CN100417082C - Method for Terminal Management of Ethernet-Based Passive Optical Network - Google Patents

Abstract

A method for terminal management based on EPON, in which an equipment management system is connected to an EPON-based optical line terminal, a network management channel is established between them, and a bearer is established between the optical line terminal and each network terminal for operation, management and maintenance. The network management channel on the protocol layer; when the equipment management system sends a network management protocol message to the optical line terminal, the optical line terminal analyzes the message, and if it is a network management protocol message for the network terminal, it It is forwarded to the network terminal through the established operation and maintenance channel; the message reported by the network terminal to the equipment management system is forwarded to the equipment management system by the optical line terminal. The present invention utilizes the existing OAM management channel resource to manage the EPON terminal without additionally defining an independent management format, and realizes unified network management and complete management of the terminal.

Description

Method for Terminal Management of Ethernet-Based Passive Optical Network

technical field

The invention relates to the technical field of communication, in particular to a terminal management method for an Ethernet-based passive optical network (EPON).

Background technique

In the increasingly large-scale broadband access network, most of the existing local area networks (LAN) run on the 100Mbit/s network, and many large-scale commercial companies are transitioning to Gigabit Ethernet (GE). On the metropolitan core network and metropolitan edge network, the bandwidth capacity of Synchronous Optical Network (SONET)/Synchronous Digital Hierarchy (SDH)/Gigabit Ethernet (GE) is very abundant, which creates a serious bandwidth bottleneck in the access network. . Compared with cable transmission, optical fiber transmission has the advantages of large capacity, low loss, and strong anti-electromagnetic interference ability. Therefore, as the cost of optical fiber transmission gradually decreases, the fiber opticization of the access network is an inevitable development trend. The access network segment representing the "last mile" has requirements such as ultra-low cost, simple structure, and easy implementation, which brings great challenges to technical implementation. The passive optical network (PON) adopts passive devices, which is the most potential technology for realizing broadband optical access network.

Classified from the content of the bearer, the passive optical network (PON) technology mainly includes APON (ATMBed PONs, that is, a passive optical network based on asynchronous transfer mode), EPON (Ethernet Based PONs, that is, a passive optical network based on Ethernet) and GPON (Gigabit PONs, Gigabit Passive Optical Network) and so on.

As shown in Figure 1, the passive optical network is usually a tree network, including an optical line terminal (OLT) located in the central office (CO) and a series of optical network units (ONU) or optical network terminals (ONT) located in the customer premises. ), in the middle of these devices is an optical distribution network (ODN) composed of optical fibers, passive optical splitters or couplers. In a PON network, a single optical fiber can be pulled from the service exchange office to the broadband service sub-area or office park, and then several branches are separated from the main optical fiber by passive optical splitters or couplers to various buildings or business equipment . This method enables multiple users to share the relatively expensive optical fiber link from the switching office to the customer premises, thus greatly reducing the cost of using fiber to the building (FTTB) and fiber to the home (FTTH).

The main international standard of EPON is IEEE802.3AH, which defines the function of OAM (operation management and maintenance), including OAM frame header format and basic maintenance functions. The main purpose of the standard definition is to realize the fault diagnosis of the terminal.

As shown in Figure 2, it is a protocol stack diagram defined in the EPON standard. In the figure, MDI is a medium-related interface, and PHY is a physical layer, including: physical medium-dependent sublayer PMD, physical medium additional sublayer PMA, physical coding sublayer PCS, FEC is Forward Error Correction. GMII is a gigabit medium independent interface, RS is a reconciliation sublayer, and OAM is an operation and maintenance sublayer. OLT is an optical line terminal, and ONU is an optical network unit. It can be seen from Fig. 2 that OAM is an extended content defined on the upper layer of MAC (Media Access Control), and OLT and ONU respectively exist in the protocol stack of this layer. The main working principle of OAM: OLT or ONU initiates an OAM message, and the opposite end obtains the state information of the opposite end by analyzing the OAM message, or performs the operation required by the opposite end.

The loopback operation shown in Figure 3 is that the OLT constructs a loopback message at the OAM layer and sends it to the ONU. After the ONU terminal receives the loopback message, it sends the message back to the OLT. If the OLT receives the message, Prove that the OAM link from the OLT to the ONU is normal, and at the same time explain that the bearer physical layer below the OAM is normal, otherwise it means that the physical layer and MAC from the OLT to the ONU may be faulty.

The ONU is used as an example for illustration above, and the operation, maintenance and management for the ONT can also be implemented. In the prior art, terminal management using an OAM channel mainly includes:

a) Remote fault indication: used to indicate the remote fault alarm state;

b) Remote loopback: Provide a mechanism to support the frame-level loopback mode of the data link layer, which can be used to diagnose whether the layers below OAM are normal;

c) Link management: mainly to maintain the links above the OAM link, which can be extended.

The disadvantage of the prior art in terms of terminal management is that it does not implement complete content management, only the simple fault information management listed above, or only abnormal content management, without management of normal maintenance information. However, for operators to develop services, especially when the number of terminals increases to a certain level, it is necessary to consider the complete management of terminals, including management of terminal interfaces, management of terminal services, detection of terminal performance and status, etc.

Contents of the invention

The technical problem to be solved by the present invention is: to overcome the deficiency that the existing technology can only realize simple fault information management for EPON terminals, and cannot manage normal maintenance information, and provide a method for managing EPON terminals, thereby realizing terminal complete management.

The technical scheme that the present invention adopts for solving the problems of the technologies described above is:

The method for terminal management of the Ethernet-based passive optical network includes: connecting an equipment management system to an optical line terminal of an Ethernet-based passive optical network, and establishing a network management channel between them; The simple network management protocol SNMP layer is added on the operation management maintenance protocol layer between each network terminal, and the equipment management system establishes a network management channel through the SNMP layer and each network terminal; the equipment management system sends the network management to the optical line terminal When receiving a protocol message, the optical line terminal analyzes the message, and if it is a network management protocol message for the network terminal, forwards the message to the network terminal through the established operation and maintenance channel; the network terminal sends the device management The message reported by the system is forwarded by the optical line terminal to the equipment management system.

When the optical line terminal forwards the network management protocol message to the network terminal, the message is carried in the payload of the operation management and maintenance message. If the equipment management system sends a network management protocol message aimed at the optical line terminal to the optical line terminal, the optical line terminal processes it directly after receiving it; the message reported by the optical line terminal is directly reported to the equipment management system. The network terminal may be an optical network unit or an optical network terminal.

The beneficial effects of the present invention are: the present invention utilizes the existing OAM management channel resources to manage the EPON ONU terminal without additionally defining an independent management format, and realizes the unified network management of the EPON OLT and the EPON ONU terminal, which is convenient for operation and maintenance, After more and more EPON terminal users, it will gradually show its management advantages.

The present invention manages terminals through the SNMP protocol, which is a current international device management protocol. The MIB (Management Information Base) defined on this protocol is the content that all manufacturers abide by. Only the definition of terminal interface management in MIB is required. , business configuration management, performance data, and status management, etc., each manufacturer implements the management content of the terminal according to this MIB, so that the terminal can be completely managed, and at the same time, the intercommunication between various manufacturers can be realized.

The invention enables the EPON terminal to be operable and manageable, and realizes the complete management of the terminal including terminal interface management, service configuration management, performance data and state management.

Description of drawings

FIG. 1 is a schematic structural diagram of a PON system;

Fig. 2 is a protocol stack diagram defined in the EPON standard;

FIG. 3 is a schematic diagram of a loopback operation principle;

FIG. 4 is a protocol stack diagram for terminal management in the present invention.

Detailed ways

Below according to accompanying drawing and embodiment the present invention will be described in further detail:

Since EPON adopts OAM channel to manage terminals, the OAM channel of EPON can be used for content expansion and perfection. The present invention aims at the problem that the current terminal management content is not perfect, and combines the internationally general XDSL terminal management technology (TR062 management standard) to manage the EPON terminal, so that the EPON terminal can be operated and managed, and the terminal interface is included. Complete management of terminals including management, service configuration management, performance data, and status management.

The present invention is established under a tree network, including EMS (Equipment management system, equipment management system), optical line terminal (OLT), a plurality of optical network units (ONU1, ONU2...ONUn, here take ONU as an example to illustrate, the same Applicable to optical network terminal ONT) and optical distribution network ODN. The EPON OLT is connected to the EMS, and an SNMP network management channel is established between them, and an SNMP network management channel carried on the operation, management and maintenance protocol layer (OAM) is established between the EPON OLT and each EPON ONU.

