(From http://www.redbooks.ibm.com/redbooks/gg243376.html translated by frank)
First part TCP / IP core protocol
Chapter 1 Architecture, History, Standards and Development Trends
1.2 INTERNET origin
If it is not the most important, the network has become a part of today's most basic information system. They have formed information sharing in the enterprise, government and scientific research groups. Information can be obtained in several ways. It may be a note, document, or other computer processing data, sent to the colleague's file and multimedia data stream.
Many of the networks were established in the late 1960s and the 1970s. At this time, the theme of network design is "artistic performance" of computer research and maturity. It leads to a variety of network reference models such as package switching technology, local area network conflict detection, score, and many excellent communication technologies.
The result of these great technologies is that any user group can find a physical network and modeling to meet their special needs. Its range is transmitted throughout the LAN in which you are transmitted from inexpensive without errors, but is restricted. Here, there is no error checking asynchronous transmission rather than a parity check, which has a reliable protocol such as a public package switched network or a private SNA network through a widely used local area network (public or private).
There is also a shortcomings of all-flowers in different protocol groups. When a user group wants to extend its information system to another user group that has implemented different network technology and different network protocols, this is a very headache. As a result, even if they agree on network technologies of the two environments, their technologies (such as mail systems) may not be able to communicate with each other because of different application protocols and interfaces.
In the 1970s, a research team funded by the US Department of Defense Research Projects Agency, a concremented DARPA, has recognized this problem. Their work is positioned in an interactive network or network connection. Other official organizations have also been involved in this area, such as ITU-T (official ccitt) and ISO, the main goal is to define a set of protocols to refine the defined protocol groups to refine the application to communicate with other applications. Regardless of the operating system running regardless of the underlying network technology and the application.
The official organization of these researchers is ARPANET Network Working Group, and its recent regular conference is October 1971. DARPA continues its network protocol group research, from the NetWork Control Program, NCP host to the host's protocol to the TCP / IP protocol group, which is formed before and after 1978. At that time, Darpa was known as a pioneer in the unlimited network and the package exchange of the satellite channel. The founding of real Internet is approximately in 1980, when Darpa starts to transfer it to a new TCP / IP protocol. By 1983, the conversion is completed, and DARPA requires all the TCP / IP protocols who wish to connect Arpanet.
Darpa also develops a contract with Bolt, Beranek, and Newman (BBN) to develop a TCP / IP of Berkeley UNIX on VAX. DARPA also subsidizes the source code of their UNIX operating system for free from University Berkeley. The first Berkeley Software Distribution containing the TCP / IP protocol group has been generated in 1983 (4.2BSD). From this point of view, TCP / IP is quickly launched in university and research centers, which has actually become the standard of Unix communication subsystems. The second release version (4.2BSD) was released in 1986, 1988 (4.3BSD TAHOE), 1999 (4.3BSD RENO) was updated, and 4.4BSD was released in 1993. Due to the pressure of bonds, the 4.4bsd of Computer System Research Group, California University Berkeley, became the last release. Due to the rapid development of the network, new large-scale networks appear in the United States and connected to arpanet. In this way, the world's other scope is not necessary to TCP / IP protocol networks also joined the collection of internet networks. This is what we said. Examples of different networks play a very important role in the development of the next part.
1.2.1 arpanet
Sometimes, as mentioned as a "parent of the information", DARPA (called Arpa called ARPA at that time) ARPANET established in the 1960s, in order to meet the research needs of the package exchange technology and the resource sharing of the defense department. The network is connected to the research center, some military bases and government venues. It is very soon being welcomed by researchers through emails and other services. By the end of 1975, the Ministry of Defense Communications Agency launched its research in 1983, which is divided into the interconnection of the Milnet of the military website and the interconnection of the ARPANET's research website. This has become the beginning of the Internet "I".
By 1974, the exchange package node (PSN) based on the 56Kbps leasing special line has been discrete throughout the North American continent and Western Europe. These are small machines running at the 1822 protocol (because of a report of its report ", they focus on package exchange tasks. Each PSN is connected to 2 PSNs (to prevent circuit failure as pre-routing) and 22 ports are connected to user computers (hosts). The 1822 system provides a reliable, stream control transmission package to the cemetery node. This is why the original NCP protocol is a simple reason for a simple protocol. It is replaced by the TCP / IP protocol, the TCP / IP protocol does not assume the reliability of the formation physical hardware, and can be used on a non-1822 network. The 1822 protocol did not turn into industry standards, so DARPA later decided to replace the 1822 packet interaction technology to CCITT X.25 standard.
The rapid increase in data transmission on the 56 kbps leaseline is no longer able to provide the necessary throughput. Today, the role of the internet of the study, ARPANET has been replaced by the new technology (refer to the NSFnet of this chapter), but Milnet continues to be a military Internet backbone.
