WO2012097538A1

WO2012097538A1 - Method and system for implementing full protection mode

Info

Publication number: WO2012097538A1
Application number: PCT/CN2011/071778
Authority: WO
Inventors: 耿丹; 何苑凌; 张伟良; 臧美燕
Original assignee: 中兴通讯股份有限公司
Priority date: 2011-01-18
Filing date: 2011-03-14
Publication date: 2012-07-26
Also published as: CN102594444B; CN102594444A

Abstract

A method and system for implementing full protection mode are provided by the invention. When a master Optical Line Terminal (OLT) in a Passive Optical Network (PON) system detects that a master fiber or a branch fiber is disconnected, or a failure occurs on the master OLT, the master OLT notifies a slave Optical Network Unit (ONU) to perform switch. In this way, when a downlink communication can not be performed by a master link, the case is avoided that the master ONU can perform switch only depending on a line failure detected by itself, accordingly, the ONU switch time is shortened, the transmission in time for the time sensitivity service in the PON system is ensured, which enables the ONU and the OLT to implement quick communication resumption, the service quality of the PON system is improved.

Description

Method and system for realizing full protection mode

The present invention relates to passive optical network (PON) technology, and more particularly to a method and system for implementing a full protection mode. Background technique

Gigabit-Capable Passive Optical Network (GPON) technology and Ethernet Passive Optical Network (EPON) are two important technology branches in the PON family. Similar to other PON technologies, GPON And EPON is also a passive optical access technology that uses a point-to-multipoint topology.

1 is a schematic diagram of a topology of an existing PON system. As shown in FIG. 1, the PON is composed of an optical line terminal (OLT) of the office side, an optical network unit (ONU) of the user side, and an optical network unit (ONU). ODN (Optical Distribution Network), such as optical splitters, usually uses a point-to-multipoint network structure. The ODN consists of passive optical components such as single mode fiber, optical splitter, and optical connector. The ODN provides optical transmission media for the physical connection between the OLT and the ONU.

In the PON system, the data transmission in the downlink direction (from the OLT to the ONU) is broadcasted. Each ONU receives all the frames, and then according to the ONU identifier (ONU-ID) and the GPON encapsulation mode port identifier (GEM-Port lD). , PONID, Logical Link Identity ) to get your own frame. For the data transmission in the uplink direction (from the ONU to the OLT), since each ONU needs to share the transmission medium, each ONU should transmit uplink data in its own time slot arranged by the OLT. The distance between each ONU and the OLT is different, in order to prevent each ONU The sent uplink data arrives at the OLT at the same time. The OLT needs to perform ranging on the ONU in the registration activation phase to implement uplink transmission synchronization.

In the deployment of passive optical networks, some users need higher security. It is hoped that operators can provide a guarantee mechanism to ensure that their service channels are not interrupted, or the next level of requirements is that they can be interrupted in the service channel. After a quick recovery. This puts forward the requirements for protection paths and fast switching paths for passive optical networks carrying user services.

2a is a schematic diagram of a passive optical network topology structure in a full protection mode in an existing PON system, and FIG. 2b is another passive optical network topology in a full protection mode in the existing PON system. Schematic diagram, as shown in Fig. 2a and Fig. 2b, OLT1 and OLT2 are respectively connected to two 1:N splitters, each of which is connected to each ONU through a fiber in the downstream direction, and two ONUs at each ONU, respectively The main ONU and the standby ONU are connected; the OLT 1 is connected to each main ONU through the optical splitter 1, and the OLT 2 is connected to each standby ONU through the optical splitter 2. The OLT1 and the OLT2 can be two independent OLTs, as shown in Figure 2a, or two PON ports of the OLT, as shown in Figure 2b. In the initial state, the OLT1 performs communication with all the active ONUs. When the OLT1 fails or the optical fiber between the OLT1 and the optical splitter 1 is interrupted, the OLT2 and all the standby ONUs perform service communication; if the optical splitter 1 If a branch fiber is interrupted, or a primary ONU fails, the OLT2 performs service communication with the interrupted branch fiber or the standby ONU corresponding to the failed ONU. In this way, full protection of the OLT, ONU and each fiber in the PON system is realized.

