JP2003348148A - Ip multicast control method and ip multicast control system employing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an IP multicast control method for simplifying the processing so as to allow a switch section of a layer 2 switch to have only to refer to a label multicast table and capable of attaining high speed multicasting and to provide an IP multicast control system employing the method. <P>SOLUTION: The IP multicast control method is characterized in such that upon the receipt of a multicast with a multicast label attached thereto, the layer 2 switch 2 refers to a label multicast table 11 in a layer 3 device 1, decides a transmission port from the multicast label, deletes the multicast label and transmits the resulting multicast frame when the label multicast table 11 stores deletion of the multicast label. <P>COPYRIGHT: (C)2004,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an IP multicast communication method used for duplicating an IP packet in an IP packet communication network and distributing the same IP packet to a plurality of destinations. The present invention relates to an IP multicast control system to be used.

[0002]

2. Description of the Related Art An IP multicast system in a conventional layer 2 switch includes an IGMP (Internet Group).
Management Protocol) Snooping method and CGM
P (Cisco Group Management Protocol). First, the IGMP snooping method will be described using the configuration in FIG. 17 and the operation in FIG. As shown in FIG. 17, the layer 2 switch 101, the layer 3
A switch or router (hereinafter, represented by a layer 3 device) comprises a layer 3 device 102 and a terminal 103. The layer 2 switch 101 is connected to the control unit 1
11, a table 112 for storing the relationship between the MAC destination address and the transmission port, and a switch unit 113.

Next, the operation will be described with reference to FIG. When the layer 2 switch 101 receives the layer 2 frame transmitted by the terminal 103, the switch unit 113
The switch unit of the port that has received the corresponding IGMP Membership Report message transfers all the frames whose destination MAC address is the multicast address to the control unit 111 by copying, and the control unit 111 analyzes and transfers the IGMP Membership Report message.
If the message is a mbership report message, the port that has received the corresponding IGMP Membership Report message is stored in the table 112 as a port that requires transmission of a layer 2 frame having the corresponding multicast address. The table 112 can store a plurality of ports as ports that need to be transmitted to the same multicast address.

When the layer 2 switch 101 receives the layer 2 frame, the switch unit 113 refers to the table 112 and, if there is a multicast address corresponding to the MAC destination address, transmits the multicast address to all the stored ports. Thus, in the layer 2 switch 101,
A multicast frame can be transmitted to all ports for which transmission has been requested from the terminal 103.

Next, the CGMP method will be described with reference to the operation shown in FIG. The configuration used for the description is the same as that in FIG. When the layer 3 device 102 receives the IGMP Membership Report message transmitted by the terminal 103, the group MAC address generated from the group address and the source MA which is the MAC address of the terminal 103
As for the C address, the relationship between the group MAC address and the transmission port is derived from the relationship between the group MAC address and the transmission source MAC address specified in the CGMP join message, and stored in the table 112. Table 1
Numeral 12 can store a plurality of ports as ports requiring transmission for the same multicast address.

When the layer 2 switch 101 receives the layer 2 frame, the switch unit 113 refers to the table 112 and, if there is a multicast address corresponding to the MAC destination address, transmits the multicast address to all the stored ports. Thus, in the layer 2 switch 101,
A multicast frame can be transmitted to all ports for which transmission has been requested from the terminal.

[0007]

However, the IGM
When the P snooping method is used, IGMP is Layer 3
Since the protocol is used, layer 3 processing must be performed while being a layer 2 switch, and there is a problem that a high-performance CPU is required. Also, if the CPU is IGMP
In order to obtain a message, a data frame having the same MAC destination address but not an IGMP message must be captured by the CPU. Particularly, when a high-speed video stream is transferred, a large number of data frames are transferred. Since there is a wasteful process of capturing and discarding a message that is not an IGMP message, there is a problem that the CPU needs more processing capability.

On the other hand, when the CGMP method is used, there is a problem that a CGMP protocol process is performed in a layer 2 switch and a layer 3 device, and a high-performance CPU is required, although not as much as IGMP snooping. Even if the layer 3 device completes the IGMP process,
Until the updating of the table contents of the layer 2 switch by the GMP join is completed, there is a problem that the multicast frame is not transmitted and the connection delay is large.

Further, in the CGMP system, Source Specifi
c There is a problem that Multicast (SSM) cannot be supported. In SSM, a multicast flow is distinguished not only by a multicast group address but also by a source IP address. That is, since only the MAC address of Layer 2 is identified in the CGMP method, there is a problem that the difference of the source IP address which is the address of Layer 3 cannot be distinguished in the same group address, so that it cannot support SSM.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems in the prior art, to simplify the processing in a layer 2 switch so that the switch section only needs to refer to the label multicast table, and to achieve high-speed processing. An object of the present invention is to provide an IP multicast control method enabling multicast and an IP multicast control system using the same.

