这是我所在组织的一位软件工程师提出的问题。我感兴趣的是最广义的定义。


当前回答

这些是基本的网络概念,所以我将以一种简单而全面的方式详细解释它们。

插座就像电话(即端到端通信设备) IP就像你的电话号码(即你的插座地址) 端口就像您想要与之交谈的人(即您想从该地址订购的服务) 插座可以是客户端也可以是服务器端(例如,在公司中,客户支持的电话是服务器,但你家里的电话主要是客户端)

因此,网络中的套接字是绑定到一对(ip,端口)=(地址,服务)的虚拟通信设备。

注意:

A machine, a computer, a host, a mobile, or a PC can have multiple addresses , multiple open ports, and thus multiple sockets. Like in an office you can have multiple telephones with multiple telephone numbers and multiple people to talk to. Existence of an open/active port necessitate that you must have a socket bound to it, because it is the socket that makes the port accessible. However, you may have unused ports for the time being. Also note, in a server socket you can bind it to (a port, a specific address of a machine) or to (a port, all addresses of a machine) as in the telephone you may connect many telephone lines (telephone numbers) to a telephone or one specific telephone line to a telephone and still you can reach a person through all these telephone lines or through a specific telephone line. You can not associate (bind) a socket with two ports as in the telephone usually you can not always have two people using the same telephone at the same time . Advanced: on the same machine you cannot have two sockets with same type (client, or server) and same port and ip. However, if you are a client you can open two connections, with two sockets, to a server because the local port in each of these client's sockets is different)

希望它能消除你的疑虑

其他回答

一般来说,你会得到很多理论,但区分这两个概念的最简单方法之一是:

为了获得服务,你需要一个服务号码。这个服务号码称为端口。就这么简单。

例如,HTTP as a service运行在端口80上。

现在,许多人都可以请求该服务,并建立了来自客户机-服务器的连接。会有很多联系。每个连接代表一个客户端。为了维护每个连接,服务器为每个连接创建一个套接字来维护其客户端。

套接字由三部分组成:

IP地址 传输协议 端口号

端口是1到65535之间的数字,表示设备中的逻辑门。 客户端和服务器之间的每个连接都需要一个惟一的套接字。

例如:

1030为端口。 (10.1.1.2, TCP,端口1030)是一个套接字。

套接字是软件中的一种结构。它差不多是一个文件;它有读和写这样的操作。它不是一个物理的东西;它是你的软件引用物理事物的一种方式。

端口是一个类似设备的东西。每台主机都有一个或多个网络(这些是物理网络);主机在每个网络上都有一个地址。每个地址可以有数千个端口。

只有一个套接字可能在某个地址上使用某个端口。套接字分配端口类似于为文件系统I/O分配设备。一旦分配了端口,就没有其他套接字可以连接到该端口。当套接字被关闭时,端口将被释放。

看一下TCP/IP术语。

这个问题已经有了理论上的答案。我想举一个实际的例子来解释这个问题,让大家对Socket和Port有一个更清晰的理解。

我在这里找到的

This example will walk you thru the process of connecting to a website, such as Wiley. You would open your web browser (like Mozilla Firefox) and type www.wiley.com into the address bar. Your web browser uses a Domain Name System (DNS) server to look up the name www.wiley.com to identify its IP address is. For this example, the address is 192.0.2.100. Firefox makes a connection to the 192.0.2.100 address and to the port where the application layer web server is operating. Firefox knows what port to expect because it is a well-known port . The well-known port for a web server is TCP port 80. The destination socket that Firefox attempts to connect is written as socket:port, or in this example, 192.0.2.100:80. This is the server side of the connect, but the server needs to know where to send the web page you want to view in Mozilla Firefox, so you have a socket for the client side of the connection also. The client side connection is made up of your IP address, such as 192.168.1.25, and a randomly chosen dynamic port number. The socket associated with Firefox looks like 192.168.1.25:49175. Because web servers operate on TCP port 80, both of these sockets are TCP sockets, whereas if you were connecting to a server operating on a UDP port, both the server and client sockets would be UDP sockets.

端口:

端口可以指物理连接点 用于外部设备,如串行、并行和USB端口。 术语端口也指某些以太网连接点 如集线器、交换机或路由器上的那些。

套接字:

套接字表示两个网络应用程序之间的单个连接。 这两个应用程序名义上运行在不同的计算机上, 但是套接字也可以用于单台计算机上的进程间通信。 应用程序可以创建多个套接字用于相互通信。 套接字是双向的,这意味着连接的任何一方都能够发送和接收数据。