Application of the hottest Ethernet Access Technol

Application of Ethernet Access Technology in intelligent residential areas

at present, broadband access technology mainly includes ADSL, HFC and Ethernet. With the acceleration of the construction of broadband intelligent residential areas in China, more and more operators begin to adopt FTTB + LAN, that is, Ethernet + twisted pair (UTP) generic cabling to build the broadband network of residential areas. Because many intelligent household appliances provide Ethernet interfaces, intelligent management and control of household appliances can be realized through Ethernet. In the newly-built community, more and more real estate developers use Ethernet + twisted pair (UTP) generic cabling to build the community broadband network. Figure 1 shows the schematic diagram of Ethernet based cell broadband network

1. Ethernet access technology

1. The structure of Ethernet access technology

Ethernet access usually adopts a two-layer Ethernet switch, which works at the data link layer and provides functions such as data flow control, transmission error handling, transmission medium access control, etc. It can connect multiple local segments to form a larger local area. Ethernet switch can establish many different point-to-point dedicated channels between ports. It adopts bandwidth exclusive mode, which greatly reduces the possibility of network congestion and significantly improves the transmission efficiency of the network. Its features include:

(1) in the network composed of Ethernet switches, any two nodes can establish a dedicated channel through the Ethernet switch, and the communication between them monopolizes the dedicated channel

(2) using virtual local area VLAN technology, the network can be divided into several smaller independent sub networks according to the requirements of users to isolate broadcast storms and improve the efficiency and security of the network

(3) expand the coverage of the network and expand the diameter of the network

(4) multiple local interconnection can be realized through Ethernet switches

2. Characteristics of Ethernet access technology

cell access is directly oriented to individual users. It is required to build a cell network at the lowest possible price, and use the network as a supporting platform to carry out a variety of community intelligent services such as security management, property management, user interconnection, online shopping, video on demand and so on. Therefore, the network should be a network with high bandwidth, high reliability, low construction and maintenance costs. Ethernet can fully meet the above requirements with its good expansion performance, simple construction and low price. Different from the Ethernet of the traditional local area mode popular abroad, the Ethernet access of the intelligent community is a broadband access mode with Chinese characteristics, which has the following characteristics:

(1) user isolation: ensure the security of the user data of the community, isolate the broadcast messages carrying the user's personal information, such as ARP, DHCP messages, etc., and prevent the key equipment from being attacked. Therefore, the network should ensure that the frame of unicast address can only be received by the designated user. For the frame of broadcast address, it is necessary to prevent it from being received by other users, avoid mac/ip address counterfeiting, and prevent some malicious broadcast packets from affecting the normal communication of users

(2) user management: users must register to open an account, and can only connect to the Internet or the application server of the community after being authenticated and authorized by the operator; Prevent illegal users from accessing the network, occupying network resources and affecting the use of legitimate users, and allow users to enjoy different service levels and corresponding rights according to the attributes of users. At the same time, billing management is carried out during communication

(3) bandwidth management and QoS guarantee: the cell Ethernet has bandwidth control capability, that is, to ensure the minimum access rate of users and limit the maximum access rate of users; For services that need to carry out voice, video multicast and other services with high bandwidth requirements, QoS guarantee can be provided

(4) centralized management and maintenance: the cell Ethernet has a centralized management function. The cell center can monitor the network operation and the user's use of the network, avoid the impact of the user's misoperation or malicious attack on the normal operation of the network, and can detect and deal with the problems in time

the intellectualization of the community is mainly reflected in the broadband of family interactive information, the automation of security and the intellectualization of property management. The community intelligence built with Ethernet technology can realize the use of a network to connect each household's home terminal, so that it has full functions, less investment, convenient installation and maintenance, and is convenient for unified management and monitoring

II. Architecture and implementation scheme of cell Ethernet access network

1. Cell Ethernet architecture

the architecture of cell Ethernet access network is shown in Figure 2. The network is composed of three-level equipment: building switches in buildings and community computer rooms. By the end of 2018, it is expected that the total capacity of lithium battery diaphragms in China will exceed 6billion square meters of tandem switches and central switches

the central switch mainly realizes inter routing and provides upper IP Metro and server interfaces. The tandem switch is composed of several switches with multiple optical interfaces, which mainly tandem the data flow of the building switch to save the number of ports of the superior central switch. Building switches connect users directly

ether first appeared as a local technology, which is mainly used in enterprises to realize the free sharing of resources. Guangxi Nannan Aluminum Co., Ltd. successfully developed 8.5-meter-class super large aluminum alloy integral rings for launch vehicles, and this free sharing of resources is not expected by operators. Although at present, many cell networks are local areas composed of hubs, it can be seen that this should be replaced; It is just a means for operators to compete for users in the initial stage. With the maturity of the market and the increase of the number of users, the network required by operators must be an operational carrier level network. Therefore, the direct application of local area technology to cell access cannot meet the future requirements of operators. The main reasons are as follows:

(1) devices in the local area, such as hub, cannot isolate broadcast storms. When there are many connected users, it is very easy to produce broadcast storms and cause network paralysis

(2) because the local area is a shared network, the information between users is not isolated from each other, and the user's data security is not guaranteed, which is vulnerable to malicious access or attack

(3) the hub has no management function and can't effectively manage users. The charging can only adopt the monthly system. Users can connect more users through the hub, so that operators lose part of the collection. The hydraulic testing machine can complete the rotary washing of the iron filings in the pipe after the rib processing in the previous process, complete the length measurement and positioning of the tested steel pipe through the photoelectric switch and mechanical device, and synchronously feed the pipe to the pressure test center through the synchronous feeding device, Through the pre sealing device, the radial pre sealing of the steel pipe head screw unit and the tail is realized, and the synchronous pressurization of the steel pipe and the pre sealing is realized by the supercharger, so as to realize the pressure test of the steel pipe When the diameters of both ends of the steel pipe are different, Wenzhou inkjet printer is also equipped with joint clamping device to realize pressure balance during pressure test Enter

the problems to be solved when applying local area technology to the cell include user management, user information isolation, centralized management and maintenance

2. user management

for network operators, user authentication, billing and other management functions are primary. Therefore, the community network must have the functions of authentication and billing. At present, the community network mainly adopts the monthly rent billing and the user has no authentication strategy. Broadband network