how to judge client's network off-line or online use JavaScript?
7519
Detect the Internet connection is offline?
2738
What is the best way to check for Internet connectivity using .NET?
108784
Fast way to check if a server is accessible over the network in C#
51481
Is there any way to view which applications are accessing the Internet on Mac OS X?
145385
How to do sites uniquely identify a computer/network online?
145100
Is it possible to log a program's network activity in Windows 7?
125935
How can I read the client's machine/computer name from the browser?
80668
NTP tool for showing deviance to a certain server
59011
Get client IP address via third party web service
43050
Can I perform a DNS lookup (hostname to IP address) using client-side Javascript?
133058
How do you test non-live sites before switching DNS?
56179
How does Windows know whether it has internet access or if a Wi-Fi connection requires in-browser authentication?
58175
Is there an API for making a Google Chrome extension that reads the network resource request activity?
11878
Identifying Between Refresh And Close Browser Actions
129422
Rails Browser Detection Methods
54695
Way to identify API usage and limits using API?
147958
What is a RELIABLE way to detect a client's browser and its version number?