You can use the OBiTalk network to route calls between the 2 OBi200s.
Use OBi Expert to make the following changes.
Home OBi200:
Voice Services -> SP1 Service -> X_InboundCallRoute: ph,pp(222222222)
This will route inbound calls to the office OBi200
Voice Services -> OBiTalk Service -> InboundCallRoute:
{222222222>(911|933):sp2},{ph}
This will route 911 and 933 from the office OBi200 to SP2
Office OBi200:
Voice Services -> OBiTalk Service -> InboundCallRoute: ph
Physical Interfaces -> Phone1 Port -> DigitMap
Add |933 after 911 in the DigitMap
Physical Interfaces -> Phone1 Port ->
Add following to the beginning of the OutboundCallRoute:
{(<111111111*>(911|933)):pp},
This will route 911 and 933 to the home OBi200
Replace 111111111 with the OBi number of the home OBi200
Make sure you leave the *
Replace 222222222 with the OBi number of the office OBi200