KR20050064095A - Method for managing multi-cast forwarding information at switch router - Google Patents

Abstract

The present invention relates to a switch router for forwarding multicast packets. The method for managing multicast forwarding information according to the present invention includes multicast forwarding information which is information used for multicast packet forwarding from a line interface for forwarding multicast packets. When the message is received, updating the multicast forwarding information base based on the multicast forwarding information included in the received message; Whenever the multicast forwarding information stored in the multicast forwarding information base is changed, the method includes outputting a message including the changed multicast forwarding information to the line interface, and processing the multicast-related operation in the management interface and processing the same. The resulting multicast forwarding information is reflected in the line interface in real time.

Description

Method for managing multi-cast forwarding information at switch router}

The present invention relates to a line interface including a network processor for providing high-speed packet forwarding, a management interface for controlling the line interface, and a switch router including a switch, and more particularly, to a switch router for forwarding multicast packets. It is about.

To provide IP (Internet Protocol) multicast services on the Internet, hosts and routers use the Internet Group Management Protocol (IGMP) and various multicast routing protocols. In recent years, many switch routers utilize network processors to transfer data of a line interface at wire speed. In a router that does not include a network processor, since all multicast packets received at the line interface are transmitted to the management interface, a lot of packet forwarding delay occurs due to the processing time at the management interface. In the case of a switch router composed of a plurality of line interfaces including a network processor, the line interface classifies the multicast packets through a fast packet classification process, and the classified multicast packets are multicast forwarding information established by the management interface. Forwarded at high speed based on the base.

However, in the case of the conventional switch router, the multicast forwarding information base of the line interface is difficult to change the multicast forwarding information base once set because the operation of the management interface is not known continuously. In addition, when information on a multicast packet input through a line interface cannot be continuously transmitted to the management interface, it is difficult to manage the multicast group in the management interface. Therefore, since the multicast packet is forwarded based on the multicast forwarding information base set once, there is a problem that it is difficult to change information related to the forwarding of the multicast packet. This causes many multicast packets to be forwarded through the management interface, making it difficult to forward the multicast packets at substantially line speeds.

An object of the present invention is to provide an apparatus and method for reflecting a multicast forwarding base constructed in a management interface on a line interface in real time, and to provide a switch router to which such an apparatus and / or method is applied.

According to an aspect of the present invention, there is provided a method for managing multicast forwarding information. The method includes: (a) receiving a message including multicast forwarding information, which is information used for multicast packet forwarding, from a line interface for forwarding a multicast packet; If so, updating the multicast forwarding information base based on the multicast forwarding information included in the received message; and (b) outputting a message including the changed multicast forwarding information whenever the multicast forwarding information stored in the multicast forwarding information base is changed.

 In accordance with another aspect of the present invention, there is provided a multicast packet forwarding method comprising: (a) a message including multicast forwarding information changed from a management interface for managing multicast forwarding information, which is information used for forwarding a multicast packet; Updating a multicast forwarding information base based on the multicast forwarding information included in the received message; And (b) when receiving a multicast data message including multicast data from a network, when the multicast forwarding information for the received multicast data message is stored in the multicast forwarding base. Forwarding the received multicast data message based on the multicast forwarding information stored in an information base.

According to another aspect of the present invention, a switch router according to the present invention receives a message including multicast forwarding information, which is information used for forwarding a multicast packet, based on the multicast forwarding information included in the message. A management interface for updating a multicast forwarding information base and outputting a message including the changed multicast forwarding information whenever the multicast forwarding information stored in the multicast forwarding information base is changed; And a line interface configured to update the multicast forwarding information base based on the multicast forwarding information included in the received message when receiving a message including the changed multicast forwarding information from the management interface.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of a fast switch router according to a preferred embodiment of the present invention.

Referring to FIG. 1, the fast switch router is composed of a management interface 1, a plurality of line interfaces 2, and a switch 3.

The management interface 1 includes a command interface 11, a system control unit 12, an address resolution protocol (ARP) processing unit 13, a routing processing unit 14, a second layer processing unit 15, and a third layer processing unit 16. , A multicast processor 17, a kernel processor 18, and a first layer processor 19.

