WO2013189361A2

WO2013189361A2 - Method for processing message and network element apparatus

Info

Publication number: WO2013189361A2
Application number: PCT/CN2013/081765
Authority: WO
Inventors: 杨明杰; 张建军; 吴胜兵
Original assignee: 中兴通讯股份有限公司
Priority date: 2012-08-20
Filing date: 2013-08-19
Publication date: 2013-12-27
Also published as: CN102843293B; WO2013189361A3; CN102843293A

Abstract

A method for processing a message and a network element apparatus. The method comprises: assembling a precision time protocol (PTP) message; and inserting the PTP message into a reserved byte of an overhead of an optical transport unit (OTU) frame or mixing the PTP message into an Ethernet message to be transmitted. This solution can implement interaction of the PTP protocol message between network elements of a wavelength division network, so that the PTP protocol message can be transferred and analyzed among the network elements, and thereby precision time transfer of the wavelength division network can be realized.

Description

Method for processing message and network element device

Technical field

The invention relates to the field of optical wave division communication, and realizes the processing of the whole network element time synchronization and the precise time transmission of the wavelength division system, and the method and the network element device. Background technique

The traditional TDM (Time Division Multiplex, time division multiplexing) network (PDH (Plesiochronous Digital Hierarchy, bad plesiochronous digital line ^{1 J) / SDH (Synchronous Digital} Hierarchy, synchronous digital hierarchy) is carrying TDM traffic (such as E1 / T1) of At the same time, the clock information can be accurately transmitted, and the receiving end can recover the service according to the extracted clock information. Meanwhile, the TDM line can also provide a synchronous reference clock for some application networks, and a more common application is a mobile Backhaul (mobile backhaul) network. With the development of WDM (Wavelength Division Multiplexing) systems to multi-bearer, multi-service, and intelligent, higher requirements are placed on the network quality and service type of WDM systems. Need to achieve time synchronization across the network and provide precise time capabilities.

According to the PTP (Precision Time Protocol) defined by IEEE1588v2, the protocol signaling used to implement the network accurate time alignment is filled in TCP (Transmission Control Protocol) / UDP in the form of payload (load). (User Datagram Protocol) layer packets are encapsulated in the IP layer and Ethernet, or the protocol signaling is directly encapsulated in Ethernet, and peer-to-peer interaction and resolution are performed between nodes in the network. Processing, realizing time synchronization of the whole network and providing precise time function. The current data communication system of Datacom and PTN (Packet Transport Network) generally adopts this method.

The WDM network is characterized in that the OTU (Optical Transmission Unit) frame is encapsulated in the user equipment for large-capacity and long-distance transmission. The device is shown in Figure 1. The typical networking mode is shown in Figure 1. 2, the processing method and steps of a one-way service flow of the wavelength division system to the user's Ethernet service are shown in Figure 3:

Figure 3 shows a typical WDM network consisting of three WDM network elements. User services are accessed from the client side. After cross-connection, they are encapsulated into OTUk frames and transmitted to the next NE for processing. The OTU frame of the user service is transmitted to the destination network element, decapsulated, restored to the user service, and sent out from the client side board. The specific steps are:

Step 301: The WDM network device client-side service receiving device 201 receives the user's GE (GigabitEthernet)/FE (Fast Ethernet) service, and encapsulates the Ethernet service into an ODUk frame through the backplane connection line. Sended to the service electrical cross processing device 203;

Step 302: The electrical cross-processing device 203 cross-processes the service, and sends the cross-processed ODUk frame to the line-side service package sending device 205 through the backplane connection line;

Step 303: The line side service encapsulation transmitting device 205 encapsulates the ODUk frame into an OTU frame and sends it to the network element 2;

Step 304: The line side service receiving device 209 of the network element 2 receives the OTU frame decapsulated into an ODUk frame, and sends it to the electrical cross processing device 208;

Step 305: The electrical cross-processing device 208 cross-processes the service, and sends the cross-processed ODUk frame to the line-side service encapsulation transmitting device 210 through the backplane connection line;

Step 306: The line side service encapsulation transmitting device 210 encapsulates the ODUk frame into an OTU frame and sends it to the network element 3;

Step 307: The line side service receiving device 214 of the network element 3 receives the OTU frame decapsulated into an ODUk frame, and sends it to the electrical cross processing device 213;

Step 308: The electrical cross processing device 213 cross-processes the service; the ODUk frame after the cross processing is sent to the client side service decapsulation transmitting device 212 through the backplane connection line;

Step 309: The client-side service decapsulation transmitting device 212 decapsulates the ODUk frame into an Ethernet service and sends the packet to the client device.