In the existing full protection mode, after the optical fiber between the OLT 1 and the optical splitter 1 is interrupted, or a certain branch optical fiber under the optical splitter 1 is interrupted, each primary ONU detects a downlink signal interruption or receives a signal from the primary OLT. After the switchover command is performed, the uplink service is switched to the standby ONU, and the standby ONU communicates with the OLT2. However, when the failure notification method uses the primary OLT to send a switching command to the primary ONU, if the primary link cannot perform downlink communication, the switching command sent by the primary OLT to the primary ONU cannot be received, then the primary ONU is not received. It can only rely on self-detection of the line fault after switching, this process can not meet the time-sensitive industry The need for rapid recovery after the interruption. Summary of the invention

In view of this, the main object of the present invention is to provide a method and system for implementing a full protection mode, which can shorten the switching time and meet the need for rapid recovery after a time-sensitive service interruption.

In order to achieve the above object, the technical solution of the present invention is achieved as follows:

A method of implementing a full protection method, including:

When the primary OLT detects an uplink fault or the primary OLT itself fails, the standby OLT is notified;

The standby OLT sends a switching command to the standby ONU. The ONU performs the switching after receiving the switching command. The notification standby OLT includes:

When the primary OLT detects an uplink fault or the primary OLT itself fails, the primary OLT sends a fault notification to the standby OLT to notify the backup OLT to initiate a switchover; or, the network management system sends a fault notification to the standby OLT. To notify the standby OLT to initiate a switchover to the standby ONU.

The sending, by the standby OLT, a switching command to the standby ONU includes:

The standby OLT manages and maintains a PLOAM message, or an ONU management control interface OMCI message, or an extended operation management and maintenance eOAM message, or an extended MAC layer control Extension MAC control message to send a switching command to the standby ONU through physical layer operation management.

After the ONU receives the switching command, the switching includes:

The standby ONU switches the uplink service sent by the primary ONU to the standby ONU, and sends the uplink service to the standby OLT through the standby ONU.

The primary ONU and the standby ONU are two logical ONUs located in the same ONU; or, two PON ports belonging to the same ONU;

Wherein, two logical ONUs or two PON ports of the same ONU have their own The optical module and the medium are connected to the control chip and managed by a common CPU.

A system for implementing a full protection mode includes at least a primary OLT, a standby OLT, a primary ONU, and a standby ONU, where

The primary OLT is configured to notify the standby OLT when an uplink fault is detected or the primary OLT itself fails.

The standby OLT is configured to receive a notification from the primary OLT and send a switching command to the standby ONU.

The primary ONU is used to receive and transmit service data between the primary OLT and the primary OLT before the switching occurs;

The standby ONU is configured to receive a switching command from the standby OLT for switching, and the uplink service sent by the primary ONU is switched to the standby ONU and sent to the standby OLT through the standby ONU.

The two PON ports of the two logical ONUs or the same ONU have their own optical modules and media access control chips, and are managed by a common CPU.

It can be seen from the technical solution provided by the present invention that the primary OLT in the PON system notifies the standby by the standby OLT when detecting that the trunk optical fiber or the branch optical fiber in the primary path is disconnected or the primary OLT fails. The ONU performs the switching. In this way, when the primary link cannot be used for downlink communication, the primary ONU can only rely on the self-detection of the line fault to perform the switching, thereby shortening the ONU switching time and ensuring the time in the PON system. The timely transmission of sensitive services enables the ONU and OLT to achieve rapid communication recovery and improve the service quality of the PON system. DRAWINGS

1 is a schematic diagram of a topology of an existing PON system;

2a is a passive optical network topology of a full protection mode in the existing PON system Schematic diagram

FIG. 2b is a schematic diagram of another passive optical network topology structure in a full protection mode in the existing PON system.

3 is a flow chart of a method for implementing a full protection mode according to the present invention. detailed description

FIG. 3 is a flowchart of a method for implementing a full protection mode according to the present invention. As shown in FIG. 3, the method includes the following steps: Step 300: When the primary OLT detects an uplink fault or the primary OLT itself fails, the standby OLT is notified.

In this step, when the active OLT detects the uplink fault or the primary OLT itself fails, the active OLT can directly send a fault notification to the standby OLT to notify the backup OLT to initiate a switchover to the standby ONU, or through the network management system. The standby OLT sends a fault notification to notify the standby OLT to initiate a switchover to the standby ONU.

Step 301: The standby OLT sends a switching command to the standby ONU, and the ONU performs the switching after receiving the switching command.

In this step, the standby OLT may pass a physical layer operation management and maintenance (PLOAM) message, or an ONU management control interface (OMCI) message, or an extended operation management and maintenance (eOAM) message, or an extended MAC layer control message. Send a switch command to the standby ONU.

After receiving the switchover command, the standby ONU switches the uplink service sent by the primary ONU to the standby ONU and sends it to the standby OLT through the standby ONU.

