CN110740094B

CN110740094B - Network equipment, BFD message transmission method and device

Info

Publication number: CN110740094B
Application number: CN201911029007.5A
Authority: CN
Inventors: 邢家茂; 刘生根
Original assignee: New H3C Security Technologies Co Ltd
Current assignee: New H3C Security Technologies Co Ltd
Priority date: 2019-10-28
Filing date: 2019-10-28
Publication date: 2021-09-21
Anticipated expiration: 2039-10-28
Also published as: CN110740094A

Abstract

The application provides a network device, a BFD message transmission method and a BFD message transmission device, wherein the network device comprises: the control management component is used for establishing a first BFD session corresponding to the main PW and establishing a second BFD session corresponding to the main tunnel; the timeout time of a first receiving timer of the first BFD session is longer than the timeout time of a second receiving timer of the second BFD session; when the second receiving timer is overtime, if a BFD message corresponding to the second BFD session is not received through the main tunnel, determining that the main tunnel is abnormal; and after the main tunnel is abnormal, sending a BFD message corresponding to the first BFD session through the standby tunnel. Through the technical scheme of the application, wrong BFD detection results can be avoided.

Description

Network equipment, BFD message transmission method and device

Technical Field

The present application relates to the field of communications technologies, and in particular, to a network device, and a method and an apparatus for transmitting a BFD packet.

Background

A PW (pseudowire) is a bidirectional virtual connection between two devices. A tunnel is a direct connection channel between two devices, and is used to carry a PW, and one tunnel may carry multiple PWs, such as an MPLS (Multi-Protocol Label Switching) tunnel, a GRE (Generic Routing Encapsulation) tunnel, and a TE (Traffic Engineering) tunnel.

Referring to fig. 1, assuming that a TE tunnel is established between device 101 and device 105, and FRR (Fast Reroute) protection is performed for the TE tunnel, TE tunnel 1 and TE tunnel 2 may be established. TE tunnel 1 may pass through device 101-device 103-device 104-device 105, and TE tunnel 2 may pass through device 101-device 102-device 104-device 105.

Referring to fig. 1, assuming that a PW is established between device 101 and device 106, and FRR protection is performed for the PW, a main PW and a backup PW may be established. The main PW is borne by a tunnel group, the tunnel group comprises a TE tunnel 1 and a TE tunnel 2, the TE tunnel 1 is a main TE tunnel, and the TE tunnel 2 is a standby TE tunnel; when the TE tunnel 1 is normal, the traffic is forwarded through the TE tunnel 1, and the traffic is not forwarded through the TE tunnel 2; and when the TE tunnel 1 is abnormal, switching the TE tunnel 1 to the TE tunnel 2 to forward the traffic. The backup PW is carried by the TE tunnel 2, i.e. traffic is forwarded through the TE tunnel 2.

In summary, when the primary PW is normal, forwarding the traffic through the primary PW, that is, when the TE tunnel 1 is normal, forwarding the traffic through the TE tunnel 1, and when the TE tunnel 1 is abnormal, switching to the TE tunnel 2 to forward the traffic. When the primary PW is abnormal, the traffic is forwarded through the backup PW, that is, the traffic is forwarded through the TE tunnel 2.

Based on the above application scenario, in order to know whether the main PW is normal, the device 101 periodically sends a BFD (Bidirectional Forwarding Detection) packet on the main PW. If the device 106 does not receive the BFD packet sent by the device 101 within the preset time, it determines that the main PW is abnormal, and switches to the backup PW forwarding flow. However, since the main PW is carried by the tunnel group, and the tunnel group includes the TE tunnel 1 and the TE tunnel 2, when the device 101 periodically sends the BFD packet on the main PW, the BFD packet is periodically sent on the TE tunnel 1. The device 106 does not receive the BFD packet sent by the device 101 within the preset time, which may be only that the TE tunnel 1 is abnormal, but the TE tunnel 2 is normal, so that the device 106 determines that the main PW is abnormal and switches to the backup PW forwarding flow, which is an erroneous BFD detection result.

Disclosure of Invention

The application provides a network equipment, establish main tunnel and reserve tunnel between network equipment and the opposite terminal equipment, main tunnel with reserve tunnel bears main PW jointly, include:

the control management component is used for establishing a first BFD session corresponding to the main PW and establishing a second BFD session corresponding to the main tunnel; wherein the timeout time of a first receiving timer of the first BFD session is greater than the timeout time of a second receiving timer of the second BFD session;

when the second receiving timer is overtime, if a BFD message corresponding to the second BFD session is not received through the main tunnel, determining that the main tunnel is abnormal;

and after the main tunnel is abnormal, sending a BFD message corresponding to the first BFD session through the standby tunnel.

The application provides a transmission method of Bidirectional Forwarding Detection (BFD) messages, which is applied to network equipment, wherein a main traffic engineering tunnel and a standby tunnel are established between the network equipment and opposite terminal equipment, and the main tunnel and the standby tunnel jointly bear a main Pseudo Wire (PW), and the method comprises the following steps:

establishing a first BFD session corresponding to the main PW, and establishing a second BFD session corresponding to the main tunnel; wherein the timeout time of a first receiving timer of the first BFD session is greater than the timeout time of a second receiving timer of the second BFD session;

The application provides a transmission device of two-way forwarding detection BFD message is applied to network equipment, it has main traffic engineering tunnel and reserve tunnel to establish between network equipment and the opposite terminal equipment, main tunnel with reserve tunnel bears main pseudo-wire PW jointly, the device includes:

the establishing module is used for establishing a first BFD session corresponding to the main PW and establishing a second BFD session corresponding to the main tunnel; wherein the timeout time of a first receiving timer of the first BFD session is greater than the timeout time of a second receiving timer of the second BFD session;

a determining module, configured to determine that the main tunnel is abnormal if a BFD packet corresponding to the second BFD session is not received through the main tunnel when the second receiving timer is overtime;

and the sending module is used for sending the BFD message corresponding to the first BFD session through the standby tunnel after the main tunnel is abnormal.

