[Samba] How SMB client recognizes when to use PDC or BDC

[Marcin Giedz]

Hi,

Maybe this was asked many time (although can't find it on google). Let's 
assume 2 scenarios:
1) I've got local network where PDC and BDC are set up. PDC is working 
fine so the BDC is. When it's possible for any XP client to use BDC 
instead of PDC? I read in samba docs that if PDC is slow client can use 
BDC - but what does it mean slow for the client? How the client knows 
what "slow" is? Can Windows client measure "some kind of ping response" 
from PDC/BDC?
2) But if I have 2 offices: first one HQ has PDC installed and branch 
has BDC. How branches clients know to use BDC and not PDC?

I tried and read Network Browsing on samba doc web but this issue isn't 
still clear to me. Can some please explain me how this works in Samba env?

Thanks,
Marcin