CN102263630A - Clock source selection method - Google Patents
Clock source selection method Download PDFInfo
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- CN102263630A CN102263630A CN2011102056629A CN201110205662A CN102263630A CN 102263630 A CN102263630 A CN 102263630A CN 2011102056629 A CN2011102056629 A CN 2011102056629A CN 201110205662 A CN201110205662 A CN 201110205662A CN 102263630 A CN102263630 A CN 102263630A
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J3/00—Time-division multiplex systems
- H04J3/02—Details
- H04J3/06—Synchronising arrangements
- H04J3/0635—Clock or time synchronisation in a network
- H04J3/0638—Clock or time synchronisation among nodes; Internode synchronisation
- H04J3/0641—Change of the master or reference, e.g. take-over or failure of the master
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J3/00—Time-division multiplex systems
- H04J3/02—Details
- H04J3/06—Synchronising arrangements
- H04J3/0635—Clock or time synchronisation in a network
- H04J3/0638—Clock or time synchronisation among nodes; Internode synchronisation
- H04J3/0658—Clock or time synchronisation among packet nodes
- H04J3/0661—Clock or time synchronisation among packet nodes using timestamps
- H04J3/0667—Bidirectional timestamps, e.g. NTP or PTP for compensation of clock drift and for compensation of propagation delays
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Abstract
The invention discloses a clock source selection method, which is applied to a precision time protocol network. The precision time protocol network comprises a master clock source and a standby clock source. The method comprises the following steps of: detecting each clock link in real time, and when an alarm is given, selecting a new master clock source according to the type of the alarm. In the method, master clock source reselection processing is performed for the alarm on influence on long-term clock precision, a master clock source direct reselection way is adopted for a link failure alarm, and the way of reselecting the master clock source by reducing clock quality to influence best master clock (BMC) selection is adopted for a link degradation alarm to optimize the conventional clock source selection methods and effectively reduce the influence of link failure/link degradation on the clock precision.
Description
Technical field
The present invention relates to the communications field, relate in particular to a kind of system of selection that realizes the clock source.
Background technology
PTP (Precision Time Protocol, Precision Time Protocol) is a kind of agreement of time synchronized, and the split-second precision that itself just is used between the equipment is synchronous, but also can be borrowed in the Frequency Synchronization between the equipment.Compare existing various time synchronized mechanism, PTP possesses can satisfy more high precision time synchronization requirement, possess advantages such as lower construction and maintenance cost.
Usually, the network of having used the PTP agreement is called the PTP territory, has and have only a synchronised clock in the PTP territory, all devices in the territory all keeps synchronously with this clock.
The port that has moved the PTP agreement on the equipment is called the PTP port, and the role of PTP port PTP port mainly can be divided into following three kinds:
Master port (Master Port): the port of issuing lock in time can be present on BC or the OC.
From port (Slave Port): receive the port of lock in time, can be present on BC or the OC.
Passive port (Passive Port): the port of neither receive lock in time, also externally not issuing lock in time only is present on the BC.
Node in the PTP territory is called clock node, the PTP protocol definition following three types fundamental clock node:
OC (Ordinary Clock, ordinary clock): this clock node has only PTP port to participate in time synchronized in same PTP territory, and by this port from upstream clock node lock in time.
BC (Boundary Clock, boundary clock): this clock node has a plurality of PTP ports and participates in time synchronized in same PTP territory.It by one of them port from upstream clock node lock in time, and by all the other ports clock node issuing time downstream.
TC (Transparent clock, transparent clock): compare with BC/OC, BC/OC need be synchronous with other clock node retention time, and TC is then not synchronous with other clock node retention time.TC has a plurality of PTP ports, but it only transmits the PTP protocol massages and it is carried out Forwarding Latency proofread and correct between these ports, and can be by any one port lock in time.
Clock nodes all in the PTP territory are all pressed certain hierarchical organization together, the reference time of entire domain be exactly optimum clock (Grandmaster Clock, GM), i.e. the clock of highest level.At present usually, after forming topology by notification packet, carry out BMC (Best Master Clock according to information such as optimum clock priority entrained in the Announce message mutual between each clock node, clock grade, time precisions, best master clock) agreement election draws the state of PTP port on master clock source in this territory and alternate clock source and each clock node.Yet, because unstable networks, problems such as link failure, link deterioration can appear in the clock chain circuit in the PTP territory, these problems have influenced clock accuracy greatly, and adopt BMC to elect the suitable clock source that can not more renew in real time according to the situation of clock chain circuit behind the clock source at present, thereby be necessary to propose the decline that a solution is avoided clock accuracy.