The command interface 11 receives a command related to multicast packet forwarding from a remote manager, and transmits the received command to the system control unit 12 and the multicast processing unit 17 so that the remote manager can control the multicast packet. Allow forwarding control. The system control unit 12 controls the entire system of the management interface 1.

The ARP processor 13 converts an IP address, which is a third layer address, into a physical network address, which is a second layer address by performing ARP. The routing processor 14 generates the forwarding information by performing a predetermined routing protocol. The second layer processing unit 15 processes a task to be processed in the link layer that is the second layer. The third layer processor 16 processes a task to be processed in the network layer, which is the third layer. The ARP (Address Resolution Protocol) processing unit 13, the routing processing unit 14, the second layer processing unit 15, and the third layer processing unit 16 perform the same functions as those in the conventional switch router.

The multicast processing unit 17 processes work related to forwarding of multicast packets. The kernel processing unit 18 serves to process the kernel inside the management interface 1 system. The first layer processor 19 processes a job to be processed in the physical layer that is the first layer. That is, the first layer processor 19 plays a role of transmitting and receiving an IPC message. Upper applications including the multicast processor 17 and the like always transmit and receive IPC messages via the kernel processor 18. Here, the IPC transfers a message between the management interface 100 and the line interface 200 according to the rules set by the system.

The line interface 2 may include a first layer processor 21, a packet transceiver 22, a network processor controller 23, a network processor API 24, a network processor 25, and a switching interface 26. It consists of

 The first layer processor 19 processes a job to be processed in the physical layer that is the first layer. That is, the first layer processing unit 19 transmits and receives an IPC message with the management interface 1. The packet transceiver 22 receives a packet from the network and transmits the packet to the network. The packet transceiver 22 corresponds to a physical layer. The network processor control unit 23 receives information related to forwarding of a packet from the management interface 1 and controls the network processor 25 according to the received information. The network processor API 24 connects the network processor control unit 23 and the network processor 25. The network processor 25 forwards the received packet. The switching interface 26 connects the line interface 2 and the switch 3.

This line interface 2 is classified into an input line interface and an output line interface. When the input line interface receives the multicast packet, the management interface 1 handles the work related to the forwarding of the multicast packet, and the switch 3 receives the multicast received by the output line interface determined through the sorting operation of the line interface. Send the packet, and the output interface outputs the multicast packet to the network through proper scheduling.

FIG. 2 is a detailed configuration diagram of the multicast processor shown in FIG. 1.

Referring to FIG. 2, the multicast processor 17 may include a multicast forwarding information base 171, an Internet Group Management Protocol (IGMP) message processor 172, a multicast routing protocol message processor 173, and a multicast data message processor. 174, an interface change message processor 175, a timer control message processor 176, a timer expiration message processor 177, and a multicast forwarding information output processor 178.

The multicast forwarding information base 171 stores multicast forwarding information, which is information used for forwarding multicast packets. When the IGMP message processing unit 172 receives an IGMP message in the form of an IPC message from the line interface 2 via the first layer processing unit 19 and the kernel processing unit 18, the multicast included in the received IGMP message is included. Add group membership information to the multicast forwarding information base. In other words, the node sending the IGMP message is included as a member of a predetermined multicast group. In particular, even when the switch router according to the present embodiment operates as a second layer switch, the IGMP snooping technique is used to receive and process an IGMP message, thereby handling the member change of the multicast group in the second layer switch. To control the network processor 25.

The multicast routing protocol message processor 173 receives the multicasting routing protocol message in the form of an IPC message from the line interface 2 via the first layer processor 19 and the kernel processor 18. Adds multicast group routing information included in the casting routing protocol message to the multicast forwarding information base. There are several multicasting routing protocols such as Distance-Vector Multicast Routing Protocol (DVMRP), Protocol Independent Multicast (PIM), Multicast Open Shortest Path First (MOSPF), and routing of predetermined multicast groups according to each multicasting routing protocol. Generates information and stores the generated routing information in the multicast forwarding information base.

The multicast data message processor 174 receives the multicast data message in the form of an IPC message from the line interface 2 via the first layer processor 19 and the kernel processor 18. Add the source address information included in the message to the multicast forwarding information base. In the line interface 2 according to the present embodiment, when a multicast packet including substantial data is received, the multicast forwarding information for the multicast packet is stored in the multicast forwarding information base in the network processor 25. If not, the multicast packet is transmitted to the management interface 1. This multicast packet is a multicast data message. The multicast data message may be a message when there is no original multicast forwarding information or a message when multicast forwarding information exists but is deleted.

