CN101094190B - Transmission method of Ethernet ring network protection control message - Google Patents

Abstract

The invention discloses a method for transmitting protection control messages of an Ethernet ring network, which comprises the following steps: a node detects the link state corresponding to a port on the ring; The corresponding port is set to the ring network control packet forwarding forbidden state, so that the corresponding port of the faulty link cannot forward the Ethernet ring network protection control packet. If the node detects that the adjacent link on the ring fails The corresponding port is set to the ring network control message forwarding allowable state, so as to forward the Ethernet ring network protection control message through the corresponding port of the fault disappearing link. The invention can prevent ring network protection switching errors and improve the anti-fault capability of the Ethernet ring network in actual networking.

Description

Transmission method of Ethernet ring network protection control message

technical field

The invention relates to the communication field, and more specifically relates to a transmission method of an Ethernet ring network protection control message.

Background technique

The Ethernet ring network protection system in RFC3619 is composed of multiple nodes connected to form a ring, and multiple domains can be defined on the ring, that is, the Ethernet ring network protection domain. A domain includes a master node, several transfer nodes, and a group of protected business virtual local area networks (Virtual Local Area Network, referred to as VLAN) for user data forwarding. Wherein, the two ports of the master node on the ring are respectively the master port and the slave port, and the protected service VLAN is the protected service VLAN. When the link on the ring is intact, the master node blocks the protection service VLAN forwarding function of the slave port, and there is no loop in the network, which prevents the "broadcast storm" caused by the network loop; The protection service VLAN forwarding function of the slave port is enabled, and user data can pass through the slave port of the master node, thereby ensuring service connectivity. The Ethernet ring network protection control message is a communication and control message between nodes in the domain. When a node blocks a port, the Ethernet ring network control message can still pass without being affected.

Figure 1 is a topology diagram of the automatic protection system of the Ethernet ring network, which is composed of nodes S1, S2, S3 and S4. An Ethernet ring network protection domain is configured on the ring composed of these four nodes. The master node (MASTER) in the domain It is S2, and the remaining nodes S1, S3, S4 are transmission nodes (TRANSIT). The two ring ports of the master node S2 are respectively a master port and a slave port, wherein port 2 is a master port (P), and port 1 is a slave port (S). In addition, a protection service VLAN is defined in the domain, and each port on the ring is configured in the protection service VLAN. When the link on the ring is intact, the master node S2 blocks the protection service VLAN data forwarding function of slave port 1, thereby preventing the existence of a loop in the network and forming a "network storm"; when the link on the ring fails, the master node S2 puts Enable the data forwarding function of the protected service VLAN from port 1, so that the data in the service VLAN can be reconnected.

The master node periodically sends a link health detection message (HELLO) to the master port. When the link on the ring is intact, the HELLO message passes through each transmission node in turn and reaches the slave port of the master node. The HELLO message can be blocked by the master node. The slave port of is received by the master node. If the master node does not receive the HELLO message within the specified time, it considers the link on the ring to be faulty.

When the transit node detects that an adjacent link fails, it sends a link failure warning message (LINK-DOWN), and the LINK-DOWN message reaches the master node through the transmission of the link on the ring. If the slave port of the master node is blocked , the LINK-DOWN message also passes through the slave port of the master node and is sent to the master node. When the master node receives a LINK-DOWN packet on the master port or the slave port, it considers that the link on the ring is faulty.

When the master node detects that the link on the ring is faulty, it releases the protection service VLAN forwarding function of the slave port, updates the MAC address table of the port on the ring, and sends a link failure notification message (FLUSH-DOWN) to notify other nodes on the ring Perform link failover, after the transmission node receives FLUSH-DOWN, it updates the MAC address table of the port on the ring, and the data in the protection service VLAN starts to be transmitted through the new path.

When the node detects that an adjacent link fails, it blocks the protection service VLAN forwarding function of the corresponding port; when the fault disappears, temporarily does not release the protection service VLAN forwarding function of the port. During the link failure, the master node still sends out the HELLO message from the main port. If the link failure disappears, the HELLO message can pass through the blocked port and the link where the failure disappears. When the slave port receives the HELLO message, it considers the link on the ring to be restored, blocks the protection service VLAN forwarding function of the slave port again, updates the MAC address table of the port on the ring, and sends a link recovery notification message (FLUSH) to the ring. -UP), notify other nodes on the ring to resume link switching, after the transmission node receives the FLUSH-UP, update the MAC address table of the port on the ring, and the transmission node that detects that the link failure disappears also releases the protection service VLAN of the corresponding port With the forwarding function, the data in the protection service VLAN starts to be transmitted through a new path.