[0011]

In order to achieve the above object, an IP multicast control method according to the present invention provides a method for controlling the relationship between a multicast label, an IP multicast group address, and a port for transmitting a corresponding IP packet.
Alternatively, an IP multicast table for storing a relationship between the multicast label, the group address and the source IP address of the IP multicast, and a port for transmitting the corresponding IP packet, and the multicast label and the corresponding multicast label are assigned. A layer 3 device comprising: a label multicast table for storing a relationship between the multicast label and a port for transmitting the frame, and whether or not to delete the multicast label when transmitting the frame. A label multicast table that stores a relationship with a port that transmits a frame to which a multicast label has been added, and whether or not to delete the multicast label when transmitting the frame. An IP multicast control method used in the IP network constituted by a pitch, the multicast label, the Layer 2
In the switch, it is defined in advance which one or more ports to transmit to. When the layer 3 device receives an IP multicast packet having no multicast label, the switch refers to the IP multicast table and receives the packet. Group address described in the destination address of the IP multicast packet
A transmission port is determined from the corresponding group address and source IP address, the multicast label is added and transmitted as a multicast frame. If an IP multicast packet having a multicast label is received, the label multicast table With reference to, to determine the transmission port from the multicast label, and if it is stored in the label multicast table to delete the multicast label, delete the multicast label and transmit a multicast frame, the Layer 2 switch, When receiving a multicast frame to which a multicast label has been added, referring to the label multicast table to determine a transmission port from the multicast label, If the multicast table remembers to delete the multicast label,
The multicast is characterized in that the label is deleted and the multicast frame is transmitted.

Further, in the IP multicast control method according to the present invention, the label multicast table in the layer 3 device and the layer 2 switch includes a relationship between the multicast label and a port for transmitting a frame to which the corresponding multicast label is added. In addition to whether or not to delete the multicast label when transmitting the corresponding frame, if the multicast label is not deleted when transmitting the corresponding frame, a multicast label to be newly added for each transmission port is stored. In addition, when the layer 3 device or the layer 2 switch receives a multicast frame to which a multicast label is assigned, the layer 3 device or the layer 2 switch refers to the label multicast table and determines a transmission port from the multicast label, And, wherein if it is stored as a label multicast table does not delete the multicast label, by applying a new multicast label each transmission port, and transmits the multicast frame.

[0013] In the IP multicast control method according to the present invention, the multicast label may be designated by an IE.
EE 802.1Q standard VLAN identifier area or I
It is provided in a label area of a label stack specified in RTF RFC3032.

Still further, in the IP multicast control method according to the present invention, each bit of the multicast label has a one-to-one correspondence with each port of the layer 2 switch, and one bit corresponding to a port to be transmitted is not transmitted. The bit corresponding to the port and the non-existing port is 0, or the bit corresponding to the port to be transmitted is 0,
The bit corresponding to the port that does not transmit and the port that does not exist is set to 1, and the bit width of the IP multicast table of the layer 3 device or the multicast label of the label multicast table is equal to the number of ports of the connected layer 2 switch. Enabled, the layer 2 switch uses only the delete flag of the label multicast table, or does not have the label multicast table, transmits from the port designated as transmitting the multicast label, and deletes all the multicast labels. Alternatively, a label multicast table including a newly assigned multicast label is provided.

Still further, in the IP multicast control method according to the present invention, the terminal is connected to the layer 2 switch, and the layer 2 switch is connected to the layer 3 device.
A P multicast control method, wherein the layer 3 device includes: the IP multicast table, the label multicast table, an IGMP processing unit, a MAC address or an IP address of the terminal, and a communication between the terminal and the layer 3 device. Layer 2 installed
A path management table for storing which port of the switch is connected, wherein the layer 3 device
When receiving an IGMP Membership Report message or a Leave-Group message from the terminal, when the IGMP processing unit determines whether to add or delete the corresponding terminal as a multicast member, the source MAC address of the corresponding terminal Or source I
From the P address, the connection port of the corresponding terminal in the layer 2 switch is obtained by referring to the path management table, and when the IGMP processing unit determines that the corresponding terminal is added as a member, the IP multicast table and the label multicast table Is updated to a multicast label indicating that the connection port of the corresponding terminal has been added, and if the IGMP processing unit determines that the corresponding terminal is to be deleted from the member, the IP multicast table And updating the multicast label of the corresponding group in the label multicast table to a multicast label indicating that the connection port of the corresponding terminal has been deleted.

On the other hand, an IP multicast control system according to the present invention is an IP multicast control system using any one of the above-described IP multicast control methods, and includes the IP multicast table and the label multicast table. It is characterized by comprising the layer 3 device and the layer 2 switch provided with the label multicast table, wherein the layer 3 device can designate an output port of the layer 2 switch.

In the present invention, the layer 3 device is I
Performs all GMP protocol processing, inserts a label indicating the transmission port in the layer 2 switch in the data frame, and performs layer transmission by referencing only the label without performing any IGMP protocol processing. The two-switch does not require a high-performance CPU, and can be switched only by the layer 2 switch unit.