When the interface change message processor 178 receives the interface change message from the administrator via the command interface 11, the interface change message processor 178 reflects the interface change information included in the received interface change message in the multicast forwarding information base. Here, the interface change information refers to the information of the interface associated with the multicast group.

When the timer control message processing unit 175 receives the timer control message from the manager via the command interface 11, the timer control message processing unit 175 stores the multicast group stored in the multicast forwarding information base based on the timer period information included in the received timer control message. Set the timer cycle. This timer control message is to set a timer period for each multicast group, and if the timer period expires, delete the multicast forwarding information of the corresponding multicast group and manage the group membership by confirming the transmission destination. In other words, the old information is deleted and new information is continuously added to facilitate the change of the multicast forwarding information. However, although a multicast packet belonging to a periodically deleted multicast group is transmitted to the management interface 1, some delay may occur, but it can be solved through buffering of the destination terminal.

When the timer expiration message processing unit 176 receives a timer expiration message indicating that the timer period set by the timer control message processing unit 175 has expired, the timer expiration message processing unit 176 receives the multicast group information included in the received timer expiration message in the multicast forwarding information base. Delete it. Here, the multicast group information included in the timer expiration message means information of the multicast group in which the timer period set by the timer control message processing unit 175 has expired. Unlike the other messages described above, the timer expiration message is a message generated inside the switch router according to the present embodiment. That is, if the period of the timer for a predetermined multicast group expires while the program is being executed in the main processor or the like, this is a message generated by itself.

When the multicast forwarding information stored in the multicast forwarding information base is changed, the multicast forwarding information output processor 178 outputs a message including the changed multicast forwarding information. The output message is transmitted to the line interface 2 in the form of an IPC message via the kernel processing unit 18 and the first layer processing unit 19. The multicast forwarding information output processor 178 matches the information stored in the multicast forwarding information base of the management interface 1 with the information stored in the multicast forwarding information base of the line interface 2 in real time, thereby managing the management interface 1. Multicast group management and member management of the network is immediately reflected on the line interface 2 so that delay-free multicast forwarding can be achieved.

FIG. 3 is a detailed configuration diagram of the network processor controller shown in FIG. 1.

Referring to FIG. 3, the network processor controller 23 may include a quality of service (QOS) processor 231, a multi protocol label switching (MPLS) processor 232, a second layer processor 233, and a third layer processor 234. ), And a multicast processing unit 235.

The QOS processing unit 231 processes a job related to the quality of service. The MPLS processing unit 232 processes a job related to MPLS. The second layer processing unit 233 processes a job related to the link layer which is the second layer. The third layer processor 234 processes a job related to the network layer, which is the third layer. The QOS processing unit 231, the MPLS processing unit 232, the second layer processing unit 233, the third layer processing unit 234, and the multicast processing unit 235 perform the same functions as those of the conventional switch router.

When the multicast processor 235 receives a message including multicast forwarding information from the network via the packet transceiver 22, the multicast processor 235 receives the received message in the form of an IPC message via the first layer processor 21. Transfer to management interface (1). Here, the message including the multicast forwarding information includes an IGMP message, a multicast routing protocol message, and the like. The multicast forwarding information included in this message is properly processed in the management interface 1 and reflected in the multicast forwarding information base 171 of the management interface 1. When the multicast processing unit 235 receives a message including the multicast forwarding information changed in the form of an IPC message from the management interface 1 via the first layer processing unit 21, the multicast included in the received message Multicast group management by managing the multicast group based on the forwarding information and managing the membership of the multicast group by an interface unit using the API inside the multicast processor 235 for managing the membership of the multicast group. In order to update the forwarding information base, it calls the network processor API 24, which directly drives and controls the network processor.

