[f-nsp] Routed sub interfaces?

[Matthew]

Hi,

We are moving from a Cisco ASR1002 to a Brocade CER2000RT but I can't 
see any way to do routed sub interfaces (router on a stick) from looking 
through the configuration guide.  For example, on the ASR we'd have 
gi1/1 going to provider X and gi1/2 going to provider Y with managed 
ethernet circuits delivered on the same VLAN tags. The config would look 
something like the example below and this wouldn't be an issue as vlan 
tag 10 on gi1/1 would be separate from vlan tag 10 on gi1/2.

int gi 1/1
desc Trunk to provider X

int gi 1/1.10
desc Link to Site A
encap dot1q 10
ip add 192.168.1.1 255.255.255.252

int gi 1/2
desc Trunk to provider Y

int gi 1/2.10
desc Link to Site B
encap dot1q 10
ip add 192.168.2.1 255.255.255.252

However from reading the configuration guide, to do this on a CER we 
would make e1/1 and e1/2 tagged ports in vlan 10 but then the virtual 
routing interface (ve10) for vlan 10 would be reachable via both Site A 
and B. What are people doing in this situation to keep vlan 10 from e1/1 
separate from vlan 10 on e1/2?

Thanks,
Matthew