At this time, a layer 3 device having a VLAN function has a means for inserting a VLAN identifier into a layer 2 frame, so that it is easy to insert a label into the layer 2 frame and has a VLAN function. The layer 2 switch can recognize and process the VLAN identifier in the extension header section of the layer 2 frame, and can easily recognize and delete the label. In addition, by changing the label in cooperation with the IGMP protocol processing unit in the same device of the layer 3 device, when the layer 3 device completes the IGMP protocol processing, the change is reflected on the label, and a high-speed connection change is performed. It becomes possible.

In the SSM, a layer 3 device capable of identifying a layer 3 address understands a group address and a source IP address, and assigns a different label to the same group if the source IP address is different. Accordingly, as long as the layer 2 switch located downstream of the corresponding layer 3 device can identify the label, the transmission port can be selected even if the source IP address which is the layer 3 address cannot be identified, so that the SSM can be supported. .

[0020]

Embodiments of the present invention will be described below in detail with reference to preferred embodiments shown in the drawings.

[Embodiment 1] A first embodiment of the present invention will be described with reference to the multicast frame configuration of FIG. 1, the IP multicast table configuration of FIG. 2, the label multicast table configuration of FIG. 3, and the first embodiment of FIG. The operation will be described with reference to a connection configuration example for explaining the operation, a sequence example 1 in FIG. 5, and a sequence example 2 in FIG. This embodiment is similar to the first embodiment.
It is related to.

First, the configuration of a multicast frame in this embodiment will be described with reference to FIGS. 1 (a) and 1 (b). The multicast frame configuration of the present embodiment is configured by adding a multicast label to the conventional frame configuration (each shown in the upper part). The multicast label is composed of an identifier indicating that a multicast label exists and a label. With this configuration, the layer 3 device and the layer 2 switch determine whether or not a multicast label has been assigned. In the first example of the multicast frame configuration, the multicast label is added in the layer 2 header (see FIG. 1A). In the multicast frame configuration example 2, an identifier is assigned to the type area of the layer 2 header, and a label is assigned to the data part (see FIG. 1B).

Next, the configuration of the IP multicast table of this embodiment will be described with reference to FIGS. 2 (a) and 2 (b). The IP multicast table of the configuration example 1 stores a group address, a transmission port of an IP packet having the corresponding address, and a multicast label given at the time of transmission (see FIG. 2A). Here, the group address is a group address described in the destination address of the received IP packet. The IP multicast table of the configuration example 2 is a table corresponding to the SSM, and a source address term is added to the configuration example 1 (see FIG. 2B). Here, the source address is an address written in the source address of the received IP multicast packet.

In this configuration example, the group address,
Although a specific address value is described in the notation of IP version 4 for both the source address and the IP address, these do not limit the present invention, and other address values or IP version 6 may be used. The same is true. Further, in the present configuration example, the multicast label has four hexadecimal digits, but this does not limit the present invention.
The same applies to other notations and numbers of digits.

Next, the configuration of the label multicast table of this embodiment will be described with reference to FIG. The label multicast table includes a multicast label, a transmission port of a frame having the label, and a deletion flag. Here, the deletion flag means whether or not the label is deleted at the time of transmission. When the deletion flag is set, the multicast label is deleted. When there is no further multicast point at the subsequent stage, the multicast label is unnecessary and is deleted. In this configuration example, the multicast label has four hexadecimal digits, but this does not limit the present invention, and the same applies to other notations and other numbers of digits.

Hereinafter, the configuration example of the IP multicast table of FIG. 2, the configuration example of the label multicast table of FIG. 3, the connection configuration example of FIG. 4, the sequence example 1 of FIG. 5, and the sequence example 2 of FIG. Next, an operation example of the present embodiment will be described.

As shown in FIG. 4, the layer 3 device 1
Is composed of an IP multicast table 11, a label multicast table 12, and a switch unit 13.
The P multicast table 11 and the label multicast table 12 are connected to the switch unit 13.
The layer 2 switch 2 includes a label multicast table 21 and a switch unit 22. The label multicast table 21 is connected to the switch unit 22. Similarly, the layer 2 switch 3 includes a label multicast table 31 and a switch unit 32, and the label multicast table 31 is connected to the switch unit 32.

For example, in the example shown in FIG. 3, when the switch unit 22 receives the multicast frame of the multicast label 0011,
, And the multicast label is deleted and transmitted to port 1 and port 2. When transmitting the multicast frame from all the notified ports, the switch unit 22 ends a series of multicast operations.

The operation of the layer 2 switch 3 is the same as that of the layer 2 switch 2, for example, in the example of FIG.
When the switch unit 22 receives the multicast frame of the multicast label 0001, it inquires of the label multicast table 31 about 0001, deletes the multicast label to the port 1 and the port 3, and transmits the port. Thus, the destination address 22 arriving at one layer 3 device
The multicast packet of 4.1.1.1 is transmitted to ports 1 and 3 of layer 2 switch 2 and layer 2 switch 3
Multicast to port 1 and port 2

Next, an operation example when the layer 3 device receives an IP multicast packet with a multicast label will be described with reference to sequence example 2 in FIG. When a multicast label is present in the arrived IP multicast packet, the switch unit 13 of the layer 3 switch 1 notifies the label multicast table 12 of the multicast label and inquires about a transmission port. Upon receiving the multicast label, the label multicast table 12 returns to the switch section 13 all necessary transmission ports and whether or not to delete the label at each port.