In this process, the service has been transmitted in the network in the form of ODUk and OTU frames, which is a complete end-to-end transmission mode. The PTP protocol packets need to be encapsulated in the Ethernet frame format for interaction. With the existing technology, PTP protocol packets cannot be stripped off on the line side. The transmission and resolution of the network between the wavelength divisions is accurate. Protocol signaling can not achieve the time synchronization of the whole network and provide accurate time. Summary of the invention

The technical problem to be solved by the present invention is to provide a method for processing a message and a network element device, so as to implement PTP protocol packet exchange between the network elements of the WDM network, so that the PTP protocol can be transmitted and parsed between the network elements.艮文, thus achieving accurate time transfer of the WDM network.

In order to solve the above technical problem, the present invention provides a method for processing a message, including: assembling a precision time protocol (PTP) message;

The PTP packet is inserted into the reserved bytes of the optical transport unit (OTU) frame overhead or mixed into the Ethernet packet and sent.

Preferably, the foregoing method further has the following features: the reserved bytes for inserting the PTP text into an OTU frame overhead include:

The PTP packet is split into a number of 1-byte fields or multi-byte fields, and the reserved bytes of the OTU frame overhead are inserted in a multiframe format.

Preferably, the foregoing method further has the following features: the inserting the PTP message into a reserved byte of an optical transmission unit (OTU) frame overhead or mixing into an Ethernet packet includes:

The PTP packet is periodically inserted into the reserved byte of the OTU frame overhead or mixed into the Ethernet packet.

Preferably, the above method further has the following features:

After receiving the Ethernet service, the device detects whether the Ethernet service includes a PTP packet, and if the PTP packet is included, the PTP packet is separated from the Ethernet service.

Preferably, the above method further has the following features:

After receiving the OTU frame, detecting whether the OTU frame carries a PTP packet, and if the PTP packet is carried, the PTP packet is parsed from the OTU frame.

In order to solve the above problem, the present invention further provides a network element device, including:

The first module is configured to: assemble a precision time protocol (PTP) message, and send the PTP message to the second module and/or the third module;

The second module is configured to: insert the PTP packet into an optical transmission unit (OTU) frame After the reserved bytes of the pin are sent;

The third module is configured to: send the PTP packet and the Ethernet packet after mixing. Preferably, the network element device further has the following features:

The second module is configured to: disassemble the PTP message into a plurality of 1-byte fields or multi-byte fields, and insert the reserved bytes of the OTU frame overhead in a multi-frame format and send the PTU message.

Preferably, the network element device further has the following features:

The first module is configured to: periodically send the PTP message to the second module and/or the third module.

Preferably, the network element device further has the following features:

The fourth module is configured to: after receiving the Ethernet service, detecting whether the Ethernet service includes a PTP packet, and if the PTP packet is included, separating the PTP packet from the Ethernet service.

Preferably, the network element device further has the following features:

The fifth module is configured to: after receiving the OTU frame, detecting whether the OTU frame carries a PTP packet, and if the PTP packet is carried, parsing the PTP packet from the OTU frame. BRIEF abstract

1 is a wavelength division network element service processing device;

Figure 2 is a schematic diagram of a typical WDM network element;

FIG. 3 is a flowchart of processing a unidirectional Ethernet service of a wavelength division network element;

4 is a schematic diagram of a wavelength division network element device according to an embodiment of the present invention;

5 is a flowchart of a method for processing, by a network element client side device, a PTP protocol packet sent by a client device according to an embodiment of the present invention;

6 is a flowchart of a method for a network element client side device to send a PTP protocol packet to a client device according to an embodiment of the present invention;

Flow chart of the method: 8 is a flowchart of a method for a network element line device to send a PTP protocol packet to a network element line receiving side according to an embodiment of the present invention;

FIG. 9 is a schematic diagram of networking of PTP protocol packets exchanged between a client device and a client device according to an embodiment of the present invention;

10 is a schematic diagram of networking of PTP protocol packets exchanged between a line side of a network element and a line side of a network element according to an embodiment of the present invention;

FIG. 11 is a diagram showing the location of an OTU frame overhead reserved word according to an embodiment of the present invention. Preferred embodiment of the invention

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, in the case of no conflict, the features in the embodiments and the embodiments in the present application may be arbitrarily combined with each other.

To implement the PTP protocol packet exchange between the NEs of the WDM network without occupying the service channel, you can split the PTP packet into several 1-byte fields or multi-byte fields and fill the OTUk frame with the frame. The reserved byte is transmitted to the peer end, and the peer device parses the field, and then re-forms the PTP protocol packet and sends it to the PTP protocol processing unit for processing.

A schematic diagram of a wavelength division network element according to an embodiment of the present invention, as shown in FIG. 4, data interaction between devices in a wavelength division network element is completed through a backplane connection line;

Contains the same modules as the original technology:

The client side service receiving processing device 403 is configured to receive the client side Ethernet service and encapsulate the ODUk frame.

