[MPICH] Profiling an application's network usage through MPI calls

[Diego M. Vadell]

Hi,  
   First of all, sorry if this is has a known answer, is a stupid question, or 
if Im out of place somehow. As I'm new to mpi and MPICH, I know I may have 
wrong concepts.
   I co-administer a couple of clusters in the university of Buenos Aires. I 
would like to know how does the MPI applications use the network: for 
example, lots of short messages, some big messages, lots of big messages, 
etc. 
    My first thought was to use tcpdump and then process it's output. Then I 
thought that if there were a log file where mpich left a timestamp and the 
size of the MPI message each time it sends one, I would have more accurate 
information.  

  My questions: is there any way to make MPICH leave such a log? also, is 
there a better way to profile an application's network usage?

Thanks in advance,
 -- Diego.