CN116232519A

CN116232519A - Clock synchronization method and network equipment

Info

Publication number: CN116232519A
Application number: CN202310199506.9A
Authority: CN
Inventors: 徐金鹏
Original assignee: New H3C Technologies Co Ltd
Current assignee: New H3C Technologies Co Ltd
Priority date: 2023-02-24
Filing date: 2023-02-24
Publication date: 2023-06-06

Abstract

The specification provides a clock synchronization method and a network device, wherein the method comprises the following steps: and receiving a clock message, acquiring a clock synchronization signal and clock path information from the clock message, judging whether the clock message contains path information of the network equipment, if so, not performing clock synchronization, and if not, performing clock synchronization according to the clock synchronization signal. By the method, the problem of Synce looping can be effectively solved, and the occurrence of abnormal full-network synchronization is avoided.

Description

Clock synchronization method and network equipment

Technical Field

The disclosure relates to the field of communication technologies, and in particular, to a clock synchronization method and network equipment.

Background

Synce: synce (synchronous Ethernet), which is a technology for recovering clock by using Ethernet link code stream, is called SyncE for short. The synchronous Ethernet recovers the clock of the transmitting end from the serial data code stream through the Ethernet physical layer chip, thereby realizing the network clock synchronization.

SSM (Synchronization Status Message, synchronization status information): the SSM level is used to directly reflect the level of the synchronization timing signal in the synchronization timing transfer link.

QL level: representing the clock quality level. The QL is further divided into an interface QL and a system QL, where the interface QL reflects the QL of the clock source corresponding to the interface, and the system QL is the QL of the optimal clock source.

Esmc (Ethernet Synchronization messaging Channel, ethernet sync message channel): for communicating SSM grades in a clock network.

Synce is to synchronize hop by configuring synchronous Ethernet devices to mutually transmit clock frequency signals (recovering the clock of a transmitting end from a serial data code stream through an Ethernet physical layer chip), and finally realize clock synchronization of the whole network.

The Synce function currently implemented (hereinafter replaced with "clock synchronization") is divided into modes including an automatic mode and a manual mode (this mode is not discussed herein). The clock source in the automatic mode is automatically selected by the system. The selection principle is that the reference source with the highest priority is selected as the clock source according to the priority of the SSM level- > priority- > numbering sequence of the reference source:

(1) First, a clock source is selected according to the SSM level of the reference source, and the reference source with the highest SSM level is selected in preference.

(2) If the SSM levels of the reference sources do not participate in the control, or the SSM levels are the same, the reference source priority with the smallest priority value is selected according to the priority of the reference source.

(3) If the priority of the reference sources is the same, selecting is carried out according to the sequence of the slot number/the sub-slot number/the port number of the reference source, and the reference source with the smallest number is selected in priority.

If the current clock source is lost or unavailable, the system automatically selects the current optimal reference source as the switching clock source according to the principle. When the original clock source is recovered, the system automatically switches back to the original clock source.

The Synce source selection rule (automatic mode) can meet the requirement of most current network operation at present, but the problem of Synce looping can exist, the abnormal synchronization of the whole network can be caused, the irrecoverable clock function can be seriously caused, and the clock function is not available.

Disclosure of Invention

The present disclosure provides a clock synchronization method and a network device, by which the problem of Synce looping can be effectively solved, and occurrence of a situation of abnormal whole network synchronization is avoided.

The embodiment of the disclosure provides a clock synchronization method, which comprises the following steps:

receiving a clock message;

and acquiring a clock synchronization signal and clock path information from the clock message, judging whether the clock message contains path information of the network equipment, if so, not performing clock synchronization, and if not, performing clock synchronization according to the clock synchronization signal.

The clock path information comprises the unique identification of the whole network of each network device of the clock message path.

Wherein, the unique identification of the whole network comprises: bridge MAC address of each network device;

the determining whether the clock message includes path information of the network device includes:

judging whether a bridge MAC address matched with the network equipment exists in the clock message, if so, not performing clock synchronization, and if not, performing clock synchronization.

The obtaining the clock path information from the clock message includes:

clock path information is obtained through a payload part and/or a reserved TLV field of the clock message.

