Accessing Problem of my sites

[qazi.farrukh]

i have developed a site for a company.for time being i upload that
site at the Server of that company which have the live IP.Now i am
facing a problem when i upload or download some file from the site
using FTP that go well.the response me for some time i can visit all
their pages but after some time its again goes down.
If i access it after some time its display the message that site is
not accessible.
Please is their anyone who can help me in this problem.

Regards

Farrukh