KR102657337B1 - Communication node for performing lossless transfer of p2mp traffic and operating method thereof - Google Patents

Abstract

A method of operating a communication node according to an embodiment of the present invention is a method of operating a communication node that includes a first line card, a second line card, and an output card and performs P2MP (Point to Multipoint) transmission, wherein the first direction receiving a member packet delivered to through a receiving port of the first line card; Comparing the sequence number of the member packet received by the first line card through the reception port with a previously stored sequence number record of the group to which the member packet belongs; Duplicating, by the first line card, a member packet whose sequence number does not match a pre-stored sequence number according to the comparison result; and transmitting, by the first line card, the duplicated member packet to the second line card and the output card.

Description

Communication node performing lossless transmission of P2MP traffic and its operating method {COMMUNICATION NODE FOR PERFORMING LOSSLESS TRANSFER OF P2MP TRAFFIC AND OPERATING METHOD THEREOF}

The present invention relates to a communication node that performs lossless transmission of P2MP traffic through packet duplication and deletion operations and a method of operating the same.

Recently, in the field of network technology, research and development is underway on time-sensitive or time-determinate networking technology to stably support various deterministic delay and high-reliability services in packet networks. These include IEEE 802.1's TSN (Time-Sensitive Networking) and IETF's DetNet (Deterministic Networking). One of the main functions provided by the technology is a lossless delivery function that can deliver traffic without interruption even when a failure occurs or is restored on the traffic delivery path.

This function is defined as IEEE Std 802.1CB ^TM -2017 FRER (Frame Replication and Elimination for Reliability) in TSN and as PREF (Packet Replication and Elimination Function) in DetNet.

In FRER or PREF, a sequence number is inserted into the packet overhead for each packet in a section that requires protected delivery of traffic, then transmitted through multiple delivery paths, and the sequence numbers of packets received from multiple delivery paths are checked. Only packets with sequence numbers that have not been received before are processed in the next step, and packets that have already been received are judged to be duplicate packets and deleted. Meanwhile, in the field of network research, research and development has been conducted on various P2MP services for streaming services, etc., and demand for real-time P2MP services through time-confirmed networks such as TSN and DetNet is also expected to increase.

However, in the DetNet ring topology, in order to implement P2MP lossless transmission, a method is used to duplicate packets from the input node and transmit them clockwise and counterclockwise, so in a normal network without any failures, the duplicated packets are transmitted through a bidirectional path. Since it is transmitted to the penalty mate node to prevent loops, it causes the problem of consuming unnecessary bandwidth.

The purpose of the present invention to solve the above problems is to provide a method of operating a communication node to realize P2MP lossless transmission.

Another purpose of the present invention to solve the above problems is to provide a communication node that realizes P2MP lossless transmission.

A method of operating a communication node according to an embodiment of the present invention for achieving the above object includes a communication node that includes a first line card, a second line card, and an output card and performs P2MP (Point to Multipoint) transmission. An operating method comprising: receiving a member packet transmitted in a first direction through a receiving port of the first line card; Comparing the sequence number of the member packet received by the first line card through the reception port with a previously stored sequence number record of the group to which the member packet belongs; Duplicating, by the first line card, a member packet whose sequence number does not match a pre-stored sequence number according to the comparison result; and transmitting, by the first line card, the duplicated member packet to the second line card and the output card.

The method of operating the communication node may further include, when the sequence numbers match as a result of comparing the sequence numbers, the first line card deleting the received member packet.

The method of operating the communication node also includes: receiving, by the first line card, the member packet transmitted in a second direction from the second line card; Comparing the sequence number of the member packet transmitted in the second direction with a previously stored sequence number record of the group to which the member packet belongs; And if the sequence numbers of the member packets transmitted in the second direction do not match as a result of comparison, the first line card transmits the member packets to another output node in the second direction through the transmission port of the first line card. The step of transmitting may further include, if the sequence numbers match as a result of comparing the sequence numbers, the first line card deleting the member packet received from the second line card.

Here, the communication node may be a communication node operating according to the DetNet ring topology.

According to the embodiments of the present invention as described above, loops can be avoided and bandwidth efficiency can be increased without using penalty mate nodes through packet duplication and deletion on a node-by-node basis.

Accordingly, the present invention provides a P2MP lossless transmission method capable of responding to a wider variety of failures.

