CN102195735B

CN102195735B - Time synchronization method for multi-subsystem equipment and subsystem

Info

Publication number: CN102195735B
Application number: CN201010123888.XA
Authority: CN
Inventors: 徐鹏飞
Original assignee: Hangzhou H3C Technologies Co Ltd
Current assignee: New H3C Technologies Co Ltd
Priority date: 2010-03-11
Filing date: 2010-03-11
Publication date: 2014-04-09
Anticipated expiration: 2030-03-11
Also published as: CN102195735A

Abstract

The invention discloses a time synchronization method for multi-subsystem equipment and a subsystem. The method comprises that: correspondence between a clock mode of precision time protocol (PTP) networking to which the equipment is to be added and the clock modes of the subsystems is configured on the multi-subsystem equipment to be added to the PTP networking; PTP initialization parameters are configured on internal ports of the multi-subsystem equipment; each subsystem of the equipment receives the announcement that the equipment is to be added to the PTP networking, determines own clock modes according to the clock mode, carried in the announcement, of the PTP networking to which the equipment is to be added, and simultaneously performs PTP initialization according to the PTP initialization parameters configured on own internal ports, and each internal port starts running PTP functions after the initialization is finished; and each subsystem of the equipment performs PTP message interaction with other equipment in the PTP networking by the ports running the PTP functions, and performs time synchronization according to interacted PTP messages. By the method, high-precision time synchronization can be realized between all the subsystems and an external clock when the multi-subsystem equipment is added to the PTP networking.

Description

The method for synchronizing time of multi-subsystem equipment and subsystem

Technical field

The present invention relates to Time synchronization technique field, be specifically related to method for synchronizing time and the subsystem of multi-subsystem equipment.

Background technology

Precision Time Protocol (PTP, Precision Time Protocol) be a kind of precise synchronization agreement that (IEEE, the Institute of Electrical and Electronics Engineers) 1588 of IEEE and IEEE802.1AS tissue propose.On the whole, PTP roughly can be divided into two large functional modules, respectively:

1) synchronous spanning tree module;

2) synchronizing function module.

The former completes the calculating of spanning tree, the time delay that the latter causes by certain interacting message computing network transmission on the basis of spanning tree, and local clock frequency and optimum clock (GM, Grand Master) ratio of frequency, finally calculate to obtain the time deviation of local clock and GM, and then adjust the local clock time and reach time synchronized.Meanwhile, local clock frequency also reaches frequency resonance by ratio adjustment.

Below provide the basic concepts in PTP:

Clock, referred to the equipment that can measure the time that passed so far in this agreement, refer in particular to the timing device that participates in the computing of PTP agreement from a certain epoch.

Territory, the maximum magnitude that PTP can affect, surpassing the clock of this scope can be asynchronous or/and do not resonate.

Boundary clock (BC, Boundary Clock) has connected the clock of a plurality of PTP ports in a PTP territory.

Ordinary clock (OC, Ordinary Clock) has only connected the clock of a PTP port in a PTP territory.

Transparent clock (TC, Transparency Clock), a kind of clock in PTP territory, is responsible for measuring PTP event (Event) message through out-of-date the consumed time, and upgrade Event message with this time, make to receive the time difference that the node of this message can perception produces on TC.

GM, refers to the final supplier of lock in time in PTP territory.

Master clock, refers to the time source supplier in a communication path, and this clock may be from clock in another communication path.

From clock, refer to recipient's lock in time in a communication path, this clock may be master clock in another communication path.

Master port, the master clock in certain communication path leads to its port from clock.

From port, the port from clock towards its master clock in certain communication path.

Single step clock, by the clock of an Event message passing time information.

Two step clocks, by the clock of an Event message and a follow-up conventional message passing time information.

Synchronised clock, the deadline synchronously, the clock that absolute time is consistent.

Resonance clock, complete frequency resonance, the identical clock of umber of pulse of same time.

PTP message can be divided into two types, is respectively Event message and conventional message.Event message is when sending and receiving, and hardware need to be its logging timestamp.

Event message comprises four subtypes:

1) synchronous (Sync) message

The public message that request response (Req_Resp) mechanism and end postpone (Peer_Delay) mechanism, is the start message of time synchronized, is sent, for initiating time synchronized by master clock.

2) time delay request (Delay_Req) message

One of message of Req_Resp mechanism, by sending from clock, for calculating to obtain backpropagation time delay.

3) end time delay request (Pdelay_Req) message

One of message of Peer_Delay mechanism, by sending from clock, for calculating to obtain propagation delay.

