[erlang-questions] Practical sizes for fully connected node groups?

[james]

Is there any information available on the way that inter-node traffic 
grows with the number of fully-connected nodes?

Ideally I'd be interested in the traffic for:
  - just maintaining the connected state
  - any addiitional for use of the global name service
  - traffic related to widely replicated (but largely static) mnesia 
databases

Are there any studies available?

I'm also interested to know whether mnesia transaction cost in elapsed 
time grows with the worst WAN round trip, or with the sum of the WAN 
round trips, or somewhere in between.

I'm interested in erlang to design a system for WAN use, but I don't 
have an appropriate lab at this point.

Thanks!
James