WO2018077110A1

WO2018077110A1 - Method for sending packets and receiving packets, and network device and packet sending system

Info

Publication number: WO2018077110A1
Application number: PCT/CN2017/106907
Authority: WO
Inventors: 刘军
Original assignee: 华为技术有限公司
Priority date: 2016-10-25
Filing date: 2017-10-19
Publication date: 2018-05-03
Also published as: CN107979442B; CN107979442A

Abstract

The present application provides a method for sending packets and receiving packets, and a network device and a packet sending system. In the method for sending a packet and receiving a packet, a first network device receives via a link a first time-division multiplexing (TDM) service signal from a third network device located in a TDM network; according to said TDM service signal, the error-code status of said first link and the payload data of the TDM service signal are obtained, a circuit emulation service (CES) packet is generated, and said CES packet is sent to the second network device; the second network device receives the CES packet and generates a second TDM service signal comprising a second error-code identifier and the payload data; said second error-code identifier is used for indicating the error-code status of the first link, and sending the second TDM service signal to a fourth network device located in a second TDM network. By means of the solution provided by the present application, a packet-switched network device is able to transparently transmit a link error-code status in a TDM network.

Description

Method for transmitting message and receiving message, network device and message sending system

This application is required to be submitted to the Chinese Patent Office on October 25, 2016, the application number is 201610940508.9, and the application for the Chinese patent application titled “A Method of Sending Messages and Receiving Messages, Network Equipment and Message Transmission System” is preferred. The entire contents are hereby incorporated by reference.

Technical field

The present application relates to the field of communications technologies, and in particular, to a method for transmitting a message and receiving a message, a network device, and a message sending system.

Background technique

The circuit emulation service (CES) technology solves the problem of transparent transmission of time division multiplexing (TDM) service signals on a packet switch network (PSN). CES provides simulation of TDM service signals traversing a PSN, enabling PSN operators to provide services to users with only TDM equipment.

The basic principle of the CES is to encapsulate the payload data of the TDM service signal into a CES message at the PSN portal, decapsulate the CES message at the PSN exit, regenerate the TDM service signal, and complete the transparent transmission.

When there are multiple links available for communication in the TDM network transmission, the network device can select according to the error state of the link. For example, the signal may be selected in the order of priority of a signal normal link, a signal degraded (SD) link, and an Excessive Error (EXC) link. In the process of transparent transmission of the TDM service signal through the PSN, the error state cannot be effectively transmitted. The network device in the TDM network that receives the TDM service signal from the PSN outlet does not know the error state of the link, and thus cannot Select the link.

Summary of the invention

In view of this, the embodiment of the present application provides a method for transmitting a message and receiving a message, a network device, and a message sending system, which are helpful for transmitting a bit error state in a circuit emulation service.

The technical solutions provided by the embodiments of the present application are as follows:

In a first aspect, a method for transmitting a message is provided, which is applied to a first network device. The first network device and the second network device are located in the same packet switched network PSN. The method includes:

The first network device receives a TDM service signal from a third network device located in the time division multiplexed TDM network via the first link.

The first network device obtains the error status of the first link and the payload data of the TDM service signal according to the TDM service signal, and generates a circuit emulation service CES message. The CES message includes an error identifier and the payload data. The error identifier is used to indicate a bit error status of the first link.

The first network device sends the CES message to the second network device.

In the above solution, the first network device adds an error identifier to the CES packet, and is used to indicate the error status of the first link. Through the CES message, the network device in the PSN can monitor the error status of the link in the TDM network, and can transmit the error status in the PSN. The network device in the TDM network that receives the TDM service signal at the PSN exit can thus know the link error status in order to select the link.

Optionally, the CESOPSN control word or the SATOP control word of the CES message includes the error identifier. By using the CESOPSN control word or the SATOP control word to pass the error status, transparent transmission is achieved quickly and easily without additional overhead.

In a second aspect, a method for receiving a message is provided, which is applied to a second network device. The second network device and the first network device are located in the same packet switching network PSN. The method includes:

The second network device receives a circuit emulation service CES message from the first network device. The CES message includes payload data and a first error identifier of the first time division multiplexed TDM service signal. The first error identifier is used to indicate a bit error status of the first link. The first link is used by the first network device to receive the first TDM service signal from a third network device located in a first time division multiplexed TDM network.

Determining, by the second network device, the error status of the first link according to the first error identifier, and generating a second TDM service signal according to the error status of the first link and the payload data . The second TDM service signal includes a second error identifier and the payload data. The second error identifier is used to indicate an error status of the first link.

The second network device sends the second TDM service signal to a fourth network device located in the second TDM network.

In the above solution, the second network device identifies the first error identifier in the CES packet, adds the second error identifier to the TDM service signal, and indicates the link error status to the fourth network device in the second TDM network. . Thereby, the network device in the TDM network of the PSN outlet can select the link according to the error state of the link indicated by the second error identifier.

Optionally, the CESOPSN control word or the SATOP control word of the CES message carries the first error identifier. By using the CESOPSN control word or the SATOP control word to pass the error status, transparent transmission is achieved quickly and easily without additional overhead.

In a third aspect, a first network device is provided. The first network device and the second network device are located in the same packet switched network PSN. The first network device includes a receiving unit, a processing unit, and a sending unit.

The receiving unit is configured to receive a TDM service signal from a third network device located in the time division multiplexing TDM network via the first link.

The processing unit is configured to obtain, according to the TDM service signal, an error state of the first link and payload data of the TDM service signal, and generate a circuit emulation service CES message. The CES message includes an error identifier and the payload data. The error identifier is used to indicate a bit error status of the first link.

The sending unit is configured to send the CES message to the second network device.

Optionally, the CESOPSN control word or the SATOP control word of the CES message includes the error identifier.

The above aspect of the third aspect has the same technical effect as the solution of the first aspect.

In a fourth aspect, a second network device is provided. The second network device and the first network device are located in the same packet switching network PSN. The second network device includes a receiving unit, a processing unit, and a sending unit.

The receiving unit is configured to receive a circuit emulation service CES message from the first network device. Said The CES message includes payload data and a first error identifier of the first time division multiplexed TDM service signal. The first error identifier is used to indicate a bit error status of the first link. The first link is used by the first network device to receive the first TDM service signal from a third network device located in a first time division multiplexed TDM network.

The processing unit is configured to determine an error status of the first link according to the first error identifier, and generate a second TDM service according to the error status of the first link and the payload data. signal. The second TDM service signal includes a second error identifier and the payload data. The error identifier is used to indicate a bit error status of the first link.

The sending unit is configured to send the second TDM service signal to a fourth network device located in the second TDM network.

Optionally, the CESOPSN control word or the SATOP control word of the CES message includes the first error identifier.

The above aspect of the fourth aspect has the same technical effect as the solution of the second aspect.

In a fifth aspect, a message sending system is provided, including a first network device and a second network device. The first network device and the second network device are located in the same packet switching network PSN.

The first network device receives a TDM service signal from a third network device located in the first time division multiplexing TDM network via the first link, and obtains the error of the first link according to the TDM service signal. The state and the payload data of the TDM service signal, generate a circuit emulation service CES message, and send the CES message to the second network device. The CES message includes a first error identifier and the payload data, where the first error identifier is used to indicate an error status of the first link.

The second network device receives the CES packet from the first network device, and determines an error status of the first link according to the first error identifier, according to the first link. The error state and the payload data generate a second TDM service signal, and send the second TDM service signal to a fourth network device located in the second TDM network, where the second TDM service signal includes a second error code And the payload data, the second error identifier is used to indicate a bit error status of the first link.

In the above solution, the network device in the PSN transmits the error status through the CES message, and notifies the error status to the network device in the TDM network located at the PSN exit. Thereby the network device in the TDM network can select the link according to the error status.

Optionally, the CES message carries the error identifier by using a CESOPSN control word or a SATOP control word. By using the CESOPSN control word or the SATOP control word to pass the error status, transparent transmission is achieved quickly and easily without additional overhead.

In a sixth aspect, a first network device is provided. The first network device and the second network device are located in the same packet switched network PSN. The first network device includes a receiving interface, a processor, and a sending interface.

The receiving interface is configured to receive a TDM service signal from a third network device located in a time division multiplexed TDM network via a first link.

The processor is configured to obtain, according to the TDM service signal, an error state of the first link and payload data of the TDM service signal, and generate a circuit emulation service CES message. The CES message includes an error identifier and the payload data. The error identifier is used to indicate a bit error status of the first link.

The sending interface is configured to send the CES message to the second network device.

The above aspect of the sixth aspect has the same technical effect as the aspect of the first aspect.

In a seventh aspect, a second network device is provided. The second network device and the first network device are located in the same packet switching network PSN. The second network device includes a receiving interface, a processor, and a sending interface.

The receiving interface is configured to receive a circuit emulation service CES message from the first network device. The CES message includes payload data and a first error identifier of the first time division multiplexed TDM service signal. The first error identifier is used to indicate a bit error status of the first link. The first link is used by the first network device to receive the first TDM service signal from a third network device located in a first time division multiplexed TDM network.

The processor is configured to determine an error status of the first link according to the first error identifier, and generate a second TDM service according to the error status of the first link and the payload data. signal. The second TDM service signal includes a second error identifier and the payload data. The second error identifier is used to indicate an error status of the first link.

The sending interface is configured to send the second TDM service signal to a fourth network device located in the second TDM network.

The above aspect of the seventh aspect has the same technical effect as the solution of the second aspect.

DRAWINGS

FIG. 1 is a schematic diagram of a possible application scenario provided by an embodiment of the present application;

2 is a corresponding relationship diagram of an error code identifier, a bit error rate level, and an error status according to an embodiment of the present application;

FIG. 3 is a corresponding relationship diagram of an error code identifier, a bit error rate level, and a bit error state according to an embodiment of the present disclosure;

FIG. 4 is a flowchart of a method for processing a message according to an embodiment of the present disclosure;

FIG. 5 is a structural diagram of a first network device according to an embodiment of the present application;

FIG. 6 is a structural diagram of a second network device according to an embodiment of the present application;

FIG. 7 is a structural diagram of a first network device according to an embodiment of the present application;

FIG. 8 is a structural diagram of a second network device according to an embodiment of the present application;

FIG. 9 is a structural diagram of a message sending system according to an embodiment of the present disclosure.

detailed description

In order to make the objects, technical solutions and advantages of the present application more clear, the embodiments of the present application will be further described in detail below with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art without creative efforts are within the scope of the present application.

The application scenarios described in the embodiments of the present application are for the purpose of more clearly illustrating the technical solutions of the embodiments of the present application, and do not constitute a limitation of the technical solutions provided by the embodiments of the present application. The technical solutions provided by the embodiments of the present application are equally applicable to similar technical problems.

FIG. 1 is a schematic diagram of a possible application scenario provided by an embodiment of the present application. As shown in FIG. 1, the packet switching network PSN includes a first network device and a second network device. The first network device is an edge network device of the PSN, and communicates with a third network device outside the PSN. The second network device is an edge network device of the PSN, and communicates with a fourth network device outside the PSN. The third network device is located in a first TDM network, and the fourth network device is located in a second TDM network. The first TDM network and the second TDM network may It is a different TDM network, or it can be the same TDM network. The third network device and the fourth network device may transmit and receive signals in a frame format of, for example, a Level 1 Synchronous Transfer Module (STM-1). The first network device receives the TDM service signal from the third network device, and encapsulates the payload data in the TDM service signal to form a circuit emulation service CES message. The payload data is, for example, the value of the payload payload field in the STM-1 frame format. The first network device sends the CES message to the second network device. The second network device receives the CES packet, decapsulates the CES packet, obtains the payload data, adds an overhead byte, and regenerates a TDM service signal. The second network device sends the regenerated TDM service signal to the fourth network device. Transparent transmission between the third network device and the fourth network device is implemented by the circuit emulation service CES. The PSN may further include a fifth network device and a sixth network device. The fifth network device and the sixth network device are both edge network devices of the PSN. The fifth network device performs an operation similar to the first network device. The sixth network device performs an operation similar to the second network device. The TDM service signal sent by the third network device is regenerated in the sixth network device and sent to the fourth network device. Thereby, the fourth network device can simultaneously receive TDM service signals having the same payload data from the second network device and the sixth network device. The fourth network device may select one of the signals as the primary signal and the other as the standby signal.

The error of the first link between the third network device and the first network device in the process of transparently transmitting the TDM service signal through the PSN in the process that the CES message has no field for transmitting the error status. The status, and the error status of the second link between the third network device and the fifth network device are not delivered to the fourth network device. Therefore, the fourth network device cannot perform the active/standby signal selection according to the error states of the first link and the second link.

The CES message uses the pseudo-wire emulation edge to edge (PWE3) control word to implement the operation management and maintenance (OAM) function. The embodiment of the present application uses the PWE3 control word to transmit the error status. The PWE3 control word is further subdivided into a structure-aware TDM circuit emulation service over PSN (CESOPSN) control word and a structure-agnostic TDM over packet (SATOP) control word. The PWE3 control word is a CESOPSN control word in structured CES message transmission. The PWE3 control word is the SATOP control word in the unstructured CES message transmission.

For the CESOPSN control word, the Internet Engineering Task Force (IETF) RFC 5086 (Structure-Aware Time Division Multiplexed Circuit Emulation Service over Packet Switched Network) Section 4.3 describes the format of the CESOPSN control word in detail. The embodiment of the present application uses the L field (1 bit) and the M field (2 bit) in the CESOPSN control word, and has a total length of 3 bits. The 3-bit combination may include eight identifiers of 000, 001, 010, 011, 100, 101, 110, and 111. In the definition of RFC5086, 000, 010, and 100 have been used, and the remaining five identifiers of 001, 011, 101, 110, and 111 are reserved for expansion. In this embodiment of the present application, 001 and 011 may be selected as the error identifier to indicate the error status. For example, the correspondence shown in FIG. 2 can be established. In Fig. 2, the L field (1 bit) and the M field (2 bit) in the CESOPSN control word constitute a 3-bit value. The value 001 corresponds to the error rate exceeding the threshold of 10-3, 10-4 or 10-5, and the value 011 corresponds to the level of the error rate exceeding the threshold of 10-6, 10-7, 10-8 or 10-9. . The correspondence shown in Figure 2 is only an example. Which of the above five identifiers are selected, which are labeled and The correspondence between the error rate threshold levels and the correspondence between the identifiers and the respective error states can be arbitrarily adjusted.

For the SATOP control word, the format of the SATOP control word is described in detail in section 4.3.1 of IETF RFC 4553 (Structure-Agnostic Time Division Multiplexing over Packet). The embodiment of the present application uses the RSV field (2 bits) in the SATOP control word, and has a total length of 2 bits. The 2-bit combination may include 4 identifiers of 00, 01, 10, and 11. 01, 10, and 11 in the definition of RFC4533 can be used for extension. In this embodiment of the present application, 01 and 10 may be selected as the error identifier to indicate the error status. For example, the correspondence shown in FIG. 3 can be established. In Fig. 3, the RSV field (2 bits) in the SATOP control word constitutes a 2-bit value. Where the value 01 corresponds to the bit error rate exceeding the threshold of 10-3, 10-4 or 10-5, and the value 10 corresponds to the level of the error rate exceeding the threshold of 10-6, 10-7, 10-8 or 10-9. . The corresponding relationship shown in FIG. 3 is only an example. The correspondence between the three identifiers, the correspondence between the identifier and each error rate threshold level, and the correspondence between the identifier and each error state can be arbitrarily adjusted.

FIG. 4 is a flowchart of a method for processing a message according to an embodiment of the present disclosure. The method shown in Figure 4 can be used in the scenario shown in Figure 1. A method for processing a message according to an embodiment of the present application is described below with reference to FIG. 1 to FIG.

401. The first network device receives the first TDM service signal from the third network device located in the first time division multiplexing TDM network via the first link.

The frame format used by the first TDM service signal may be, for example, STM-1 or the like.