4) end time delay response (Pdelay_Resp) message

One of message of Peer_Delay mechanism, master clock sends while responding from the Pdelay_Req of clock, for calculate to obtain propagation delay from clock.

Conventional message comprises six subtypes:

1) notice (Announce) message

Be used to form synchronous layered structure, determine GM, master clock, from clock, master port and from port.

2) follow (Follow_Up) message closely

The public message of Req_Resp mechanism and Peer_Delay mechanism, in two step clocks, with Sync message, send, why the transmitting time point t1 that carries Sync message, used this message, is mainly the problem that provides high-precision timestamp when some chip cannot guarantee to send message for solving.

3) time delay response (Delay_Resp) message

One of message of Req_Resp mechanism, master clock sends while responding from the Delay_Req of clock, for calculate to obtain reverse path time delay from clock.

4) end time delay response follows (Pdelay_Resp_Follow_Up) message closely

One of message of Peer_Delay mechanism, master clock follows Pdelay_Resp message closely and sends, for calculate to obtain propagation delay from clock.

5) management (Management) message

For the message of managing.

6) signal (Signaling) message

Message for signal designation.

PTP is a kind of Time synchronization technique that is applied to mobile network's passback/bearer network, maintains time synchronized and the Frequency Synchronization of each time-sensitive equipment in network.Fig. 1 is an existing PTP networking exemplary plot, as shown in Figure 1, each clockwork (except TC equipment) carries out information interaction by sending Announce message, when a clockwork receives Announce message, this message is sent to the optimum master clock (BMC of this equipment, Best Master Clock) algoritic module calculates relatively, finally selects the clock that possesses limit priority in network: GM, non-GM equipment select its from port for carrying out time synchronized to GM.Be connected to split-second precision source as: the clockwork of global positioning system (GPS, GlobalPositioning System) has higher priority.

Fig. 2 be existing while initially powering on the clockwork in PTP networking carry out the schematic diagram of time synchronized, as shown in Figure 2, take any two node A, B is example, its detailed process is as follows:

Step 201: node A, B power on, respectively with from as GM, and is made as bridge self priority vector by the Master priority vector of self.

The all of the port of GM is master port.

Step 202: node A, B broadcast Announce message, in message, carry the Master priority vector of self.

Step 203: node A, B receive the other side's Announce message, the legitimacy of checking message.

Step 204: legitimate verification passes through, the Master priority in the Announce message that node A, B relatively receive and the Master priority of self.

Step 205: node A finds that the Master priority of self is high, does not deal with; Node B finds that the Master priority in message is high, the port of receiving Announce message is made as from port, and using node A as GM, by the Master priority update of self, be the Master priority in message, start the time that receiving node A synchronously comes.

Fig. 3 has provided when having the new clockwork of higher priority to add PTP networking, clockwork in PTP networking re-starts the schematic diagram of clock synchronous, as shown in Figure 3, establishes the clockwork that node N is the higher priority that newly adds, node A is existing clockwork, and its detailed process is as follows:

Step 301: node N powers on, with from as GM, is made as bridge self priority vector by Master priority vector.

Step 302: node N sends Announce message, carries the Master priority of self in message.

Step 303: node A receives Announce message, the legitimacy of checking message.

Step 304: legitimate verification passes through, the Master priority in the Announce message that node A relatively receives and the Master priority of self.

Here, the Master priority that the Master priority of node A is current GM, as: current GM is node G, and the Master priority of node A is the Master priority of node G.

Step 305: node A finds that the Master priority in message is high, the port of receiving Announce message is made as from port, using node N as GM, by the Master priority update of self, be the Master priority in message, start the time that receiving node N synchronously comes; Meanwhile, what self was original is set to master port from port, by this master port, to former GM, sends Announce message, and this message is carried the new Master priority vector of self.

In addition, due to after each node powers on, can timed sending Announce message.Therefore, node N also can receive the Announce message that node A sends, and after node N passes through the legitimate verification of this message, the Master priority in discovery message, lower than the Master priority of self, does not deal with.

IEEE 1588-2008 has defined two kinds of propagated time delay computing mechanisms, and this two covers mechanism is respectively request-reply mechanism (Req_Resp) and end delay strategy (Peer_Delay).

The prerequisite of Req_Resp mechanism is that network is symmetrical, and master clock is to from the transmission delay of clock, with the transmission delay from clock to master clock be basically identical.If network is asymmetric, this mechanism cannot be worked.