For example, in the example of FIG.
Receives a packet with a multicast label of fffe,
To the fffe, and obtains the reply that the multicast label is continuously used and transmitted from four ports 1, 3, 4, and 7. The switch unit 13 transmits a multicast frame from the designated port. At this time,
If there is a reply that the label is not deleted at each port, the multicast label is directly added and transmitted. Also,
If there is a reply to delete, the multicast label is deleted from the multicast frame transmitted from the corresponding port. After transmitting the multicast frame from all the notified ports, the switch unit 13 ends a series of multicast operations.

In this way, the layer 3 device 1
When a packet with the multicast label fffe is received, it continues from four ports 1, 3, 4, and 7.
Send a multicast frame with a multicast label of fffe.

The operation of the layer 2 switch shown in FIG.
This is the same as the description in FIG. 5 described later. For example, FIG.
4, when the layer 2 switch 2 and the layer 2 switch 3 receive the multicast frame having the multicast label of fffe from the layer 3 device 1, the layer 2 switch 2 and the layer 2 switch 3 transmit the multicast frame from the ports 1, 3, 4, and 7. Thus, the packet having the multicast label of fffe arriving at the layer 3 device 1 is transmitted to the layer 2 switch 2
And the ports 1, 3, 4, and 7 of the layer 2 switch 3 and the ports 1, 3, 4, and 7.

According to the first embodiment, the following effects can be obtained. That is, the conventional multicast output is output to all ports including unnecessary ports, but in the first embodiment, the output port of the layer 2 switch is instructed from the layer 3 device, and only the ports that need multicast are output. The effect of improving security and avoiding traffic congestion can be obtained.

[Second Embodiment] A second embodiment of the present invention will be described with reference to a configuration example of a label multicast table shown in FIG. This embodiment relates to claim 2. The port 1 of the switch unit 13 of the layer 3 device 1 is connected to the switch unit 22 of the layer 2 switch 2, and the port 3 is connected to the switch unit 32 of the layer 2 switch 3. Here, the connection relationship between the layer 3 device and the layer 2 device,
And the number of each port is an example, and does not limit the present invention.

First, an operation example when the layer 3 device 1 receives an IP multicast packet without a multicast label will be described using sequence example 1 in FIG. In the IP multicast table 11, a group address or a group address, a source address, a transmission port of an IP packet having the corresponding address, and a multicast label to be given at the time of transmission are set in advance. For example, as shown in IP multicast table configuration example 1 of FIG. 2, the destination group address is 224.1.1.
One IP packet is transmitted from port 1 and port 2 and registered with multicast labels 0011 and 0001, respectively.

The label multicast table 21
, A multicast label, a transmission port of a frame having the label, and whether or not to delete the label at the time of transmission are set. For example, as shown in the example of the label multicast table configuration in FIG. 3, a frame with a multicast label of 0001 is transmitted from ports 1 and 3 with the multicast label deleted, and a frame with a multicast label of 0011 is deleted with the multicast label deleted. It is registered that data is transmitted from port 1 and port 2.

In the switch unit 13 of the layer 3 device 1,
When an IP multicast packet having a destination address of 224.1.1.1 arrives, it is determined whether or not a multicast label exists.
1 is notified of the group address or the group address and the source address, and inquires about the transmission port and the multicast label. For example, the transmission port of 224.1.1.1 is queried. At this time, it is assumed that the value to be notified is only the group address or the value corresponding to the SSM, and both the group address and the source address are set in advance.

The IP multicast table 11 receives the group address or the group address and the source address, and stores all necessary transmission ports and all the multicast labels corresponding to each transmission port in the switch unit 13.
Reply to For example, in the example of FIG.
If it is 1.1, the transmission ports are 1 and 3, and the multicast labels are 0011 and 0001, respectively.

The switch unit 13 adds the notified multicast label to the received IP packet, and transmits the packet from the designated port as a multicast frame.
For example, by assigning a multicast label 0011 to port 1
From the port 3, with the multicast label 0001 added, and transmitted from the port 3. When transmitting the multicast frame from all the notified ports, the switch unit 13 ends a series of multicast operations.

Next, the switch unit 2 of the layer 2 switch 2
If the multicast frame is received in step 2, if the multicast label exists, the multicast label is notified to the label multicast table 21 and the transmission port is queried. Label multicast table 21
Receives the multicast label and returns to the switch unit 22 all necessary transmission ports and whether or not to delete the multicast label at each port.

The switch section 22 transmits a multicast frame from a designated port. At this time, if there is a reply of deletion, the multicast label is deleted from the multicast frame transmitted from the corresponding port. If there is a reply indicating that the message is not to be deleted, the multicast label is directly added and transmitted.