Under the control of the network processor API 24, the network processor 25 that processes the forwarding operation based on the multicast forwarding information base linked with the multicast forwarding information base 171 of the management interface 1 transmits and receives packets from the network. When the multicast data message including the multicast data is received via the unit 22, the multicast forwarding information base when the multicast forwarding information for the received multicast data message is stored in the multicast forwarding base. Forwards the received multicast data message based on the multicast forwarding information stored in the multicast data message, and if the multicast forwarding information for the received multicast data message is not stored in the multicast forwarding base, First tier By way of the portion 21 it is sent in the form of an IPC message to the management interface (1).

As described above, in the present embodiment, the multicast processing unit 17 is provided in the management interface 1, and the multicast processing unit 235 which operates in cooperation with the multicast processing unit 17 is provided in the line interface 2. Delete the multicast forwarding information base of the line interface 1 periodically so that forwarding does not occur (usually, this period is set to a time small enough to receive one packet), and the multicast data message is managed. The multicast processing unit 17 of (1) enables reception of the multicast group's transmission destination based on this message, and also allows management of the IGMP message, the multicast routing protocol message, and the like. Membership information and routing of the multicast group based on the message by allowing the multicast processing unit 17 of the The information can be verified, enabling the construction of multicast forwarding information. Through this, the newly generated multicast forwarding information is lowered to an appropriate line interface to enable continuous line speed based multicast packet transmission.

4 is a flowchart of a multicast forwarding information management method according to an embodiment of the present invention.

Referring to FIG. 4, the method for managing multicast forwarding information includes the following steps. The multicast forwarding information management method is mainly performed by the multicast processing unit 17 shown in FIG.

When the switch router system according to the present embodiment is initialized, the tasks related to multicast are also initialized (41). Subsequently, the multicast processor 17 enters a waiting state for receiving a message (42). If a received message exists, the received message is examined to determine what message it is.

If the IGMP message is received in the form of an IPC message from the line interface 2 via the first layer processor 19 and the kernel processor 18 (43), the multicast group membership included in the received IGMP message is received. The information is added to the multicast forwarding information base (431). Subsequently, it is checked whether the multicast forwarding information stored in the multicast forwarding information base has been changed, and if the check result has been changed (491), a message including the changed multicast forwarding information is output (492). The output message is sent to the line interface 2 in the form of an IPC message and returns to the message reception waiting state 42 again. If the check result has not been changed (491), it immediately returns to the message receiving wait state (42).

If the multicasting routing protocol message is received from the line interface 2 in the form of an IPC message via the first layer processing unit 19 and the kernel processing unit 18 (44), the received multicasting routing protocol message is received. The included multicast group routing information is added to the multicast forwarding information base (441). Subsequently, it is checked whether the multicast forwarding information stored in the multicast forwarding information base has been changed, and if the check result has been changed (491), a message including the changed multicast forwarding information is output (492). The output message is sent to the line interface 2 in the form of an IPC message and returns to the message reception waiting state 42 again. If the check result has not been changed (491), it immediately returns to the message receiving wait state (42).

If a multicast data message is received from the line interface 2 via the first layer processor 19 and the kernel processor 18 in the form of an IPC message (45), it is included in the received multicast data message. The source address information is added to the multicast forwarding information base (451). Subsequently, it is checked whether the multicast forwarding information stored in the multicast forwarding information base has been changed, and if the check result has been changed (491), a message including the changed multicast forwarding information is output (492). The output message is sent to the line interface 2 in the form of an IPC message and returns to the message reception waiting state 42 again. If the check result has not been changed (491), it immediately returns to the message receiving wait state (42).

If an interface change message is received from the manager via the command interface 11 (46), the interface change information included in the received interface change message is reflected in the multicast forwarding information base (461). Subsequently, it is checked whether the multicast forwarding information stored in the multicast forwarding information base has been changed, and if the check result has been changed (491), a message including the changed multicast forwarding information is output (492). The output message is sent to the line interface 2 in the form of an IPC message and returns to the message reception waiting state 42 again. If the check result has not been changed (491), it immediately returns to the message receiving wait state (42).

If the timer control message is received from the manager via the command interface 11 (47), the timer period of the multicast group stored in the multicast forwarding information base is based on the timer period information included in the received timer control message. (47). Subsequently, it is checked whether the multicast forwarding information stored in the multicast forwarding information base has been changed, and if the check result has been changed (491), a message including the changed multicast forwarding information is output (492). The output message is sent to the line interface 2 in the form of an IPC message and returns to the message reception waiting state 42 again. If the check result has not been changed (491), it immediately returns to the message receiving wait state (42).

