown in FIG. The figure includes registers 14 and 15 that store two addresses to be compared, an arithmetic unit 12 that performs a comparison for each digit of the register, and a register 16 that stores the operation result.

In this configuration, two addresses are represented in binary numbers and stored in registers 14 and 15, and the exclusive OR of each digit is calculated by a calculator 12. The result is stored in the register 16, and when the operation result becomes 0 in all the digits, it is determined that the two addresses match. When the value of the source address is “arbitrary” in the entry of the routing control table 80, the comparison calculator 3 does not perform the comparison calculation as shown in FIG. It is determined that the two source addresses of the entries in the table 80 match.

Source address of the arriving IP packet,
If there is an entry in the routing control table 80 that matches both for each multicast address,
For the input packet, the packet transmission controller 7 outputs the input IP packet to all interfaces described in the matched entry. If there is no matching entry, or if there is no interface in the entry, the input IP packet is discarded by the packet transmission controller 7.

[0011]

However, in the above-mentioned conventional method, it is impossible to apply the same control of the routing table to a plurality of IP address groups that are continuous in a specific digit area. There's a problem. Here, a plurality of consecutive IP addresses in a specific digit area are defined below. That is, a specific digit area is a digit of a specific area adjacent to each other when a numerical value is expressed in a binary number, and a plurality of continuous IP address groups is a minimum value in the digit of the area. To the maximum value, and the other digits indicate the same IP address group. For example, four addresses of 224.0.0.3, 224.1.0.3, 224.2.0.3, and 224.3.0.3 are this example. That is, in this example, when the address is displayed in binary, the following is performed. 11100000.00000000.00000000.00000011 11100000.00000001.00000000.00000011 11100000.00000011.00000000.00000011 11100000.00000011.00000000.00000011 MSB (Most Significant Bit: Most significant bit)
The 15th and 16th digits are the digits of a specific area adjacent to each other, and in this address group, the digits of this area have values ranging from 0 to 3. And the other digits have exactly the same value.

In the above conventional method, even when the same control is to be performed on such an address group,
There is no other choice but to hold independent entries. For example, in the above example, four entries are required.
Therefore, when a large number of such route controls are performed, a problem occurs in that the route control table becomes enormous.

The present invention has been made in view of the above points, and has been made in view of the above points. A communication capable of applying the same control of the routing table to a plurality of consecutive IP address groups in a specific digit area. It is an object to provide a route control method and device.

[0014]

FIG. 1 is a diagram for explaining the principle of the present invention.

According to a first aspect of the present invention, there is provided a communication path control method for an IP packet having a multicast address as a destination address in an IP network path control apparatus. When a packet arrives (step 1), the IP packet is temporarily stored in a register (step 2), and the IP mask corresponds to the bit mask in the routing table consisting of an entry having a source address, a bit mask, a multicast address, and an interface. When the value of a digit is a binary representation of the destination address and the source address, only the digits of the specific digit area adjacent to each other are compared, and for the digits that are not, regardless of the values of the two addresses Match ( Step 3), the source address of IP packets arriving for each multicast address, if the entry both match was in the routing control table (Step 4, Yes), and the arrival I
The P packet is output to all the interfaces described in the entry (step 5). If there is no matching entry or if there is no interface in the entry (step 4, No), the arriving IP packet Is discarded (step 6).

FIG. 2 is a diagram showing the principle of the present invention.

The present invention (claim 2) is a communication route control device for an IP packet having a multicast address as a destination address in a route control device of an IP network, wherein an interface of the route control device has a multicast address as a destination address. When an IP packet having the packet arrives, a register 2 for temporarily storing the IP packet, a source address, a bit mask, a multicast address, a routing control table 81 consisting of an entry having an interface, and a bit mask in the routing control table 81 When the value of the corresponding digit of the destination address and the source address of the IP packet are expressed in binary notation, the comparison is made only for the digits of the specific digit area adjacent to each other. Matches regardless of address value And comparison means 3, shall have the source address of IP packets arriving for each multicast address, if the entry both match was in the routing control table 81, and the arrived I
The P packet is output to all interfaces described in the entry, and if there is no matching entry, or if there is no interface in the entry, the packet transmission control means 7 for discarding the arriving IP packet Have.

As described above, according to the present invention, two digits (destination address / multicast address) coincide with each other for a digit having a certain value according to the value of the bit mask of the routing table. For this purpose, it is possible to apply the same routing control table control to a plurality of IP address groups that are continuous in a specific digit area when the address is expressed in binary.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, an entry of a routing control table has information on a bit mask for an IP address, and a comparison operation unit performs an address comparison operation in consideration of the bit mask.

FIG. 3 shows the basic configuration of the communication path control device of the present invention.

The configuration shown in FIG. 1 includes a path selector 1 for controlling the transmission of an arriving IP packet, a register 2 therein for temporarily storing the arriving IP packet, and an address of the arriving IP packet. , A comparison operation unit 3 for comparing the entries of the routing control table stored therein, a packet transmission control unit 7 for controlling the transmission of the IP packet according to the result of the comparison operation, and a storage device 8 for holding the routing control table 81 And interfaces 9, 10, and 11 for inputting and outputting IP packets.