The EPONOAM channel is established between the EPON OLT and each ONU terminal through the OAM message handshake to ensure that the OAM bearer protocol layer is normal. The current EMS and EPON OLT devices are managed by SNMP (Simple Network Management Protocol), and the transmission protocol between them follows the SNMP V2 protocol standard. The EPON OLT device, as the SNMP agent device of the EPON ONU, uniformly receives the SNMP message from the network management device EMS, and analyzes the message to know whether the message is aimed at the OLT itself or the ONU device. The message for OLT is processed in this module, and the SNMP management message of EPON ONU is forwarded to EPON ONU device. Similarly, if the message is reported by the OLT, the OLT directly reports the SNMP message to the network management, while the message reported by the ONU needs to be reported to the OLT through the SNMP message, and then forwarded to the network management system by the OLT. For the received query or setting, most of the modification messages need to respond to the network management to confirm receipt, and feed back the information that the network management needs to know to the network management system. After the EPON ONU receives the SNMP management message, it responds to the EMS, and the EPON OLT will directly forward the message to the network management system. In terms of OAM information encapsulation between EMS, EPON OLT and ONU, the protocol stack is shown in Figure 4.

EMS can manage EPON OLT and EPON ONU/ONT. The management messages are unified into SNMP message format. EPON OLT acts as the agent of SNMP and is responsible for parsing SNMP messages. If it is a management message for EPON OLT equipment, it can directly Otherwise, if it is an SNMP message of an EPON ONU, the message is forwarded to the EPON ONU terminal, and this message is carried in the payload of the EPON OAM message, that is, the OAM message removes the defined part of the header Expandable section.

The equipment management system EMS of the present invention can provide SNMP mode to manage equipment, and can provide management interface to users. The optical line terminal (OLT) can provide the SNMP agent function, can distinguish the network management content of the device and the network management content for the EPON ONU, can process the network management content belonging to the EPON OLT, forward the network management message belonging to the EPON ONU to the EPON ONU terminal, and send the The management message is encapsulated in the payload of the EPON OAM message. At the same time, if the report message from the EPON ONU is received, it can be forwarded to the equipment network management system. Optical network units (ONU1, ONU2...ONUn) can receive EPON OAM management messages, and analyze the content of SNMP messages, and after execution, can send response messages to EMS.

Using SNMP to manage terminals, standard MIB (Management Information Base) management content can be defined, including terminal interface management, service configuration management, performance data, and status management. The present invention manages the terminal through the SNMP protocol, which is currently an international general equipment management protocol. The MIB file defined on this protocol is the content that all manufacturers abide by. It only needs to define terminal interface management and business configuration management in MIB. , performance data, status management and other content, each manufacturer implements the management content of the terminal according to this MIB, so that the terminal can be completely managed, and at the same time, the intercommunication of various manufacturers can be realized.

In this way, the present invention utilizes the existing OAM management channel resource to manage the EPON ONU terminal, without additionally defining an independent management format. Adopting the present invention can also realize the unified network management of EPONOLT and EPON ONU terminals, which is convenient for operation and maintenance, and will gradually show its management advantages after more and more EPON terminal users.

Those skilled in the art do not depart from the essence and spirit of the present invention, there can be many variants to realize the present invention, the above description is only a preferred and feasible embodiment of the present invention, and it does not limit the scope of rights of the present invention. The equivalent structural changes made in the description of the invention and the accompanying drawings are all included in the scope of rights of the present invention.

Claims (4)

1. A method for carrying out terminal management to an Ethernet-based passive optical network, characterized in that it comprises: Connect the device management system to the optical line terminal of the passive optical network based on Ethernet, and establish a network management channel between them; Adding a simple network management protocol SNMP layer on the operation management maintenance protocol layer between the optical line terminal and each network terminal, and the equipment management system establishes a network management channel through the SNMP layer and each network terminal; When the equipment management system sends a network management protocol message to the optical line terminal, the optical line terminal analyzes the message, and if it is a network management protocol message for the network terminal, forwards the message through the established operation and maintenance channel to the network terminal; the message reported by the network terminal to the equipment management system is forwarded to the equipment management system by the optical line terminal. 2. The method for terminal management of an Ethernet-based passive optical network according to claim 1, characterized in that: when the optical line terminal forwards the network management protocol message to the network terminal, the message is carried on the In the payload of the operation management maintenance message. 3. The method for terminal management of an Ethernet-based passive optical network according to claim 1 or 2, wherein if the equipment management system sends a network management protocol report for the optical line terminal to the optical line terminal text, the optical line terminal will process it directly after receiving it; the message reported by the optical line terminal will be directly reported to the equipment management system. 4. The method for terminal management of an Ethernet-based passive optical network according to claim 3, wherein the network terminal is an optical network unit or an optical network terminal.

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