Figure 1 shows the concept of a typical P2MP lossless forwarding method in DetNet single ring topology.
Figure 2 is a conceptual diagram to explain the bandwidth waste problem of a typical P2MP lossless transmission method in the DetNet dual ring topology.
Figure 3 is a conceptual diagram to explain the traffic disconnection problem due to loop prevention in the typical P2MP lossless delivery method in the DetNet dual ring topology.
Figure 4 is a block diagram of an output node in a typical DetNet single ring topology.
Figure 5 is a block diagram of an output node on a ring topology that realizes P2MP lossless transmission according to an embodiment of the present invention.
Figure 6 is a conceptual diagram of P2MP lossless transmission in a single ring topology according to an embodiment of the present invention.
Figure 7 is a conceptual diagram of P2MP lossless transmission in a dual ring topology according to an embodiment of the present invention.
Figure 8 is an example of failure response in a dual ring topology according to an embodiment of the present invention.
Figure 9 is a flowchart of a method of operating a communication node according to an embodiment of the present invention.

Since the present invention can make various changes and have various embodiments, specific embodiments will be illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all changes, equivalents, and substitutes included in the spirit and technical scope of the present invention. While describing each drawing, similar reference numerals are used for similar components.

Terms such as first, second, A, B, etc. may be used to describe various components, but the components should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, a first component may be named a second component, and similarly, the second component may also be named a first component without departing from the scope of the present invention. The term “and/or” includes any of a plurality of related stated items or a combination of a plurality of related stated items.

When a component is said to be "connected" or "connected" to another component, it is understood that it may be directly connected to or connected to the other component, but that other components may exist in between. It should be. On the other hand, when it is mentioned that a component is “directly connected” or “directly connected” to another component, it should be understood that there are no other components in between.

The terms used in this application are only used to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the technical field to which the present invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and should not be interpreted in an ideal or excessively formal sense unless explicitly defined in the present application. No.

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the attached drawings.

Figure 1 shows the concept of a typical P2MP lossless forwarding method in DetNet single ring topology.

Reflecting requirements related to the increasing demand for real-time P2MP services through time-confirmed networks, standardization is in progress at DetNet to provide P2MP lossless transmission function on ring topology, which is widely used in various transmission networks. Figure 1 is intended to explain the problem of unnecessary bandwidth consumption in the prior art. For convenience of explanation, an example is taken where one input node and all remaining nodes are set as output nodes.

A method of implementing P2MP lossless forwarding in the DetNet ring topology can be seen in Figure 1. Referring to Figure 1, the input node (for example, node 1 in Figure 1) where a packet enters the ring topology inserts a sequence number for the input packet and duplicates the packet to create a clockwise path and a counterclockwise path. Each is delivered through In addition, in order to prevent loops in member packets transmitted in both directions, similar to the conventional MPLS-TP (Multi-Protocol Label Switching-Transport Profile) ring topology protection switching method, packets are transmitted from the penalty node of each path. stop. At the output node where the packet goes out of the ring topology, the packet is multicast to the port and output port for forwarding to the penalty mate node. At this time, the output port outputs only one of the same packets received through the clockwise path and the counterclockwise path out of the ring.

More specifically, referring to Figure 1, for ring topology P2MP lossless forwarding function, input node 1 adds a sequence number to the received packet. Duplicated packets can be delivered in a clockwise path from node 1 to node 8 and in a counterclockwise path from node 1 to node 2. Both paths can use various paths, such as a section label switching path or a multicast label switching path.

In the case of Figure 1, the penalty mate node of the clockwise path is node 8, and the penalty mate node of the counterclockwise path is node 2. Assuming that the same equipment is used in all links and nodes and that they are separated by the same distance, the member packet replicated from input node 1 is transmitted from node 2 to node 5 through a clockwise path for the same amount of time, and counterclockwise. It is delivered from node 8 to node 5 through the directional path, completing packet delivery to all output nodes of the ring topology.

However, for lossless delivery, traffic continues to be delivered to nodes 8 and 2 through a bidirectional path. For this reason, in a network in a steady state, unnecessary packets are transmitted from node 5 to node 8 through a clockwise path and from node 5 to node 2 through a counterclockwise path to deliver packets to be dropped as duplicate packets at the output port. A problem arises where bandwidth is wasted. In Figure 1, for convenience of explanation, a ring topology is used as an example, but the same problem occurs in P2MP on various topologies such as mesh.

Figure 2 is a conceptual diagram to explain the bandwidth waste problem of a typical P2MP lossless transmission method in the DetNet dual ring topology.