Fig. 4 is the schematic diagram of calculating path propagation delay under existing Req_Resp mechanism, and as shown in Figure 4, its detailed process is as follows:

Step 401: master clock to send Sync message from clock, and records transmitting time t1 by master port.

Step 402: receive Sync message from clock, and record time of reception t2.

Step 403: master clock, after sending Sync message, and then sends a Follow_Up message, carries t1 in Follow_Up message.

Step 404: from time clockwise master clock send Delay_Req message, for initiating the computational process of reverse transfer time delay, and record transmitting time t3.

Step 405: master clock receives Delay_Req message, and records time of reception t4, replys subsequently a Delay_Resp message, and this message is carried t4.

Complete after above-mentioned steps 401～405, from clock, had t1, t2, t3 and tetra-time points of t4, and calculate the deviation Offset with master clock with this:

Offset＝(t2-t1)-propagation_time

＝(t2-t1)-[(t2-t1)+(t4-t3)]/2＝[(t2-t1)-(t4-t3)]/2

Master clock issues from the transmitting time basis of clock whether need Follow_Up message, is divided into single step mode and two step modes.

Under single step mode, the transmitting time of Sync message stamp t1 carries in Sync message, does not send Follow_Up message, in the Sync message in step 401, carries t1, does not perform step 403 simultaneously.Under two step modes, the transmitting time of synchronization message stamp t1 carries in Follow_Up message, visible, Fig. 4 for be pair step modes.

Peer_Delay mechanism also with network to being called prerequisite, concrete mode is similar with Req_Resp mechanism, difference is that it has adopted Pdelay message when calculating propagation_time.

Fig. 5 is the schematic diagram of calculating path propagation delay under existing Peer_Delay mechanism, and as shown in Figure 5, its detailed process is as follows:

Step 501: master clock to send Sync message from clock, and records transmitting time t1 by master port.

Step 502: receive Sync message from clock, and record time of reception t2.

Step 503: master clock, after sending Sync message, and then sends a Follow_Up message, carries t1 in Follow_Up message.

Step 504: from time clockwise master clock send Pdelay_Req message, for initiating the computational process of reverse transfer time delay, and record transmitting time t3.

Step 505: master clock receives Pdelay_Req message, and records time of reception t4, replys subsequently a Pdelay_Resp message, and this message is carried t4, records the transmitting time t5 of Pdelay_Resp message simultaneously.

Step 506: receive Pdelay_Resp message from clock, record time of reception t6.

Step 507: master clock, after sending Pdelay_Resp message, and then sends a Pdelay_Resp_Follow_Up message, carries t5 in Pdelay_Resp_Follow_Up message.

Complete after above-mentioned steps 501～507, from clock, had six time points of t1～t6, and calculate the deviation Offset with master clock with this:

Offset＝(t2-t1)-propagation_time＝(t2-t1)-[(t4-t3)+(t6-t5)]/2

Equally, master clock issues from the transmitting time basis of clock whether need Follow_Up message, is divided into single step mode and two step modes.

Under single step mode, the transmitting time of Sync message stamp t1 carries in Sync message, does not send Follow_Up message, and in Pdelay_Resp message, will carry t5-t4 difference, does not send Pdelay_Resp_Follow_Up message.

Under two step modes, the transmitting time of Sync message stamp t1 carries in Follow_Up message, and for t5, t4, has two covers to carry scheme:

1) t5-t4 difference disposable carrying in Pdelay_Resp_Follow_Up message;

2) t5 carries in Pdelay_Resp_Follow_Up message, and t4 carries in Pdelay_Resp, visible, Fig. 5 for be this scheme.

Peer_Delay mechanism is only applicable to point-to-point link.

By Announce message and BMC algorithm, calculate, PTP network take by generating one the time synchronized spanning tree that GM is root, starts toward downstream, to carry out time synchronized one by one subsequently from GM.Take two step clocks as example description time synchronizing process:

Adopt Peer_delay mechanism calculating path Forwarding Latency, with Sync message can be separated.Between two adjacent point-to-point clock as: BC, OC, P2PTC between any two, carry out calculating in the path delay of time.It is example that Fig. 6 be take OC and P2PTC, has provided the computational process in the path delay of time under Peer_delay mechanism, and as shown in Figure 6, its concrete steps are as follows:

Step 601:OC sends Pdelay_Req message to P2PTC, and records transmitting time t1.

Step 602:P2PTC receives Pdelay_Req message, records time of reception t2, replys subsequently a Pdelay_Resp message, and this message is carried t2, records the transmitting time t3 of Pdelay_Resp message simultaneously.