Summary of the invention
The object of the present invention is to provide the system of selection in a kind of clock source, can when detecting chain circuit alarming, reselect the clock source, thereby clock selecting is optimized, reduce of the influence of link emergency situations clock accuracy.
The objective of the invention is to be achieved through the following technical solutions.
The system of selection in a kind of clock source, be applied to the accurate clock synchronization protocol network, comprise master clock source and alternate clock source in the described accurate clock synchronization protocol network, this method comprises: detect each clock chain circuit in real time, when producing alarm, select new master clock source according to alarm type.
Preferably, when producing the clock chain circuit fault alarm, be master clock source if unusual clock node takes place, then directly from alternate clock source, select the highest clock source of clock grade as master clock source; Otherwise it is constant to keep current master clock source.
Preferably, when detecting the alarm of clock chain circuit deterioration, if it is master clock source that unusual clock node takes place, then after the temporal quality parameter of unusual clock node takes place deterioration, carry out the election of best master clock agreement again, from all clock nodes, select the master clock source that makes new advances; Otherwise it is constant to keep current master clock source.
Preferably, the mode of the temporal quality parameter of unusual clock node takes place and is in described deterioration: reduce the clock grade that unusual clock node takes place.
Preferably, in the said method, if produce the transient state alarm, it is constant then to keep current master clock source.
Preferably, said method also comprises: recover or the clock chain circuit failure recovery if detect the clock chain circuit deterioration, then directly carry out the election of best master clock agreement again, select the master clock source that makes new advances from all clock nodes.
Preferably, said method also comprises: become the link deterioration if detected clock chain circuit from link failure, then after the temporal quality parameter of unusual clock node takes place deterioration, carry out the election of best master clock agreement again, from all clock nodes, select the master clock source that makes new advances.
Preferably, in the said method, adopt ping, bidirectional forwarding detection (BFD) method, multiprotocol label change detection method or service quality analyzing detecting method to detect each clock chain circuit.
Preferably, in the said method, described deterioration required when reducing the clock grade that unusual clock node takes place is several to be disposed according to current packet loss.
Compared with prior art, the embodiment of the invention has following beneficial effect:
The master clock source re-selection process is carried out in the alarm that the present invention is directed to the long-term clock accuracy of influence, the mode of directly reselecting master clock source is adopted in the link failure alarm, link deterioration alarm employing is reselected master clock source by the mode that the reduction clock grade influences the BMC selection, optimized the system of selection in existing clock source, effectively reduced of the influence of link failure/link deterioration clock accuracy.
Description of drawings
Accompanying drawing described herein is used to provide further understanding of the present invention, constitutes a part of the present invention, and illustrative examples of the present invention and explanation thereof are used to explain the present invention, does not constitute improper qualification of the present invention.In the accompanying drawings:
Fig. 1 is a fundamental clock node schematic diagram in the embodiment of the invention;
Fig. 2 is the handling process when link failure appears in circuit in the embodiment of the invention;
Fig. 3 is the handling process when the link deterioration appears in circuit in the embodiment of the invention;
Fig. 4 is when go wrong handling process when recovering again then of circuit in the embodiment of the invention;
Fig. 5 is a transient state alarming processing flow process in the embodiment of the invention.
Embodiment
In order to make technical problem to be solved by this invention, technical scheme and beneficial effect clearer, clear,, the present invention is further elaborated below in conjunction with drawings and Examples.Should be appreciated that specific embodiment described herein only in order to explanation the present invention, and be not used in qualification the present invention.
Chain circuit alarming is divided into two kinds: the 1) alarm of the long-term clock accuracy of influence mainly comprises link failure and link deterioration; 2) influence the alarm of transient state clock accuracy, comprise that mainly forward link defective and forward link switch.Among the present invention,, adopt the method for directly carrying out the circuit selection again to come the gravity treatment master clock source for the link failure alarm; For the alarm of link deterioration, adopt the state of the method affect BMC that reduces clock quality to select, reach the master clock source gravity treatment; For alarms such as forward link defectives, protocol status can not change, but has noise to introduce to clock frequency and bit recovery mutually, and alarm will be assisted clock frequency and phase place recovery algorithms accelerating ated test (concrete convergence method is not in this patent scope) as parameter.