For convenience of explanation, an example is taken where there is only one input node and all other nodes are set as output nodes. In P2MP lossless forwarding in the DetNet dual ring topology, packets copied from the input node of the left ring are forwarded through clockwise and counterclockwise paths in the right ring, and to prevent loops in packets transmitted to the right ring, the packets copied from the input node of the left ring are transmitted through the left ring and In the same way, packets are deleted from the penalty mate node.

Referring to FIG. 2, among the member packets received through the clockwise path and the counterclockwise path at node 4 of the left ring, the packet that arrives first is delivered to the clockwise path of the right ring, and duplicate member packets are deleted. Likewise, node 5 also forwards the packet that arrived first among the member packets received through the clockwise path and the counterclockwise path to the counterclockwise path of the right ring, and duplicate member packets are deleted. To prevent loops in the right ring, node 14 for the clockwise path and node 9 for the counterclockwise path delete member packets received as penalty mate nodes.

In summary, in the case of dual ring topology P2MP lossless forwarding, the packet replicated from node 1, which is the input node, travels through a clockwise path from node 2 to node 4 in the left ring and from node 9 to node 12 in the right ring. It is delivered. The packet replicated from node 1, which is the input node, is also delivered from node 8 to node 5 in the left ring and from node 14 to node 12 in the right ring through a counterclockwise path. Even after completing packet delivery to all output nodes in the dual ring topology, the same problem of unnecessary bandwidth waste occurs as the packet is delivered to the penalty mate nodes in the bidirectional path of the left ring and right ring for lossless delivery.

Figure 3 is a conceptual diagram to explain the traffic disconnection problem due to loop prevention in the typical P2MP lossless delivery method in the DetNet dual ring topology.

Figure 3 assumes the same settings as described in Figure 2, but describes the operation when a failure occurs on two links.

As shown in Figure 3, when a failure occurs in the link between node 1 and node 2, packets cannot be delivered through the clockwise path on the left ring. In this case, the packet can be delivered to node 2 through the counterclockwise path of the left ring, but if the link between nodes 4 and 5 also fails, the packet can be delivered to node 4 through the counterclockwise path of the left ring. The packet cannot be forwarded. Member packets delivered from node 5 through the counterclockwise path of the right ring are deleted at penalty mate node 9 to prevent loops, causing a fatal problem in which packets cannot be delivered to nodes 2, 3, and 4. do.

This is the same problem that can occur when performing the P2MP lossless forwarding function using non-overlapping paths without loops occurring for reasons such as loop prevention in various topologies.

Figure 4 is a block diagram of an output node in a typical DetNet single ring topology.

Figure 4 shows detailed blocks that can be included in an output node in a typical DetNet single ring topology to implement P2MP lossless forwarding.

Referring to Figure 4, packets replicated from the input node on the DetNet ring and delivered along a clockwise path are received at the west in-port 211. The received packet is delivered to the replication block 213 through the connection matrix 212 according to settings. The replication block 213 replicates the input packet and delivers the packet to the east port and the egress port. If the node in Figure 2 is not a penalty mate node for the clockwise path, packets delivered to the east port are delivered to the adjacent node connected to the east port.

Likewise, packets replicated from an input node on the ring and received at the east in-port 221 along a counterclockwise path are forwarded to the replication block 223 through the connectivity matrix 222 according to the settings. The replication block 223 replicates the packet and delivers it to the west port and output port. If the node in Figure 2 is not a penalty mate node for the counterclockwise path, the packet delivered to the west port is delivered to the adjacent node connected to the west port.

Packets delivered to the output port through the clockwise path and the counterclockwise path are delivered to the deletion block of the output port 230. If a duplicate packet is confirmed through the sequence number, the deletion block deletes the duplicate packet and deletes one. Only packets are output.

The present invention utilizes packet duplication and deletion to insert a sequence number at the input node and then deliver the duplicated packet to the output node through multiple possible paths. When the output node receives the packet, it checks the sequence number of the packet and determines whether the packet has not been received. Only packets with sequence numbers are delivered to other output nodes or to output ports depending on the settings, and duplicated packets are deleted to prevent the propagation of additional packets, suggesting a P2MP lossless delivery method that does not waste unnecessary bandwidth. In particular, the present invention prevents loops from occurring even if a penalty mate node is not defined to prevent loops when transmitting packets through all connectable paths between the input node and the output node, and even in various failure situations, as long as there is an available path. We present a P2MP lossless delivery method that does not cause traffic interruption.

