Yes. I found iout later it may not be forwarding sp1 to sp2. More like ph1 to ph2.
I use obi202 with google voice and sprint. Sp1--- sprint+google voice, call in and out with ph1; sp2----just google voice,call in and out with Ph2;sp3---google voice call in with ph2. I also have Obibt for ph1.
When someone call in to sp1 number, ph1 rings first and then the cell phone, and then ph2 ring.when I heard 2rings, I try to answer with ph1,I couldn't.because after two rings , it goes to ph2 , so I pick up ph 2 but couldn't here anything.