Significance of network tunnel protocol in communication (1)

Source: Internet
Author: User

In the communication industry, the embodiment of network tunnel protocol is full. Now let's talk about the network tunnel protocol in VPDN in the communication field. To put it simply, the network tunnel protocol means to transmit the Protocol in the form of encapsulation. For details, refer to the following section.

When a VPDN user dials the Network Access Server NAS (NetworkAccessServer) of the NSP (Network Service Provider) and sends a PPP connection request, after the NAS receives the call, it establishes a PPP link between the user and the NAS. Then, NAS authenticates the user and determines that the user is a valid user. It starts the VPDN function and connects to the company headquarters to access its internal resources. The dial-up server directly establishes a tunnel with the company's enterprise gateway, in this process, user data, such as IPX and IP, is encapsulated in a series, transmitted to the enterprise gateway through tunnel, unwrapped, and transmitted to the Enterprise 。

The core technology of VPDN is tunneling and security. Network tunneling refers to the use of one network protocol to transmit another network protocol, it mainly uses the network tunnel protocol to implement this function 。

Main node devices:

(1) client device (CPE: mermerpremisesequipment ):

The user end must be a gateway device of VPDN. It is located at the user headquarters and can be implemented by a vro inside the enterprise network. You can select a network device with both the routing and VPDN functions 。

(2) Access Server (NAS: NetworkAccessServer ):

NAS is provided by network operators such as China Unicom and is responsible for O & M. As a VPDN Access Server, NAS can provide Wan interfaces for VPN connections with enterprise private networks, it also supports various LAN protocols, security management and authentication, and tunneling and related technologies 。

(3) user terminals:

Users must have terminal devices that can access the Internet using GPRS/CDMA. Currently, available methods include GPRS/CDMA wireless network adapter, GPRS/CDMA mobile phone connection laptop, GPRS/CDMA mobile phone connection desktop computer, GPRS/CDMA M2M modew, DTU, router and other communication device 。

(4) User-side Authentication Server:

The user-end authentication server is an optional device used for authentication of login users. To facilitate the management of user account and password information, it is generally recommended to set 。

Industries applicable to VPDN

1. Mobile Office

(1) An enterprise already owns or plans to build an internal network belonging to the enterprise. This network can be a comprehensive large-scale office network with special applications, it can also be a small network mainly used for mail and Web message Publishing 。

(2) employees of an enterprise need to work on a mobile phone. No matter whether the employees are on a business trip or at home, the employees want to work anywhere without leaving the company's LAN to handle the company's affairs 。

(3) enterprises want their internal networks to be isolated from the public network to make their internal networks vulnerable to adverse attacks from the public network; at the same time, enterprises want to connect themselves to the company's internal network, which will be safe and reliable and not easily listened 。

2. Enterprise Application

Users have special enterprise application requirements. For example, users have a global service network or professional system at the headquarters, and users have many branch sites, the customer's branches hope to communicate with the customer's headquarters securely and reliably, and exchange information. For example, the sales enterprise extends the Enterprise Information Network to the sales point, and each sales point uses VPDN to contact the headquarters, exchange information in real time 。

3. Special Professional

Users have special professional application requirements and hope to solve the problem by using China Unicom GPRS/CDMA wireless Internet access and VPDN Technology. For example, real-time monitoring system based on mobile personnel, the user needs to transmit the monitoring content of mobile office staff to the server in real time or quasi real time 。

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