Configure multiple delivery paths between input nodes and output nodes, duplicate and deliver packets containing sequence numbers through all possible routes, process member packets with the same sequence number only once for each node, and delete duplicate member packets. It is characterized as a P2MP lossless packet delivery method. When transmitting a packet with an added sequence number to all nodes that can transmit it, it is characterized as a loop prevention method that uses only the node-level duplicate member packet deletion function without loop prevention functions such as setting non-overlapping paths or deleting additional packets to prevent loops. do.

Figure 5 is a block diagram of an output node on a ring topology that realizes P2MP lossless transmission according to an embodiment of the present invention.

As shown in Figure 5, the output node on the ring topology according to a preferred embodiment of the present invention is an individual node in which the input, output, east, and west line cards of each node are all separated based on the MPLS-based DetNet ring topology. It is assumed that the node is composed of line cards.

That is, the output node according to an embodiment of the present invention may include a west line card 310, an east line card 320, an output line card 330, and a switch fabric 340 connecting them. Line card 310 and east line card 320 may include a reception port and an output port, respectively. Additionally, the west line card 310 may include a delete block 312, a connection matrix block 313, and a replication block 314 connected to the receiving port. Similarly, the east line card 320 may also include a delete block 322, a connection matrix block 323, and a replication block 324 associated with the receive port 321.

In addition, according to embodiments of the present invention, the input node transmits the member packet with the same sequence number through a bidirectional transmission path, and the presence or absence of member packet propagation of the corresponding protection group is determined based on the sequence number of the bidirectional member packet received at the output node. By deleting duplicate member packets, the P2MP lossless transmission function can be performed. However, the present invention is not limited to this embodiment, and can be applied to P2MP lossless transmission technology of various topologies other than ring topology.

Referring to FIG. 5, when the output block according to an embodiment of the present invention receives a member packet through the west receiving port 311 from a clockwise path, it forwards the packet to the west delete block 312. The west deletion block 312 compares the sequence number of the received member packet with the sequence number record of the protection group to which the member packet belongs. As a result of the comparison, in the case of a member packet with no processed record, the sequence number is stored and transmitted to the connection metric 313.

The connection metric 313 transfers the received member packet to the replication block 314 according to the settings, and the replication block 314 replicates the packet and delivers it to the east line card 320 and the output port. Packets input from the west line card to the east line card through the switch fabric 340 are delivered to the erase block 322 of the east line card. Likewise, in the east deletion block 322, the sequence number record of the protection group to which the member packet belongs is compared with the sequence number of the delivered member packet, and if there is no processed record, the sequence number is recorded and the packet is connected to the connection matrix (323 ) is transmitted. The member packet delivered from the delete block to the connection metric is delivered to the east transmission port 325 according to the settings and transmitted to other output nodes in the clockwise path.

In other words, as shown in FIG. 5, the delete block of the present invention determines whether the member packet received through the receiving port of another line card and delivered to the switch side overlaps with the member packet received through its own receiving port, the line side. I do it. For this reason, according to embodiments of the present invention, the transmission port and reception port on the same line side operate in only one direction for member packets of the same protection group, thereby preventing unnecessary bandwidth waste or loops.

Figure 6 is a conceptual diagram of P2MP lossless transmission in a single ring topology according to an embodiment of the present invention.

When an input node (e.g., node 1 in FIG. 6) receives a series of packets requesting a P2MP lossless forwarding function, a sequence number is added to the received packets and the duplicated member packet is transmitted through a bidirectional path. Member packets are transmitted in both directions from node 2 to node 5 through a clockwise path and from node 8 to node 5 through a counterclockwise path. At this time, node 5 records the sequence numbers of member packets received from the western receiving node and the eastern receiving node in each deletion block and transmits them to each replication block through the connection metric. Each replication block replicates member packets and delivers them to the east transmission node, west transmission node, and output node. More specifically, in the output node according to the present invention, before transmitting the packet to the bidirectional transmission node, the packet is transmitted to a bidirectional deletion block and the line side checks whether the member packet of the protection group to which the corresponding member packet belongs is received. do.

Therefore, if a bidirectional member packet arrives at the bidirectional receiving port at the same time, it can be deleted through a bidirectional delete block before being delivered to the bidirectional transmitting port, preventing unnecessary bandwidth waste. Additionally, when bidirectional member packets arrive sequentially, only the member packet in the direction that arrived first can be delivered to the next output node. For example, the packet passed through output node 5 in FIG. 6 to the next output node, output node 4 or 6, because the transmission record of the member packet of the same protection group transmitted through the bidirectional path is already stored. , Additional received member packets are deleted, so only bandwidth in one direction is consumed at most, and the problem of bandwidth wastage for additional transmission to other output nodes can be prevented.

