Just as communicating between people in different countries, a language that understands each other is needed. Computers in the network must be "communication", but also to choose a "public language" that can be understood from each other. That is, we usually say the network communication protocol (Protocol).
At present, the communication protocol used in the LAN (Campus Network) mainly has three kinds of NetBeui, IPX / SPX, and TCP / IP.
NetBeui protocol
NetBEUI (NetBIOS Extended User Interface, User Extended Interface) was initially developed by IBM for implementing communication between PCs. Microsoft has further expanded and improved NetBeui, starting NetBeui as a basic communication protocol of network systems of its "client / server" mode, such as DOS, LAN Manager, Windows 3.x And in Windows for Workgroup. In Windows 95/98 and Windows NT, NetBeui is installed as the default protocol.
NetBeui is designed for small and medium-sized local area networks, using single-partnames, which does not support multi-network segment network, which is usually said "ineffective", this is a NetBeui is not suitable for large networks. important reason. NetBeui also has its advantages, such as the installation is very simple, no configuration is required, and occupy the least memory in three protocols.
IPX / SPX protocol
IPX / SPX (InternetWork Packet Exchange)
Sequences Packet Exchange, Internet Packet Exchange / Sequence Pack Switching is a communication protocol set developed by Novell. IPX / SPX has strong adaptability in complex environments, considering the problem of multi-network segments at the beginning of design, with powerful routing features, suitable for large networks. IPX / SPX is the best choice for NetWare networks, in a non-NetWare network environment, generally not using IPX / SPX. Especially in the Windows NT network and the peer network consisting of Windows 95/98, IPX / SPX Communication Protocol cannot be directly used.
In order to achieve the Internet with the NetWare platform, the Windows series operating system provides two IPX / SPX compatibility protocols: "NWLink SPX / SPX Compatibility Agreement" and "NWLink NetBIOS", all of which are collectively referred to as "NWLink Communication Agreement". "NWLINK IPX / SPX Compatibility Protocol" is similar to the "IPX / SPX Compatibility Protocol" in Windows 95/98, which can only be accessed to the NetWare server as a client's protocol, while the "NWLink Netbios" protocol can not only be in the NetWare platform. The Windows platform passes information, and can be used as a communication protocol between the Windows series operating system.
TCP / IP protocol
TCP / IP (Transmission Control Protocol / Internet Protocol, Transmission Control Protocol / Internet Protocol) is the most widely used network communication protocol, whether in the LAN, WAN or Internet, whether it is a UNIX system Windows platform, it supports, you can say The TCP / IP protocol is a general "language" of the computer world.
TCP / IP is also a routing protocol, which uses a grading naming rule that configures an IP address, a subnet mask, a gateway, and a host name, making it easy to determine the network and subnets by configuring an IP address, a subnet mask, a gateway, and a host name. The relationship between segments, gets good network adaptability, manageability, and higher network bandwidth efficiency. But at the same time, the configuration and management of TCP / IP protocols is more complicated than NetBeui and IPX / SPX protocols. NetBeui and IPX / SPX and their compatible protocol do not need to be configured, while TCP / IP protocols first perform complex settings. The "four elements" (IP address, subnet mask, default gateway, and host name) of the network node are very difficult, which is very difficult for some primary network users. 1, IP address
The IP address consists of two parts: network address and host address. A complete IP address consists of a 32-bit (bit) binary number, and each 8-bit (1 byte) is a segment, a total of 4 sections, and the segment and segments are separated from the segment. In order to facilitate the application, the IP address does not use binary when practical use, but is expressed as a familiar decimal number, such as 192.168.0.1, etc.
At present, the IP address is mainly divided into three categories A, B, and C (in addition to this, there are D and E two types of addresses for research and testing). Class A for large networks, class C is used for medium-sized networks, and Class C is generally used in small networks such as local area networks.
2, subnet mask
Subnet mask is used to define which parts of the IP address are network addresses, which parts are host addresses and extension of network address portions in the IP address in multiple network segment environments.
3, gateway
The gateway is a device that connects two network segments that use different protocols. Its role is to translate translation conversion to each other in two network segments, so that two networks running different protocols can communicate with each other. If Windows NT users running TCP / IP protocols To access NetWare network resources running the IPX / SPX protocol, they must be used as an intermediary.
4, host name
There is no doubt that the IP address can distinguish between the identity of the host in the network, but the IP address is not easy to remember, and it is not convenient to operate. Therefore, the TCP / IP protocol has also used the host name and gives each host a meaningful name, such as "CCE". In the network, the host name corresponds to the IP address one by one.
Selection principle
When building a campus network, specific choice which network communication protocol depends primarily on network size, network application requirements, network platform compatibility, and network management.
If a small single network segment is being built, it is only for simple files and devices sharing, and there is no need to connect to the external connection, you can choose the NetBeui protocol.
If there is multiple network segments or when they are connected to the outside, the NetBeui protocol that does not have routing and cross-network segment operations must be selected, but the IPX / SPX or TCP / IP protocol must be selected.
If the campus network operating system is migrated from NetWare to Windows NT, it is also an inevitable choice for IPX / SPX and its compatible NWLINK communication protocols.
Some people may feel that the three agreements will not be adapted to all situations? In fact, this is not advisable, because each protocol occupies the computer's memory, the more protocols, the more the memory resources occupying the computer, the speed of the network will affect the speed of the network.
