I’m trying to create a SIP client that logs all the received calls.
I’m using Python with the pyVoIP library, this is the code:

from pyVoIP.VoIP import VoIPPhone, CallState, PhoneStatus, InvalidStateError
import time
import datetime

def answer(call): # This will be your callback function for when you receive a phone call

   try:
     print(call.state)
     anum = call.request.headers["From"]["number"]
     print(','+ datetime.datetime.now().strftime("%Y%m%d")+', '+ datetime.datetime.now().strftime("%X")+', '+ datetime.datetime.now().strftime("%f")+',,,,,,,'+anum+',0662279775,,,')
     open('tmp.csv', 'w+')
     f.write(','+ datetime.datetime.now().strftime("%Y%m%d")+', '+ datetime.datetime.now().strftime("%X")+', '+ datetime.datetime.now().strftime("%f")+',,,,,,,'+anum+',0662279775,,,')
     print(anum)
     call.answer()
     call.hangup()
   except InvalidStateError:
     print(InvalidStateError)
     pass

if __name__ == "__main__":
   vp = VoIPPhone('79.98.45.133',5060,'0662279775','065+eMl6Ttd6$T',callCallback=answer)
   print('VOIP PHONE INIZIALIZATED: status = '+str(vp._status))
   vp.start()
   print('VoIP PHONE STARTED: status = '+str(vp._status))
   while(vp._status==PhoneStatus.REGISTERING or vp._status==PhoneStatus.INACTIVE):
     continue
   print('WHILE LOOP STATUS ENDED: status = '+str(vp._status))
   input('Press ENTER to stop')
   time.sleep(5)
   vp.stop()
   print('STOPPED VOIP PHONE: status = '+str(vp._status))
   time.sleep(5)

The registration phase is ok, the client is able to register to the SIP Server so I get:

WHILE LOOP STATUS ENDED: status = PhoneStatus.REGISTERED

When I call the number associated to the SIP account sometimes the call is received by the client and sometime isn’t.
I made a trace of the SIP packet received by the client and I see that the SIP Server sends OPTIONS messages to the client but the client doesn’t answer to them.
I guess that this is the problem: the server doesn’t receive an answer to the OPTIONS messages so it thinks that the client is down so it doesn’t forward the call to the client.

Is there a way to configure pyVoIP to answer to OPTIONS messages?