Assumptions: GV defined on SP1 and SP4 is free.
Use OBi Expert to make these changes.
I know nothing about a Mac or your softphones, but they should function the same as a softphone on a PC.
OBi200:
Service Providers -> ITSP Profile D SIP -> ProxyServer: 127.0.0.1
Service Providers -> ITSP Profile D SIP -> X_SpoofCallerID: Checked
Voice Services -> SP4 Service -> AuthUserName: OBi200
Voice Services -> SP4 Service -> AuthPassword: OBi200PW
Voice Services -> SP4 Service -> X_RegisterEnable: Unchecked
Voice Services -> SP4 Service -> X_ServProvProfile: D
Voice Services -> SP4 Service -> X_Proxy: Checked
Voice Services -> SP4 Service -> X_InboundCallRoute: {OBi200>(Msp1):sp1},{ph}
Voice Services -> SP1 Service -> X_InboundCallRoute:
ph,sp4(OBi200@local_client)
Softphone:
Proxy: 192.168.1.100 (IP address of the OBi200)
Proxy Port: 5063 (X_UserAgentPort of OBi200 SP4 trunk)
Proxy: 192.168.1.100:5063 (If port is included with IP address)
UserID: OBi200
Password: OBi200PW