The label multicast table 21 of the present embodiment includes a reception multicast label, a transmission port,
It consists of a deletion flag and a transmission multicast label. The terms for the delete flag and the outgoing multicast label are
Provided for each transmission port. When the deletion flag is not set, the term of the transmission multicast label is valid, and when the deletion flag is set, the multicast label is deleted and the term of the transmission multicast label is invalid. In the configuration example of FIG. 7, the multicast label has four hexadecimal digits, but this does not limit the present invention, and the same applies to other notations and numbers of digits.

The operation of this embodiment will be described below. For the sake of clarity, the connection configuration is the same as that of FIG. 4 used in the description of the first embodiment, and the sequence is the same as that of FIG. When a multicast label is present in the arrived IP multicast packet, the switch unit 13 of the layer 3 switch 1 in FIG. 4 notifies the label multicast table 12 of the multicast label and inquires about the transmission port.
Upon receiving the multicast label, the label multicast table 12 returns to the switch unit 13 all necessary transmission ports, whether or not to delete the label at each port, and the transmission multicast label when the label is not deleted. At this time, if there is a transmission multicast label without removing the label, the transmission multicast label is replaced and transmitted.

For example, in the example of FIG.
When a packet having a multicast label of ff00 is received, fffe is inquired to the label multicast table 12, and the relationship between the transmission port and the transmission multicast label is as follows: 0001 for port 1 and 0011 for port 3; The multicast frame is transmitted from port 1 to the multicast label 0001 from port 0001, and the multicast frame is transmitted from port 3 to the multicast label 0011.

At this time, if there is a layer 3 device or a layer 2 switch that will be a multicast point further in the subsequent stage, it is replaced with an appropriate multicast label and transmitted, and a layer 3 device or a multicast point further in the subsequent stage. If the layer 2 switch does not exist, the multicast label is unnecessary and is deleted. When transmitting the multicast frame from all the notified ports, the switch unit 13 ends the series of multicast operations.

The operation in the layer 2 switch is also the layer 3
This is the same as the operation in the device. The operation for deleting a label is the same as in the first embodiment. According to the second embodiment, in addition to the above-described effects, an effect is obtained that it is possible to cope with a case where the number of layer 2 switches is multiple.

[Third Embodiment] A third embodiment of the present invention will be described with reference to a multicast frame configuration shown in FIG. In addition,
This embodiment relates to claim 3. In the frame configuration of the present embodiment, two frames defined in the IEEE802.3Q standard are used.
An identifier is described in a byte VLAN protocol ID area, and a label of a 12-bit VLAN identifier area is described.

In the IP multicast table configuration and the label multicast table configuration, the multicast label has 12 bits. The multicast label item in FIGS. 2 and 3 and the reception multicast label item and the transmission multicast label item in FIG. 7 have 12 bits. The operation is the same as in the first and second embodiments. According to the third embodiment, in addition to the effects described above, there is obtained an effect that the present invention can be realized by a slight change of the layer 2 switch.

[Embodiment 4] Embodiment 4 of the present invention will be described with reference to the multicast frame configuration shown in FIG. In addition,
This embodiment relates to claim 4. In the frame configuration of the present embodiment, as shown in FIG. 9, the identifier is described in a 16-bit length / type area. In the configuration 1, the multicast label is described in a 20-bit label area of a label stack specified in IETF RFC3032,
L is used as Time To Live.

In the configuration 2, the multicast label is described in a 24-bit area of the label, the test use, and the stack bottom of the label stack specified in IETF RFC3032, and the TTL is used as Time To Live. In the configuration 3, the multicast label is IE
It is described in the 32-bit area of the label, test use, stack bottom, and TTL of the label stack specified in TF RFC3032.

The configuration of the IP multicast table and the configuration of the label multicast table are as follows. In the configuration 1, the multicast label items of FIGS.
The receiving multicast label item and the transmitting multicast label item of FIG.
The multicast label item in FIG. 3 and the received multicast label item in FIG. 7 and the transmitted multicast label item in FIG. 7 have 24 bits. In the configuration 3, the multicast label item in FIGS. 2 and 3 and the received multicast label in FIG. The item and the transmission multicast label item have 32 bits.

The operation is described in the first and second embodiments.
Is the same as According to the fourth embodiment, in addition to the effects described above, an effect is obtained that the present invention can be realized with a small change even when the number of the layer 2 switches is multi-stage.

Fifth Embodiment A fifth embodiment of the present invention will be described with reference to FIG.
, An IP multicast table configuration in FIG. 11, and a label multicast table configuration in FIG. This embodiment relates to claim 5. As shown in FIG. 10, a configuration example in which the layer switch 2 is connected to the port 1 of the layer 3 device 1 and the layer 2 switch 3 is connected to the port 3 will be described. Although FIG. 10 shows an example in which a layer 2 switch having five ports is used, the configuration and the number of ports do not limit the present invention, and the same applies to other cases.