Optionally, the method further comprises:

and acquiring the unique network identifier of the network equipment, and transmitting the clock synchronization signal and the unique network identifier of the network equipment to downstream network equipment.

The step of sending the clock synchronization signal and the unique identifier of the whole network of the network device to the downstream network device comprises the following steps:

and the load part of the clock message is used for carrying a clock synchronization signal, and the load part of the clock message and/or the reserved TLV field are used for carrying the unique whole network identifier of the network equipment and transmitting the unique whole network identifier to downstream network equipment.

According to the method, as the clock message carries the clock path information of each network device through which the clock message passes, the network device can judge whether the clock path information contains the path information of the network device or not, if not, the network device can synchronize because the network device receives the clock message for the first time and does not generate the condition of a path loop, and if so, the clock message is sent from the network device at the previous moment and reaches the network device through the loop, so that synchronization is not performed to avoid the problem of abnormal full network synchronization caused by Synce looping.

The embodiment of the disclosure also provides a network device, which includes:

the receiving module is used for receiving the clock message;

and the processing module is used for acquiring the clock synchronization signal and the clock path information from the clock message, judging whether the clock message contains the path information of the network equipment, if so, not performing clock synchronization, and if not, performing clock synchronization according to the clock synchronization signal.

The clock path information comprises a unique identifier of the whole network of each device of the clock message path.

The processing module is specifically configured to obtain clock path information through the payload portion and/or the reserved TLV field of the clock packet.

The network device further includes:

and the sending module is used for carrying the clock synchronization signal by utilizing the load part of the clock message and sending the whole network unique identifier carrying the equipment by utilizing the load part of the clock message and/or the reserved TLV field to the downstream equipment.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the specification and together with the description, serve to explain the principles of the specification.

Fig. 1 is a schematic diagram of a network architecture according to an embodiment of the disclosure.

Fig. 2 is a flowchart of a clock synchronization method according to an embodiment of the disclosure.

Detailed Description

Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, the same numbers in different drawings refer to the same or similar elements, unless otherwise indicated. The implementations described in the following exemplary examples do not represent all implementations consistent with the present specification. Rather, they are merely examples of apparatus and methods consistent with some aspects of the present description as detailed in the accompanying claims.

The terminology used in the description presented herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the description. As used in this specification and the appended 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 refers to and encompasses any or 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 this specification to describe various information, these information should not be limited to these terms. These terms are only used to distinguish one type of information from another. For example, the first information may also be referred to as second information, and similarly, the second information may also be referred to as first information, without departing from the scope of the present description. The word "if" as used herein may be interpreted as "at … …" or "at … …" or "responsive to a determination", depending on the context.

As shown in fig. 1, it is assumed that two BITS (BITS 1, BITS 2) are configured, accessed through the 2MBit external clock port of the network element. The priority of the reference source and the reference source of each network element is planned manually, and then configuration is performed manually in a priority table of the network manager: NE1 (EXT 1 (priority configuration optimal), W, E, internal source), NE2 (W (priority configuration optimal), E, internal source), NE3 (W (priority configuration optimal), E, internal source), NE4 (W (priority configuration optimal), EXT1, E, internal source), BITS and network elements all enable SSM protocol.

Under the normal working state, the tracking path is as follows: BITS 1-NE 2-NE 3-NE 4 because there is no tracking relationship between NE1 and NE4, SSMs sent to each other between NE1 and NE4 are PRCs. If the GPS source of BITS1 is lost, NE1 will immediately receive the SSU-A quality level of BITS1 and pass SSU-A down. But since it takes some time to pass to the NE4, the behavior does not change at all until the NE4 receives the SSU-a. Thus, the reference source sent by NE4 to NE1 will maintain PRC, then NE1 compares the reference sources participating in the sync selection, finds that the reference source sent by NE4 is PRC, and switches to tracking NE4 with the highest priority among the several reference sources. After NE1 tracks NE4, SSM passed down is changed to PRC, so NE4 continues to track NE1, forming a loop of NE 1-NE 2-NE 3-NE 4-NE 1, resulting in clock synchronization anomalies.

