What is a real dual-line host

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The so-called dual-line, it is in order to solve the domestic and south-north telecommunications and Netcom users of the issue of interoperability of the smart dual-line mainframe services. Refers to the same server has both the telecommunications network and Netcom network two lines. By routing intelligence to judge the user's IP address when the telecom users visit the website to visit the Telecom line, Netcom users visit the Web site to visit the Netcom line, so as to achieve the purpose of the North-South exchange.

Dual-line host classification has single IP and single card, dual IP address, dual network card, dual IP address three ways. One single network card dual IP and dual IP two kinds have a telecommunications IP address and a netcom IP address, in this case, the way is the telecommunications user access to telecommunications IP address, Netcom user access to the network IP address.

In recent years, the emergence of a two-wire multi-line technology called BGP routing, the implementation of the same way as the early dual-card dual-line is the biggest feature is that the server only needs a network card, this dual-line technology is also known as "full route Two-line", today to say, that is,

BGP (Boundary Gateway Protocol) Protocol is mainly used to interconnect the Internet as (autonomous system), the most important function of BGP is to control the transmission of Routing and select the best route. Netcom and China Telecom both have the as number (autonomous system number), the country's major network operators are mostly through the BGP protocol and its own as number to interconnect. Use this scheme to achieve dual line needs in CNNIC (China Internet Information Center) to apply for IDC's own IP address segment and as number, and then through the BGP protocol to broadcast this IP address to Netcom, telecom and other network operators, Using BGP interconnection, all backbone routing devices of netcom and Telecom will judge the best route of IP segment of IDC room to ensure the high-speed access of Netcom and telecom users.

The use of BGP dual-line schemes has the following advantages:

1. The server only needs to set an IP address, and the best access route is determined by the backbone routers on the network based on the route hops and other technical metrics, not on any system resources that occupy the server. The upstream routing and downlink routing of the server can choose the best path, so it can realize high-speed single IP dual-line access.

2. Because the BGP protocol itself has redundant backup, eliminates the characteristic of the loop, so when the IDC service provider has many BGP interconnection line can realize the route mutual backup, when one line fails, the route automatically switches to other lines.

3. The use of BGP protocol can also make the network has a strong scalability can be the IDC network with other operators to interconnect, easy to achieve a single IP multiple lines, so that all the Internet operators access to users are very fast. This is a dual-IP dual-line unmatched.

Although the BGP solution is the best solution but because this project needs the IDC provider's equipment input and the bandwidth input aspect to be bigger and the technology is more complex, therefore at present the domestic adoption this plan is limited to the strength strong professional IDC service provider.

To sum up, the above a variety of dual-line implementation of each has advantages and disadvantages, dual-IP dual-line cost is lower, but the network is not stable and occupy a large number of server resources, ordinary single IP dual line only to achieve the effect of a part of the two lines, so access speed is poor, The CDN method is good for static web pages, but it is not ideal for interactive Web pages. BGP single IP dual line solves all of the above problems is the best way to achieve but the domestic use of such a program IDC service providers less, if the BGP single IP dual-line and CDN acceleration will be the best solution. At present, there are many data centers with BGP technology scheme, but most of them provide service for special customers, few have the room for ordinary users and IDC business.

Many IDC service providers in China claim to be "real dual-line", "dual-line single IP", "full route double line", but is there any moisture? They're both BGP? Is the threshold of BGP really so low?

First of all, to build real BGP two-line, need to have their own room, why? Because you can not in the telecommunications room to connect a netcom line, the same, you can not in the Netcom's room to pull a line of telecommunications, so operators can only build the computer room, and then with two ISP cable; Those who use the telecommunications room with telecom, or with telecommunications to build the computer room operators, using a double line is a problem, but also to use BGP is a bit of a dream.

In addition, the BGP two-line should have its own IP segment, autonomous domain. How do you get this? Apply with Cnnic. However, to have their own line operators to apply, this is definitely not a random IDC company can do, can do this company, its strength has been very strong, the domestic reach this level can also count out, if a company you even have not heard the name, Look at the size of their company is also an ordinary small and medium-sized enterprises, you believe that such companies can have the eligibility to apply?

So, a word to wear, domestic so-called BGP two-line companies are mostly not in line with the above conditions, of course, some if it is an agent, it also depends on his agent who is the BGP two-line, such as the independent IP host network, is the agent of the BGP two-line host. In Zhongguancun dual-line computer room (Zhongguancun dual-line room is one of the best room in Asia, is the largest data communication in Beijing, the best hardware conditions, network equipment, the most perfect data communication center) has 8 c IP address, and invested heavily to buy exclusive bandwidth. Only a small number of high-quality virtual Host service providers have their own IP address and the use of exclusive bandwidth to serve users! The soil is one of the best. Due to the limitations of various conditions, we are not here to list all the real BGP dual-line operators in China, but one can tell the readers that the true BGP dual-line multiple lines in the domestic is relatively limited; Of course, we expect more operators to adopt this technology in the big picture, Bring more practical benefits to everyone, not just propaganda.

In addition to the computer room router switches to use with the BGP protocol, the operators must also use the router and switch with BGP, so the real BGP room cost can be imagined, and BGP operation and maintenance technology also needs a good talent, so "BGP" is not a casual, the threshold is not low, The real BGP room in the Beijing area is limited to just 7.

So, can the high cost of BGP achieve the same value as the input to it? The answer is certainly, otherwise the BGP room has long been aborted in the market economy, summed up the advantages of the main two points:

1. Removing obstacles to North-south access

Because BGP can be netcom, telecom two major telecommunications operators of the line "merger" makes China's north-south barrier-free communication possible, implementation to the Access layer makes "netcom, telecommunications," the term disappeared, more practical significance is a Web site resources unrestricted national accessibility, Unlike in the past to achieve access to a remote barrier-free to do VPN or off-site acceleration station.

2, high-speed interconnection and interoperability

It is not difficult to infer the meaning of high-speed interconnection, the original line access to another line often have to go around a lot of routes, but to achieve BGP after the entry into the expressway, followed by the increase in speed, said is to improve the "restore", restore the original due to the speed of interconnection. The original bandwidth utilization is generally around 40%, the realization of BGP can reach more than 80%.