[c-nsp] VPLS hub & spoke assistance

[Lobo]

Hi everyone.  I'm trying to understand vpls with a hub & spoke topology 
a little better but I'm having a hard time grasping which site(s) need 
to have the no split-horizon configuration added to them.  Not sure if 
this is even possible with the autodiscovery option vs using manual.

So right now I've got four sites setup in a full mesh with the following 
configuration on each PE router (ME3600X):

l2 vfi TEST1 autodiscovery
  vpn id 3000
!
interface GigabitEthernet0/4
  service instance 3000 ethernet
   encapsulation dot1q 3000
   rewrite ingress tag pop 1 symmetric
   bridge-domain 3000
  !
!
interface Vlan3000
  no ip address
  xconnect vfi TEST1
!

So if I want sites 2, 3 and 4 to not be able to talk to each other 
except by going via site 1 what configuration change would I need to 
do?  I thought that adding "split horizon" to the bridge-domain under 
the service instance was the way to go but I'm not so sure.

Ideally, I'd like a scenario where I can have one site as the hub and be 
able to take advantage of the autodiscovery for instances when a new 
spoke is added to the domain.  Granted only the hub is benefiting from 
this auto discovery but does that mean that the spokes should be 
configured as "manual"?

Thanks for any suggestions.

Jose