If the timer expiration message generated internally in the switch router system according to the present embodiment is received (48), the multicast group information included in the received timer expiration message is deleted from the multicast forwarding information base (481). Subsequently, it is checked whether the multicast forwarding information stored in the multicast forwarding information base has been changed, and if the check result has been changed (491), a message including the changed multicast forwarding information is output (492). The output message is sent to the line interface 2 in the form of an IPC message and returns to the message reception waiting state 42 again. If the check result has not been changed (491), it immediately returns to the message receiving wait state (42).

5 is a flowchart of a multicast packet forwarding method according to an embodiment of the present invention.

Referring to FIG. 5, the multicast packet forwarding method includes the following steps. The multicast forwarding information management method is mainly performed by the multicast processor 235 shown in FIG.

When the switch router system according to the present embodiment is initialized, a task related to multicast is also initialized (51). Subsequently, the multicast processor 235 enters a waiting state for receiving a message (52). If a received message exists, the received message is examined to determine what message it is.

If a message including multicast forwarding information added in the form of an IPC message is received from the management interface 1 via the first layer processor 21 (53), the multicast forwarding included in the received message is received. The information is added to the multicast forwarding information base (531). Subsequently, the process returns to the message reception waiting state 52. Examples of the added multicast forwarding information may include new multicast group information and new membership information.

If a message including the deleted multicast forwarding information is received from the management interface 1 via the first layer processing unit 21, the multicast forwarding information included in the received message may be stored in the multicast forwarding information base. Delete it. Subsequently, the process returns to the message reception waiting state 52. An example of deleted multicast forwarding information may include information of a multicast group whose timer period has expired.

If a message including the multicast forwarding information is received from the network via the packet transceiving unit 22 (55), the first layer processing unit 21 sends the received multicast forwarding information message to the management interface 1. Send in the form of an IPC message via. Subsequently, the process returns to the message reception waiting state 52. Examples of the message including the multicast forwarding information include an IGMP message, a multicast routing protocol message, and the like.

If a multicast data message including multicast data is received from the network via the packet transceiver 22 (56), the multicast forwarding information for the received multicast data message is stored in the multicast forwarding base. If so, the received multicast data message is forwarded based on the multicast forwarding information stored in the multicast forwarding information base (562), and the multicast forwarding information for the received multicast data message is stored in the multicast forwarding base. If not, the received multicast data message is transmitted to the management interface (563). Subsequently, the process returns to the message reception waiting state 52.

Meanwhile, the above-described embodiments of the present invention can be written as a program that can be executed in a computer, and can be implemented in a general-purpose digital computer that operates the program using a computer-readable recording medium.

In addition, the structure of the data used in the above-described embodiment of the present invention can be recorded on the computer-readable recording medium through various means.

The computer-readable recording medium may be a magnetic storage medium (for example, a ROM, a floppy disk, a hard disk, etc.), an optical reading medium (for example, a CD-ROM, a DVD, etc.) and a carrier wave (for example, the Internet). Storage medium).

So far I looked at the center of the preferred embodiment for the present invention. Those skilled in the art will appreciate that the present invention can be implemented in a modified form without departing from the essential features of the present invention. Therefore, the disclosed embodiments should be considered in descriptive sense only and not for purposes of limitation. The scope of the present invention is shown in the claims rather than the foregoing description, and all differences within the scope will be construed as being included in the present invention.

According to the present invention, the multicast-related operation is processed in the management interface, and the multicast forwarding information as a result of the processing is reflected on the line interface in real time, thereby providing a basis for the multicast forwarding information base that is most suitable for the current multicast environment. Multicast packets can be forwarded, which allows fewer multicast packets to be forwarded via the management interface, thereby forwarding the multicast packets at substantial line speeds.

1 is a block diagram of a fast switch router according to a preferred embodiment of the present invention.

FIG. 2 is a detailed configuration diagram of the multicast processor shown in FIG. 1.

FIG. 3 is a detailed configuration diagram of the network processor controller shown in FIG. 1.

4 is a flowchart of a multicast forwarding information management method according to an embodiment of the present invention.

5 is a flowchart of a multicast packet forwarding method according to an embodiment of the present invention.

