Web Performance Tuning

Figuring Out Why the Browser Is Hanging

Is your modem still on and connected to your computer?

If you have an external modem, diagnosing problems is easier. At the least, a power light should be lit to indicate that the modem is on. If the modem is definitely on, try manually sending something to the modem to prove it is connected to your computer. On Linux you can do this:

% echo AT > /dev/modem

From a DOS shell on a Windows machine you can do this:

> echo AT > COM1

If your modem is connected, you will see the send and read lights flash. If the lights do not flash, either the modem is not connected, or you have configured it for the wrong COM port, PCMCIA slot, or other attachment point.

Are you still online, transmitting and receiving?

Your modem should also have a light labelled CD (Carrier Detect) to indicate if there is a carrier signal, that is, whether you are online. If it is not lit, it may be that the remote end hung up on you, or you lost your connection through too much noise on the line.

If you have carrier detect and can manually get your modem to respond but your browser cannot, then the browser is not communicating correctly with your operating system, implying a TCP/IP stack problem or a PPP problem.

Open another window and make another request. If you have an external modem, look at the modem lights. The read and send lights should be flashing. The send light will tell you that your modem is trying to send data out to the Internet. The read light will tell you if your ...