why does 'cvs update' create heavy upstream traffic?

[Martin Henne]

Hi all,

I have a DSL connection with a downstream, that is
6 times faster than my upstream capabilities. 

Im working on some projects that are controlled 
via cvs. I notices, that a simple 'cvs update' 
sometimes causes heavy upstream traffic. 

I guess, that the local version and the remote
version are compared at the servers side. can I 
change this?



Martin