Remote Management Technology for home network devices (reposted)

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Remote Management Technology for home network devices

Liu Qian

【Key words] Home Network Remote Management System TR-069

SummaryFirstly, the necessity, content and related technical problems of remote management of home network equipment are expounded. Then, the network architecture, protocol level and workflow of remote management system stipulated by TR-069 specifications are introduced; finally, the running process of the remote management system is analyzed based on the instance. 1. Necessity of remote management of home network devices The physical location of the home network device is in the user's home. One idea is that since these devices are all in the user's home, the operator does not need to manage these devices and the user can manage them on his own. However, the actual situation is that the home network carries a large number of telecom services. To ensure the end-to-end service quality of telecom services, telecom operators need to coordinate and manage various devices involved in end-to-end communication, this requires control and management of home network devices. If the home network device is managed by the user at will, it is difficult to coordinate and unify with the core telecom network device. Therefore, it is impossible to ensure the end-to-end service quality of telecom services. Since the device of the home network needs to be managed by the operator, you need to carefully analyze the characteristics of the home network device in terms of the management method: first, the number of network elements in the public telecommunications network is usually relatively small, the number of network elements in the home network is very large. Therefore, without good operation and management tools, the home network cannot be maintained and managed, traditional manual operations and troubleshooting methods are difficult to meet the maintenance and management requirements of the home network. Secondly, the users of the home network are ordinary users, ordinary users cannot abide by Security Regulations as professional staff in the machine room, and do not do operations harmful to network security. Therefore, the maintenance and management of the home network should pay more attention to the control capability and security performance of the equipment by the operator. Finally, remote management is essential for the distribution of the home network in various regions, on-site services are only available in special circumstances. Based on these characteristics of home network devices, the management of home network devices must be managed remotely and automatically. 2. Remote Management of home network devices Since it is necessary to remotely and automatically manage the devices in the home network, what management measures can be taken to facilitate the operator to carry out business and ensure the service quality? According to the requirements of carriers, the main management content should include automatic configuration of equipment, software and hardware upgrades of equipment, equipment status and performance monitoring, and fault diagnosis. (1) Automatic Device Configuration The device identifies itself in the Protocol (for example, the model or version) According to configurable rules, the remote management system can assign configurations to a specific user device or a group of user devices. After the device is started, it automatically requests configuration information from the remote management system. The remote management system can also take the initiative to deliver the configuration whenever needed. This feature enables the "Install without configuration" function of your device, or allows you to dynamically change service parameters from the network side. (2) software and hardware upgrades The remote management system can identify the version number of your device, determine whether to remotely update the software version of your device, and whether the update is successful. For example, when a user device needs to load new software to implement new business functions or the current software has bugs that must be fixed, this function can be used to remotely upgrade the software of the User device. (3) device status and performance monitoring The remote management system can identify the current status of the device to determine whether the software and hardware of the device can be upgraded. The remote management system can also monitor the performance of the device for immediate active repair when the device performance degrades, rather than waiting for the fault to be rectified, thus reducing the fault reporting rate. (4) Fault Diagnosis When a device fails, the remote management system can ping or other means to check the connectivity and bandwidth between the device and the core network device. The detection result is returned to the remote management system. In this way, through remote operations, the operator can simply locate and handle the device faults reported by the user. 3. Remote Management of home network devices Management channels and management protocols are the main technical problems to be solved for remote management of home network devices. The remote management information is carried on the IP package. The management channel problem is mainly about how to transmit the IP packet that carries the management information, which is mainly related to the specific access technology. How to ensure the availability of the management channel and the bandwidth of the management channel are the problems that need to be solved by the relevant Access Technologies. Management Protocols refer to management content transfer protocols on the IP layer. Currently, they mainly include SNMP and DSL forum TR-069 developed by IETF. The choice of management protocols mainly needs to weigh the security and protocol complexity. 4. the development trend of home network device Remote Management Technology -- TR-069 TR-069 is one of the technical specifications developed by DSL forum. It is called "CPE Wan Management Protocol ". It specifies the general framework and protocol used by the home gateway for remote management configuration, and is used to remotely and centrally manage the home gateway from the network side. TR-069 can be considered as the basis of DSL forum for remote management of a series of devices on the home network. According to the management idea of TR-069, DSL forum has developed a series of specifications about the home network equipment, including for the set-top box, IP telephone adapter and other relevant specifications, the specific standards include: ● TR-069--CPE Wan management protocol; ● TR-098-home gateway data model; ● TR-104 -- VoIP CPE configuration parameters; ● General Data Model of TR-106--TR-069; ● TR-110-VoIP-related configuration reference model; TR-111-remote management of home network devices based on TR-069. DSL forum is currently being studied on TR-069 related topics, including: ● Guide to WT-121--TR-069 implementation; ● Data Model of WT-135--STB; ● WT-140-Data Model for network storage devices. 