I could not get my phone to transfer the call to my OBi110, but I was able to get a 3 way conference call with the OBi and the inbound call.
This is what I did:
In CSipSimple
Settings -> Call Options -> Support multiple calls = Checked
This is my OBi110 SP2 Service Inbound Call Route:
{robert>(Msp1):sp1},{robert>(Mli):li},{robert>(Msp2):sp2},{robert>(110):ph},{>(SP2UID):ph}
If I receive a call on SP2 from robert (My Sip2Sip UID) with number 110 the call will be routed to my OBi110 phone port.
After I received a call on my Android I hit "Add Call" on the Dialer, then dialed "110" and I was connected to the Phone Port on my OBi110 and had a 3-way conference call. At this point I didn't know how to hang up without killing the conference call. There might be a way on my Android to transfer the call, but I couldn't find it and didn't want to spend any more time looking. Anyway, every phone is going to be different so give it a try.
Update:
It just hit me that this post could be confusing because I don't prefix the call with **7 and don't use **n when dialing the number, therefore add something like the following to your Inbound Call Route:
{robert>(**7110):ph}
