With InboundCallRoute for SP2 set to {ph}, do incoming calls to the SP2 number ring the phone port? If not, debug that first (check whether registered, check whether outbound calls via SP2 work, check GV is set to route to Google Chat).
Once incoming calls on SP2 are working, change InboundCallRoute back to aa and retest. If it still fails, report what, if anything, is shown in Call History for a failing call.