The primary ONU and the standby ONU are two logical ONUs located inside the same ONU, or two PON ports belonging to the same ONU. The two logical ONUs or the two PON ports of the same ONU each have their own optical modules and media access control chips, and are managed by a common CPU.

In the method of the present invention, the active OLT in the PON system detects the main light in the main path. When the fiber or the branch fiber is disconnected, or the primary OLT fails, the standby OLT is notified by the standby OLT to perform the switchover. This prevents the primary ONU from relying on the self-detected line when the primary link cannot be used for downlink communication. After the fault is reversed, the ONU switching time is shortened, and the timely transmission of time sensitive services in the PON system is ensured, so that the ONU and the OLT realize fast communication recovery and improve the service quality of the PON system.

The system of the present invention further provides a system for implementing a full protection mode, including at least a primary OLT, a standby OLT, a primary ONU, and a standby ONU, where

The method of the present invention will be described in detail below with reference to the embodiments.

As shown in Fig. 2a or Fig. 2b, the OLT 1 is connected to all the main ONUs through the optical splitter 1, and the OLT 2 is connected to all the standby ONUs through the optical splitter 2. The ONU registration activation and the transmission of service data between the OLT and the ONU are performed between the OLT1 and the primary ONU according to the prior art in the GPON or the GPON-based next-generation PON. When the optical fiber between the OLT 1 and the optical splitter 1 is disconnected, or part or all of the optical fibers between the optical splitter 1 and the primary ONU are disconnected, and the OLT 1 detects that the uplink frame of the partial ONU or all the ONUs is lost or the uplink signal is lost, The process of restoring communication between the OLT and the ONU includes:

First, when the OLT1 detects that the uplink frame of some or all of the active ONUs is lost or the uplink signal is lost, the OLT1 sends a fault notification to the OLT2. Here, in other embodiments, the fault may be reported to the network management system by using the OLT1. Sent by the network management system to OLT2, and OLT2 sends a failure notification;

In addition, when the OLT1 fails, the OLT1 sends a failure notification to the OLT2, so that the OLT2 notifies all the ONUs to perform the switching; or, the OLT1 reports its own fault to the network management system, and then the network management system sends a failure notification to the OLT2, so that the OLT2 notifies all the ONUs. Switched.

Then, after receiving the fault notification, the OLT2 sends a PLOAM message (or an OMCI message, or an eOAM message, or an Extension MAC control message) to the standby ONU of the ONU1 to notify the standby ONU to perform the switching;

Then, after receiving the message from the OLT 2 to perform the switching, the standby ONU of the ONU1 performs the switching, and the uplink service to be sent by the primary ONU of the ONU1 is switched to the standby ONU, and is sent to the uplink bandwidth allocated by the OLT2. OLT2.

In this embodiment, the primary ONU and the standby ONU are two logical ONUs located inside the same ONU, or two PON ports belonging to the same ONU. The two logical ONUs or the two PON ports of the same ONU each have their own optical modules and media access control chips, and are managed by a common CPU.

This embodiment is applicable to GPON systems, EPON systems, and next-generation PON systems based on GPON technology or EPON technology, such as XG PON systems and 10G EPON systems.

The above description is only for the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included. Within the scope of protection of the present invention.

Claims

Claim

A method for implementing a full protection mode, comprising:

The primary optical line terminal notifies the standby OLT when the OLT detects an uplink fault or the primary OLT itself fails;

The standby OLT sends a switching command to the standby optical network unit ONU, and the ONU performs switching after receiving the switching command.

The method according to claim 1, wherein the notifying the standby OLT comprises: when the primary OLT detects an uplink fault or the primary OLT itself fails, sending a failure notification to the standby OLT, The standby OLT is notified to initiate a switchover to the standby ONU. Alternatively, the network management system sends a fault notification to the standby OLT to notify the backup OLT to initiate a switchover to the standby ONU.

The method according to claim 1, wherein the sending, by the standby OLT, a switching command to the standby ONU includes:

The method according to claim 3, wherein the switching, after the ONU receives the switching command, includes:

The method according to claim 4, wherein the primary ONU and the standby ONU are two logical ONUs located inside the same ONU; or two PON ports belonging to the same ONU;

A system for implementing a full protection mode, comprising: at least an active OLT, a standby OLT, a primary ONU, and a standby ONU, wherein

The system according to claim 6, wherein the primary ONU and the standby ONU are two logical ONUs located inside the same ONU; or two PON ports belonging to the same ONU;