In order to solve the above technical problems, an embodiment of the present disclosure provides a clock synchronization method, as shown in fig. 2, including:

s201, receiving a clock message;

s202, acquiring a clock synchronization signal and clock path information from the clock message, judging whether the clock message contains path information of the network equipment, if so, not performing clock synchronization, and if not, performing clock synchronization according to the clock synchronization signal.

In this embodiment, the network device may be a network node device, such as a router, a switch, a server, and the like.

In this embodiment, the clock message may be an emc message, and in other embodiments, the clock message may also be another message that may carry a clock signal.

In this embodiment, clock path information may be carried through a payload portion of the emc packet and/or a reserved TLV, where the clock path information includes: the unique identifier of the whole network of each network device through which the clock packet passes, for example, the bridge MAC address of each network device, and it is assumed that the clock packet passes through the network device 1, the network device 2, and the network device 3, respectively, where the bridge MAC of the network device 1 is a, the bridge MAC of the network device 2 is B, and the bridge MAC of the network device 3 is C, then the clock path information may be ABC, so as to indicate that the clock packet is forwarded through the network device 1, the network device 2, and the network device 3.

In step S201, after the network device receives the clock packet, it may be determined whether the clock packet carries clock path information, and if not, the clock path information may be considered unreliable.

In step S202, the network device obtains the clock path information from the payload portion and/or the reserved TLV field of the clock packet, and then performs buffering, and matches the bridge MAC address of the network device itself with the clock path information item by item, if there is a matching item, it indicates that the clock packet has a possibility of generating a ring network, synchronization is not performed according to the clock packet, otherwise, if there is no matching item, it indicates that the clock packet has no possibility of a ring network, and clock synchronization may be performed according to the clock packet.

In another embodiment, after the bridge MAC address of the network device is matched with the clock path information and no matching item exists, operations such as comparing the SSM level of the reference source, that is, adding the matching detection of the clock path information before the existing reference source SSM are performed, so that the occurrence of the situation of generating the ring network message is effectively avoided.

In this embodiment, when the network device forwards the clock message to the downstream network device, the load part of the clock message may be used to carry the clock synchronization signal, and the load part of the clock message and/or the reserved TLV field may be used to carry the unique identifier of the whole network of the network device and send the unique identifier to the downstream network device, so that the downstream network device executes steps S201 to S202, so as to solve the problem of sync looping, and avoid occurrence of abnormal whole network synchronization.

Based on the above method embodiments, the embodiment of the present disclosure further provides a network device, where the network device includes:

the receiving module is used for receiving the clock message;

The network device further includes:

The foregoing describes specific embodiments of the present disclosure. Other embodiments are within the scope of the following claims. In some cases, the actions or steps recited in the claims can be performed in a different order than in the embodiments and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

Other embodiments of the present description will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. This specification is intended to cover any variations, uses, or adaptations of the specification following, in general, the principles of the specification and including such departures from the present disclosure as come within known or customary practice within the art to which the specification pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the specification being indicated by the following claims.

It is to be understood that the present description is not limited to the precise arrangements and instrumentalities shown in the drawings, which have been described above, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present description is limited only by the appended claims.

The foregoing description of the preferred embodiments is provided for the purpose of illustration only, and is not intended to limit the scope of the disclosure, since any modifications, equivalents, improvements, etc. that fall within the spirit and principles of the disclosure are intended to be included within the scope of the disclosure.

Claims

1. A method of synchronizing clocks, the method comprising:

receiving a clock message;

2. The method of claim 1, wherein the clock path information comprises a network-wide unique identification of each network device of the clock message pathway.

3. The method of claim 2, wherein the network-wide unique identification comprises: bridge MAC address of each network device;

4. The method of claim 1, wherein the obtaining clock path information from the clock message comprises:

5. The method according to claim 1, wherein the method further comprises:

6. The method of claim 5, wherein transmitting the clock synchronization signal and the network-wide unique identification of the local network device to the downstream network device comprises:

7. A network device, the network device comprising:

the receiving module is used for receiving the clock message;

8. The network device of claim 7, wherein the clock path information includes a network-wide unique identification of each device of the clock message path.

9. The network device of claim 7, wherein the network device,

10. The network device of claim 7, wherein the network device further comprises: