I think my network is congested because of the relatively large discards and errors data. They should be zero or at least close to that.
Here is the output of netstat -e on my computer:
Interface Statistics Received Sent Bytes 810900096 72544495 Unicast packets 695440 505220 Non-unicast packets 1692 13352 Discards 1924553324 1924553324 Errors 4054803476 619997124 Unknown protocols 0
Here is my setup:
ISP > Modem/Router > Computer
I think I should just mention that our connection is dsl and we signed a bundled package - telephone + internet. The data is then filtered and goes through a splitter. I am not sure if that contributes to the problem, though, but every time someone uses the telephone the connection gets disrupted very often. Our connection is very unstable, too. Specially when it is raining.