402. The first network device obtains, according to the first TDM service signal, an error state of the first link and payload data of the first TDM service signal, and generates a circuit emulation service CES message. The second network device sends the CES message. The CES message includes a first error identifier and the payload data. The first error identifier is used to indicate an error status of the first link.

The first network device detects a bit error rate on the first link, and may be aware of an error status of the first link and a corresponding first error identifier. For example, when the CESOPSN control word is used, according to the correspondence relationship of FIG. 2, the bit error rate is 10-6, the corresponding error status is SD, the corresponding first error code is 011, and the bit error rate is 10-5. The corresponding error status is EXC, and the corresponding first error code is 001. For example, when the SATOP control word is used, according to the correspondence relationship of FIG. 3, the bit error rate is 10-6, the corresponding error state is SD, the corresponding first error code is 10, and the bit error rate is 10-5. The corresponding error status is EXC, and the corresponding first error code is 10.

The first network device obtains payload data from the first TDM service signal. The payload data, that is, the remaining data after the overhead byte is removed from the first TDM service signal, for example, the value of the payload payload field in the STM-1 frame format. The first network device generates a CES message including the first error identifier and the payload data. The first error identifier may be placed in a CESOPSN control word of the CES message, such as an L field and an M field. The first error identifier may also be placed in a SATOP control word of the CES message, such as an RSV field. By transmitting the CES message to other network devices in the PSN, other network devices in the PSN can also detect the error status of the link in the TDM network. The first network device sends the CES message to the second network device. The first network device and the second network device are located in the same packet switching network PSN, and both are edge network devices of the PSN.

403. The second network device receives the CES packet from the first network device, and generates a second TDM service signal, where the second TDM service signal includes a second error identifier and the payload data. The second The error identifier is used to indicate the error status of the first link.

After receiving the CES message, the second network device obtains payload data of the first TDM service signal from the CES message. The second network device further determines, according to the first error identifier in the CES packet, an error status of the first link, such as an EXC or an SD. The second network device generates a second TDM service signal according to the error status of the first link and the payload data. The generating process may be, for example, the second network device adding an overhead byte for transmitting a TDM service signal on the basis of the payload data, and adding a second error identifier in the overhead byte. The error status of the first link is indicated by the second error identifier. The overhead byte is, for example, the segment overhead and channel overhead in the STM-1 frame format. The second error identifier may be, for example, a bit value used by the Huawei OSN 1500, the OSN 3500, and the OSN 7500 device to transmit a B1_EXC, B2_EXC, B3_EXC, B1_SD, B2_SD, or B3_SD alert signal in the STM-1 frame. Where B1_EXC or B2_EXC indicates that the regenerator section B1 or the multiplex section B2 in the STM-1 frame reaches the EXC state, and B1_SD or B2_SD indicates that the regenerator section B1 or the multiplex section B2 in the STM-1 frame reaches the SD state, and B3_EXC or B3_SD indicates the STM-1. The higher order channel B3 in the frame reaches the EXC or SD state.

404. The second network device sends the second TDM service signal to a fourth network device that is located in the second TDM network.

Therefore, the fourth network device may know the error status of the first link according to the second error identifier in the second TDM service signal. Further, when the fourth network device further receives the third TDM service signal that is sent by the sixth network device and includes the second error identifier, the fourth network device may include the second error according to the TDM service signal. The logo is selected. For example, the second error identifier of the TDM service signal received from the second network device indicates that the error status is SD, and the second error identifier of the TDM service signal received from the sixth network device indicates that the error status is EXC. The fourth network device may select the TDM service signal received from the second network device as the primary signal, and use the TDM service signal received from the sixth network device as the standby signal.

Thereby the transparent transmission TDM of the third network device to the fourth network device via the packet switching network

In the process of the service signal, the transmission of the error state is maintained. Through the transmission of the error state, the fourth network device can select a signal of a link with better communication quality. The above error state is transmitted in the CES message, and the original PWE3 control word is used, and the transparent transmission is realized simply and quickly without adding extra overhead.