1.2.2 nsfnet
NSFNET, National Science Foundation network, is a three-level internet network in the United States, which has the following composition:
• Backbone: It is a network that connects the intermediate network and the NSF fund of the Hualian Network and the NSF Fund. The backbone also has transport links through the continent to other networks, such as EBONE, European IP backbone.
• Intermediate network: three (geographical, discipline-based and supercomputer community networks).
• Campus Network: The network connected to the intermediate network, whether academic or commercial.
How many years have passed, backbone network constantly upgrade to cater to its customers' growing demand. The first generation backbone: The original NSF has been developed to allow 0 researchers and scientists to access NSF supercomputers. The first NSFNET backbone network is 6 DEC LSI / 11 microcomputer as a package exchange, and the 56kpbs rental line interconnect. The most important interconnect NSFNET and AEPANET are at Carnegie - Mellon University, which allows users to route the routes of packets in each network it connect. The second generation of backbone: The need to appear in 1987 in 1987, when the first generation of backbone is overloaded (estimated at that time, the growth rate is 100%). The nsf and merit INC Company, Michigan, an eight state support school, a computer network community, agreed to develop and manage a new, high-speed backbone network, which will have a larger transmission rate and greater capacity. To manage it, they define information services (IS), which consists of one information center and a technical support group. The responsibility of the information center is information distribution, information resource management and electronic communication. Technical support groups directly provide technical support in this area. The purpose of this is to provide an information integration system, which is easy to use, easy to manage interface access of any of the services in any network.
MERIT and NSF cooperate with IBM and MCI in management. IBM provides software, package exchange, and network management requirements, while MCI provides long-distance transmission devices. In 1988, new networks connect 13 node switched systems (NSS) using 448kbps rental circuits, which is supported by IBM. Each NSS is connected to the two IBM token-Ring networks (as redundant) connections from 9 IBM RISC systems (running on IBM 4.3BSD UNIX machines). Each integrated digital network exchange (idnx), it is IBM support, installed in 13 places, provided:
• Dynamic alternating routing
• Dynamic bandwidth distribution
Third generation backbone: In 1989, the transmission mechanism of the NSFNET backbone network circuit topology, using fibers, the speed of the rental line has increased to T1 (1.544 Mbps).
Attributed a need for continuous improvement of package exchange and data transmission capacity, three NSS adds the backbone network, and the speed of the connection has also been improved. NSFNET backbone nets were transplanted from T1 to T3 (45MBSP) in subsequent 1992. Today, the subsequent ported to the GB level has begun and remain continues.
In August 1995, the US government gave up the NSFNET Fund. This has a certain impact on the commercial application of the network. At the same time, NSFNET gradually transplant the main backbone network of the United States. Providing business network services, NSFNET restored to network research communities. The main backbone network that is now running with MCI is a widely known VBNS (very high-speed backbone network service, Very High Speed Backbone Network Service).
NSFNET has played a key role in the development of Internet. However, many other networks also play another role and (or) becomes part of today's network.
1.2.3 Internet commercial use
In recent years, Internet is exceeded by anyone in size or in the range of huge development. Many key factors affect its growth. Some milestones, such as the free distribution of Gopher in 1991, the placement of hypertext norms, and the first graphic-based browser MOSAIC release in 1993. Today, most of the maincoming of Internet is commercial. This is a region with the original intention of the Internet, where the original intention is to encourage the open communication between the college and research institutions. However, Internet growing growth commercial use is inevitable, so it can be used very well to explain how this development is replaced. An important active consideration is acceptable to use policy (ACCEPTABLE USE Policy, AUP). This is the first policy proposed in 1992, which is suitable for NSFNET users. The core commitment of AUP is "supporting open research and education". "Use the interest drive activity" in "unacceptable use" unless it is mentioned in General Princi or as a specific acceptable use. However, despite this obvious restrictive gesture, NSFNET has been utilized before 1995, and NSFNET has been utilized, including many business nature.
Provide AUP, which is a very generous thing to provide in the Internet service, although AUP has gradually been more suitable for business applications. Some networks still offer free AUP services.
Now let's focus on the Internet service provider that introduces the Internet business app. The two worth mentioning are PSinet and UUNET, and they start providing Internet access to business and individuals late at the late 1980s. Free AUP service is available based on California's CERF network. An organization connected to Psonet, UUNET, and CERF NET was then set up, called Commercial Internet Exchange, which is based on whether the transfer of any member in the network is based on the team member network, and the transmission of any member in the network may be Understanding of submerged. In July 1997, CIX has grown to more than 146 members connected to the Internet around the world. Almost at the same time, CIX is established. He is a non-profit company, Advance Network and Services, ANS, which is the intent of T1 (later T3) backbone networks in IBM, MCI and MERIT. Connect to NSFNET, this organization value is quite positive in increasing business phenomena.
ANS established a commercial guidance assist, called ANS CO RE, providing connection between business support and scientific education research. In 1995, ANS was obtained online by the United States.