Based on the above technical solution, in the embodiment of the present application, a first BFD session is established for the main PW, and a second BFD session is established for the main tunnel, where the timeout time of a first receiving timer of the first BFD session is greater than the timeout time of a second receiving timer of the second BFD session. And when the second receiving timer is overtime, if the BFD message corresponding to the second BFD session is not received through the main tunnel, determining that the main tunnel is abnormal. Since the timeout time of the first reception timer is greater than the timeout time of the second reception timer, when the second reception timer times out, the first reception timer does not time out, that is, when an abnormality occurs in the main tunnel, it is not yet determined that the main PW has an abnormality. Furthermore, after the main tunnel is abnormal, the BFD message corresponding to the first BFD session is sent through the standby tunnel, so that the BFD message of the main tunnel is switched to the standby tunnel to be sent, and the standby tunnel is not abnormal, so that the BFD message can be correctly sent through the standby tunnel.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments of the present application or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments described in the present application, and other drawings can be obtained by those skilled in the art according to the drawings of the embodiments of the present application.

FIG. 1 is a schematic diagram of a network topology of TE tunnels and PWs;

fig. 2 is a flowchart of a transmission method of a BFD packet according to an embodiment of the present application;

FIG. 3 is a diagram of a hardware configuration of a network device in one embodiment of the present application;

fig. 4 is a schematic diagram of a sending time of a BFD packet in an embodiment of the present application;

fig. 5A and 5B are schematic diagrams illustrating sending conditions of a BFD packet according to an embodiment of the present application;

FIGS. 6A and 6B are block diagrams of a network device in one embodiment of the present application;

fig. 7 is a block diagram of a BFD packet transmission apparatus according to an embodiment of the present invention.

Detailed Description

The terminology used in the embodiments of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this application and the claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein is meant to encompass any and all possible combinations of one or more of the associated listed items.

It should be understood that although the terms first, second, third, etc. may be used in the embodiments of the present application to describe various information, the information should not be limited to these terms. These terms are only used to distinguish one type of information from another. For example, first information may also be referred to as second information, and similarly, second information may also be referred to as first information, without departing from the scope of the present application. Depending on the context, moreover, the word "if" as used may be interpreted as "at … …" or "when … …" or "in response to a determination".

In the embodiment of the present application, a method for transmitting a BFD packet is provided, where a main tunnel and a backup tunnel are established between a network device (i.e., a home network device) and an opposite device (i.e., an opposite network device, which is called an opposite device for convenience of distinguishing), and a main PW and a backup PW are established between the network device and the opposite device.

In one possible embodiment, the primary PW may be commonly carried by the primary tunnel and the standby tunnel, that is, the primary PW may be carried by the primary tunnel and the standby tunnel. In addition, the backup PW may be separately carried by the backup tunnel, that is, the backup PW may be carried by the backup tunnel.

The network device and the peer device may be a router, a switch, a PE (Provider Edge) device, and the like, which is not limited to this. The main PW is a bidirectional virtual connection between the network device and the opposite terminal device, and the backup PW is also a bidirectional virtual connection between the network device and the opposite terminal device.

For convenience of description, in the embodiment of the present application, a TE tunnel is taken as an example for explanation, that is, the main tunnel is a main TE tunnel, and the standby tunnel is a standby TE tunnel. The primary TE tunnel and the standby TE tunnel may be both TE tunnels between the network device and the opposite-end device, or may be TE tunnels between the network device and the designated device, and the designated device may be a device located between the network device and the opposite-end device.

Fig. 1 is a schematic view of an application scenario in the embodiment of the present application. Assuming that the network device is the device 101 and the opposite device is the device 106, in order to perform FRR protection on the PW, a main PW and a backup PW are established between the device 101 and the device 106, where the main PW is carried by a main TE tunnel and a backup TE tunnel, the backup PW is carried by a backup TE tunnel, and the backup PW may also be carried by other tunnels, which is not limited herein.

Referring to fig. 1, to FRR protect the TE tunnel, TE tunnel 1 and TE tunnel 2 may be established between device 101 and device 106. TE tunnel 1 passes through device 101-device 103-device 104-device 105-device 106, and TE tunnel 2 passes through device 101-device 102-device 104-device 105-device 106. Based on this, the main TE tunnel is TE tunnel 1, the standby TE tunnel is TE tunnel 2, the main PW is carried by TE tunnel 1 and TE tunnel 2, and the backup PW is carried by TE tunnel 2. Alternatively, TE tunnel 1 and TE tunnel 2 are established between device 101 and device 105 (i.e., a designated device located between the network device and the peer device). TE tunnel 1 passes through device 101-device 103-device 104-device 105, and TE tunnel 2 passes through device 101-device 102-device 104-device 105. The primary TE tunnel may be a TE tunnel 1, the standby TE tunnel may be a TE tunnel 2, the primary PW is carried by the TE tunnel 1 and the TE tunnel 2, and the backup PW is carried by the TE tunnel 2.

For convenience of description, in this embodiment, taking the primary TE tunnel/the standby TE tunnel as the TE tunnel between the network device (i.e., device 101) and the opposite device (i.e., device 106) as an example, when the primary TE tunnel/the standby TE tunnel is the TE tunnel between the network device and the specified device, the implementation processes are similar, and details are not described later.

