standard transit arrangements

[Sven Huster <sven () huster me uk>]

Hello

I just wanted to find out what the "standard" arrangements are when 
one buys transit traffic.  I've been left in charge of this now, 
without haven't been doing this before :-(

So what normally you buy x amount of bandwidth over a physical line
e.g. 45Mb/s over FastEthernet or so. They then charge you for excessive
usage based on 95th percentile.
Is there anything else I need to keep an eye on?

Thanks
Sven