In order to operate the communication path control device having the above configuration, first, the path control table 81 is configured. The contents of the routing control table 81 are logically composed of a plurality of entries having the following configuration.

[0023] In the above configuration, the interface has two or more values depending on the situation. Also, a value indicating “arbitrary” is allowed for the source address. The configuration of the routing control table 81 is performed before the communication routing controller 1 starts the IP packet transfer operation.

In this state, any interface
For example, when an IP packet having a multicast address as a destination address arrives at the interface 9, the IP
The P packet is temporarily stored in the register 2, and each address of the destination and the source address is compared with each entry in the routing control table 81 by the comparison calculator 3.

In the configuration of the present invention, the comparison of the address is performed only for the digit whose corresponding digit of the bit mask in the routing control table 81 has a certain specific value. The other digits are determined to be the same regardless of the values of the two addresses. The routing control table 81
If the value of the source address is “arbitrary” in the entry of “1”, the comparison operation unit 3 determines that the arriving IP packet and the two source addresses of the entry of the routing control table 81 match.

Source address of the arriving IP packet,
If there is an entry in the routing control table 18 that matches both for each multicast address,
The input packet is output by the packet transmission controller 7 to all interfaces described in the matching entry. When there is no matching entry or when there is no interface in the entry, the input IP packet is discarded by the packet transmission controller 7.

As described above, in the configuration shown in FIG. 3, for a digit having a certain value according to the value of the bit mask, it is determined that the two addresses match, so the addresses are represented in binary. In this case, the same control of the routing table 18 can be applied to a plurality of IP address groups that are continuous in a specific digit area, and the routing control table 81 can be significantly consolidated. .

[0028]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 4 shows the configuration of a communication path device according to one embodiment of the present invention.

The communication path device shown in FIG.
A path selector 1 for controlling the transmission of a packet, a register 2 for temporarily storing an arriving IP packet therein, and a comparison between an address of the arriving IP packet and an entry of a stored path control table. The logical AND of the respective arithmetic operation results of the comparison arithmetic unit 3 to be performed, the masked comparison arithmetic units 31 and 32 for comparing two numerical values in consideration of the bit mask therein, and the comparison arithmetic units 31 and 32 A logical product operator 33, and a packet transmission controller 7, which controls transmission of IP packets according to the result of the comparison operation,
A storage device 8 for holding a routing control table 81, and interfaces 9, 10, 11 for inputting and outputting IP packets
Consists of

FIG. 5 is a diagram for explaining the comparison operation processing of one embodiment of the present invention. In the comparison operation units 31 and 32 with the mask of the comparison operation unit 3, the coincidence of two addresses is determined. The configuration of the part to be determined is shown. In this configuration,
The address registers 24 and 25 for storing two addresses to be compared, the register 26 for storing a bit mask, the exclusive OR operator 12 for comparing each digit of the address registers 24 and 25, the address comparison operation result and A logical product operator 13 for performing an operation with a bit mask and an output register 27 for storing the operation result are provided.

In order to operate the communication path control device shown in FIG. 4, first, a path control table 81 is constructed. The contents of the routing control table 81 are logically composed of a plurality of entries having the following configuration.

[0033] In this configuration, the interface is 2 depending on the situation.
It has more than one value. Also, the source address is
Values indicating "any" are allowed. The configuration of the routing control table 81 is performed before the communication routing controller starts the IP packet transfer operation.

FIG. 6 is a flowchart of the route control according to one embodiment of the present invention.

Step 101) An IP packet arrives.

Step 102) The arriving IP packet is temporarily stored in a register.

Step 103) Destination of IP packet,
The binary representation of the source address is compared with the corresponding digit in the routing table. If they match, the process proceeds to step 105; otherwise, the process proceeds to step 104.

Step 104) The mismatched digit is compared with the corresponding digit in the bit mask of the routing control table. If they match, the process proceeds to step 105; otherwise, the process proceeds to step 106.

Step 105) Output the interface described in the entry of the routing control table.

Step 106) Discard the IP packet.

In this state, an IP having a multicast address as a destination address from an arbitrary interface
When a packet arrives, the destination and source addresses of the IP packet are compared with their respective entries in the routing control table 81.

In the comparators 31 and 32, first, two addresses (destination address and source address) and a bit mask are respectively represented in binary numbers, and the values of respective digits are stored in registers 24, 25 and 26, respectively. Next, the exclusive OR of the corresponding digits of the two registers 24 and 25 is calculated by the exclusive OR calculator 12. Further, the logical product operator 13 calculates the logical product of the output of the calculator 12 as the comparison result and the bit mask of the register 26 for each digit, and stores the result in the output register 27. When the result of this operation in the output register 27 is 0 in all digits, the comparison operators 31 and 32 determine that the two addresses match. When the value of the source address is “arbitrary” in the entry of the routing control table 81, the comparison calculator 3 does not perform the comparison calculation as shown in FIG. It is determined that the two source addresses in the entry of the control table 81 match.