Referring to fig. 2, a schematic flow chart of a transmission method of a BFD packet is shown, where the method includes:

step 201, the network device establishes a first BFD session corresponding to the main PW and establishes a second BFD session corresponding to the main TE tunnel; and the opposite terminal equipment establishes a first BFD session corresponding to the main PW and establishes a second BFD session corresponding to the main TE tunnel. Wherein the timeout time of the first receive timer of the first BFD session is greater than the timeout time of the second receive timer of the second BFD session. The timeout time of the first transmit timer of the first BFD session is greater than the timeout time of the second transmit timer of the second BFD session.

Referring to fig. 1, device 101 and device 106 may negotiate to establish a first BFD session corresponding to the main PW, and the BFD session establishment procedure is not limited, see the conventional BFD session establishment procedure.

After the device 101 establishes the first BFD session corresponding to the main PW, it records session information of the first BFD session, where the session information includes but is not limited to: a source IP address (e.g., device 101 IP address), a destination IP address (e.g., device 106 IP address), LD (Local descriptor, i.e., the unique identifier assigned by device 101 to the first BFD session, such as 100011), RD (Remote descriptor, i.e., the unique identifier assigned by device 106 to the first BFD session, such as 100021), packet transmission interval a1, packet reception interval B1, etc. Of course, the above are just a few examples, and there is no limitation on this session information.

After the device 106 establishes the first BFD session corresponding to the main PW, session information of the first BFD session is also recorded, and the session information is not limited to this, see the session information recorded by the device 101.

The packetization interval A1 can be empirically configured, but is not limited thereto, and the packetization interval A1 can be 50 milliseconds, for example. The packet receiving interval B1 can be empirically configured, but is not limited thereto, e.g., the packet receiving interval B1 can be N × the packet sending interval a1, and the packet receiving interval B1 can be 150 ms if N is 3.

After the device 101 establishes the first BFD session corresponding to the main PW, a first sending timer is set for the first BFD session, and the timeout time of the first sending timer is a packet sending interval a 1. When the first sending timer times out each time, the device 101 sends, through the main PW, a BFD packet corresponding to the first BFD session, that is, a BFD packet constructed according to the session information of the first BFD session, where the source IP address is an IP address of the device 101, the destination IP address is an IP address of the device 106, the LD is 100011 allocated to the first BFD session by the device 101, and the RD is 100021 allocated to the first BFD session by the device 106, which is not limited herein.

When the first sending timer times out each time, the device 101 restarts the first sending timer, so that the device 101 may periodically send the BFD packet corresponding to the first BFD session through the main PW, that is, send the BFD packet once through the main PW every packet sending interval a1(50 ms).

After the device 106 establishes the first BFD session corresponding to the main PW, a first receiving timer is set for the first BFD session, and the timeout time of the first receiving timer is a packet receiving interval B1. Before the first receiving timer expires, if the device 106 receives, through the main PW, a BFD packet corresponding to the first BFD session, which is sent by the device 101, the device 106 determines that the main PW is not abnormal, and restarts the first receiving timer. When the first receiving timer times out, if the device 106 does not receive, through the main PW, the BFD packet corresponding to the first BFD session, which is sent by the device 101, the device 106 determines that the main PW is abnormal.

After the device 106 establishes the first BFD session corresponding to the main PW, the device 106 may also periodically send a BFD packet corresponding to the first BFD session through the main PW, see the BFD packet transmission process of the device 101.

After the device 101 establishes the first BFD session corresponding to the main PW, a first receiving timer is set for the first BFD session, and the timeout time of the first receiving timer is a packet receiving interval B1. Before the first receiving timer expires, if the device 101 receives, through the main PW, a BFD packet corresponding to the first BFD session, which is sent by the device 106, the device 101 determines that the main PW is not abnormal, and restarts the first receiving timer. When the first receiving timer times out, if the device 101 does not receive, through the main PW, the BFD packet corresponding to the first BFD session, which is sent by the device 106, the device 101 determines that the main PW is abnormal.

In summary, the device 101 and the device 106 may negotiate to establish a first BFD session corresponding to the main PW, and detect whether the main PW is abnormal according to the first BFD session corresponding to the main PW.

Referring to fig. 1, the device 101 and the device 106 may negotiate to establish the second BFD session corresponding to the primary TE tunnel, and the BFD session establishment procedure is not limited, see the conventional BFD session establishment procedure.

After the device 101 establishes the second BFD session corresponding to the primary TE tunnel, session information of the second BFD session is recorded, where the session information includes but is not limited to: the source IP address (IP address of device 101), the destination IP address (IP address of device 106), LD (unique identifier assigned by device 101 for the second BFD session, e.g., 100012), RD (unique identifier assigned by device 106 for the second BFD session, e.g., 100022), transmit interval a2, receive interval B2, and so on. Of course, the above are only a few examples and are not limiting.

After the device 106 establishes the second BFD session corresponding to the primary TE tunnel, session information of the second BFD session is also recorded, which is not limited to this session information, see the session information recorded by the device 101.

The packet interval a2 may be configured empirically, but is not limited thereto, and the packet interval a2 needs to be smaller than the packet interval a1, for example, the packet interval a2 may be 10 ms. The packet receiving interval B2 may be configured empirically, and is not limited thereto, and the packet receiving interval B2 needs to be smaller than the packet receiving interval B1, for example, the packet receiving interval B2 may be M × the packet sending interval a2, and for example, when M is 3, the packet receiving interval B2 may be 30 ms.

