CN110166158A

CN110166158A - A kind of guard method of OTN equipment clock

Info

Publication number: CN110166158A
Application number: CN201910389350.4A
Authority: CN
Inventors: 赵小威; 沈李峰
Original assignee: Shanxi Shanshui Optoelectronic Technology Co Ltd
Current assignee: Shanxi Shanshui Optoelectronic Technology Co Ltd
Priority date: 2019-05-10
Filing date: 2019-05-10
Publication date: 2019-08-23

Abstract

A kind of guard method of OTN equipment clock, method includes the following steps: (1), which retains expense transmitting additional clock information with OTN frame, to prevent from forming clock loop, expense transmits the clock ID and clock subnet number of clock quality information and locking；(2) equipment inside the same subnet, it must successively be compared according to the sequence of the clock ID and clock subnet number of clock quality information and locking, judging all clock sources, which is optimal, while passing through clock ID, and clock subnet number, it can be very good to prevent clock loop from generating.This method is related to OTN network, and retaining expense transmitting additional clock information with OTN frame prevents from forming clock loop.

Description

A kind of guard method of OTN equipment clock

Technical field

The present invention relates to a kind of guard methods of OTN equipment clock.

Background technique

OTN concept and overall technology framework are formally to be proposed in 1998 by ITU.T, before 2000, the mark of OTN Standardization uses thinking identical with SDH substantially, based on G.872 optical-fiber network layered structure, respectively from Network-Node Interface (G.709), physical layer interface (G.959.1), network jitter performance (G.8251) etc. define OTN.Hereafter, OTN conduct New-generation digital light tranmission techniques system after PDH, SDH.

Optical transfer network includes Metropolitan Area Network (MAN) (core layer, convergence layer and access layer) and arterial grid (main line and provincial inside the province at present Main line), OTN needs the spy carried according to heterogeneous networks level service as transmission network technology more than carrying 1Gbit/s particle Point is to consider whether to be adapted for introduction into.

With 3G, even more stringent requirements are proposed for service delay for 5G business by 4G, simultaneously for the requirement of clock It can be higher and higher.

Summary of the invention

Its of the invention purpose, which is that, provides a kind of guard method of OTN equipment clock, solves due to link failure, when Clock source failure and other reasons cause clock to shake, may be at the problem in clock cyclization.

It adopts the technical scheme that achieve the above object, a kind of guard method of OTN equipment clock, this method includes Following steps: (1) retaining expense transmitting additional clock information with OTN frame prevents from forming clock loop, and expense transmits clock matter Measure the clock ID and clock subnet number of information and locking；(2) equipment inside the same subnet, it is necessary to according to clock quality information And the clock ID and the sequence of clock subnet number of locking are successively compared, judge all clock sources which to be optimal, simultaneously By clock ID and clock subnet number, can be very good to prevent clock loop from generating.

G.781, the mark clock source quality that the clock quality is defined according to ITU-T, using a reserved word of OTN Section transmitting, wherein using first locking device external clock reference, the equipment MAC of GPS and port are transmitted to down as clock ID Each equipment of one equipment, downstream is first selected according to standard according to quality, then compares whether clock ID is oneself, if It is not oneself, then can choose as preferably clock source, port of the MAC plus 16BIT that the clock ID is 48BIT uses Reserve bytes transmitting.

The comparison complete clock quality after clock ID, is adding clock subnet, it is same again to power on default all devices Subnet, clock subnet are that 16BIT is transmitted by network management configuration using reserve bytes, lead to all devices inside a subnet, must Must be according to clock quality, the sequence of clock ID and clock subnet number successively judges optimal clock source.

Beneficial effect

The present invention has the following advantages that compared with prior art.

It is an advantage of the invention that being able to solve due to link failure, the reasons such as clock source failure cause clock to shake, may At the problem in clock cyclization.

Detailed description of the invention

Below in conjunction with attached drawing, the invention will be further described.

Fig. 1 is simple ring network figure in the present invention；

Fig. 2 is polycyclic networking diagram in the present invention；

Fig. 3 is OTUk frame structure diagram in the present invention；

Fig. 4 is ODUk frame structure diagram in the present invention.

Specific embodiment

Below with reference to examples and drawings, the invention will be further described.

A kind of guard method of OTN equipment clock, method includes the following steps:

(1) retaining expense transmitting additional clock information with OTN frame prevents from forming clock loop, and expense transmits clock quality information And the clock ID and clock subnet number of locking；

(2) equipment inside the same subnet, it is necessary to according to the clock ID and clock subnet number of clock quality information and locking Sequence successively compares, judge all clock sources which for optimal, while passing through clock ID and clock subnet number, can be with Prevent clock loop from generating well.

A kind of method and system of clock protection of major design of the present invention, prevent the generation of clock loop；First G.781 The Option1 clock source credit rating of definition is as shown in table 1 below:

The definition of 1 SSM credit rating of table

Upper table is common clock quality grade, and according to putting in order, credit rating is from high to low, that is to say, that a carrying The clock source of QL-PRC SSM information, credit rating are higher than the clock source of a carrying QL-SSU-A SSM information, equipment When selecting source, it can preferentially the high reference source of selection credit rating track, but under networking or configuration, be easy to cause clock loop Generation, as shown in Figure 1, 2, especially Fig. 2, networking is complicated, and thus the ad hoc following scheme of meter avoids the generation of clock loop.

