What does this mean?

[BeLgaRiOn]

Hey guys,

Almost every site I visit gives me the following error message:

504 Gateway Timeout
The following error occurred:

 A gateway timeout occurred. The server is unreachable. Retry the request. 

What does this mean?

Thank you.

 

[matt156]

Can you ping these sites?

 

[BeLgaRiOn]

Can you ping these sites?

Yes I can...but the ping times are very erratic.