Original link: http://www.72e.net/cdnspeed/cdnyuanli.aspx First, let's look at the basic structure and data transfer of a traditional Internet network, as shown in. The basic structure of Internet network and the way of data transmission according to the traditional network structure, the user's access process is basically as follows:
The user enters the domain name of the website to visit in his or her browser
Browser to local DNS request resolution of the domain name
Local DNS sends requests to a DNS server authorized by the Web site
Authorize DNS to send the server's IP address as a result of the resolution to the local DNS
Local DNS Returns the result of the resolution to the user and saves the resolution in its own cache until the corresponding TTL (lifetime) expires before it resolves to the site's authoritative DNS request
After obtaining the IP address, the user accesses the server of the website to which the address is directed;
The traditional access model has the following links which seriously affect the access efficiency and quality of Internet users:
First, the traditional DNS parsing process when the site host domain name is converted to an IP address, does not prejudge whether the server is working properly, even if the server has been down to provide services, the user's request will still be sent to this server, resulting in service interruption.
Secondly, the Internet from the first day of birth, there is a lack of a dedicated central management structure, but also the lack of uniform product and technical standards. This has been the advantage of the rapid development of the Internet. However, with the increasing scale of the Internet, this has resulted in the coexistence of many different network structures. The data flow is limited by the compatibility between different networks and the transmission bottleneck between different network operators/isp. According to statistics, the average transmission rate on the existing Internet is not higher than 30Kbps.
In addition, the existing Internet on the basis of packet transmission, any one packet loss or error must be re-sent, and the average one retransmission process takes 3 seconds, resulting in delay. and the existing HTTP protocol also has a delay factor, according to the survey, the full download of a Web page, the user and the server need to round-trip 20~100 times.
Finally, the existing routing technology is based on the historical data of the router's working state to determine the transmission path of the current packet, and cannot reflect the current routing and Network connection status. This often results in a path that passes through the data transfer and is not the best path currently. Moreover, many routers and switches not only increase the time delay of data transmission, but also increase the chance of error, because any one router problem will affect the entire transmission process.
Linkage World CDN Working principle: Linkage World CDN to the Network optimization role:
Linkage World CDN is through the existing Internet to add a new layer of network architecture, the content of the site to the closest to the user's network "edge", so that users can get the required content, solve the Internet congestion situation, improve the response speed of users to visit the site. Its technical principle is to avoid the Internet as far as possible to affect the speed and stability of data transmission bottlenecks and links, the system through a carefully selected network place node servers, so that the content of the site to the nearest and fastest place, to avoid the above impact on the Internet transmission performance of the "first kilometer" and " Network interconnection bottleneck "and so on, so as to achieve cross-regional, inter-operator network acceleration Services.
Its technical advantages, CDN Global network mirroring and acceleration engine using local cache acceleration, image services, remote acceleration, bandwidth optimization, scalability, VPN high-speed compression channel and cluster anti-attack technology to achieve Network Load Balancing, intelligent multi-line, automatically obtain the fastest path and support Netcom, Telecom, Hong Kong and Education Network mirroring, achieve real-world network acceleration.
Compared with intelligent DNS resolution, the World CDN Global Network mirroring and acceleration engine not only achieve Network Load balancing, and on the basis of intelligent DNS resolution, using local cache acceleration, mirroring services, remote acceleration, bandwidth optimization, scalability, VPN high-speed compression channel and cluster anti-attack and other latest technologies, Achieve intelligent multi-line, automatically get the fastest path. It can be seen that using CDN for Intelligent DNS resolution provides users with better, faster, more secure network services and a real sense of network acceleration.
Using linkage World CDN, can effectively speed up their own website browsing speed, so that it has similar to Sina, Sohu-like page quick access response speed, effectively solve the current due to network distance and router transfer process of technical delay, resulting in a slow landing site visit.
The optimization of the network by the CDN is mainly embodied in the following aspects:
Solve the "first kilometer" problem on the server side
Mitigate and even eliminate the impact of the bottleneck of interconnection between different operators
Reduced export bandwidth pressure in each province
Relieves the stress of the backbone network
Optimized the distribution of hotspot content on the Internet
Linkage World CDN to the Network optimization function schematic as follows:
CDN Acceleration Principle