Source address of the arriving IP packet,
For each multicast address, if there is an entry that matches both in the routing control table 81,
The result is calculated by the logical product calculator 33, and the input IP packet is output to all the interfaces described in the entries of the routing control table 81. If there is no matching entry, or if there is no interface in the entry, the input IP packet is discarded by the packet transmission controller 7.

For example, if an entry whose multicast address is 224.0.2.3 and its bit mask is 225.0.225.225 exists in the routing table 81, this entry 1 All consecutive input IP packets whose multicast address is from 224.0.2.3 to 224.2225.2.3 for each match and are output to the interface described there.

This means that the value of the common routing control table is applied to the group of multicast addresses. That is, in this configuration, the bit mask and the register previously stored in the routing control table 81 are used. 26,
By the operation of the logical product operator 13, a common routing control table can be applied to successive multicast addresses. This cannot be expected with the configuration of the conventional route control device. In the conventional configuration, the configuration of the route control table and the configuration of the route selection arithmetic unit are such that the comparison between the IP packet and the address of the entry in the route control table can only be performed to determine whether or not both bits completely match. It has become. Therefore, in the above embodiment, 255 independent entries are required in the routing table.

Although the above embodiment has been described based on the configuration of FIG. 4, the operation of the path selector 1 is constructed as a program, and a disk unit of a computer used as a communication path unit or a floppy (registered) The present invention can be easily realized by storing it in a portable storage medium such as a trademark (trademark) disk, a CD-ROM, or the like and installing it when implementing the present invention.

The present invention is not limited to the above embodiment, but can be variously modified and applied within the scope of the claims.

[0048]

As described above, according to the present invention, a bit mask value can be specified in the entry of the path control table, and the path selection using the bit mask is performed by the register and the operation unit in the path selection operation unit. By performing the operation, it is possible to aggregate a plurality of routing control table entries by applying a common routing control table with respect to consecutive multicast addresses, and it is possible to realize the same routing control as before by using a small number of entries. .

[Brief description of the drawings]

FIG. 1 is a diagram for explaining the principle of the present invention.

FIG. 2 is a principle configuration diagram of the present invention.

FIG. 3 is a basic configuration diagram of a communication path control device of the present invention.

FIG. 4 is a configuration diagram of a communication path control device according to an embodiment of the present invention.

FIG. 5 is a diagram illustrating a comparison operation process according to an embodiment of the present invention.

FIG. 6 is a flowchart of a route control method according to an embodiment of the present invention.

FIG. 7 is a configuration diagram of a conventional IP multicast route control device.

FIG. 8 is a diagram for explaining a mechanism for performing a comparison operation in a conventional typical multicast IP packet path control device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 path selector 2 register 3 comparison means, comparator, comparison operation unit 7 packet transmission control device 8 storage device 9, 10, 11 interface 12 exclusive OR operation unit 13 AND operation unit 24, 25 address register 26 bit mask Register 27 Output register 31, 32 Comparison operation unit with mask 33 AND operation unit 81 Route control table

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Noboru Sonehara 2-3-1 Otemachi, Chiyoda-ku, Tokyo Within Nippon Telegraph and Telephone Corporation (72) Inventor Kazuhiko Okada 2-3-3 Otemachi, Chiyoda-ku, Tokyo No. 1 Nippon Telegraph and Telephone Corporation F term (reference) 5K030 GA03 HA08 HC01 KX28 LB05

Claims (2)

[Claims] In a communication route control method for an IP packet having a multicast address as a destination address in a route control device of an IP network, when an IP packet having a multicast address as a destination address arrives at an interface of the route control device,
The IP packet is temporarily stored in a register, and the corresponding digit value of the bit mask in the routing table including the source address, the bit mask, the multicast address, and the entry having the interface indicates the destination address and the source address. In the case of binary representation, comparison is made only for the digits of the specific digit area adjacent to each other, and for the other digits, it is assumed that they match regardless of the values of the two addresses. If there is an entry in the routing table that matches both the source address and the multicast address, the arriving IP packet is output to all interfaces described in the entry, and the matching entry is Missing or no interface in entry If have a communication path control method characterized by discarding the IP packet the arrival. 2. A communication route control device for an IP packet having a multicast address as a destination address in a route control device of an IP network, wherein an IP packet having a multicast address as a destination address arrives at an interface of the route control device.
A register for temporarily storing the IP packet, a source address, a bit mask, a multicast address, a routing control table consisting of entries having an interface, and a value of a corresponding digit of the bit mask in the routing control table, When the destination address and the source address of the IP packet are expressed in binary notation, only the digits of the specific digit area adjacent to each other are compared, and the other digits are the same regardless of the values of the two addresses. Comparing means for determining that the source IP address and the multicast address of the arriving IP packet are the same, and if the routing control table has an entry that matches both, the arriving IP packet is described in the entry. Output to all interfaces No entry, or, if no interface in the entry, the communication path control apparatus characterized by having a discarding packet transmission control unit an IP packet the arrival.