Claims (17)

(a) when a message including multicast forwarding information, which is information used for multicast packet forwarding, is received from the line interface for forwarding the multicast packet, multicast based on the multicast forwarding information included in the received message. Updating the forwarding information base; (b) whenever the multicast forwarding information stored in the multicast forwarding information base is changed, outputting a message including the changed multicast forwarding information to the line interface. How to manage. The method of claim 1, In the step (a), when the IGMP message is received, multicast group membership information included in the received IGMP message is added to the multicast forwarding information base. The method of claim 1, In the step (a), when the multicasting routing protocol message is received, multicast forwarding information, wherein the multicast group routing information included in the received multicasting routing protocol message is added to the multicast forwarding information base. How to manage. The method of claim 1, In the step (a), when the multicast data message is received, the source address information included in the received multicast data message is added to the multicast forwarding information base. The method of claim 1, Before the step (b), when receiving the interface change message from the administrator, comprising the step of reflecting the interface change information included in the received interface change message to the multicast forwarding information base How to manage multicast forwarding information. The method of claim 1, In step before the step (b), when a timer control message is received from an administrator, the timer period of the multicast group stored in the multicast forwarding information base is based on the timer period information included in the received timer control message. Setting step; And And when the timer expiration message indicating that the set timer period has expired is deleted, deleting the multicast group information included in the received timer expiration message from the multicast forwarding information base. How Information is Managed. (a) when a message including changed multicast forwarding information is received from a management interface managing multicast forwarding information, which is information used for forwarding a multicast packet, based on the multicast forwarding information included in the received message. Updating the multicast forwarding information base with; And (b) when the multicast data message including the multicast data is received from the network, when the multicast forwarding information for the received multicast data message is stored in the multicast forwarding base, the multicast forwarding information. And forwarding the received multicast data message based on the multicast forwarding information stored in a base. The method of claim 7, wherein In step (a), when the message including the added multicast forwarding information is received, multicast packet forwarding comprises adding the multicast forwarding information included in the received message to the multicast forwarding information base. Way. The method of claim 7, wherein In the step (a), when the message including the deleted multicast forwarding information is received, the multicast packet forwarding information, wherein the multicast forwarding information included in the received message is deleted from the multicast forwarding information base. Way. The method of claim 7, wherein And when the multicast forwarding information message including the multicast forwarding information is received from the network, transmitting the received multicast forwarding information message to the management interface. The method of claim 7, wherein In step (b), if the multicast forwarding information for the received multicast data message is not stored in the multicast forwarding base, the received multicast data message is transmitted to the management interface. Multicast packet forwarding method. When a message including multicast forwarding information, which is information used for forwarding a multicast packet, is received, the multicast forwarding information base is updated based on the multicast forwarding information included in the message, and the multicast forwarding information base is updated. A management interface for outputting a message including the changed multicast forwarding information whenever the multicast forwarding information stored in the apparatus is changed; And And a line interface for updating the multicast forwarding information base based on the multicast forwarding information included in the received message when receiving the message including the changed multicast forwarding information from the management interface. Switch router. The method of claim 12, The management interface is And receiving an IGMP message from the line interface, and including an IGMP message processing unit to add multicast group membership information included in the received IGMP message to the multicast forwarding information base. The method of claim 12, The management interface is And a multicast routing protocol message processor for adding multicast group routing information included in the received multicasting routing protocol message to the multicast forwarding information base when receiving a multicasting routing protocol message from the line interface. Switch router characterized by the above. The method of claim 12, The management interface is And a multicast data message processing unit for adding the destination address information included in the received multicast data message to the multicast forwarding information base when the multicast data message is received from the line interface. router. The method of claim 12, The management interface is And receiving an interface change message from an administrator, and including an interface change message processor to reflect the interface change information included in the received interface change message to the multicast forwarding information base. The method of claim 12, The management interface is A timer control message processor configured to set a timer period of a multicast group stored in the multicast forwarding information base based on timer period information included in the received timer control message when receiving a timer control message from an administrator; And And a timer expiration message processor for deleting the multicast group information included in the received timer expiration message from the multicast forwarding information base when receiving a timer expiration message indicating that the timer period set by the timer control message processor has expired. Switch router, characterized in that.