FIG. 5 is a schematic structural diagram of a first network device 500 according to an embodiment of the present application. The first network device 500 can be used to perform step 401 and step 402 in FIG. The first network device 500 and the second network device are located in the same packet switched network PSN. The first network device 500 includes a receiving unit 501, a processing unit 502, and a transmitting unit 503.

The receiving unit 501 is configured to receive, by using the first link, a TDM service signal from a third network device located in the time division multiplexing TDM network.

The processing unit 502 is configured to obtain, according to the TDM service signal, the error status of the first link and the payload data of the TDM service signal, and generate a circuit emulation service CES message. The CES message includes a first error identifier and the payload data. The first error identifier is used to indicate an error status of the first link.

The sending unit 503 is configured to send the CES message to the second network device.

FIG. 6 is a schematic structural diagram of a second network device 600 according to an embodiment of the present application. The second network device 600 can be used to perform step 403 and step 404 in FIG. Second network device 600 and first network device Located in the same packet switching network PSN. The second network device 600 includes a receiving unit 601, a processing unit 602, and a transmitting unit 603.

The receiving unit 601 is configured to receive a circuit emulation service CES message from the first network device. The CES message includes payload data and a first error identifier of the first time division multiplexed TDM service signal. The first error identifier is used to indicate a bit error status of the first link. The first link is used by the first network device to receive the first TDM service signal from a third network device located in a first time division multiplexed TDM network.

The processing unit 602 is configured to determine, according to the first error identifier, an error status of the first link, and generate a second TDM service signal according to the error status of the first link and the payload data. . The second TDM service signal includes a second error identifier and the payload data. The second error identifier is used to indicate an error status of the first link.

The sending unit 603 is configured to send the second TDM service signal to a fourth network device located in the second TDM network.

FIG. 7 is a schematic structural diagram of a first network device 700 according to an embodiment of the present application. The first network device 700 can be used to perform step 401 and step 402 in FIG. The first network device 700 is located in the same packet switched network PSN as the second network device. The first network device 700 includes a receiving interface 701, a processor 702, and a transmitting interface 703.

The receiving interface 701 is configured to receive, by using the first link, a TDM service signal from a third network device located in the time division multiplexed TDM network.

The processor 702 is configured to obtain, according to the TDM service signal, the error status of the first link and the payload data of the TDM service signal, and generate a circuit emulation service CES message. The CES message includes a first error identifier and the payload data. The first error identifier is used to indicate an error status of the first link.

The sending interface 703 is configured to send the CES message to the second network device.

The first network device 700 can be a packet transport network (PTN) device. For example, Huawei PTN 910, PTN 950, PTN 960, PTN 3900, and PTN 7900.

The receiving interface 701 can be an SDH interface. The SDH interface is an optical interface, an electrical interface, or a combination thereof.

The processor 702 can be a central processing unit (CPU), a network processor (NP), or a combination of a CPU and an NP.

The transmit interface 703 can be an Ethernet interface. The Ethernet interface is an optical interface, an electrical interface, or a combination thereof.

The first network device 700 can be used to implement the functions of the first network device 500. The receiving interface 701 can be used to implement the receiving unit 501, the processor 702 can be used to implement the processing unit 502, and the sending interface 703 can be used to implement the sending unit 503.

FIG. 8 is a schematic structural diagram of a second network device 800 according to an embodiment of the present application. The second network device 800 can be used to perform steps 403 and 404 of FIG. The second network device 800 and the first network device are located in the same packet switched network PSN. The second network device 800 includes a receiving interface 801, a processor 802, and a transmitting interface 803.

The receiving interface 801 is configured to receive a circuit emulation service CES message from the first network device. The CES message includes payload data and a first error identifier of the first time division multiplexed TDM service signal. The first error The code identifier is used to indicate the error status of the first link. The first link is used by the first network device to receive the first TDM service signal from a third network device located in a first time division multiplexed TDM network.

The processor 802 is configured to determine, according to the first error identifier, an error status of the first link, and generate a second TDM service signal according to the error status of the first link and the payload data. . The second TDM service signal includes a second error identifier and the payload data. The second error identifier is used to indicate an error status of the first link.