In the layer 2 switch 2, 224.1.1.1
Is connected to ports 1, 2, and 4, and in layer 2 switch 3, the member at 224.1.1.1 is connected to ports 1, 4, 5, and 7. At this time,
The multicast label in the IP multicast table 11 corresponds to each port of the connected layer 2 switch. In the transmission port 1, that is, the layer 2 switch 2, the multicast frame whose destination group is 224.1.1.1 Since transmission is performed from ports 2 and 4, bits are set in multicast labels 1, 2, and 4, and bits are not set in ports 0 and 3 that are not transmitted and ports 5 through 8 that are not present.

Therefore, as a multicast label,
011010000. Similarly, in the layer 2 switch 2 connected to the port 3 of the layer 3 device, the multicast frame having the destination group of 224.1.1.1 is transmitted from the ports 1, 4, 5, and 7. Therefore, the multicast label is 010011010. Becomes

In the layer 3 device 1, the destination is 224.1.1.1
When a packet arrives, a multicast label of 011010000 is assigned to port 1 and a port number of 010011010 is assigned to port 3.
And send it. Layer 2
When the switch 2 receives the multicast frame with the multicast label of 011010000, the switch 2 transmits the multicast frame to the ports 1, 2, and 4 where the bit is set. The layer 3 switch 3 sends the multicast frame with the multicast label of 010011010 to the multicast frame. Is transmitted to ports 1, 4, 5, and 7 where the bit is set.

At this time, the layer 2 switch further comprises a layer 3 device, which is a multicast point,
Alternatively, if there is no layer 2 switch (that is, if it is a layer 2 switch that connects all terminals), there may be no label multicast table and all multicast labels are deleted. Also,
The layer 2 switch may be provided with a label multicast table at the subsequent stage as shown in FIG. 12 in consideration of the existence of a layer 3 device or a layer 2 switch serving as a multicast point. In this case, the label multicast table includes a transmission port,
It consists of a deletion flag and a multicast label item to be newly added.

According to the fifth embodiment, in addition to the above-described effects, since the layer 2 switch can be configured by hardware, it is possible to obtain an effect that the speed can be increased.

Sixth Embodiment A sixth embodiment of the present invention will be described with reference to FIG.
This will be described with reference to the layer 3 device configuration of FIG. This embodiment relates to claim 6. As shown in FIG. 13, the layer 3 device of this embodiment includes an IP multicast table 11, a label multicast table 12, a switch unit 13, an IGMP processing unit 14, and a route management table 15.

The configurations of the IP multicast table 11 and the label multicast table 12 have already been described in the other embodiments, so that the description will be omitted. The configuration of the route management table 15 will be described with reference to FIG. The route management table 15 includes a port of the layer 3 device,
It is composed of a port of the layer 2 switch connected to the port, and a source address of the receiving terminal connected to the port. Although FIG. 14 shows the case of an IP address, the source address of the receiving terminal is
There can be both a case of unifying with a MAC address and a case of unifying with an IP address.

The IP multicast table 11, the label multicast table 12, and the IGMP processing unit 14
Is connected to the switch unit 13 and the route management table 15
Is connected to the IGMP processing unit 14. Since the configuration of the layer 2 switch 2 is the same as that of the first embodiment, the description is omitted. It is assumed that the receiving terminal 4 is connected to the layer 2 switch 2.

Hereinafter, the operation of the sixth embodiment will be described using Sequence Example 1 of FIG. 15 and Sequence Example 2 of FIG. FIG. 15 shows a sequence when a new multicast flow reception request is made, and FIG. 16 shows a sequence when the received multicast flow is stopped. In the route management table 15, the port of the layer 3 device, the port of the layer 2 switch connected to the port, and the source address of the receiving terminal connected to the port are registered in advance.

First, an operation example when a new multicast flow reception request is made will be described with reference to FIG. When requesting reception of a multicast frame, the receiving terminal 4 requests the layer 3 device 1 to specify the requested group address or the requested group address and the transmission source IP address.
Send ip Report. Here, IGMP version 2
In the case of IGMP version 3, it is possible to specify the source IP address in addition to the requested group address.
In this case, the source IP address is the IP address of the device that transmits the multicast packet, not the IP address of the receiving terminal.

The switch unit 13 receives an IGM signal from the receiving terminal 4.
When the P Membership Report is received, it is transferred to the IGMP processing unit 14. When the IGMP processing unit 14 determines to transfer the multicast frame, the IGMP processing unit 14
The source MAC address of the receiving terminal or the source IP address of the receiving terminal attached to the IGMP Membership Report frame to which port the relevant receiving terminal is connected to in the layer 2 switch 2. Get the information of.

Next, the IGMP processing unit 14 generates a new multicast label for adding the obtained port. Alternatively, taking the method of Embodiment 5 as an example, 221.1.1.
To explain using the case where the transmission port of the layer 3 device of 1 is 1, the old multicast label is 011010000, and if the receiving terminal of 3, that is, port 8 is added to the transmission port, the new multicast label is 011010.
It becomes 001. However, this is merely an example, and in the present invention, a new multicast label may be determined based on the relationship between a predefined multicast label and a group of transmission ports.