Step 603:OC receives Pdelay_Resp message, records time of reception t4.

Step 604:P2PTC, after sending Pdelay_Resp message, and then sends a Pdelay_Resp_Follow_Up message, in Pdelay_Resp_Follow_Up message, carries t3.

As shown in Figure 6, when the time of P2PTC side is t2, the time of OC side is t1 '; When the time of P2PTC side is t3, the time of OC side is t4 ', and the time deviation offset between known OC and P2PTC is:

Offset＝t2-t1’＝t2-(t1+path_dealy)＝t2-t1-path_delay

Offset＝t3-t4’＝t3-(t4-path_dealy)＝t3-t4+path_delay

, the path delay Path_delay between OC and P2PTC is:

Path_delay＝[(t2-t1)+(t4-t3)]/2＝[(t4-t1)-(t3-t2)]/2

＝[1234：506.27-1234：500.67-(1234：515.27-1234：512.47)]/2

＝(5.6-2.8)/2＝1.4ns

Be that OC can, according to said process, calculate Path_delay and offset between OC and P2PTC.

What Fig. 6 provided is thereby that OC initiates the process that Pdelay_Req message calculates Path_delay; Equally, P2PTC also can initiate Pdelay_Req message and calculate Path_delay, and this process and Fig. 6 are similar, only " OC " in figure and " P2PTC " need be exchanged.

Fig. 7 is the time synchronization process schematic diagram of existing two step P2PTC, and as shown in Figure 7, its concrete steps are as follows:

Step 701:OC initiates Sync message, and records transmitting time t1.

Step 702:P2PTC receives Sync message, this message is forwarded, and record this message at the residence time rt of self.

Step 703:BC receives Sync message, records time of reception t2.

Step 704:OC, after sending Sync message, and then sends a Follow_Up message, in Follow_Up message, carries t1.

As shown in Figure 7, t1 is comprised of two parts: CF and OriTS, and wherein, OriTS is the integer part of t1, CF is the fractional part of t1.

Step 705:P2PTC receives Follow_Up message, and the t1 in this message is modified to t1+pd1+rt, and this message is forwarded.

As shown in Figure 7, P2PTC revises t1 by revising CF, and CF is modified to CF+pd1+rt, and OriTS is constant.

Wherein, pd1 be P2PTC by and the OC that obtains of the similar flow process of Fig. 6 and the path delay between P2PTC, rt is the rt in step 702.

Step 706:BC receives Follow_Up message, records t1.

As shown in Figure 7, the time of BC side, while being t2, the time of OC side was t1 ', and:

t1’＝OriTS+CF+pd2＝1234：500+(0.67+1.4+108.5)+1.23

＝1234：611.8

t2＝1234：622.27

Wherein, BC can by and the similar flow process of Fig. 6 obtain the pd2 between BC and P2PTC.

, the time deviation offset between BC and OC is:

Offset＝t2-t1’＝1234：622.27-1234：611.8＝10.47ns

As seen from Figure 7: the former time deviation r_offset=10.3ns between BC and OC, after adjusting according to new time deviation offset=10.47ns, the time synchronized alignment error accuracy between BC and OC is:

accuracy＝offset-r_offset＝10.47-10.3＝0.17ns。

While adopting Req_resp mechanism calculating path Forwarding Latency, must calculate in the lump with Sync message, can not be separated.Fig. 8 is time synchronized and the path delay computational process schematic diagram of existing two step E2E TC, and as shown in Figure 8, its concrete steps are as follows:

Step 801:OC initiates Sync message, and records transmitting time t1.

Step 802:E2ETC receives Sync message, this message is forwarded, and record the residence time rt1 of this message.

Step 803:BC receives Sync message, records time of reception t2.

Step 804:OC, after sending Sync message, and then sends a Follow_Up message, in Follow_Up message, carries t1.

As shown in Figure 8, t1 is comprised of two parts: CF and OriTS, and wherein, OriTS is the integer part of t1, CF is the fractional part of t1.

Step 805:E2ETC receives Follow_Up message, and the t1 in this message is modified to t1+rt1, and this message is forwarded.

As shown in Figure 8, E2ETC revises t1 by revising CF, and CF is modified to CF+rt1, and rt1 is the rt1 in step 802; OriTS is constant.

Step 806:BC receives Follow_Up message, records t1.

Step 807:BC initiates Delay_Req message, records transmitting time t3.

Step 808:E2ETC receives Delay_Req message, this message is forwarded, and record the residence time rt2 of this message.

