Get a free IP Freedom account at Callcentric
https://www.callcentric.com/rate/plans/ip_freedom/Install a softphone on your Android.
I use CSipSimple which has a wizard for Callcentric setup
Zoiper is another free softphone.
Register your softphone to Callcentric:
Proxy:
callcentric.comUserID: 1777xxxxxxx (Your Callcentric Acct#)
Password
OBi212
Define a dummy trunk on SP4:
Service Providers -> ITSP Profile D SIP -> ProxyServer: 127.0.0.1
Service Providers -> ITSP Profile D SIP -> X_SpoofCallerID: Checked
Voice Services -> SP4 Service -> X_ServProvProfile: D
Voice Services -> SP4 Service -> AuthUserName: anything
Voice Services -> SP4 Service -> X_RegisterEnable: (unchecked)
Route inbound Line calls to Phone Port and Callcentric:
Physical Interfaces -> Line Port > InboundCallRoute:
ph,sp4(1777xxxxxxx@in.callcentric.com)
The above might have a shorter delay than GV.
There is a Line Port parm (RingDelay) that introduces a 4 second delay. A delay is needed to acquire the CallerID before routing the inbound call. I have mine set to 3.2 seconds. Some people need a number greater than 4 seconds. The default is 4000 milliseconds. Continue to reduce this number until you stop receiving the callerid then increase it by a tenth of a second until you start receiving the callerid again.
Physical Interfaces -> Line Port -> RingDelay