A question to the specialists:
How much traffic can go through an 2Mbps line?
In theory and in praxis ?
Can I operate one or more servers at such a line (T1/E1)
Thanks for your answer in advance.

In theory, 1 Mbps can handle about 316 GB of transfer, but in practise, I would say around 300GB ... So 2 mbps can handle around 632 GB of data transfer (again, in theory assuming the connectivity is fully used every single seconds).

It's easy to calculate it ... you should know the basic conversion:
8 bits = 1 byte
1 KB = 1024 bytes
1 MB = 1024 KB
1GB = 1024 MB

So, 1 Mbps (Mega Bits per second) = 1/8 MBps (Mega Bytes per second).
Taking 1 month = 30 days and 1 day = 86400 seconds,
In one month, 1 Mbps (1/8 MBps) can handle: (1/8 MBps) * (86400 seconds) * (30 days) = 324000 Mega Bytes = 316.4063 GB ...

Yes, you can operate a server or even several server on a T1. I know Burst was operating on a T1 (s) before they put DS3 ... But one single line (T1 or even DS3) might not be good enough, since what really matters is redundancy. What happens if the one single line is down? Not to mention that you need to have all hardwares (routers, switch, etc) yourself. It might be better to colo your servers on a NOC ... they offer more redundancy and much more bandwith .... for a smaller price too.

Cheers,
:beer:

In theory? About 650GB. But that's assuming 2mbps sustained usage. You could never run servers like that, since you're going to have peaks in traffic. It depends on your traffic patterns. But to maintain decent speed you probably wouldn't be able to do anything more than 300GB (about 50% average usage).