Next, the IGMP processing unit 14 reflects the change of the multicast label on the IP multicast label 11 or the multicast table 12.
After that, the new multicast label is reflected from the multicast packet arriving at the layer 3 device,
The layer 2 switch 2 starts transmission to the port 8, and the receiving terminal 4 receives the multicast frame of the requested multicast group.

Second, a sequence for stopping the received multicast flow will be described with reference to FIG. When stopping the reception of the multicast frame, the receiving terminal 4 notifies the layer 3 device 1 of an IGMP Leave Group that specifies a group address to be stopped.
Or the group address to stop and the source IP
IGM with explicit or exclusive address
Send P Membership Report. Note that IGMP version 2 is the former and IGMP version 3
If so, the latter. In this case, the source IP address is the IP address of the device that transmits the multicast packet, not the IP address of the receiving terminal.

The switch unit 13 receives an IGMP signal from the receiving terminal.
Upon receiving a version 2 Leave Group or an IGMP version 3 Membership Report,
The data is transferred to the MP processing unit 14. When determining to stop the transfer of the multicast frame, the IGMP processing unit 14 stores the source MAC address of the receiving terminal or the source IP address of the receiving terminal added to the frame of the received IGMP message in the path management table 15. Transfer,
The layer 2 switch 2 acquires information on which port the corresponding receiving terminal is connected to.

Next, the IGMP processing unit 14 generates a new multicast label for deleting the acquired port. Alternatively, taking the method of the fifth embodiment as an example, 221.1 in FIG.
To explain using the case where the transmission port of the layer 3 device of 1.1 is 1, assuming that the old multicast label is 011010001 and the receiving terminal 4, that is, port 8 is deleted from the transmission port, the new multicast label is 011010000. Become. However, this is merely an example, and in the present invention, a new multicast label may be determined based on the relationship between the predefined multicast label and the transmission port group.

Next, the IGMP processing unit 14 reflects the change of the multicast label on the IP multicast table 11 or the label multicast table 12. After that, from the multicast packet arriving at the layer 3 device, the new multicast label is reflected, the transmission to the port 8 is stopped in the layer 2 switch 2, and the receiving terminal 4 receives the multicast frame of the multicast group requested to be stopped. Will not be.

According to the sixth embodiment, in addition to the effects described above, by specifying the receiving terminal, a further effect that security can be improved can be obtained.

Each of the above embodiments is merely an example of the present invention, and the present invention should not be limited to these embodiments, and appropriate modifications and improvements may be made without departing from the scope of the present invention. It goes without saying that it may be performed. For example, the IP multicast control method according to claims 1 to 6 can be realized by program control by a computer, and a recording medium on which such a program is recorded can be distributed as a product. It is. The scope of the present invention extends to such embodiments.

[0074]

As described above in detail, according to the present invention, in the layer 2 switch, the processing is simplified so that the switch section only needs to refer to the label multicast table, and high-speed multicast is performed. IP multicast control method and I using the same
This has a remarkable effect that a P multicast control system can be realized.

More specifically, in the layer 2 switch, since the switch section only needs to refer to the label multicast table, high-speed multicast can be performed at low cost without requiring high-performance CPU processing. The effect is obtained, and the effect that the SSM can be supported by the low-cost layer 2 switch without performing the IP processing using the layer 3 device is also obtained.

[Brief description of the drawings]

FIG. 1 shows a multicast frame configuration according to a first embodiment of the present invention.

FIG. 2 is an IP multicast table configuration according to the first embodiment of the present invention.

FIG. 3 is a configuration of a label multicast table according to the first embodiment of the present invention.

FIG. 4 is a connection configuration example used for explaining the operation of the first embodiment of the present invention.

FIG. 5 is a sequence example 1 of the first embodiment of the present invention.

FIG. 6 is a sequence example 2 of the first embodiment of the present invention.

FIG. 7 is a configuration of a label multicast table according to the second embodiment of the present invention.

FIG. 8 shows a multicast frame configuration according to a third embodiment of the present invention.

FIG. 9 shows a multicast frame configuration according to a fourth embodiment of the present invention.

FIG. 10 is a connection configuration example used for describing the operation of Embodiment 5 of the present invention.

FIG. 11 is an IP multicast table configuration according to a fifth embodiment of the present invention.

FIG. 12 is a configuration of a label multicast table according to a fifth embodiment of the present invention.

FIG. 13 is a connection configuration example used for explaining the operation of the sixth embodiment of the present invention.

FIG. 14 is a configuration of a route management table according to a sixth embodiment of the present invention.

FIG. 15 is a sequence example 1 of the sixth embodiment of the present invention.

FIG. 16 is a sequence example 2 of the sixth embodiment of the present invention.

FIG. 17 shows a connection configuration used for explaining the operation of the conventional system.

FIG. 18 is a sequence example of the IGMP snooping method.

FIG. 19 is a sequence example of the CGMP method.