Clock grade is the clockClass field among the IEEE1588V2 agreement clock quality ClockQuality, and the parameter value of clock grade is high more, shows that clock grade is low more, clock quality is low more.Also comprise other fields among the clock quality ClockQuality, as parameters such as time precision, variances.In actual applications, at the clock grade of each clock node not simultaneously, the BMC algorithm is selected master clock source according to the height of clock grade and from the clock source; Under the identical situation of clock grade, the BMC algorithm is selected master clock source according to other calculation of parameter and from the clock source.Core concept of the present invention is exactly when producing alarm, to reduce the clock quality that unusual clock node takes place by deterioration clock quality parameter, thereby influence the selection result of BMC algorithm.Owing to compare with other parameters, the height of clock grade has more clearly reflected the clock quality of clock node, thus in the embodiment of the invention being that example is described by revising clock grade.
With reference to figure 1,5 clock nodes are arranged, and wherein equipment 1,2,3,4 is as BC (boundary clock) equipment, and 5 as TC (transparent clock) equipment, equipment 1 has 2,3,4 three clock chain circuits of the equipment of coming from, and supposes that equipment 1 to the clock grade of equipment 4 is respectively 130,110,115,120.Equipment 1 is created PTP port one, 2 respectively on the port of connection device 2, equipment 5, create the PTP port of connection device 1 on equipment 2, equipment 3, the equipment 4 respectively.At initial time, carry out selecting after BMC calculates equipment 2 according to information such as the clock grade of each equipment, time precisions and be alternate clock source for master clock source, equipment 3 and equipment 4, and the PTP port one of equipment 1 and PTP port 2 are respectively SLAVE state, PASSIVE state, and the PTP port on equipment 2, equipment 3, the equipment 4 is the MASTER state.Below with the handling process that is described in respectively when producing various alarm.
Consult Fig. 2, handling process when link failure appears in circuit:
201, three clock chain circuits are carried out wireline inspection; Circuit inspect method can adopt the general wireline inspection technology in the communications field, as ping, BFD (bidirectional forwarding detection (BFD) method), MPLS-OAM (multiprotocol label change detection method), SQA (service quality analyzing detecting method) etc., also can come the detection line quality by Detection of Stability to the line delay of sync message;
202, the clock chain circuit (being clock link 3) that detects between the PTP port of the PTP port 2 of equipment 1 and equipment 2 lost efficacy;
203, mark clock chain circuit 3 lost efficacy;
204, do not re-use equipment 2 and be master clock source, directly select the highest alternate clock source of clock grade as new master clock source according to the clock grade size of all alternate clock sources; In the present embodiment, because alternate clock source comprises 4 two of equipment 3 and equipment, and the clock grade of equipment 3 is higher than the clock grade of equipment 4, thereby selection equipment 3 carries out clock synchronization as master clock source in this step.
With reference to figure 3, the handling process when the link deterioration appears in circuit:
301, three clock chain circuits are carried out wireline inspection, simultaneously the deterioration number of pre-configured clock grade is that 6 (the deterioration number also can adopt algorithm to come dynamic calculation to draw.Such as the algorithm that calculates according to packet loss);
302, the clock chain circuit (being clock link 3) that detects between the PTP port of the PTP port 2 of equipment 1 and equipment 2 lost efficacy;
303, mark clock chain circuit 3 deteriorations;
304, the clock grade of reduction equipment 2 is (in the present embodiment, after the clock grade parameter value of equipment 2 is 116 (110+6) at this moment, again carry out the election of BMC agreement again, slave unit 1 is selected the master clock source that makes new advances to the equipment 4, because this moment, the clock grade of equipment 3 was the highest, be that the clock quality is the highest, so selection equipment 3 carries out clock synchronization as master clock source.
With reference to figure 4, when go wrong handling process when recovering again then of circuit:
401, three clock chain circuits are carried out wireline inspection, simultaneously the deterioration number of pre-configured clock grade is that 6 (the deterioration number also can adopt algorithm to come dynamic calculation to draw.Such as the algorithm that calculates according to packet loss);
402, detect clock chain circuit 3 uplink deterioration/link failures and recover, or from losing efficacy to deterioration;
403, wait for WTR (the recovering the stand-by period) time;
If 404 link deterioration/link failure recoveries adopt the BMC agreement to elect equipment 2 and are master clock source; If from losing efficacy,, walk the degradation treatment flow process with reference to figure 3 to deterioration.