Blocking or unblocking the protection service VLAN function of ports on the ring has no effect on the transmission of Ethernet ring network protection control packets, so Ethernet ring network protection control packets can pass through the blocked port to reach the destination node, completing the control communication between nodes.

The actual link failure situation is more complicated. Usually, a link is composed of two parts: the sending and receiving parts. When only the receiving part or the sending part fails, the link will appear unidirectional. As shown in FIG. 2 , a one-way link failure occurs between nodes S3 and S4, node S3 cannot receive information from node S4, but node S4 can receive information from node S3. Node S3 detects a link failure, blocks port 2 corresponding to the failed link, and sends a LINK-DOWN message to the master node, and the master node performs link failover after receiving the LINK-DOWN message. During the link failure, the master node still sends HELLO messages from the master port to the ring, and the HELLO messages can pass through port 2 of node S3, pass through the link between nodes S3 and S4, and then reach the master node through node S4 the slave port. When the master node receives the HELLO message at the slave port, it considers that the link is restored, and performs link recovery switching to block the protection service VLAN forwarding function of the slave port again, so that the data in the protection service VLAN cannot be transmitted through the slave port of the master node. However, the link between nodes S3 and S4 is one-way, and the data communication in the protection service VLAN may fail in one direction. For example, the data in the protection service VLAN of node S4 cannot be transmitted to node S1.

For some link fault detection methods, when the software operation of a node on a ring fails, the adjacent nodes will also consider the link to be faulty. As shown in Figure 3, node S3 and node S4 detect link failures by sending detection messages to each other. When the node fails to receive the detection message sent by the other end within a specified time, the link is considered to be faulty. The hardware of node S3 can forward data normally, but when the software fails, it cannot send the detection message to node S4 within the specified time, and node S4 thinks that the link with S3 has failed. After node S4 detects a link failure, it blocks the port corresponding to the failed link, and sends a LINK-DOWN message to the master node. After receiving the LINK-DOWN message, the master node considers the link to be faulty and performs link failover. During link failure, the master node still sends HELLO messages from the master port to the ring, and the HELLO messages can be forwarded to port 2 through the hardware of node S3, pass through the link between nodes S3 and S4, and then reach the master through node S4. The slave port of the node. When the master node receives the HELLO message at the slave port, it considers that the link is restored, and performs link recovery switching to block the protection service VLAN forwarding function of the slave port again, so that the data in the protection service VLAN cannot be transmitted through the slave port of the master node. However, the link between S3 and S4 detected by node S4 is still in a fault state, and the master node thinks that the link state of the entire ring network is intact, resulting in a wrong judgment, and subsequent operations may cause faults. After the ring network is restored and switched, the data that needs to be forwarded by software between nodes cannot communicate normally, for example, the communication data between nodes S1 and S4 that needs to be forwarded by the software of node S3 is interrupted. In addition, when the communication of the link between node S3 and node S4 is completely interrupted, since node S4 has recorded the link state as a fault state, it will not send a LINK-DOWN message to the master node to notify the link failure, and the master node Nodes can only rely on the timeout of HELLO packets to judge and detect link failures, which delays the time required for link failure switchover and cannot meet the needs of high real-time services.

Other Ethernet ring network protection methods, such as patent EP1727313, also have similar problems.

Contents of the invention

In view of one or more problems described above, the present invention provides a new method for transmitting Ethernet ring network protection control messages.

According to the transmission method of the Ethernet ring network protection control message of the present invention, it comprises the following steps: the node detects the link state corresponding to the port on the ring; Set to the ring network control packet forwarding prohibition state, so that the port corresponding to the faulty link cannot forward the Ethernet ring network protection control packet. If the node detects that the adjacent link on the ring fails Set to the ring network control message forwarding allowable state, so as to forward the Ethernet ring network protection control message through the corresponding port of the failed link.

Wherein, if the node detects that an adjacent link on the ring fails, it also needs to block the protection service virtual local area network forwarding function of the port corresponding to the failed link. The node does not send or forward the Ethernet ring network protection control message to the destination port in the ring network control message forwarding forbidden state. When the destination port in the ring network control message forwarding prohibited state receives the Ethernet ring network protection control message, the Ethernet ring network protection control message is discarded.

Wherein, the node only sends or forwards the Ethernet ring network protection control message to the destination port in the ring network control message forwarding allowed state. When receiving the Ethernet ring network protection control message, the destination port in the state of allowing the ring network control message sends or forwards the Ethernet ring network protection control message.