Step 809:OC receives Delay_Req message, records time of reception t4, and replys a Delay_Resp message, and Delay_Resp message is carried t4.

As shown in Figure 8, t4 is comprised of two parts: CF and OriTS, and wherein, OriTS is the integer part of t4, CF is the fractional part of t4.

Step 810:E2ETC receives Delay_Resp message, and the t4 in this message is modified to t4+rt2, and this message is forwarded.

As shown in Figure 8, E2ETC revises t4 by revising CF, and CF is modified to CF+rt2, and rt2 is the rt2 in step 808; OriTS is constant.

Step 811:BC receives Delay_Resp message.

As shown in Figure 8, the time of BC side, while being t2, the time of OC side was t1 ', and:

t1’＝t1+rt2+path_delay＝1234：500+0.67+108.5+path_delay

＝1234：609.17+path_delay

t4’＝t4-rt2-path_delay＝1234：793+0.87-90.2-path_delay

＝1234：703.67-path_delay

Time deviation offset between BC and OC is:

Offset=t2-t1 '=t3-t4 ', that is:

1234：622.27-(1234：609.17+path_delay)＝1234：710.97-(1234：703.67-path_delay)

path_delay＝2.9

:

Offset＝t2-t1’＝1234：622.27-(1234：609.17+2.9)＝10.2ns

As seen from Figure 8: the former time deviation r_offset=10.3ns between BC and OC, after adjusting according to new time deviation offset=10.2ns, the time synchronized alignment error accuracy between BC and OC is:

accuracy＝offset-r_offset＝10.2-10.3＝-0.1ns。

The equipment in PTP networking of more than having provided carries out the scheme of time synchronized, but, because PTP agreement is moved based on whole equipment, for some inside, form complicated equipment, as distributed apparatus, frame stack equipment, frame cascade device etc., these equipment externally performance are as a whole, its inside is but comprised of some relatively independent subsystems, between subsystem, do not have high-precision time synchronized chip to remain synchronous, like this, when such equipment with a plurality of subsystems adds in PTP networking, usually there will be: the parton system of the direct-connected equipment to PTP networking keeps synchronizeing with outside time source, and other not with the direct-connected subsystem of PTP networking still for local zone time or cannot reach the high-precise synchronization that keeps expection with time source.The current solution of this aspect not also.

Summary of the invention

Multi-subsystem equipment the invention provides the method for synchronizing time of multi-subsystem equipment and the subsystem in multi-subsystem equipment, so that while adding PTP networking, can be realized all subsystems and all reach precise synchronization with external clock.

Technical scheme of the present invention is achieved in that

A method for synchronizing time for multi-subsystem equipment, the method comprises:

On the multi-subsystem equipment that will add PTP networking, configuration device adds the clock module of PTP networking and the corresponding relation of subsystem clock pattern; On the internal port of multi-subsystem equipment, configure PTP initiation parameter;

Each subsystem receiving equipment of equipment adds the notice of PTP networking, each subsystem adds the clock module of PTP networking to determine the clock module of self according to the equipment carrying in this notice, simultaneously according to the PTP initiation parameter being configured on self each internal port, carry out PTP initialization, initialization is complete, each internal port PTP function that brings into operation;

Each subsystem in equipment carries out PTP interacting message by the port of operation PTP function and the miscellaneous equipment in PTP networking, according to mutual PTP message, carries out time synchronized.

Each subsystem in described equipment carries out PTP interacting message by the port of operation PTP function and the miscellaneous equipment in PTP networking, carries out time synchronized comprise according to mutual PTP message:

The direct-connected outside port of equipment and PTP networking receives the PTP message that the miscellaneous equipment in PTP networking is sent, this port place subsystem carries out time synchronized according to this message, and the while forwards this PTP message to other outside port and each internal port in this subsystem; Other subsystem in equipment receives PTP message from internal port, according to this message, carries out time synchronized, and outside port and other internal port to this subsystem forwards this message simultaneously.

Described each subsystem adds the clock module of PTP networking to determine that the clock module of self comprises according to the equipment carrying in this notice:

When equipment adds the clock module of PTP networking to be ordinary clock OC, each subsystem determines that the clock module of self is boundary clock BC;

When equipment adds the clock module of PTP networking to be boundary clock BC, each subsystem determines that the clock module of self is boundary clock BC;

When equipment adds the clock module of PTP networking to be end-to-end transparent clock P2PTC, each subsystem determines that the clock module of self is P2PTC;

When equipment adds the clock module of PTP networking to be terminal-to-terminal service transparent clock E2ETC, each subsystem determines that the clock module of self is E2ETC.