Figure 7 is a conceptual diagram of P2MP lossless transmission in a dual ring topology according to an embodiment of the present invention.

Referring to FIG. 7, in the case of nodes 4 and 5, which are interconnected nodes in the dual ring topology, member packets are copied and delivered to both the left ring and right ring connected for the two-way path. In the case of node 4, when it receives the member packet of the clockwise path of the left ring from node 3, it copies and delivers it to node 5, which is the clockwise path of the left ring, and node 9, which is the clockwise path of the right ring. Additionally, when node 4 receives a member packet from node 5 on the counterclockwise path of the left ring, it copies and delivers it to node 3, which is the counterclockwise path of the left ring, and node 9, which is the clockwise path of the right ring. . Node 4 also receives the member packet of the counterclockwise path of the right ring from node 9 and replicates the packet to node 5, which is the clockwise path of the left ring, and node 3, which is the counterclockwise path of the left ring. and deliver it.

In this way, according to embodiments of the present invention, packets can be copied and transmitted through all possible forwarding paths without the need to consider loops on the packet path, which means that member packets of the same protection group can only be transmitted in one direction through deletion blocks in each direction. Because it is transmitted. Through this, it is possible to prevent loops, prevent unnecessary bandwidth waste, and provide a lossless transmission function that can respond to a wider range of failure situations.

Figure 8 is an example of failure response in a dual ring topology according to an embodiment of the present invention.

In a dual ring topology environment as shown in Figure 8, when a failure occurs on the link between Node 1 and Node 2, and Node 4 and Node 5, in the case of existing DetNet dual ring topology P2MP lossless forwarding, the penalty mate node is used to prevent loops. Because member packets are deleted, a hole occurs where packets are not delivered to output nodes 2, 3, and 4.

On the other hand, according to embodiments of the present invention on the dual ring topology of the same setting, the member packet delivered from node 1 to node 5 through the counterclockwise path of the left ring is transmitted through the counterclockwise path of the right ring, and the member packet transmitted from node 1 to node 5 is transmitted through the counterclockwise path of the right ring. The member packet delivered to node 4 through the ring counterclockwise path is not deleted again and is delivered through the counterclockwise path of the left ring. That is, according to embodiments of the present invention, the P2MP lossless transmission function can be performed without holes occurring even when a failure occurs.

The conventional technology causes the problem of consuming unnecessary bandwidth because packets copied from the input node must be delivered to the penalty mate node for loop prevention through a bidirectional path in a normal network with no errors.

Figure 9 is a flowchart of a method of operating a communication node according to an embodiment of the present invention.

A communication node according to an embodiment of the present invention includes a first line card, a second line card, and an output card, and can perform an operation to perform P2MP (Point to Multipoint) lossless transmission. At this time, the communication node may operate according to the DetNet ring topology.

When receiving a member packet transmitted in the first direction through the reception port of the first line card of the communication node (S910), the sequence number of the member packet received by the first line card through the reception port is stored in The member packet is compared with the sequence number record of the group to which it belongs (S911).

According to the comparison result (S912), the first line card duplicates the member packet whose sequence number does not match the pre-stored sequence number (S913), and the first line card copies the duplicated member packet to the second line It is transmitted to the card and the output card (S914).

If the sequence numbers match as a result of comparing the sequence numbers in step 912, the first line card deletes the received member packet (S930).

Meanwhile, when the first line card receives the member packet transmitted in the second direction from the second line card (S920), the sequence number of the member packet transmitted in the second direction is previously stored in the Compare with the sequence number record of the group to which the member packet belongs (S921).

If the comparison result (S922) of the sequence numbers of the member packets transmitted in the second direction do not match, the first line card transmits the member packets to another output node in the second direction through the transmission port of the first line card. Transmit to (S923). Conversely, if the sequence numbers match as a result of comparing the sequence numbers, the first line card deletes the member packet received from the second line card (S930).

The embodiments of the present invention as described above are the bandwidth used throughout the network for lossless delivery of P2MP traffic requiring link bandwidth of C in a single ring topology composed of N nodes, up to (N+1) In C, it provides improved bandwidth efficiency by (N+1) / [2 x (N-1)] compared to the conventional P2MP lossless delivery method, which requires a bandwidth of 2 x (N-1) x C.