4.1 TR-069 Network Architecture Network Architecture 1 for the TR-069 is shown. The remote and centralized management of home network devices is mainly completed by automatic configuration of the server (ACS). The managed devices include home gateways, set-top boxes, IP Phone adapters, and network storage devices. Figure 1 network architecture of TR-069 4.2 protocol levels for TR-069 The protocol stack 2 for TR-069 is shown. Figure 2 protocol stack for TR-069 The description of each layer is shown in table 1. Table 1 protocol stack layers for TR-069 The basic idea of TR-069 protocol stack is to use the RPC Method Based on s0ap which is widely used in Web services. Its session protocol uses HTTP 1.1 protocol, therefore, TR-069 can easily apply Transport Layer Security technologies (such as SSL/TLS) applied in the web ). The following layers of the TR-069 protocol stack make full use of the communication protocols widely used on the Internet, such as TCP, HTTP, soap, etc. Through these mature protocols, ACS and home network devices can easily establish basic communication channels. On top of soap, The TR-069 defines specific RPC methods for configuration, query, diagnosis, and other operations) you can call RPC to complete the execution of a specific function and obtain the returned results. 4.3 Working Process of Remote Management System The working process of the remote management system defined in the TR-069 mainly includes the process of ACS discovery, the process of establishing the connection between ACS and the home network device, and the process of ACS to authenticate the home network device. There are three methods to discover the process of ACS: ● The acs ip address is configured locally on the home network device, for example, through the domestic network port; ● If the IP address of the home network device is obtained through DHCP, the DHCP server sends the ACS information to the home network device through DHCP option field 43; ● The home network device has a default acs url in the factory configuration. There are two ways to establish a connection between ACS and a home network device: ● The home network device initiates a connection request to the ACs at any time and the ACS responds to the request; ● ACS initiates a connection request to the home network device on the premise that ACS knows the IP address of the home network device. If the home network device does not use SSL/TLS authentication, ACS must pass HTTP authentication on the home network device. 4.4 system running instance analysis After the home network device passes the ACS authentication, the remote management system can automatically configure and upgrade, remotely monitor, diagnose, and discover faults. The following examples illustrate how the system completes these tasks. (1) Helpdesk call When a user finds that a device in the home network cannot work properly, he or she calls the carrier's service hotline to report a fault. After answering the call, the helpdesk personnel should diagnose and recover the fault: ① You can use the Northbound Interface to view the status of the device for repair on the GUI; ② Real-time status information of the home device, such as the device information and configuration, Home Network Information and configuration, and log information, is found through the GUI; ③ The operator deduced a possible fault cause based on the above information and proposed a solution. If necessary, the operator can further perform operations such as real-time access to the home network and perform some tests, push a new configuration or firmware to the device. Finally, the operator can perform additional monitoring on the faulty device for a period of time to verify whether it can work properly. (2) automatic configuration Automatic configuration can also be called "zero-touch configuration ". After connecting to the home gateway, the user starts the home network device and the remote management system starts to configure the home gateway. The remote management system should be designed to be completely plug-and-play without any user interaction. The process is as follows: ① The user purchased a value-added service from the operator, including a home gateway; ② Carrier staff enter data in the order system; ③ The Remote Management System submits user-related information, such as the user name and password, to the OSS; ④ When the user is at home, connect the cable to the home gateway; ⑤ The home gateway starts with the default boot file, and contacts the remote management system to provide identification information; ⑥ The remote management system captures input information; 7. check whether all necessary information has been obtained by the Remote Management System (for example, the user's PPP user name and password, and business combination ); After the above work is completed, the home network device is considered trustworthy; ⑨ The remote system pushes the required configuration file to the home network device; ⑩ The home network device saves the configuration locally and restarts it if necessary; The remote management system notifies the BSS/OSS system users through the Northbound Interface that the connection has been completed. (3) software upgrade The operator needs to upgrade all devices of a certain manufacturer to the latest version. The administrator can select the device to be upgraded based on some information (such as the device serial number and version) and set the upgrade schedule. For the upgrade schedule, the operator has the following options: ● Immediate execution; ● Execution by schedule; ● Executed at a specific time (for example, when the home network device is started; ● Remote Management System Preparation and upgrade; ● The remote management system completes the work according to the schedule; ● The Remote Management System collects the success/failure rates of home network device upgrades; ● Remotely manage the system to store information and upgrade the database. (4) Service configuration and Activation An existing user has used the high-speed Internet service and has now subscribed to the digital TV service over the Internet, including a home network device (STB ). The workflow may be as follows: ① The user subscribes to the digital TV business through the web portal. ② OSS requires business confirmation through the Northbound Interface. Through the Order Management System of the carrier, users' requests are converted to Service Activation steps in several different systems (including the home network management system and access network management system. ③ OSS triggers the home network remote management system, through the Northbound Interface, with the terminal service ID (S-ID) to activate the service. ④ S-ID corresponds to a script, which defines a series of actions that need to be executed in order, the script is set by the operator according to the service provided in advance. The remote management system provides interfaces for script generation and management. The script usually includes software upgrade and configuration upgrade, such as configuration modification, firmware upgrade, and additional monitoring. ⑤ After the script is executed, the remote management system returns a success or failure report to the interface north.