The most important thing in network communication is network communication protocol. Today there are many network protocols, LAN is the most commonly used in three network protocols：MICROSOFT of NETBEUI、NOVELL and IPX/SPX and TCP/IP Protocol. The appropriate network protocol should be selected as needed.

   
      In the face of many network protocols, we may have no choice. However, if the prior understanding of the main purpose of network protocol network communications, you
can have a targeted choice. The following are some commonly used network protocols：

        NetBEUI（NetBIOS Enhanced UserInterface）

        NetBEUI is IBM Was introduced in 1985.NetBEUI Mainly designed for small local area networks of 20 to 200 workstations，Used for NetBEUI、LanMan、Windows For WorkgroUPS and Windows NT。NetBEUI Is a compact, fast protocol, but because NetBEUI no routing capabilities, that is not from a LAN through the router to another LAN, can not adapt to a larger network. If you need to route to another LAN, you must install TCP / IP or IPX / SPX protocol.

         IPX/SPX（Internetwork Packet Exchange/Sequential PacketExchange）

It is a network protocol that is proposed by Novell for client / server connections. Use the IPX / SPX protocol to run programs that typically require NetBEUI support. The IPX / SPX protocol can access other networks across the router。

         HDLC（High-Level Data Link Control）

It is a set of protocols used to transfer data between network nodes. In HDLC, the data is composed of one unit (called a frame) sent over the network and received by the recipient. The HDLC protocol also manages the interval between data flow and data transmission. HDLC is one of the most widely used protocols in the data link layer. As the ISO standard, HDLC is based on IBM's SDLC protocol, SDLC is widely used in IBM's mainframe environment. In HDLC, belonging to SDLC is called pass-through mode (NRM). In the normal response mode, the base station (usually the mainframe) sends data to the local or remote secondary station. Different types of HDLC are used for networks and frame relay networks that use the X.25 protocol, which can be used on a local area network or wide area network, whether public or private.

          HTTP1.1（Hypertext Transfer Protocol Vertion 1.1）

It is used to send hypertext on the Internet delivery protocol. It is running on the TCP / IP protocol family above the HTTP application protocol, it can make the browser more efficient, so that network transmission is reduced. Any server in addition to including HTML files, there is an HTTP resident program, used to respond to user requests. Your browser is an HTTP client that sends a request to the server. When the browser enters a start file or clicks on a hyperlink, the browser sends an HTTP request to the server, which is sent to the IP address URL. The resident program receives the request and returns the requested file after making the necessary operations.

          HTTPS（Secure Hypertext Transfer Protocol）

It was developed by Netscape and built into its browser for compressing and decompressing data and returning the results returned on the network. HTTPS actually applies Netscape's fully socket layer (SSL) as a sublayer of the HTTP application layer. (HTTPS uses port 443 instead of using port 80 as HTTP to communicate with TCP / IP.) SSL uses 40 bits.