Construction of ATM Optical Fiber multimedia platform

With the development of the economy, the wave of information is surging, and the demand for communication infrastructure in the world is unprecedentedly high. The opening of new data businesses, business users, residential users, Internet applications, and the telecom market puts pressure on business operators. The maturity of optical transmission technology and the improvement of broadband investment technology have inspired telecom operation and manufacturing to invest a lot of money in broadband access construction. It is expected that broadband access will surely form a very impressive market.
1. Broadband Access Technology
Internet-based broadband services can be divided into two types: LAN and WAN. In just over 20 years, the data exchange technology has evolved from the fixed bandwidth distributed DDNTDM, x.25pmma) to the frame relay FR and asynchronous transfer mode ATM ). At present, the focus of the debate is the hierarchy and interconnection of SDH, ATM and IP technology on the network. In fact, these three technologies have their own advantages and disadvantages and are complementary.
SDH-TDM is a mature and widely used technology, and is the most basic infrastructure of the existing network. To consider the economics and reliability of the broadband network, it is necessary to establish it on the existing SDH network. IP is a type of connectionless. Routing Technology. In this aspect, IP applications on the Internet show their advantages in price and performance.
ATM is a connection-oriented technology that uses cell Packet Exchange. The bandwidth statistics reuse function and service quality QoS of ATM) management function can provide the best way to "three networks in one.
The interconnection solutions of the above three technologies include ATM overSDH, IP over ATM, and IP over SDH. IPover ATM is currently a hot topic in technology research. The combination of IP and ATM is a combination of connection-oriented ATM and non-connected IP addresses, as well as a combination of routing and switching, and an important means of network development.
2. Asynchronous Transfer Mode (ATM)
At present, the construction of global ATM networks is booming in China. However, for equipment suppliers, it seems necessary to consider the following question: why do network operators invest in building ATM networks? How can we reasonably build an ATM network? How can we make full use of ATM network resources?
First, the use of ATM technology in data networks can improve the following aspects: 1) fixed cells used by ATM
The switching speed is greatly improved by the 53-byte method. The switching capacity can be increased from 1 Gbit/s to 1 Tb/s, which can meet the requirements of high bandwidth data communication; 2) ATM divides inbound services into fixed bit rate CBR, variable bit rate VBR, uncertain bit rate UBR, and Available Bit Rate ABR, and then uses advanced traffic control methods, guarantees QoS of various services. For example, a credit card project is a non-real-time variable bit rate (ntr-VBR) service that has high requirements on data security, as few data drops as possible, but has low requirements on real-time performance. 3) as business needs grow, ATM can provide voice, data, and video services as needed, including VOD, interactive remote education, telemedicine, online shopping, E-mail, and Internet browsing.
Secondly, successful ATM networks can be divided into core layer backbone layer and edge layer connected to eight layers by adopting a modular layered structure based on the experience of public network construction ). The core layer provides functions such as high-speed switching, high-speed convergence, high-speed transmission, and high-performance traffic control and management. The core layer has high requirements on device reliability, because a set of core layer devices often affect the operation of dozens of edge layer devices connected to it. The edge layer completes multiple services. Multi-function access also has QoS performance requirements. The requirements for transmission devices for a broadband network with a layered function are as follows:
1) There must be many types of business interfaces. In addition to providing new services, the broadband network is also used to effectively interconnect existing data networks and terminals. The diversity of the four categories ensures the bandwidth requirements of various users, thus bringing the most direct benefits to network operators.
2) must have rich business capabilities. It not only provides E1 interfaces, but also needs to carry out ATM, FR, IP, circuit simulation, and atm ima services on it to fully meet users' broadband access requirements.
3) provide QoS Assurance for different service types. For example, if the credit card project is an ntr-VBR Service, the system must provide sufficient storage, but the CBR service can be used in sorting.
4) ensure that the network is not congested. That is, a strong traffic control mechanism is required.
5) from the perspective of the whole network, ATM should also establish a "full network integration" concept to plan a sustainable network.
3 broadband service transmission platform CellworxTMSTN
CellworxTMSTN is a single device that combines the ATM Cell mode for optical fiber transmission and multimedia access functions with multiple service interfaces. First, the STN is a next-generation optical transport device that combines SDH and ATM advantages. It maintains the self-healing and environmental protection capability of SDH optical terminals, and has the ATM Traffic Control and QoS functions to make full use of the transmission bandwidth, improve network reliability. Second, the STN can achieve high-speed access and transmission of Internet services, voice, data and video on a unified network platform, and support ADSL, ATM, FR, and leased line services. These services are managed by an integrated network management software, which makes it easy for operators to establish a cost-effective broadband service network structure. The characteristics of the STN are:
1) support multiple service interfaces, including cell relay, FR, E1/E3, Transparent LAN and ADSL; 2) rich service capabilities; 3) support multiple QoS levels, support for CBR, VBR, and UBR, and transmit Available Bit Rate (ABR) services; 4) Powerful traffic control mechanism. The statistical bandwidth reuse method of STN avoids the waste caused by the fixed bandwidth allocation of SDH-TDM. You can determine the bandwidth required for each business based on the price and performance level. For example, if sdh adm is used to transmit a 10 Mbit/s LAN Service, the carrier must allocate an e334mbit/s bandwidth to it. If the STN is used, a 10 Mb/sLAN service and a 6 Mb/sMPEG2 video service can be implemented on the same E3 line, other services can also be transmitted on the same E3 line until 34 Mb/s is full. 5) The STN provides the fractional ATM network and digital user line access multiplexing (LSIHM) for the broadband access network) two Application Methods. Before
Users can reduce the cost of the ATM switch, simplify the network structure and increase security. The latter can increase network flexibility, reduce network costs, and provide network service scalability.
4 network implementation
In the actual network planning, the STN can be used as the transmission in the network to connect to the Taiping station. There are three application Hotspots: 1) replacing the ATM edge switch to reduce network costs; 2) replacing the SDH transmission device, avoid unnecessary solidification of SDH-TDM Frame Structure between ATM core switching network and Internet data users, resulting in limited bandwidth, achieve the bandwidth statistics reuse function of the whole network; 3) it can implement port convergence of LAN or DSLAM devices to save the resources of ATM core switches.