After the device 101 establishes the second BFD session corresponding to the primary TE tunnel, a second sending timer is set for the second BFD session, and the timeout time of the second sending timer is a packet sending interval a 2. When the second sending timer times out each time, the device 101 sends a BFD packet corresponding to the second BFD session through the main TE tunnel, that is, the BFD packet constructed according to the session information of the second BFD session, for example, the source IP address is the IP address of the device 101, the destination IP address is the IP address of the device 106, the LD is 100012 allocated to the second BFD session by the device 101, and the RD is 100022 allocated to the second BFD session by the device 106.

When the second sending timer times out each time, the device 101 restarts the second sending timer, so that the device 101 periodically sends the BFD packet corresponding to the second BFD session through the main TE tunnel, that is, sends the BFD packet once through the main TE tunnel every packet sending interval a2(10 ms).

After the device 106 establishes the second BFD session corresponding to the primary TE tunnel, a second receiving timer is set for the second BFD session, and the timeout time of the second receiving timer is a packet receiving interval B2. Before the second receiving timer expires, if the device 106 receives, through the main TE tunnel, a BFD packet corresponding to the second BFD session, which is sent by the device 101, the device determines that the main TE tunnel is not abnormal, and restarts the second receiving timer. When the second receiving timer times out, if the device 106 does not receive, through the main TE tunnel, the BFD packet corresponding to the second BFD session, which is sent by the device 101, it is determined that the main TE tunnel is abnormal.

After the device 106 establishes the second BFD session corresponding to the main TE tunnel, the BFD packet corresponding to the second BFD session is also periodically sent through the main TE tunnel, see the BFD packet transmission process of the device 101.

After the device 101 establishes the second BFD session corresponding to the primary TE tunnel, a second receiving timer is set for the second BFD session, and the timeout time of the second receiving timer is a packet receiving interval B2. Before the second receiving timer expires, if the device 101 receives, through the main TE tunnel, a BFD packet corresponding to the second BFD session, which is sent by the device 106, the main TE tunnel is determined to be not abnormal, and the second receiving timer is restarted. When the second receiving timer times out, if the device 101 does not receive, through the main TE tunnel, the BFD packet corresponding to the second BFD session, which is sent by the device 106, it is determined that the main TE tunnel is abnormal.

In summary, the device 101 and the device 106 may negotiate to establish the second BFD session corresponding to the main TE tunnel, and detect whether the main TE tunnel is abnormal according to the second BFD session corresponding to the main TE tunnel.

In the above embodiment, the timeout time of the first reception timer of the first BFD session is packet reception interval B1, the timeout time of the second reception timer of the second BFD session is packet reception interval B2, and packet reception interval B1 is greater than packet reception interval B2, so the timeout time of the first reception timer of the first BFD session (packet reception interval B1) is greater than the timeout time of the second reception timer of the second BFD session (packet reception interval B2).

In the above embodiment, the timeout time of the first transmission timer of the first BFD session is packet interval a1, the timeout time of the second transmission timer of the second BFD session is packet interval a2, and packet interval a1 is greater than packet interval a2, and thus, the timeout time of the first transmission timer of the first BFD session (packet interval a1) is greater than the timeout time of the second transmission timer of the second BFD session (packet interval a 2).

Step 202, when the second receiving timer of the second BFD session is overtime, if the BFD packet corresponding to the second BFD session is not received through the main TE tunnel, the network device determines that the main TE tunnel is abnormal. Or before the second receiving timer of the second BFD session is overtime, if the network device receives a BFD packet corresponding to the second BFD session through the main TE tunnel, it determines that the main TE tunnel is not abnormal.

Referring to fig. 1, when the second sending timer times out each time, the device 106 may send a BFD packet corresponding to the second BFD session through the main TE tunnel. Before the second receiving timer expires, if the device 101 receives a BFD packet corresponding to the second BFD session through the main TE tunnel, it may determine that the main TE tunnel is not abnormal; when the second receiving timer is overtime, if the device 101 does not receive the BFD packet corresponding to the second BFD session through the main TE tunnel, it may determine that the main TE tunnel is abnormal.

Similarly, as shown in fig. 1, when the second sending timer times out each time, the device 101 may send, through the main TE tunnel, a BFD packet corresponding to the second BFD session, so that the device 106 determines whether the main TE tunnel is abnormal according to the BFD packet corresponding to the second BFD session, which is not repeated herein.

Step 203, after the main TE tunnel is abnormal, the network device sends a BFD packet corresponding to the first BFD session through the standby TE tunnel, so that when the opposite device receives the BFD packet corresponding to the first BFD session through the standby TE tunnel before the first receiving timer times out, it is determined that the main PW is not abnormal.

Illustratively, the network device sends the BFD packet corresponding to the first BFD session through the backup TE tunnel, which may include but is not limited to: acquiring tunnel information of the standby TE tunnel, generating a BFD message corresponding to the first BFD session according to the tunnel information of the standby TE tunnel, and sending the BFD message corresponding to the first BFD session through the standby TE tunnel. Obviously, the BFD message carries the tunnel information of the standby TE tunnel, so the BFD message corresponding to the first BFD session may be sent through the standby TE tunnel.

In an example, when the main TE tunnel is not abnormal, the network device sends a BFD packet corresponding to the first BFD session through the main TE tunnel, so that the peer device determines that the main PW is not abnormal when receiving the BFD packet corresponding to the first BFD session through the main TE tunnel before the first receiving timer expires.

In an example, when the first receiving timer expires, if the network device does not receive a BFD packet corresponding to the first BFD session through the main TE tunnel or the standby TE tunnel, the network device determines that the main PW is abnormal, and switches a service between the network device and the peer device to the standby PW.