With reference to figure 5, transient state alarming processing flow process:
501, three clock chain circuits are carried out wireline inspection;
502, detect the transient state alarm;
503, it is constant as master clock source to keep current device 2, and the notice clock recovery algorithm is carried out relevant treatment.
When having multilink to connect on a PTP port, for example: equipment 1 is with the link of equipment 3,4, and testing result will have influence on the selection and the above-mentioned processing basically identical of PTP port former generation data set.
Above-mentioned explanation illustrates and has described a preferred embodiment of the present invention, but as previously mentioned, be to be understood that the present invention is not limited to the disclosed form of this paper, should not regard eliminating as to other embodiment, and can be used for various other combinations, modification and environment, and can in invention contemplated scope described herein, change by the technology or the knowledge of above-mentioned instruction or association area.And change that those skilled in the art carried out and variation do not break away from the spirit and scope of the present invention, then all should be in the protection range of claims of the present invention.
Claims (9)
1. the system of selection in a clock source, be applied to the accurate clock synchronization protocol network, comprise master clock source and alternate clock source in the described accurate clock synchronization protocol network, it is characterized in that, this method comprises: detect each clock chain circuit in real time, when producing alarm, select new master clock source according to alarm type.
2. the system of selection in clock as claimed in claim 1 source, it is characterized in that, in this method, when producing the clock chain circuit fault alarm, if it is master clock source that unusual clock node takes place, then directly from alternate clock source, select the highest clock source of clock grade as master clock source; Otherwise it is constant to keep current master clock source.
3. the system of selection in clock as claimed in claim 1 source, it is characterized in that, when detecting the alarm of clock chain circuit deterioration, if it is master clock source that unusual clock node takes place, then after the temporal quality parameter of unusual clock node takes place deterioration, carry out the election of best master clock agreement again, from all clock nodes, select the master clock source that makes new advances; Otherwise it is constant to keep current master clock source.
4. the system of selection in clock as claimed in claim 3 source is characterized in that, the mode that the temporal quality parameter of unusual clock node takes place described deterioration is: reduce the clock grade that unusual clock node takes place.
5. the system of selection in clock as claimed in claim 1 source is characterized in that, in this method, if produce the transient state alarm, it is constant then to keep current master clock source.
6. as the system of selection in the arbitrary described clock of claim 1 to 5 source, it is characterized in that, this method also comprises: recover or the clock chain circuit failure recovery if detect the clock chain circuit deterioration, then directly carry out the election of best master clock agreement again, from all clock nodes, select the master clock source that makes new advances.
7. as the system of selection in the described clock of claim 1 to 6 source, it is characterized in that, this method also comprises: become the link deterioration if detected clock chain circuit from link failure, then after the temporal quality parameter of unusual clock node takes place deterioration, carry out the election of best master clock agreement again, from all clock nodes, select the master clock source that makes new advances.
8. the system of selection in clock as claimed in claim 1 source is characterized in that, adopts ping, bidirectional forwarding detection (BFD) method, multiprotocol label change detection method or service quality analyzing detecting method to detect each clock chain circuit.