Described PTP initiation parameter comprises the whole or combination in any in following parameter:

The propagated delay strategy of supporting, the propagated delay strategy of acquiescence, the clock synchronization mode of support are, the enabled state of the clock synchronization mode of acquiescence, PTP function.

Between the subsystem of described multi-subsystem equipment, adopt a physical connection, or adopt many physical connections that are operated in link aggregation pattern, or adopt many physical connections that are operated in backup mode.

Described multi-subsystem equipment is distributed apparatus or frame stack equipment or frame cascade device.

A subsystem, is arranged in the multi-subsystem equipment that can add PTP networking, and this subsystem comprises:

Module is preserved in configuration, and preservation equipment adds the clock module of PTP networking and the corresponding relation of subsystem clock pattern; Preserve the PTP initiation parameter of each internal port of this subsystem;

PTP initialization module, receiving equipment adds the notice of PTP networking, the clock module that adds PTP networking according to the equipment carrying in this notice, from configuration, preserve the clock module that module is obtained this subsystem, according to configuration, preserve the PTP initiation parameter of each internal port of this subsystem of module preservation simultaneously, each internal port is carried out to PTP initialization, and initialization is complete, each internal port PTP function that brings into operation;

Time synchronized module, carries out PTP interacting message by moving the port of PTP function and the miscellaneous equipment in PTP networking in this subsystem, according to mutual PTP message, carries out time synchronized.

Described time synchronized module comprises:

Forwarding module, receives PTP message from the port of this subsystem, and the port repeat by this message to other operation PTP function of this subsystem, meanwhile, sends to synchronization module by this message;

Synchronization module, the PTP message of sending according to forwarding module is carried out time synchronized.

Described PTP initialization module is when equipment adds the clock module of PTP networking to be ordinary clock OC, and the clock module of determining this subsystem is boundary clock BC;

When equipment adds the clock module of PTP networking to be boundary clock BC, the clock module of determining this subsystem is boundary clock BC;

When equipment adds the clock module of PTP networking to be end-to-end transparent clock P2PTC, the clock module of determining this subsystem is P2PTC;

When equipment adds the clock module of PTP networking to be terminal-to-terminal service transparent clock E2ETC, the clock module of determining this subsystem is E2ETC.

Between other subsystem of described subsystem and place equipment, adopt a physical connection, or adopt many physical connections that are operated in link aggregation pattern, or adopt many physical connections that are operated in backup mode.

Compared with prior art, in the present invention, on the multi-subsystem equipment that will add PTP networking, configuration device adds the clock module of PTP networking and the corresponding relation of subsystem clock pattern, on the internal port of multi-subsystem equipment, configure PTP initiation parameter, when equipment adds PTP networking, each subsystem adds the clock module of PTP networking to determine the clock module of self according to equipment, simultaneously according to the PTP initiation parameter being configured on self each internal port, carry out PTP initialization, initialization is complete, each internal port PTP function that brings into operation, then by the port of operation PTP function and the miscellaneous equipment in PTP networking, carry out PTP interacting message, according to mutual PTP message, carry out time synchronized, thereby when multi-subsystem equipment adds PTP networking, can realize all subsystems and all reach precise synchronization with external clock.

Accompanying drawing explanation

Fig. 1 is an existing PTP networking exemplary plot;

Fig. 2 be existing while initially powering on the clockwork in PTP networking carry out the schematic diagram of time synchronized;

Fig. 3 is for when having the new clockwork of higher priority to add PTP networking, and the clockwork in PTP networking re-starts the schematic diagram of clock synchronous;

Fig. 4 is the schematic diagram of calculating path propagation delay under existing Req_Resp mechanism;

Fig. 5 is the schematic diagram of calculating path propagation delay under existing Peer_Delay mechanism;

Fig. 6 is example for take OC and P2PTC, the computational process in the path delay of time under Peer_delay mechanism;

Fig. 7 is the time synchronization process schematic diagram of existing two step P2PTC;

Fig. 8 is the time synchronization process schematic diagram of existing two step E2ETC;

The multi-subsystem equipment that Fig. 9 provides for the embodiment of the present invention carries out the method flow diagram of time synchronized;

The composition diagram of the subsystem that Figure 10 provides for the embodiment of the present invention.

Embodiment

Below in conjunction with drawings and the specific embodiments, the present invention is further described in more detail.