The sending interface 801 is configured to send the second TDM service signal to a fourth network device located in the second TDM network.

The second network device 800 can be a packet transport network (PTN) device. For example, Huawei PTN 910, PTN 950, PTN 960, PTN 3900, and PTN 7900.

The receiving interface 801 can be an Ethernet interface. The Ethernet interface is an optical interface, an electrical interface, or a combination thereof.

The processor 802 can be a central processing unit (CPU), a network processor (NP), or a combination of a CPU and an NP.

The transmit interface 803 can be an SDH interface. The SDH interface is an optical interface, an electrical interface, or a combination thereof.

The second network device 800 can be used to implement the functions of the second network device 600. The receiving interface 801 can be used to implement the receiving unit 601, the processor 802 can be used to implement the processing unit 602, and the sending interface 803 can be used to implement the sending unit 603.

FIG. 9 is a schematic structural diagram of a message sending system according to an embodiment of the present disclosure. The message sending system includes a first network device and a second network device. The first network device and the second network device are located in the same packet switching network PSN. The first network device and the second network device may be the first network device 500 and the second network device 600 in FIG. 5 and FIG. 6, respectively. The first network device and the second network device may also be the first network device 700 and the second network device 800 in FIG. 7 and FIG. 8, respectively.

Receiving, by the first network device, a first TDM service signal from a third network device located in the first time division multiplexing TDM network via the first link, and obtaining the first chain according to the first TDM service signal The error state of the road and the payload data of the first TDM service signal, generate a circuit emulation service CES message, and send the CES message to the second network device. The CES message includes a first error identifier and the payload data, where the first error identifier is used to indicate an error status of the first link.

In the above system, the network device in the PSN transmits the error status through the CES message, and notifies the error status to the network device in the TDM network located at the PSN exit. Thereby the network device in the TDM network can select the link according to the error status. Optionally, the CES message carries the first error identifier by using a CESOPSN control word or a SATOP control word. By using the CESOPSN control word or the SATOP control word to pass the error status, transparent transmission is achieved quickly and easily without additional overhead.

Those skilled in the art can understand that all or part of the steps in the method of implementing the above embodiments can be The program is executed by the processor, and the program may be stored in a computer readable storage medium, which is a non-transitory medium such as a random access memory, a read only memory, a flash memory, Hard disk, solid state disk, magnetic tape, floppy disk, optical disc, and any combination thereof.

The above description is only a preferred embodiment of the present application, but the scope of protection of the present application is not limited thereto, and any person skilled in the art can easily think of changes or within the technical scope disclosed in the present application. Replacement should be covered by the scope of this application. Therefore, the scope of protection of the present application should be determined by the scope of protection of the claims.

Claims

A method for sending a message is applied to a first network device, where the first network device and the second network device are located in a same packet switching network PSN, and the method includes:

Receiving, by the first network device, a TDM service signal from a third network device located in a time division multiplexed TDM network via a first link;

The first network device obtains, according to the TDM service signal, the error status of the first link and the payload data of the TDM service signal, and generates a circuit emulation service CES message, where the CES message includes An error identifier and the payload data, where the error identifier is used to indicate a bit error status of the first link;

The first network device sends the CES message to the second network device.
The method of claim 1 wherein the CESOPSN control word or SATOP control word of the CES message includes the error identification.
A method for receiving a packet is applied to a second network device, where the second network device and the first network device are located in a same packet switching network PSN, and the method includes:

The second network device receives a circuit emulation service CES message from the first network device, where the CES message includes payload data and a first error identifier of the first time division multiplexed TDM service signal. The first error identifier is used to indicate a bit error status of the first link, and the first link is used by the first network device to receive from a third network device located in the first time division multiplexing TDM network. The first TDM service signal;

Determining, by the second network device, the error status of the first link according to the first error identifier, and generating a second TDM service signal according to the error status of the first link and the payload data The second TDM service signal includes a second error identifier and the payload data, where the second error identifier is used to indicate an error status of the first link.