Referring to fig. 1, after the device 101 establishes the first BFD session corresponding to the main PW, when a first sending timer of the first BFD session times out each time, the device 101 sends a BFD packet corresponding to the first BFD session through the main PW, and when the device 101 sends the BFD packet corresponding to the first BFD session through the main PW, if the main TE tunnel is not abnormal, the device 101 sends the BFD packet corresponding to the first BFD session through the main TE tunnel.

Before the first receiving timer of the first BFD session is overtime, if the BFD packet corresponding to the first BFD session is received through the main TE tunnel, the device 106 determines that the main PW is not abnormal. When the first receiving timer times out, if the BFD message corresponding to the first BFD session is not received through the main TE tunnel, or the BFD message corresponding to the first BFD session is not received through the standby TE tunnel, it is determined that the main PW is abnormal, and the service between the device 106 and the device 101 is switched to the backup PW, without limitation to the switching process.

Referring to fig. 1, when the device 101 sends a BFD packet corresponding to the first BFD session through the master PW, if the master TE tunnel is abnormal, that is, it is determined that the master TE tunnel is abnormal based on the second BFD session, the device 101 may send the BFD packet corresponding to the first BFD session through the standby TE tunnel.

Before the first receiving timer is overtime, if the device 106 receives a BFD packet corresponding to the first BFD session through the backup TE tunnel, it determines that the main PW is not abnormal. And when the first receiving timer is overtime, if the BFD message corresponding to the first BFD session is not received through the main TE tunnel, and the BFD message corresponding to the first BFD session is not received through the standby TE tunnel, determining that the main PW is abnormal.

Referring to fig. 1, after the device 106 establishes the first BFD session corresponding to the main PW, when a first sending timer of the first BFD session times out each time, the device 106 sends a BFD packet corresponding to the first BFD session through the main PW, and when the device 106 sends the BFD packet corresponding to the first BFD session through the main PW, if the main TE tunnel is not abnormal, the device 106 sends the BFD packet corresponding to the first BFD session through the main TE tunnel.

Before the first receiving timer of the first BFD session is overtime, if the device 101 receives a BFD packet corresponding to the first BFD session through the main TE tunnel, it determines that the main PW is not abnormal. And when the first receiving timer is overtime, if the BFD message corresponding to the first BFD session is not received through the main TE tunnel, the BFD message corresponding to the first BFD session is not received through the standby TE tunnel, and the main PW is determined to be abnormal.

Referring to fig. 1, when the device 106 sends a BFD packet corresponding to the first BFD session through the main PW, if the main TE tunnel is abnormal, that is, it is determined that the main TE tunnel is abnormal based on the second BFD session, the device 106 may send the BFD packet corresponding to the first BFD session through the standby TE tunnel.

Before the first receiving timer expires, the device 101 determines that the main PW is not abnormal if receiving a BFD packet corresponding to the first BFD session through the backup TE tunnel. And when the first receiving timer is overtime, if the BFD message corresponding to the first BFD session is not received through the main TE tunnel, and the BFD message corresponding to the first BFD session is not received through the standby TE tunnel, determining that the main PW is abnormal.

Based on the foregoing technical solution, in this embodiment of the application, since the timeout time of the first receiving timer is greater than the timeout time of the second receiving timer, when the second receiving timer times out, the first receiving timer does not time out, that is, when determining that the main TE tunnel is abnormal based on the second BFD session, it is not yet determined that the main PW is abnormal based on the first BFD session. Furthermore, after the main TE tunnel is abnormal, the BFD message corresponding to the first BFD session is sent through the standby TE tunnel, the BFD message of the main TE tunnel is switched to the standby TE tunnel to be sent, and the standby TE tunnel is not abnormal, so that the BFD message can be correctly sent through the standby TE tunnel.

Referring to fig. 3, which is a schematic structural diagram of a network device, the network device may include a control management component 31, a sending and receiving component 32, and a forwarding chip 33. The control management part 31 includes, but is not limited to: CPU (Central Processing Unit). The transceiver component 32 includes, but is not limited to, a CPU, a Logic chip (e.g., an FPGA (Field Programmable Gate Array), a CPLD (Complex Programmable Logic Device), an ASIC (Application Specific Integrated circuit), etc.), a forwarding chip, and the like.

And a control management component 31, configured to establish a first BFD session corresponding to the main PW and establish a second BFD session corresponding to the main TE tunnel. The timeout time of the first receive timer of the first BFD session is greater than the timeout time of the second receive timer of the second BFD session. The timeout time of the first transmit timer of the first BFD session is greater than the timeout time of the second transmit timer of the second BFD session. And when the second receiving timer is overtime, if the BFD message corresponding to the second BFD session is not received through the main TE tunnel, determining that the main TE tunnel is abnormal. And after the main TE tunnel is abnormal, sending a BFD message corresponding to the first BFD session through the standby TE tunnel, so that when opposite-end equipment receives the BFD message corresponding to the first BFD session through the standby TE tunnel before the first receiving timer is overtime, the main PW is determined not to be abnormal.

In one possible embodiment, the control management part 31 records the session information of the first BFD session after the first BFD session is established, and the control management part 31 may record the session information of the second BFD session after the second BFD session is established. Further, the transmission reception section 32 sets a first transmission timer for the first BFD session, and the transmission reception section 32 sets a second transmission timer for the second BFD session.

