Voice Services -> SP1 Service -> X_InboundCallRoute:
{(MWhitelist):ph},{(MTelemarketers):},{sp2(0@127.0.0.1:5061)}
Service Providers -> ITSP Profile B -> SIP -> ProxyServer: 127.0.0.1
Service Providers -> ITSP Profile B -> SIP -> X_SpoofCallerID: Checked
Voice Services -> SP2 Service -> Enable: Uncheck
Voice Services -> SP2 Service -> AuthUserName: anything
Voice Services -> SP2 Service -> X_RegisterEnable: unchecked
Voice Services -> SP2 Service -> X_ServProvProfile: B
Voice Services -> SP2 Service -> X_UserAgentPort: 5061
If you don't get a match with the 1st 2 rules in the inbound route, the call will be routed out SP2.
SP2 is disabled (Enable unchecked), so calls will fail.
Enable SP2 (see below) to have these calls ring the phone.
127.0.0.1 is a loop back address for your OBi.
Port 5061 points to SP2.
When SP2 is enabled these calls will loop back to SP2 and ring the attached phone.
Disable SP2 to start blocking these calls again.
Enable SP2 by dialing: ***0 200# 11# 1
Disable SP2 by dialing: ***0 200# 10# 1
***0 sends you to the Auto Attendant 2
200# you are modifying SP2
1 indicates a new value
1# = enable
0# = disable
1 = save
After dialing the above your OBi will re-boot.
Again, I did not test this.
Edit:
I had a typo. I was modifying the SP2 inbound route. It has been corrected to SP1.