The multi-subsystem equipment that Fig. 9 provides for the embodiment of the present invention carries out the method flow diagram of time synchronized, and as shown in Figure 9, its concrete steps are as follows:

Step 901: configuration device adds the clock module of PTP networking and the corresponding relation of subsystem clock pattern on the multi-subsystem equipment that will add PTP networking; On each internal port of multi-subsystem equipment, configure PTP initiation parameter.

The internal port of multi-subsystem equipment refers on certain subsystem that is positioned at multi-subsystem equipment and the port being connected with another subsystem of multi-subsystem equipment.

Here, when equipment adds the clock module of PTP networking to be OC, subsystem clock pattern is BC, and even equipment adds PTP networking as OC, and the subsystems in equipment adds PTP networking with BC pattern;

When equipment adds the clock module of PTP networking to be BC, subsystem clock pattern is BC, and even equipment adds PTP networking as BC, and the subsystems in equipment adds PTP networking with BC pattern;

When equipment adds the clock module of PTP networking to be P2PTC, subsystem clock pattern is P2PTC, and even equipment adds PTP networking as P2PTC, and the subsystems in equipment adds PTP networking with P2PTC pattern;

When equipment adds the clock module of PTP networking to be E2ETC, subsystem clock pattern is E2ETC, and even equipment adds PTP networking as E2ETC, and the subsystems in equipment adds PTP networking with E2ETC pattern.

PTP initiation parameter is: the needed basic configuration parameter of port operation PTP function.Basic configuration parameter can comprise the whole or combination in any in following parameter:

1, the propagated delay strategy of supporting.

When subsystem is BC or OC, this parameter can be Req_Resp mechanism and/or Peer_Delay mechanism;

When subsystem is P2PTC, this parameter can be Peer_Delay mechanism;

When subsystem is E2ETC, this parameter can be Req_Resp mechanism.

2, the propagated time delay computing mechanism of acquiescence.

When subsystem is BC or OC, this parameter can be Req_Resp mechanism or Peer_Delay mechanism.

When subsystem is P2PTC, this parameter can be Peer_Delay mechanism;

When subsystem is E2ETC, this parameter can be Req_Resp mechanism.

3, the clock synchronization mode of supporting.

This parameter can be single step mode and/or two step mode.

4, the clock synchronization mode of acquiescence.

This parameter can be single step mode or two step mode.

5, the enabled state of PTP function.

When carrying out PTP initialization, the enabled state of PTP function is set to " enabling ".

Step 902 a: multi-subsystem equipment adds PTP networking, each subsystem of equipment receives the notice that equipment adds PTP networking, and this notice Portable device adds the clock module of PTP networking.

Equipment adds the notice of PTP networking to be waited when equipment adds PTP networking by keeper, is handed down to each subsystem of equipment by forms such as order lines.

Step 903: each subsystem of equipment adds in the clock module of PTP networking and the corresponding relation of subsystem clock pattern at the equipment of self configuration, find subsystem clock pattern corresponding to clock module that the equipment carrying in notice adds PTP networking, start the subsystem clock work pattern to find; And carry out PTP initialization according to the PTP initiation parameter being configured on self each internal port, PTP initialization is complete, each internal port PTP function that formally brings into operation.

Step 904: the direct-connected outside port of equipment and PTP networking receives the PTP message that the miscellaneous equipment in PTP networking is sent, this port place subsystem carries out time synchronized according to this message, and the while forwards this PTP message to each internal port and other outside port in this subsystem.

The outside port of multi-subsystem equipment refers on certain subsystem that is positioned at multi-subsystem equipment and the port being connected with external equipment.

Step 905: other subsystem in equipment receives PTP message from internal port, carries out time synchronized according to this message, other internal port and each outside port to this subsystem forwards this message simultaneously.

Each subsystem in equipment also can send PTP message to external equipment by internal port or outside port, and this PTP message finally can be by arriving external equipment with the direct-connected outside port of PTP networking.

From flow process shown in Fig. 9, can find out: when multi-subsystem equipment adds PTP networking, the internal port of each subsystem can carry out PTP initialization, initialization is complete, each internal port can move PTP function, because the outside port of equipment directly accesses PTP networking, outside port is received after the PTP message that the miscellaneous equipment in PTP networking sends, can forward this message to each internal port and the outside port of operation PTP function, like this, each subsystem all can receive the PTP message from external equipment, thereby just can carry out time synchronized according to the miscellaneous equipment in this PTP message and PTP networking, thereby realizing all subsystems in equipment reaches high precision clock with clock source in PTP networking and synchronizes.