OTN data frame format and expense should meet the definition of ITU-T relevant criterion, clock quality information and extension information point (13,14 byte) is not transmitted by the RES overhead byte of OUTK, the reserve bytes of ODUK expense (second row 1-3 byte, the Four row 9-14 bytes), position of the clock expense in OTN frame structure is as shown in Figure 3,4.

Firstly, the clock source of a specified equipment is external clock (BIT, GPS etc.) or is oneself internal clocking (SSU- A), this equipment can be edge device, the equipment that can be docking base station, and external clock is configured in equipment or oneself is Maximum clock source, and oneself clock source credit rating and clock ID, the information such as clock subnet pass through OTU, the frame overhead of ODU It is transmitted to upstream device.

When the more a ports the OTU of second equipment receive clock quality information and clock ID, the information such as clock subnet are first Clock quality is compared, optimum quality is selected, then compare and whether be the clock ID of oneself, if it is, filtering this clock source, otherwise Then compare clock subnet information, if subnet is consistent, select this clock for optimal clock source, and the clock quality of locking and Clock ID is being transmitted to next equipment.Subsequent equipment locks clock source according to this process step by step.

After the completion of network equipment locking of being such as taken in all locks, this is that configuration specifies another equipment internal soundness grade Higher (PRC), at this moment, this equipment will change the clock status of oneself, and the clock quality clock ID of oneself, clock subnet etc. Information passes, and after other equipment receive, reselects one time according to second equipment selection clock source procedure.

In the polycyclic networking of Fig. 2, environment is especially complex, and due to link failure, the reasons such as clock source failure lead to clock Concussion, may be at the problem in clock cyclization, in this case, we introduce the probability of clock subnet, leads to a subnet Clock could be locked normally, and the clock of different sub-network cannot directly participate in clock source selection, the node between two subnets, be needed The clock of one subnet is introduced into next subnet by special configuration, after next subnet equipment locking, oneself Clock ID, clock subnet is transmitted to other equipment inside subnet, enables inside subnet other equipment according to the link of priority Relationship locks clock source.

It is embodied as follows:

Embodiment 1

Simple looped network clock networking process flow is as follows:

S1: such as Fig. 1, the clock priority that external clock is configured first in A equipment is highest；

S2:A equipment clock protective module checks external clock to select this clock after highest priority；

After S3:A equipment locks external clock, the system MAC Address of A equipment, the clock subnet number of network management configuration are obtained, and be inserted into Into the overhead clock of OTUK；

S4:B, C equipment receive the clock quality that A equipment sends over, the clock priority of clock ID etc. and B, C device configuration, Judge whether it is optimal clock source, if it is optimal clock source, then lock this clock, and returns DNU and give A equipment.

The clock quality of A equipment is passed to each other simultaneously again after the completion of the locking of S5:B, C equipment, B at this time, C equipment according to The clock priority of configuration, judges whether optimal clock changes, and in case of changing, then modifies the clock of equipment locking Source.And DNU is returned in the port of locking；

After the completion of the locking of S6:A, B, C equipment, stable state is kept；

Embodiment 2

Process flow between polycyclic networking diagram equipment:

S1: being a kind of polycyclic networking situation such as Fig. 2, so we first selects the multiple subnets of division, first equipment A, B, D, H are divided into a subnet 1, and equipment C, E, F, G, H are another subnet 2, and the clock priority that external clock is configured in A equipment is Highest；

S2:A equipment clock protective module checks external clock to select this clock after highest priority

After S3:A equipment locks external clock, the system MAC Address of A equipment is obtained, according to the clock subnet number of network management configuration, And it is inserted into the overhead clock of OTUK；

S4: the other equipment of subnet 1 successively lock the clock source that A equipment comes；

S5: the C device configuration on subnet 2 selects the clock source from subnet 1, after the completion of locking, according to the clock matter of locking Amount and the clock ID of oneself, clock subnet are issued on other of subnet 2.

The equipment such as S6:E, F, G, H successively lock.

S7:C equipment and subnet 1 have 3 connections, so even if any two lines road for occurring connecting with subnet 1 goes out Existing failure, appoints the clock source that can so lock subnet 1.

Claims

1. a kind of guard method of OTN equipment clock, which is characterized in that method includes the following steps:

2. a kind of guard method of OTN equipment clock according to claim 1, which is characterized in that the clock quality The mark clock source quality G.781 defined according to ITU-T is transmitted using a reserve bytes of OTN, wherein using first Locking device external clock reference, the equipment MAC of GPS and port are transmitted to next equipment as clock ID, downstream each Equipment first is selected according to standard according to quality, then compare clock ID whether be oneself, if not be oneself, can choose for Preferably clock source, the clock ID are that the MAC of 48BIT adds the port of 16BIT, are transmitted using reserve bytes.

3. a kind of guard method of OTN equipment clock according to claim 1, which is characterized in that when the comparison is complete Clock quality after clock ID, is adding clock subnet, powers on the default all devices same subnet again, and clock subnet is 16BIT, It by network management configuration, is transmitted using reserve bytes, leads to all devices inside a subnet, it is necessary to according to clock quality, clock ID, And the sequence of clock subnet number successively judges optimal clock source.