When the main TE tunnel is not abnormal, the transmission process of the BFD packet may include the following cases:

when the control management component 31 needs to send a BFD packet corresponding to the first BFD session through the main PW, the session information of the first BFD session and the tunnel information of the main TE tunnel may be obtained, and the session information of the first BFD session and the tunnel information of the main TE tunnel are sent to the sending and receiving component 32.

Transmitting and receiving section 32 may construct a BFD packet corresponding to the first BFD session according to the session information of the first BFD session and the tunnel information of the main TE tunnel. When the first sending timer times out each time, the sending and receiving part 32 sends the BFD packet corresponding to the first BFD session to the forwarding chip 33.

The forwarding chip 33 is configured to provide a channel for the BFD packet, that is, after the forwarding chip 33 receives the BFD packet corresponding to the first BFD session, because the BFD packet includes the tunnel information of the main TE tunnel, the forwarding chip 33 sends the BFD packet corresponding to the first BFD session through the main TE tunnel.

When the BFD packet corresponding to the second BFD session needs to be sent through the main TE tunnel, the control management component 31 acquires the session information of the second BFD session and the tunnel information of the main TE tunnel, and sends the session information of the second BFD session and the tunnel information of the main TE tunnel to the sending and receiving component 32.

Transmitting and receiving section 32 may construct a BFD packet corresponding to the second BFD session according to the session information of the second BFD session and the tunnel information of the main TE tunnel. When the second sending timer times out each time, the sending and receiving component 32 sends the BFD packet corresponding to the second BFD session to the forwarding chip 33.

After the forwarding chip 33 receives the BFD packet corresponding to the second BFD session, because the BFD packet corresponding to the second BFD session includes the tunnel information of the main TE tunnel, the forwarding chip 33 may send the BFD packet corresponding to the second BFD session through the main TE tunnel.

When the main TE tunnel is abnormal, the transmission process of the BFD message comprises the following conditions:

when the second receiving timer is overtime, if the BFD packet corresponding to the second BFD session is not received through the main TE tunnel, the control management component 31 determines that the main TE tunnel is abnormal. After the main TE tunnel is abnormal, the control management component 31 sends a BFD packet corresponding to the first BFD session through the standby TE tunnel. Specifically, after the main TE tunnel is abnormal and before the first sending timer of the first BFD session is overtime, the BFD packet corresponding to the first BFD session may be sent through the standby TE tunnel, for example, one or more BFD packets may be sent through the standby TE tunnel, that is, the BFD packet corresponding to the first BFD session may be sent through the standby TE tunnel without waiting for the first sending timer to be overtime.

Referring to fig. 4, time a1, time A3, and time a4 are transmission times determined based on the first transmission timer, that is, BFD packets corresponding to the first BFD session are transmitted at time a1, time A3, and time a 4. Assuming that an abnormality occurs in the main TE tunnel at the time a2, during the period between the time a2 and the time A3, the backup TE tunnel may transmit the BFD packet corresponding to the first BFD session without waiting until the time A3 to transmit the BFD packet corresponding to the first BFD session.

Obviously, the above method can send the BFD message in advance through the backup TE tunnel, thereby avoiding detecting that the main PW is abnormal and avoiding a wrong BFD detection result. For example, it is assumed that the BFD packet (hereinafter, referred to as BFD packet 1) is transmitted through the backup TE tunnel only at time A3, and the device 106 receives the BFD packet 1 at a time after time A3. If the device 106 needs to process a large number of BFD packets, which consume a relatively long time, then, when processing the BFD packet 1, it may already be a certain time X after the time a3, and if the first receiving timer of the first BFD session has timed out before the time X, then the device 106 has already determined that the main PW is abnormal, that is, an erroneous BFD detection result is obtained.

Different from the above manner, the control and management component 31 sends the BFD packet 1 through the backup TE tunnel in advance at a time between the time a2 and the time A3, so that the device 106 can receive the BFD packet 1 in advance, and even if the device 106 needs to process a large number of BFD packets, the device 106 can process the BFD packet 1 before the timeout of the first receiving timer, thereby determining that the main PW is not abnormal, i.e., obtaining a correct BFD detection result.

The process of sending the BFD packet corresponding to the first BFD session through the backup TE tunnel by the control management component 31 may be implemented in the following two ways, which is only an example and is not limited to this.

In the first mode, the control management component 31 generates a BFD packet corresponding to the first BFD session according to the tunnel information of the backup TE tunnel. And sending the BFD message corresponding to the first BFD session to the forwarding chip 33, so that the forwarding chip 33 sends the BFD message corresponding to the first BFD session through the backup TE tunnel.

Specifically, when determining that the main TE tunnel is abnormal, the control management component 31 acquires the session information of the first BFD session and the tunnel information of the standby TE tunnel, and constructs a BFD packet corresponding to the first BFD session according to the session information of the first BFD session and the tunnel information of the standby TE tunnel. Then, the control management component 31 sends the BFD packet corresponding to the first BFD session to the forwarding chip 33, and after the forwarding chip 33 receives the BFD packet corresponding to the first BFD session, since the BFD packet includes the tunnel information of the main TE tunnel, the forwarding chip 33 sends the BFD packet corresponding to the first BFD session through the main TE tunnel.

In the first mode, after the control management component 31 constructs the BFD packet corresponding to the first BFD session, the BFD packet corresponding to the first BFD session is not sent to the sending and receiving component 32, so that the influence of the first sending timer is avoided, and the BFD packet corresponding to the first BFD session can be sent to the forwarding chip 33 without waiting for the first sending timer to be overtime, thereby realizing the early sending of the BFD packet.

In the second mode, the control management component 31 sends the tunnel information of the standby TE tunnel to the sending and receiving component 32, so that the sending and receiving component 32 generates a BFD packet corresponding to the first BFD session according to the tunnel information of the standby TE tunnel, and sends the BFD packet corresponding to the first BFD session to the forwarding chip 33, so that the forwarding chip 33 sends the BFD packet corresponding to the first BFD session through the standby TE tunnel.

For example, after an exception occurs in the main TE tunnel, the control management component 31 may further set a sending permission flag for BFD sessions corresponding to all PWs carried by the main TE tunnel, where the sending permission flag is an arbitrary flag (e.g., a, b, 1, 2, etc., and the type of the sending permission flag is not limited). The transmission permission flag indicates that the BFD packet corresponding to the BFD session is permitted to be transmitted immediately without waiting for the transmission timer to expire, i.e., before the transmission timer expires, the BFD packet corresponding to the BFD session is permitted to be transmitted.

After generating the BFD packet corresponding to the first BFD session according to the tunnel information of the standby TE tunnel, the sending and receiving component 32 may determine whether the first BFD session is provided with a transmission permission flag. If so, sending and receiving component 32 sends the BFD packet corresponding to the first BFD session to the forwarding chip, that is, the BFD packet corresponding to the first BFD session is sent to the forwarding chip without waiting for the first sending timer of the first BFD session to time out. If not, when the first sending timer of the first BFD session times out, sending and receiving component 32 sends the BFD packet corresponding to the first BFD session to the forwarding chip.

Referring to fig. 5A, the transmitting and receiving section 32 sets a transmission timer for each BFD session, the timeout time of the transmission timer is determined at the time of BFD session establishment, and the transmission time of the BFD packet cannot be changed by modifying the timeout time of the transmission timer. In view of the above discovery, in order to send the BFD packet corresponding to the first BFD session before the first sending timer of the first BFD session expires, the following method is adopted:

after the main TE tunnel is abnormal, the control management component 31 determines all PWs carried by the main TE tunnel, and sets a transmission permission flag for the BFD session corresponding to the PW carried by the main TE tunnel, for example, adds the transmission permission flag to the BFD session, which is not limited to this, as long as the correspondence between the BFD session and the transmission permission flag can be recorded, and indicates that the BFD packet corresponding to the BFD session does not need to consider a transmission timer, and the BFD packet corresponding to the BFD session is allowed to be transmitted before the transmission timer expires.

Referring to fig. 5B, assuming that BFD session 1 and BFD session 2 are the first BFD session corresponding to the PW carried by the primary TE tunnel, a clear-to-send flag is set for BFD session 1 and BFD session 2.

Illustratively, when determining that the primary TE tunnel is abnormal, the control management component 31 further obtains the session information of the first BFD session and the tunnel information of the standby TE tunnel, and sends the session information of the first BFD session and the tunnel information of the standby TE tunnel to the sending and receiving component 32. Transmitting and receiving section 32 constructs a BFD packet corresponding to the first BFD session according to the session information of the first BFD session and the tunnel information of the backup TE tunnel.

Then, the transmission reception section 32 determines whether the first BFD session is set with a transmission permission flag. Referring to fig. 5B, assuming that the first BFD session is BFD session 1 or BFD session 2, since BFD session 1 or BFD session 2 is provided with a permission-to-send flag, sending and receiving component 32 directly sends a BFD packet corresponding to the first BFD session to forwarding chip 33, and sending and receiving component 32 may send one or more BFD packets corresponding to the first BFD session to forwarding chip 33. Assuming that the first BFD session is the BFD session 3 or the BFD session 4, since the BFD session 3 or the BFD session 4 does not set the transmission permission flag, the transmitting and receiving component 32 needs to wait until the first transmission timer of the first BFD session is overtime, and then can transmit the BFD packet corresponding to the first BFD session to the forwarding chip 33.

After the forwarding chip 33 receives the BFD packet corresponding to the first BFD session, because the BFD packet includes the tunnel information of the standby TE tunnel, the BFD packet corresponding to the first BFD session is sent through the standby TE tunnel.

Illustratively, after setting the transmission permission flag for the BFD sessions corresponding to all PWs carried by the primary TE tunnel, the control management component 31 deletes the transmission permission flag set for the first BFD session if the first transmission timer of the first BFD session expires. For example, as shown in fig. 5B, after the transmission permission flag is set for the BFD session 1, when the transmission timer corresponding to the BFD session 1 times out, the transmission permission flag set for the BFD session 1 is deleted, so that, for the BFD session 1, the BFD packet can be transmitted only when the transmission timer of the BFD session 1 times out again, and the BFD packet is not transmitted in advance.

In summary, when the main TE tunnel is abnormal, the sending-allowed flag is set for the BFD session corresponding to all PWs carried by the main TE tunnel, so that the sending and receiving component 32 can send the BFD packet corresponding to the BFD session to the forwarding chip 33 without waiting for the sending timer to time out. When the BFD session is provided with the transmission permission flag, the transceiver component 32 may periodically transmit a plurality of BFD messages corresponding to the BFD session until the transmission permission flag of the BFD session is deleted.

Further, when the sending timer of the BFD session is overtime, the sending permission flag set for the BFD session may be deleted, so that the sending and receiving component 32 recovers the conventional implementation procedure, and only when the sending timer is overtime, the BFD packet corresponding to the BFD session is sent.

In summary, in the first embodiment, the control management unit 31 is expanded, and referring to fig. 6A, a forwarding path is added between the control management unit 31 and the forwarding chip 33. The control management component 31 directly sends the BFD to the forwarding chip 33, so as to implement sending the BFD message in advance. In the second mode, as shown in fig. 6B, by extending the transmission/reception section 32, the transmission/reception section 32 sets a transmission permission flag for the BFD session, so that the transmission/reception section realizes the early transmission of the BFD packet.

Based on the same application concept as the method, an embodiment of the present application further provides a device for transmitting a BFD packet, which may be applied to a network device, where a main tunnel and a standby tunnel are established between the network device and an opposite device, and the main tunnel and the standby tunnel jointly carry a main PW, as shown in fig. 7, which is a schematic structural diagram of the device, and the device may include:

an establishing module 71, configured to establish a first BFD session corresponding to the main PW, and establish a second BFD session corresponding to the main tunnel; wherein the timeout time of a first receiving timer of the first BFD session is greater than the timeout time of a second receiving timer of the second BFD session;

a determining module 72, configured to determine that the main tunnel is abnormal if a BFD packet corresponding to the second BFD session is not received through the main tunnel when the second receiving timer is overtime;

and a sending module 73, configured to send, after the main tunnel is abnormal, a BFD packet corresponding to the first BFD session through the standby tunnel.

The sending module 73 is specifically configured to, when sending the BFD packet corresponding to the first BFD session through the backup tunnel: acquiring tunnel information of the standby tunnel;

generating a BFD message corresponding to the first BFD session according to the tunnel information of the standby tunnel;

and sending the BFD message corresponding to the first BFD session through the standby tunnel.

The disclosed embodiments provide a machine-readable storage medium storing machine-executable instructions that, when invoked and executed by a processor, cause the processor to implement the above-described BFD packet transmission method.

Here, a machine-readable storage medium may be any electronic, magnetic, optical, or other physical storage device that can contain or store information such as executable instructions, data, and so forth. For example, the machine-readable storage medium may be: a RAM (random Access Memory), a volatile Memory, a non-volatile Memory, a flash Memory, a storage drive (e.g., a hard drive), a solid state drive, any type of storage disk (e.g., an optical disk, a dvd, etc.), or similar storage medium, or a combination thereof.

The systems, devices, modules or units illustrated in the above embodiments may be implemented by a computer chip or an entity, or by a product with certain functions. A typical implementation device is a computer, which may take the form of a personal computer, laptop computer, cellular telephone, camera phone, smart phone, personal digital assistant, media player, navigation device, email messaging device, game console, tablet computer, wearable device, or a combination of any of these devices.

For convenience of description, the above devices are described as being divided into various units by function, and are described separately. Of course, the functionality of the units may be implemented in one or more software and/or hardware when implementing the present application.

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, embodiments of the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

Furthermore, these computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (which may include, but is not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The above description is only an example of the present application and is not intended to limit the present application. Various modifications and changes may occur to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A network device, wherein a main tunnel and a standby tunnel are established between the network device and an opposite terminal device, and the main tunnel and the standby tunnel jointly carry a main PW, includes:

2. The network device of claim 1,

the network equipment also comprises a forwarding chip; when the control management component sends the BFD packet corresponding to the first BFD session through the backup tunnel, the control management component is specifically configured to:

and sending the BFD message corresponding to the first BFD session to the forwarding chip so that the forwarding chip sends the BFD message corresponding to the first BFD session through the backup tunnel.

3. The network device of claim 1,

the network equipment also comprises a sending and receiving component and a forwarding chip; when the control management component sends the BFD packet corresponding to the first BFD session through the backup tunnel, the control management component is specifically configured to:

and sending the tunnel information of the standby tunnel to the sending and receiving component, so that the sending and receiving component generates a BFD message corresponding to the first BFD session according to the tunnel information of the standby tunnel, and sends the BFD message corresponding to the first BFD session to the forwarding chip, so that the forwarding chip sends the BFD message corresponding to the first BFD session through the standby tunnel.

4. The network device of claim 3,

the control management component is further configured to: after the main tunnel is abnormal, setting a sending permission mark for BFD sessions corresponding to all PWs loaded by the main tunnel;

after the sending and receiving component generates a BFD message corresponding to the first BFD session according to the tunnel information of the standby tunnel, determining whether the first BFD session is provided with a sending permission mark or not; and if so, sending the BFD message corresponding to the first BFD session to the forwarding chip.

5. The network device of claim 4,

the transmit receive component is further configured to: after determining whether the first BFD session is provided with a sending permission mark, if not, sending a BFD message corresponding to the first BFD session to the forwarding chip when a first sending timer of the first BFD session is overtime.

6. The network device of claim 4,

the control management component is further configured to: after the allowed sending flags are set for the BFD sessions corresponding to all PWs carried by the main tunnel, if the first sending timer of the first BFD session is overtime, the allowed sending flags set for the first BFD session are deleted.

7. A transmission method for Bidirectional Forwarding Detection (BFD) messages is characterized in that the method is applied to network equipment, a main tunnel and a standby tunnel are established between the network equipment and opposite terminal equipment, and the main tunnel and the standby tunnel jointly bear a main Pseudo Wire (PW), and the method comprises the following steps:

8. The method of claim 7,

the sending of the BFD packet corresponding to the first BFD session through the backup tunnel includes:

acquiring tunnel information of the standby tunnel;

9. The utility model provides a transmission device of two-way forwarding detection BFD message which characterized in that is applied to network equipment, main tunnel and reserve tunnel have been established between network equipment and the opposite terminal equipment, main tunnel with reserve tunnel bears main pseudo-wire PW jointly, the device includes:

10. The apparatus according to claim 9, wherein the sending module, when sending the BFD packet corresponding to the first BFD session through the backup tunnel, is specifically configured to:

acquiring tunnel information of the standby tunnel;