The client side service decapsulation transmitting device 404 is configured to decapsulate the ODUk frame into an Ethernet service, and the electrical cross processing device 406 is configured to perform cross processing on the ODUk frame.

The line side service receiving and processing device 407 is configured to decapsulate the OTU frame into an ODUk frame, and the line side service encapsulating device 408 is configured to encapsulate the ODUk frame into an OTU frame.

Also included are the newly added modules:

The client side PTP packet separating apparatus 401 is configured to separate the Ethernet packet containing the PTP information from the client service; The client side PTP message integration device 402 is configured to combine PTP signaling into a client service for sending;

The PTP 4 集中 centralized processing device 405 is configured to perform centralized processing and calculation of PTP signaling, and perform signaling interaction of the PTP protocol;

The line side PTP signaling separation device 409 is configured to receive an OTU frame on the line side, and separately recover the PTP signaling from the OTU frame;

The line side PTP signaling insertion transmitting device 410 is configured to insert a message containing PTP signaling into a reserved byte of an OTU frame overhead in a multiframe format, and the reserved byte of the OTU frame overhead may be located on the first line of the OTU frame. -14 bytes, line 2 1-2 bytes, line 4 9-14 bytes, PTP overhead position configurable, as shown in Figure 11;

The method used in the embodiment of the present invention uses the PTP packet to be forwarded and processed in a centralized manner, and the PTP signaling carried in the Ethernet frame is transmitted on the line side by inserting the OTU frame overhead reserved byte, thereby realizing each PTP protocol packets exchange between NEs.

5 and FIG. 6 are flowcharts of a method for a PTP protocol packet exchanged between a client side of a network element and a client device according to an embodiment of the present invention;

FIG. 9 is a diagram of a network element client side interacting with a client device (using a PTN device as an example) according to an embodiment of the present invention.

PTP protocol ^ Network diagram of the text.

For example, as shown in FIG. 5, the method includes the following steps: Step 501: The PTP packet separating apparatus 901 on the client side receives the Ethernet service with the PTP packet mixed;

Step 502: The PTP packet separation device 901 on the client side separates the PTP packet from the normal service and sends the PTP packet to the corresponding device for processing.

Step 503: The client-side PTP packet separating apparatus 901 processes the separated common service and forwards the existing service and processing mode to the client-side service receiving and processing device 903, that is, the device 903 encapsulates the Ethernet service into an ODUk frame. The backplane connection line is forwarded to the electrical cross processing device 906 for processing;

Step 504: The device 906 cross-processes the ODUk frame.

Step 505: The line side service device 908 encapsulates the ODUk frame into an OTU frame transmission. Step 506: The client side PTP packet separating apparatus 901 transfers the separated PTP packet to the PTP centralized processing apparatus 905 for processing;

Step 507: The device 905 performs processing calculation on the file.

The device 905 uses the BMC (Best Master Clock) algorithm to calculate the protocol state machine, determines the state of the time port, determines which time ports are enabled to receive and enable the transmission of time protocol packets, and sends the time protocol packets according to the state of the time port. Specific protocol message.

FIG. 6 is a flowchart of a method for a network element client to send a PTP protocol packet to a client device according to an embodiment of the present invention. As shown in FIG. 6, the method includes the following steps:

Step 601: The PTP packet centralized processing device 905 assembles the PTP packet, and forwards the PTP text integration device 902 to the client side;

Step 602: The client side PTP message merging device 902 receives the normal Ethernet service transferred from the client side service decapsulation transmitting device 904.

Step 603: The client side PTP message merging device 902 receives the PTP 艮 message transmitted from the PTP message concentrating device 905;

Step 604: The common Ethernet packet and the PTP packet are mixed and sent to the client device. FIG. 10 is a schematic diagram of a networking diagram in which a PTP protocol is exchanged between a line side of a network element and a line side of a network element according to an embodiment of the present invention. The method for sending a PTP protocol packet to the network element side of the network element side of the embodiment of the present invention, as shown in FIG. 7, includes the following steps:

Step 701: The line side PTP signaling separation device 1009 receives the OTU frame sent by the line side. Step 702: The line side PTP signaling separation device 1009 monitors whether the reserved byte of the OTU frame carries the PTP signaling in a multiframe manner. Then, the process proceeds to step 706; otherwise, the process proceeds to step 703; step 703: the device 1007 resolves the OTU frame into an ODUk frame, and the device is processed by the electrical cross processing device 1006.

Step 704: The device 1006 performs point cross processing on the ODUk frame.

Step 705: The client side service decapsulation transmitting apparatus 1004 decapsulates the ODUk frame into an Ethernet frame or encapsulates it into an OTUk frame transmission. Step 706: Parsing the PTP signaling, reassembling the packet into a packet, and forwarding the decoded packet to the processing device 1005;

Step 707: The processing unit 1005 performs calculation processing on the text.

