NGN network

In computer networks, the “this generation” network is the Internet based on IPv4, and the next generation network is NGI (Next Generation Internet) based on high bandwidth and IPv6. In the transmission network, the “this generation” network is based on TDM, represented by SDH and WDM, and the next generation network is based on ASON (Automatic Switching Optical Network) and GFP (General Frame Protocol). In the mobile communication network, the “this generation” network is represented by GSM, and the next generation network is represented by 3G (mainly WCDMA and CDMA2000).

1. What is NGN network

NGN is the abbreviation of NextGenerationNetwork, which literally means Next Generation Network. The current so-called next-generation network is a very loose concept, and different fields have different views on the next-generation network. Generally speaking, the so-called next-generation network should be based on the “this generation” of networks. Only breakthroughs or revolutionary advancements based on the “this generation” of networks can be called next-generation networks.

2. Features of NGN network

1. NGN is a network where services are independent of the bearer
The business network of the traditional telephone network is the bearer network, and the result is that it is difficult to develop new services. NGN allows services and networks to be provided and developed independently, provides flexible and effective service creation, service applications and service management functions, supports the use of various bandwidths, real-time or non-real-time multimedia services, and makes the provision of services and applications more effective. Great flexibility, so as to meet the growing needs of users for new services, but also enables the network to have sustainable development capabilities and competitiveness.
2. NGN adopts packet switching as a unified service bearing mode

Traditional telephone networks use Circuits (time slots) to carry voices. Although they can effectively transmit voices, they cannot effectively carry data. The voice and data of the NGN network structure adopts a packet-based transmission mode and adopts a unified protocol. NGN separates the functional Modules of traditional switches into independent network components. They are interconnected through standard open interfaces, making the original telecommunications network gradually open. Operators can freely combine the functional products of each part according to business needs. Form a new network. The standardization of protocol interfaces between components can realize the intercommunication of various heterogeneous networks.
3. NGN can interoperate with existing networks such as PSTN, ISDN and GSM

The existing telecommunications network is large in scale, and NGN can be interconnected with the existing network through gateways and other equipment to protect existing investments. At the same time, NGN also supports existing terminals and IP smart terminals, including analog phones, fax machines, ISDN terminals, mobile phones, GPRS terminals, SIP terminals, H248 terminals, MGCP terminals, Ethernet phones via PCs, and cable modems.
4. NGN is a secure network that supports quality of service

The traditional telephone network is based on time slot exchange, and a two-way 64kbit/s virtual Circuit is prepared for each pair of users. The transmission network provides point-to-point dedicated lines, and there are few service quality problems. NGN is based on packet switching, and security and service quality issues must be considered. The current Internet using the IPv4 protocol only provides best-effort services. To provide multiple services including video, NGN must ensure a certain degree of security and service quality.
5. NGN is a multi-service network that provides multimedia streaming media services

The current telecom network services mainly focus on voice services. Although data business has surpassed voice, it still needs to be improved in terms of profitability. Large-scale concurrent streaming media and interactive multimedia services are representative of current broadband services. Therefore, NGN, which still focuses on voice and traditional Internet data services, is meaningless. NGN must provide multimedia streaming media services under the guarantee of service quality and safety.

3. NGN network architecture

In the early stage of construction, a small-scale commercial experimental network will be established, using a single-domain networking structure, with a total capacity of about 50,000-100,000 ports. Use a small amount of softswitch equipment and distributed gateways to carry out small-scale experimental operations on the entire network or in some areas, conduct network business verification, and accumulate network operation experience. The softswitch equipment logically divides each city into different domains, supports terminal access in all cities, calls within the network of IP phones within the domain, and the switch completes the call processing, and completes the establishment, call, and disconnection of a call in the network. process. When interworking with the PSTN is required, the relevant Relay gateways in each city must be interconnected with the local PSTN network.
In the second step, on the basis of the commercial experimental network, the country is divided into multiple domains by using the method of processing call traffic by domains, each domain is equipped with softswitch equipment and distributed gateways, and the entire network is divided into regions to carry out large-scale operations. There are one or more sets of softswitch equipment in the area to provide network services and are responsible for maintaining the routing data in the area.
The third step is based on the success of the first two stages of network operations, combined with softswitch technology, and make full use of the operator’s network resources to realize the large-scale construction of NGN networks based on softswitch technology, and finally form an NGN network.