Bandwidth improvement according to the present invention is effective in a ring topology consisting of three or more nodes, and as the number of ring nodes increases, a bandwidth savings of close to 50% can be expected compared to the conventional P2MP lossless transmission method. In addition, unlike the conventional P2MP lossless transmission method, loops do not occur even if packets are duplicated and transmitted through all available paths, so it has the advantage of being able to guarantee zero loss even in various failure situations than the conventional method.

The operation of the method according to an embodiment of the present invention can be implemented as a computer-readable program or code on a computer-readable recording medium. Computer-readable recording media include all types of recording devices that store data that can be read by a computer system. Additionally, computer-readable recording media can be distributed across networked computer systems so that computer-readable programs or codes can be stored and executed in a distributed manner.

Additionally, computer-readable recording media may include hardware devices specially configured to store and execute program instructions, such as ROM, RAM, flash memory, etc. Program instructions may include not only machine language code such as that created by a compiler, but also high-level language code that can be executed by a computer using an interpreter, etc.

Although some aspects of the invention have been described in the context of an apparatus, it may also refer to a corresponding method description, where a block or device corresponds to a method step or feature of a method step. Similarly, aspects described in the context of a method may also be represented by corresponding blocks or items or features of a corresponding device. Some or all of the method steps may be performed by (or using) a hardware device, such as a microprocessor, programmable computer, or electronic circuit, for example. In some embodiments, one or more of the most important method steps may be performed by such an apparatus.

In embodiments, a programmable logic device (e.g., a field programmable gate array) may be used to perform some or all of the functionality of the methods described herein. In embodiments, a field programmable gate array may operate in conjunction with a microprocessor to perform one of the methods described herein. In general, the methods are preferably performed by some hardware device.

Although the present invention has been described with reference to preferred embodiments of the present invention, those skilled in the art may make various modifications and changes to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. You will understand that it is possible.

Claims (4)

Communication comprising a first line card, a second line card, and an output line card and a switch fabric connecting the first line card, the second line card, and the output line card, and performing point to multipoint (P2MP) transmission. As a method of operating a node,
When receiving the first member packet transmitted in the first direction through the reception port of the first line card, the sequence number inserted into the first member packet by the first deletion block in the first line card is As a result of comparing with the previously stored sequence number record of the group to which the first member packet belongs, if it is a member packet with a processed record, the first member packet is deleted, and if it is a member packet without a processed record, the first member packet is deleted. storing a sequence number and then transferring it to a first replication block of the first line card through a connection metric block of the first line card;
replicating the first member packet by the first replication block and delivering it to a second output port of the second line card through the switch fabric;
When receiving a second member packet transmitted in a second direction that is different from the first direction through a receiving port of the second line card, the second member packet is transmitted by a second delete block in the second line card. As a result of comparing the sequence number inserted in the group with the previously stored sequence number record of the group to which the second member packet belongs, if it is a member packet with a processed record, the second member packet is deleted, and the member packet does not have a processed record. If it is a packet, storing the sequence number of the second member packet and then transferring it to a second replication block of the second line card through the connection metric block of the second line card; and
A method of operating a communication node comprising replicating, by the second replication block, the second member packet and delivering it to a first output port of the first line card through the switch fabric. In claim 1,
The first member packet input from the first line card to the second line card through the switch fabric is transmitted to the second output port through a second erase block of the second line card,
As a result of comparing the sequence number inserted in the first member packet by the second deletion block with the pre-stored sequence number record of the group to which the first member packet belongs, if the sequence number matches, the first member packet Deleting a packet, and if the sequence numbers do not match, storing the sequence number of the first member packet in the second deletion block and then forwarding the first member packet to the second output port. Including, a method of operating a communication node. In claim 1,
The second member packet input from the second line card to the first line card through the switch fabric is delivered to the first output port through a first erase block of the first line card,
As a result of comparing the sequence number inserted in the second member packet by the first deletion block with the pre-stored sequence number record of the group to which the second member packet belongs, if the sequence number matches, the second member packet Deleting a packet, and if the sequence numbers do not match, storing the sequence number of the second member packet in the first deletion block and then forwarding the second member packet to the first output port. Including, a method of operating a communication node. The method according to any one of claims 1 to 3,
When traffic enters the packet network, before forwarding the packets of the traffic to the first replication block and the second replication block, if there is no sequence number in the packet overhead, inserting a sequence number for each packet, further comprising: How a communication node operates.