FIG. 8 is a flowchart of a method for transmitting a protocol packet by a network element line side to a network element line receiving side according to an embodiment of the present invention. As shown in FIG. 8, the method includes the following steps:

As an example, the line side of the WDM network line is connected to the line side of the WDM network, which explains the process of receiving the packet on the line side of the WDM network:

Step 801: ΡΤΡ ^艮 The centralized processing device 1005 assembles ΡΤΡ ^艮文 to the line side 信令 signaling insertion transmitting device 1010;

Step 802: The device 1010 receives the frame transmitted from the line side service encapsulation device 1008. Step 803: The device 1010 receives the message transmitted from the device 1005.

Step 804: The device 1010 splits the ΡΤΡ message into a number of 1-byte fields, inserts the ΟΤΝ frame reserved byte in a multi-frame format, and transmits it from the line side.

The specific configurable row and column number only supports the OTU reserved overhead field, including the first row of 13-14 bytes, the second row of 1-2 bytes, and the fourth row of 9-14 bytes.

For example, the peer-to-peer packet exchange cannot be performed between the existing WDM network elements. The best method is to add a time slot to the processing board. This requires a separate device slot and separate. Transmission channel.

By adding new devices and service processing methods, accurate time transfer of the WDM network can be realized, and new software devices are added, which do not require newly added hardware boards and devices, and do not occupy device slots and transmission channels.

One of ordinary skill in the art will appreciate that all or a portion of the above steps may be performed by a program to instruct the associated hardware, such as a read only memory, a magnetic disk, or an optical disk. Alternatively, all or part of the steps of the above embodiments may also be implemented using one or more integrated circuits. Correspondingly, each module/unit in the foregoing embodiment may be implemented in the form of hardware, or may be implemented in the form of a software function module. The invention is not limited to any specific form of combination of hardware and software. The above is only a preferred embodiment of the present invention, and of course, the present invention may be embodied in various other embodiments without departing from the spirit and scope of the invention. Corresponding changes and modifications are intended to be included within the scope of the appended claims.

Industrial applicability

In summary, the embodiment of the present invention provides a method for processing a message and a network element device, which can implement PTP protocol packet exchange between the network elements of the WDM network, so that the PTP protocol can be transmitted and parsed between the network elements. Thus, to achieve accurate time transfer of the WDM network.

Claims

claims

1. A method of processing messages, including:

Assemble Precision Time Protocol (PTP) messages;

The PTP message is inserted into the reserved bytes of the optical transmission unit (OTU) frame overhead or mixed into the Ethernet message before being sent.

2. The method of claim 1, wherein the reserved bytes of overhead of inserting the PTP message into the OTU frame include:

The PTP message is disassembled into several 1-byte fields or multi-byte fields, and the reserved bytes of the OTU frame overhead are inserted in the form of a multiframe.

3. The method of claim 1, wherein inserting the PTP message into the reserved bytes of the optical transmission unit (OTU) frame overhead or mixing it into the Ethernet message includes:

The PTP message is regularly inserted into the reserved bytes of the OTU frame overhead or mixed into the Ethernet message.

4. The method according to any one of claims 1-3, further comprising:

After receiving the Ethernet service, detect whether the Ethernet service includes a PTP message, if it includes

PTP message, then separate the PTP message from the Ethernet service.

5. The method according to any one of claims 1 to 3, further comprising:

After receiving the OTU frame, it is detected whether the OTU frame carries a PTP message. If it carries a PTP message, the PTP message is parsed from the OTU frame.

6. A network element device, including:

The first module is configured to: assemble a Precision Time Protocol (PTP) message and send the PTP message to the second module and/or the third module;

The second module is configured to: insert the PTP message into the reserved bytes of the optical transmission unit (OTU) frame overhead and send it;

The third module is configured to: mix the PTP message and the Ethernet message and send them.

7. The network element device as claimed in claim 6, wherein,

The second module is configured to: disassemble the PTP message into several 1-byte fields or more Byte field, inserted into the reserved bytes of the OTU frame overhead in the form of a multiframe and then sent.

8. The network element device as claimed in claim 6, wherein,

The first module is configured to: regularly send the PTP message to the second module and/or the third module.

9. The network element device according to any one of claims 6 to 8, further comprising:

The fourth module is configured to: after receiving the Ethernet service, detect whether the Ethernet service includes a PTP message, and if it includes a PTP message, separate the PTP message from the Ethernet service.

10. The network element device according to any one of claims 6 to 8, further comprising:

The fifth module is configured to: after receiving the OTU frame, detect whether the OTU frame carries a PTP message, and if it carries a PTP message, parse the PTP message from the OTU frame.