The composition diagram of the subsystem that Figure 10 provides for the embodiment of the present invention, this subsystem is arranged in the multi-subsystem equipment that can add PTP networking, as shown in figure 10, this subsystem mainly comprises: module 101, PTP initialization module 102 and time synchronized module 103 are preserved in configuration, wherein:

Module 101 is preserved in configuration: preservation equipment adds the clock module of PTP networking and the corresponding relation of subsystem clock pattern; Preserve the PTP initiation parameter of each internal port of this subsystem.

PTP initialization module 102: receiving equipment adds the notice of PTP networking, the equipment of preserving module 101 preservations in configuration adds in the clock module of PTP networking and the corresponding relation of subsystem clock pattern, search the equipment carrying in this notice and add the subsystem clock pattern corresponding to clock module of PTP networking, clock module using this subsystem clock pattern as this subsystem, from configuration, preserve the PTP initiation parameter that module 101 is obtained each internal port of this subsystem simultaneously, according to this PTP initiation parameter, each internal port is carried out to PTP initialization, initialization is complete, each internal port PTP function that brings into operation, to time synchronized module 103, send the complete notice of initialization.

PTP initialization module 101 is when equipment adds the clock module of PTP networking to be ordinary clock OC, and the clock module of determining this subsystem is boundary clock BC;

Time synchronized module 103: receive the complete notice of initialization, carry out PTP interacting message by moving the port of PTP function and the miscellaneous equipment in PTP networking on this subsystem, carry out time synchronized according to mutual PTP message.

Time synchronized module 103 can comprise: forwarding module and synchronization module, wherein:

Forwarding module: receive PTP message from a port of this subsystem, the port repeat by this message to other operation PTP function of this subsystem, meanwhile, sends to synchronization module by this message.

Synchronization module: the PTP message of sending according to forwarding module is carried out time synchronized.

In the present invention, for the connected mode between the subsystem of device interior, it can be a physical connection, also can be many physical connections that are operated in link aggregation pattern, also can be operated in backup mode many physical connections: many physical connections backup each other, synchronization only has a physical connection job, but need to avoid: the broadcast storm that is connected to form PTP message between subsystem.Here, avoid the connected mode that forms broadcast storm can adopt prior art, do not repeat them here.

In the present invention, at least comprise two subsystems in multi-subsystem equipment, multi-subsystem equipment can be distributed apparatus, frame stack equipment, frame cascade device etc.

The foregoing is only process of the present invention and embodiment of the method, not in order to limit the present invention, all any modifications of making within the spirit and principles in the present invention, be equal to replacement, improvement etc., within all should being included in protection scope of the present invention.

Claims

1. a method for synchronizing time for multi-subsystem equipment, is characterized in that, the method comprises:

On the multi-subsystem equipment that will add Precision Time Protocol PTP networking, configuration device adds the clock module of PTP networking and the corresponding relation of subsystem clock pattern; On the internal port of multi-subsystem equipment, configure PTP initiation parameter;

Each subsystem in equipment carries out PTP interacting message by the port of operation PTP function and the miscellaneous equipment in PTP networking, according to mutual PTP message, carries out time synchronized;

2. the method for claim 1, is characterized in that, described each subsystem adds the clock module of PTP networking to determine that the clock module of self comprises according to the equipment carrying in this notice:

3. the method for claim 1, is characterized in that, described PTP initiation parameter comprises the whole or combination in any in following parameter:

4. the method for claim 1, is characterized in that, adopts a physical connection between the subsystem of described multi-subsystem equipment, or adopts many physical connections that are operated in link aggregation pattern, or adopts many physical connections that are operated in backup mode.

5. the method for claim 1, is characterized in that, described multi-subsystem equipment is distributed apparatus or frame stack equipment or frame cascade device.

6. a subsystem, is arranged in the multi-subsystem equipment that can add PTP networking, it is characterized in that, this subsystem comprises:

Time synchronized module, carries out PTP interacting message by moving the port of PTP function and the miscellaneous equipment in PTP networking in this subsystem, according to mutual PTP message, carries out time synchronized;

Described time synchronized module comprises forwarding module and synchronization module:

7. subsystem as claimed in claim 6, is characterized in that, described PTP initialization module is when equipment adds the clock module of PTP networking to be ordinary clock OC, and the clock module of determining this subsystem is boundary clock BC;

8. subsystem as claimed in claim 6, it is characterized in that, between other subsystem of described subsystem and place equipment, adopt a physical connection, or adopt many physical connections that are operated in link aggregation pattern, or adopt many physical connections that are operated in backup mode.