[Explanation of symbols]

1 Layer 3 device 2,3 Layer 2 switch 4 receiving terminal 5 terminal 11 IP multicast table 12,21,31 Label multicast table 13,22,32 Switch section 14 IGMP processing unit 15 Route management table

Claims (7)

[Claims] 1. A relationship between a multicast label, an IP multicast group address, and a port for transmitting a corresponding IP packet, or transmitting the multicast label, the IP multicast group address, a source IP address, and a corresponding IP packet. Multicast table that stores the relationship with the port to be transmitted, the relationship between the multicast label and the port that transmits the frame to which the multicast label is assigned, and the multicast label is deleted when the frame is transmitted. A layer 3 device having a label multicast table for storing whether or not to perform the operation, a relationship between the multicast label and a port for transmitting a frame to which the corresponding multicast label is added, and a corresponding frame. And a label multicast table that stores whether or not to delete the multicast label when transmitting the multicast label. In the layer 2 switch, it is previously defined to which one or more ports to transmit. When the layer 3 device receives an IP multicast packet having no multicast label, the layer 3 device updates the IP multicast table. By referring to the group address described in the destination address of the received IP multicast packet, or the corresponding group address and the source IP address, a transmission port is determined, and the multicast label is added to the multicast port to determine the transmission port. Transmitted as preparative frame and, when receiving the IP multicast packets to the presence of multicast label refers to the label multicast table,
Determine the transmission port from the multicast label, and
If it is stored in the label multicast table to delete the multicast label, the multicast label is deleted and the multicast frame is transmitted.When the layer 2 switch receives the multicast frame with the multicast label, Referring to the label multicast table, a transmission port is determined from the multicast label, and if it is stored in the label multicast table that the multicast label is to be deleted, the multicast is deleted and the multicast frame is transmitted. An IP multicast control method, comprising: 2. The label multicast table in the layer 3 device and the layer 2 switch includes: a relationship between a multicast label and a port for transmitting a frame to which the corresponding multicast label is added; and a multicast when transmitting the corresponding frame. In addition to whether to delete the label, if the multicast label is not deleted when transmitting the corresponding frame, a multicast label to be newly added is stored for each transmission port, and the layer 3 device or the layer When the switch receives the multicast frame to which the multicast label is assigned, the switch refers to the label multicast table, determines a transmission port from the multicast label, and sets the multicast port in the label multicast table. If it is stored and does not delete the bell, by applying a new multicast label each transmission port, IP multicast control method according to claim 1, characterized by transmitting a multicast frame. 3. The method according to claim 3, wherein the multicast label is an IEEE label.
3. The IP multicast control method according to claim 1, wherein the IP multicast control method is provided in a VLAN identifier area of the 802.1Q standard. 4. The method according to claim 1, wherein the multicast label is an IRTF
3. The method according to claim 1, wherein the label is provided in a label area of a label stack specified in RFC3032.
P multicast control method. 5. The multicast label is such that each bit corresponds to each port of the layer 2 switch on a one-to-one basis, a bit corresponding to a transmitting port is 1, a bit corresponding to a non-transmitting port and a non-existing port is 0, Alternatively, the bit corresponding to the port to transmit is 0, the bit corresponding to the port not transmitting and the port not present is 1, and the bit width of the multicast label of the IP multicast table of the layer 3 device or the label multicast table is The number of ports of the connected layer 2 switch is set to be valid, and the layer 2 switch uses only the deletion flag of the label multicast table or does not have the label multicast table and specifies that the multicast label is transmitted. port And et transmission, multicast label to delete all, or, IP multicast control method according to claim 1, characterized in that it comprises a label multicast table including a multicast label to be newly applied. 6. An IP network used in an IP network in which a terminal is connected to the layer 2 switch and the layer 2 switch is connected to the layer 3 device.
P multicast control method, wherein the layer 3 device comprises: the IP multicast table; the label multicast table;
A P processing unit, a route management table for storing a MAC address or an IP address of the terminal, and a port connected to the layer 2 switch installed between the terminal and the layer 3 device, The layer 3 device receives an IGMP Memb from the terminal.
When receiving the ership Report message or the Leave-Group message, when the IGMP processing unit determines whether to add or delete the corresponding terminal as a multicast member, the source MAC address or the source IP of the corresponding terminal is determined. From the address, the connection port of the corresponding terminal in the layer 2 switch is acquired by referring to the path management table, and when the IGMP processing unit determines that the corresponding terminal is added as a member, the IP multicast table and the label multicast table The multicast label of the corresponding group is updated to a multicast label indicating that the connection port of the corresponding terminal has been added. If the IGMP processing unit determines that the corresponding terminal is to be deleted from the member, the IP multicast multicast And updating the multicast label of the corresponding group in the label multicast table and the label multicast table to a multicast label indicating that the connection port of the corresponding terminal has been deleted. IP multicast control method. 7. The I according to claim 1, wherein
An IP multicast control system using a P multicast control method, comprising: the layer 3 device including the IP multicast table and the label multicast table; and the layer 2 switch including the label multicast table. An IP multicast control system, wherein three devices can designate an output port of the layer 2 switch.