To protect the security of the computer, in addition to anti-virus software, another means is a firewall. The firewall has two main purposes: 1) To resist the attack of the external network on the local computer; 2) To effectively control the access of the local program to the Internet. It's a pity that Windows' built-in firewall has a single function and poor usability, so there are a large number of third-party firewall programs. Of course, all third-party firewalls implement corresponding functions based on the operating mechanism of Windows' built-in firewall.

NetMet (full name: MiTeC Network Meter) is a tiny and portable real-time monitor for the upload and download transfer & speed of various network connections (such as ADSL, modem, LAN, and WLAN), free to use for both private and commercial users. In its simple user interface, you can monitor the network traffic of one or more LAN and WAN simultaneously and intuitively.

BWMeter is a tiny but powerful broadband/traffic monitor and controller based on WinpkFilter network drivers. It can perform real-time measure and control to any Internet/Network traffic through your computer. Meanwhile, it visually shows them in the way of chart.