The second network device sends the second TDM service signal to a fourth network device located in the second TDM network.
The method of claim 3 wherein the CESOPSN control word or the SATOP control word of the CES message includes the first error flag.
A first network device, where the first network device and the second network device are located in the same packet switching network PSN, wherein the first network device includes:

a receiving unit, configured to receive, by using the first link, a TDM service signal from a third network device located in the time division multiplexing TDM network;

a processing unit, configured to obtain, according to the TDM service signal, the error status of the first link and the payload data of the TDM service signal, and generate a circuit emulation service CES message, where the CES message includes an error a code identifier and the payload data, where the error identifier is used to indicate an error status of the first link;

And a sending unit, configured to send the CES message to the second network device.
The first network device according to claim 5, wherein the CESOPSN control word or the SATOP control word of the CES message includes the error identifier.
A second network device, where the second network device and the first network device are located in the same packet switching network PSN, wherein the second network device includes:

a receiving unit, configured to receive a circuit emulation service CES message from the first network device, where the CES message includes payload data of a first time division multiplexed TDM service signal and a first error identifier, First error code Knowing to indicate an error status of the first link, the first link being used by the first network device to receive the TDM service signal from a third network device located in a first time division multiplexed TDM network ;

a processing unit, configured to determine, according to the first error identifier, an error status of the first link, and generate a second TDM service signal according to the error status of the first link and the payload data, The second TDM service signal includes a second error identifier and the payload data, where the second error identifier is used to indicate an error status of the first link.

And a sending unit, configured to send the second TDM service signal to a fourth network device located in the second TDM network.
The second network device according to claim 7, wherein the CESOPSN control word or the SATOP control word of the CES message includes the first error identifier.
A packet sending system, comprising: a first network device and a second network device, where the first network device and the second network device are located in a same packet switching network PSN,

The first network device receives a TDM service signal from a third network device located in the first time division multiplexing TDM network via the first link, and obtains the error of the first link according to the TDM service signal. a state and a payload data of the TDM service signal, generating a circuit emulation service CES message, and sending the CES message to the second network device, where the CES message includes a first error identifier and the net Loading data, the first error identifier is used to indicate a bit error status of the first link;

The second network device receives the CES packet from the first network device, and determines an error status of the first link according to the first error identifier, according to the first link. The error state and the payload data generate a second TDM service signal, and send the second TDM service signal to a fourth network device located in the second TDM network, where the second TDM service signal includes a second error code And the payload data, the second error identifier is used to indicate a bit error status of the first link.
The message transmitting system according to claim 9, wherein the CESOPSN control word or the SATOP control word of the CES message includes the first error code identifier.
A first network device, where the first network device and the second network device are located in the same packet switching network PSN, wherein the first network device includes:

a receiving interface, configured to receive, by using the first link, a TDM service signal from a third network device located in the time division multiplexing TDM network;

a processor, configured to obtain, according to the TDM service signal, an error status of the first link and payload data of the TDM service signal, to generate a circuit emulation service CES message, where the CES message includes an error a code identifier and the payload data, where the error identifier is used to indicate an error status of the first link;

And a sending interface, configured to send the CES message to the second network device.
The first network device according to claim 11, wherein the CESOPSN control word or the SATOP control word of the CES message includes the error identifier.
A second network device, where the second network device and the first network device are located in the same packet switching network PSN, wherein the second network device includes:

a receiving interface, configured to receive a circuit emulation service CES message from the first network device, where the CES message includes payload data of a first time division multiplexed TDM service signal and a first error identifier, The first error identifier is used to indicate a bit error status of the first link, and the first link is used by the first network The device is configured to receive the first TDM service signal from a third network device located in the first time division multiplexing TDM network;

a processor, configured to determine, according to the first error identifier, an error status of the first link, and generate a second TDM service signal according to the error status of the first link and the payload data, The second TDM service signal includes a second error identifier and the payload data, where the second error identifier is used to indicate an error status of the first link.

And a sending interface, configured to send the second TDM service signal to a fourth network device located in the second TDM network.
The second network device according to claim 13, wherein the CESOPSN control word or the SATOP control word of the CES message includes the error identifier.
A computer readable storage medium comprising instructions which, when executed on a computer, cause the computer to perform the method of any of claims 1-4.