Through the present invention, it is possible to prevent the control messages in the Ethernet ring network from being transmitted through the detected link, thereby preventing ring network protection switching errors and improving the fault resistance capability of the Ethernet ring network in actual networking.

Description of drawings

The accompanying drawings described here are used to provide a further understanding of the present invention and constitute a part of the application. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations to the present invention. In the attached picture:

Fig. 1 is the topological diagram of the automatic protection system of the Ethernet ring network;

Figure 2 is a topology diagram of a link single-pass failure in the Ethernet ring network protection system;

Fig. 3 is a topology diagram of a node software failure in the Ethernet ring network protection system;

Fig. 4 is the flow chart of the Ethernet ring network node setting port ring network control message forwarding state according to an embodiment of the present invention;

Fig. 5 is a flowchart according to an embodiment of the present invention when a ring network control message is sent or forwarded; and

Fig. 6 is a flow chart of receiving a ring network control message according to an embodiment of the present invention.

Detailed ways

In the present invention, the function of the port on the node ring to forward the Ethernet ring network control message is defined as the ring network control message forwarding allowed state and the ring network control message forwarding forbidden state. When the port is in the ring network control message forwarding enabled state, the Ethernet ring network control message can pass through the port; when the ring network control message forwarding disabled state is in the port, the Ethernet ring network control message cannot pass through the port. The Ethernet ring network control packet forwarding status of the port only has an effect on the Ethernet ring network control packet, and has no effect on user data packets. When a node on the ring detects a link failure, it sets the corresponding port to the state of prohibiting the forwarding of ring network control packets to prevent Ethernet ring network control packets from passing through the port. When the node on the ring detects that the link is restored, it sets The corresponding port is set to the ring network control message forwarding allowable state, so that the Ethernet ring network control message passes through the port. The specific implementation manners of the present invention will be described in detail below with reference to the accompanying drawings.

Referring to FIG. 4 , the process of setting the port ring network control message forwarding state of the Ethernet ring network node according to the embodiment of the present invention is described. As shown in Figure 4, the process of setting the port ring network control message forwarding state of the Ethernet ring network node includes the following steps: S402, the node in the Ethernet ring network protection domain detects the link state of the port on the ring; S404, the node detects the corresponding When an adjacent link fails, perform ring network protection processing (such as blocking the protection service VLAN forwarding function of the port corresponding to the faulty link, and notify the master node that the link is faulty), and set the port corresponding to the faulty link as ring network control Message forwarding prohibition state; S406, when the node detects that the fault of the adjacent link disappears, the port corresponding to the fault disappearing link is set to the ring network control message forwarding state.

Referring to FIG. 5 , the process of sending or forwarding the ring network control message according to the embodiment of the present invention is described. As shown in Figure 5, the process of sending or forwarding the ring network control message includes the following steps: S502, the node needs to send the ring network control message to the port on the ring; S504, if the destination port is prohibited from forwarding the ring network control message state, the message is not sent; S506, if the destination port is in the ring network control message forwarding allowed state, the message can be sent.

Referring to FIG. 6 , the process of receiving the ring network control message according to the embodiment of the present invention is described. As shown in Figure 6, the process when the ring network control message is received includes the following steps: S602, the Ethernet ring network control message arrives at the node port; S604, if the node port is in the ring network control message forwarding prohibition state, the The message is discarded; S606, if the node port is in the ring network control message forwarding allowed state, the message can pass through the port.

It can be seen from the descriptions in Fig. 4 to Fig. 6 that the transmission method of the Ethernet ring network protection control message according to the embodiment of the present invention includes the following steps: the node detects the link state corresponding to the port on the ring; If the adjacent link fails, set the corresponding port of the failed link to the state of prohibiting the forwarding of the ring network control message, so that the corresponding port of the failed link cannot forward the Ethernet ring network protection control message. If the node detects that the adjacent link on the ring When the link failure disappears, the corresponding port of the link with the failure disappearance is set to the ring network control message forwarding allowable state, so as to forward the Ethernet ring network protection control message through the corresponding port of the link with the failure disappearance. During the link failure of the ring network, the link health detection message sent by the master node cannot pass the link where the fault occurred. When the fault disappears, the link health detection message sent by the master node can pass the detected link link, thereby preventing the master node from erroneously judging the status of the ring network due to the fact that the detected link can still transmit the Ethernet ring network control message, and improving the anti-fault capability of the ring network protection system.