9. clock source selecting method as claimed in claim 4 is characterized in that, described deterioration required when reducing the clock grade that unusual clock node takes place is several to be disposed according to current packet loss.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201110205662.9A CN102263630B (en) | 2011-07-21 | 2011-07-21 | A kind of system of selection of clock source |
| PCT/CN2012/077018 WO2013010417A1 (en) | 2011-07-21 | 2012-06-15 | Clock source selecting method |
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| CN201110205662.9A CN102263630B (en) | 2011-07-21 | 2011-07-21 | A kind of system of selection of clock source |
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| CN102263630A true CN102263630A (en) | 2011-11-30 |
| CN102263630B CN102263630B (en) | 2017-06-16 |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2013010417A1 (en) * | 2011-07-21 | 2013-01-24 | 中兴通讯股份有限公司 | Clock source selecting method |
| CN103001759A (en) * | 2012-11-23 | 2013-03-27 | 北京东土科技股份有限公司 | Time synchronization method, system and device based on network |
| WO2013152569A1 (en) * | 2012-04-13 | 2013-10-17 | 烽火通信科技股份有限公司 | Planning method for node clock synchronization in mesh network |
| CN105024798A (en) * | 2014-04-28 | 2015-11-04 | 中兴通讯股份有限公司 | Method and device for time synchronization |
| CN105099806A (en) * | 2014-05-21 | 2015-11-25 | 中兴通讯股份有限公司 | Clock switch method and device |
| CN105763279A (en) * | 2016-02-24 | 2016-07-13 | 华东交通大学 | Method for determining optimal master block among distributed node clocks of network system |
| CN106533648A (en) * | 2016-12-06 | 2017-03-22 | 南京南瑞继保电气有限公司 | IEEE 1588 clock synchronizing and monitoring method based on HSR (High-availability Seamless Redundancy) network |
| CN106603187A (en) * | 2016-12-29 | 2017-04-26 | 广东大普通信技术有限公司 | Method for automatically selecting reference source of clock device and clock device |
| CN106851696A (en) * | 2017-04-07 | 2017-06-13 | 深圳市普渡科技有限公司 | A kind of scheduling system of the UWB multi-tag many base stations synchronous based on Wireless clock |
| CN107342831A (en) * | 2017-06-07 | 2017-11-10 | 北京东土军悦科技有限公司 | A kind of main timing source determines method and device |
| CN108540379A (en) * | 2018-04-19 | 2018-09-14 | 南方电网科学研究院有限责任公司 | Time synchronization disturbance switching method, time synchronism apparatus and system based on IEEE 1588V2 |
| US10178636B2 (en) | 2014-03-05 | 2019-01-08 | Huawei Technologies Co., Ltd | Clock synchronization method and device and communications system |
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| JP2019068190A (en) * | 2017-09-29 | 2019-04-25 | 株式会社明電舎 | Network apparatus |
| US10594422B2 (en) | 2016-01-19 | 2020-03-17 | Huawei Technologies Co., Ltd. | Method and apparatus for transmitting clock packet |
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| WO2013152569A1 (en) * | 2012-04-13 | 2013-10-17 | 烽火通信科技股份有限公司 | Planning method for node clock synchronization in mesh network |
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| WO2015176442A1 (en) * | 2014-05-21 | 2015-11-26 | 中兴通讯股份有限公司 | Clock switching method and device |
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| CN105763279A (en) * | 2016-02-24 | 2016-07-13 | 华东交通大学 | Method for determining optimal master block among distributed node clocks of network system |
| CN106533648A (en) * | 2016-12-06 | 2017-03-22 | 南京南瑞继保电气有限公司 | IEEE 1588 clock synchronizing and monitoring method based on HSR (High-availability Seamless Redundancy) network |
| CN106603187A (en) * | 2016-12-29 | 2017-04-26 | 广东大普通信技术有限公司 | Method for automatically selecting reference source of clock device and clock device |
| CN106851696B (en) * | 2017-04-07 | 2023-10-13 | 深圳市普渡科技有限公司 | UWB multi-label multi-base station scheduling system based on wireless clock synchronization |
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| CN108540379A (en) * | 2018-04-19 | 2018-09-14 | 南方电网科学研究院有限责任公司 | Time synchronization disturbance switching method, time synchronism apparatus and system based on IEEE 1588V2 |
| CN111061338A (en) * | 2019-11-30 | 2020-04-24 | 苏州浪潮智能科技有限公司 | Method, system and equipment for updating time sequence of baseboard management controller |
| CN111355569A (en) * | 2020-02-27 | 2020-06-30 | 无锡华云数据技术服务有限公司 | Time synchronization method, device, system, node and readable storage medium |
| CN111355569B (en) * | 2020-02-27 | 2024-01-09 | 华云数据控股集团有限公司 | Time synchronization method, device, system, node and readable storage medium |
| CN113691337A (en) * | 2020-05-19 | 2021-11-23 | 瑞昱半导体股份有限公司 | Control method for seamless precision time protocol and time-aware bridging device |
| WO2022127924A1 (en) * | 2020-12-18 | 2022-06-23 | 华为技术有限公司 | Method and device for selecting clock source |
| WO2023236048A1 (en) * | 2022-06-07 | 2023-12-14 | Telefonaktiebolaget Lm Ericsson (Publ) | Method and network device for ptp clock synchronization |
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| Publication number | Publication date |
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| WO2013010417A1 (en) | 2013-01-24 |
| CN102263630B (en) | 2017-06-16 |
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