In 1995, when the NSF network is changing its previous academic roles, the Internet architecture transitions from a single US dominated backbone network into a large number of commercial operations. In order to allow different backbone network to exchange data, NSF establishes 4 network access points (NAPS) services as data exchange between different backbone services.
Another type of exchange is the Metropolitan Area Ethernet, MAE. There are several MAEs have been established by the Metropolitan Fiber System, MFS, which already has its own backbone. NAP and MAE also involve the public exchange point (Exchange Points, IXPS). As a representative, Internet Service Provider (ISPS) will connect to a large amount of IXPS to improve performance and support. If you want to get the current IXPS list, please refer to "Switch", the URL is: http://www.ep.net
Similar to North American Cix, European Internet Provider has established RIPE (Réseaux IP Européens) organization to ensure technology and management coordination. Founded in 1989, RIPE provides a unified IP service to users in Europe. Today, the largest Internet backbone operates in OC48 (2.4Gbps) or OC192 (96 Gbps). 1.2.4 internet2
The success of the Internet and the congestion of NSFNET, and the replacement of its business led to the defeat of the research agency, these communities were originally enjoys exclusive Internet. Therefore, the university community is jointly with government and industrial partners, which has been encouraged by the next-generation Internet (Next Generation Internet), which has established Internet2 projects.
NGI Active is a joint research project, its purpose is to develop advanced network technologies, introduce revolutionary applications, and these applications require advanced network technology and high-speed network test environment for these technologies.
1.2.4.1 mission
The mission of Internet2 is to promote and coordinate some tasks development, operation, and technology transmission. These tasks refer to advanced, web-based applications and network services to ensure new services and applications for research and higher education and promotion of Internet services in the future. The leadership of the availability.
The task of Internet2 is as follows:
• Demonstrates significantly improve the new application of researchers in experimentation.
• Due to the transmission of education and other services (such as health care, environmental monitoring, etc.), dealing with the virtual proximity created by advanced communication infrastructure.
• Develop and provide advanced applications in the form of intermediate parts and development tools.
• Promote communication infrastructure, based on research and education community requirements to support different QoS capacity development and operation.
• Promote the test of next-generation communication technology.
• Coordinating in multi-structured work standards and common practices to ensure the connection and interactivity of quality services.
• Promote cooperation between government and private organizations.
• Encourage the technology of Internet2 to migrate to other Internet.
• Research on new infrastructure, services and applications in higher education and general Internet community.
1.2.4.2 participants of Internet2
The Internet has 180 participants in the United States. Organized members provide valuable inputs to the project. All participants in the Internet project are members of the University's Advanced Internet Development Collaboration (University Corporation for Advanced Internet Development, Ucaid).
In most aspects, cooperation and bond funds for Internet2 will be similar to those of the previous academic and government-friendly network achievements, and NSF NET project is a good example. The US government will share Internet2 through NGI activities and related projects.
Internet2 also creates advanced network services with all the leaders to meet the needs of broadband, web applications. Industrial collaborators are mainly serving and products that provide applications that must be implemented by universities and regional universities. The main companies currently have Alcatel, Cisco Systems, IBM, Nortel Networks, Sprint, and Sun Microsystems. Internet2 Additional non-profit organizations from research and education networks. Members include MCNC, MERIT, National Health Association (National Institutes of Helth, Hit) and Foliida State Learning System.
For more information about Internet, please visit their website:
http://www.internet2.edu
1.1.5 Open System Interconnection (OSI) Reference Model
Open Systems Interconnect Reference Model (ISO 7498) defines a seven-layer data transfer model that is physically transmitted at a lower layer, and the application protocol is at a higher layer. This model, shown in Figure 5, as a basic understanding of how the network protocol stack is widely accepted, and also as a reference tool implemented by a comparison network protocol stack. Each layer provides a series of functions for its upper layer, which is dependent on the functionality provided below. Although the message can only be passed through vertical passage of the places, it is seen from a logical point of view, each layer communicates with the peer of the other nodes. These seven layers are:
Application: Network application, such as terminal utilization and file transfer.
Representation: Format the data and encodes.
Session Layer (session): Confirm and maintain a session.
Transport: Provides reliable and unreliable continuous transmission.
Network: package transfer, including routing.
Data Link: Extracted and error check of unit information.
Physical: Bits Transport on physical hardware.
Compared with TCP / IP, the OSI method begins with a clean slate and defined standard, adhere to their own model, handling it in a formal committee, does not require any implementation. The Internet protocol uses a unaware engineering method, so anyone can recommend and comment on RFCS, and implementation must be feasible. The OSI Agreement has developed very slow, and because the resources used to run the entire protocol stack are quite deep, they have not widely launched, especially at the desktop and small machine market. At the same time, TCP / IP and Internet have developed quite fast and expanded at a very high speed.