The transmission of the Ethernet ring network protection control message in a certain Ethernet ring network protection system to which the present invention is applied is described below.

For example, suppose there are 5 transmission nodes and 1 master node on the ring, and the links between adjacent nodes are two optical fibers for sending and receiving, and a single optical fiber between two nodes is disconnected to make the link one-way . In the Ethernet ring network protection system that does not apply the present invention, after the master node detects that a link failure occurs in the ring network, the HELLO message sent to the master port can still be received at the slave port through a single-pass link, and the ring network is considered Link recovery, carry out link recovery switch and block from the port, cause the data of protection service VLAN to only be one-way; The corresponding port is set to the ring network control message forwarding disabled state, the HELLO message sent by the master node cannot pass through the port where the link failure is detected, and the HELLO message cannot be received at the slave port, so it will not affect the ring network status. Misjudgment.

In addition, assuming that there are 5 transmission nodes and 1 master node on the ring, the link fault detection is performed between adjacent nodes by sending detection messages to each other. When a packet is detected, the link is considered to be faulty. Reset the Central Processing Unit (CPU) of a transmission node. When the CPU resets, the hardware can still forward data, but the software cannot run. After the CPU is reset for a period of time, the hardware stops forwarding data. The peer node of the reset node does not detect the detection packet within the specified time, and considers that the link is faulty. In the Ethernet ring network protection system that does not apply the present invention, after the master node detects that a link failure occurs in the ring network, the HELLO message sent to the master port can still be received at the slave port through the hardware forwarding of the reset node. The link is restored, the link is restored and the slave port is blocked, resulting in a wrong judgment on the state of the ring network. At this time, the hardware of the node that resets the CPU stops forwarding data, but the adjacent node has recorded that the link state is in the fault state, so it will not Then notify the master node of link failure, so the master node cannot detect the failure of the ring network link, and the slave port is still in the blocked state, resulting in the failure of user data in the protected service VLAN. After the Ethernet ring network protection system applies the present invention, when a node detects a link fault, the port corresponding to the faulty link is set to the ring network control message forwarding prohibition state, and the HELLO message sent by the master node cannot pass through the detected link. If the port fails, the slave port cannot receive the HELLO message, and the ring network status will not be misjudged.

In summary, the present invention classifies the modes of transmitting Ethernet ring network protection control messages through node ports. When a link failure is detected, the Ethernet ring network protection control message is prohibited from passing through the corresponding port of the faulty link, preventing Misjudgment of the state of the ring network in the case of a complex link failure improves the reliability and stability of the system. In addition, the present invention can be used in various Ethernet ring network protection technologies.

The above description is only an embodiment of the present invention, and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of the claims of the present invention.

Claims (6)

1. the transmission method of an Ethernet ring protection control message is characterized in that, may further comprise the steps:

Node detection ring upper port link corresponding state;

If described node detection goes up adjacent link to ring and breaks down; then the corresponding port of faulty link is set at the forwarding of looped network control message and forbids attitude; so that the corresponding port of described faulty link can not be transmitted Ethernet ring protection control message; if going up the adjacent link fault to ring, described node detection disappears; the corresponding port of the link that then fault disappeared is set at looped network control message and transmits the permission attitude, to transmit described Ethernet ring protection control message by the corresponding port of described fault disappearance link.

2. the transmission method of Ethernet ring protection control message according to claim 1; it is characterized in that; if described node detection goes up adjacent link to ring and breaks down, then described node also needs to block the professional VLAN forwarding capability of protection of the corresponding port of described faulty link.

3. the transmission method of Ethernet ring protection control message according to claim 1 and 2 is characterized in that, described node is not transmitted the destination interface transmission of forbidding attitude or transmitted described Ethernet ring protection control message to being in looped network control message.

4. the transmission method of Ethernet ring protection control message according to claim 1 and 2; it is characterized in that; when being in looped network control message and transmitting the destination interface of forbidding attitude and receive described Ethernet ring protection control message, described Ethernet ring protection control message is given up.

5. the transmission method of Ethernet ring protection control message according to claim 1 and 2 is characterized in that, described node only allows the destination interface of attitude to send or transmit described Ethernet ring protection control message to being in the forwarding of looped network control message.

6. the transmission method of Ethernet ring protection control message according to claim 1 and 2; it is characterized in that; when being in destination interface that looped network control message allows attitude and receiving described Ethernet ring protection control message, described Ethernet ring protection control message is sent or transmits.

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