[Serusers] OPTION using sipsak

Hello, Having 1 boxes with SIP service Box A: ip a.b.c.d with sip at udp 5060 and a NMS machine with ip x.y.z.t I am looking to monitor the SIP service via OPTION sent from NMS (x.y.z.t) to the box A (no user defined on the box) Any one to help how to write the OPTION request using sipsak I tried this way but no success sipsak -f option -s sip:a.b.c.d (I don't know if we have to set the udp port with sipsak) On file option I have: OPTIONS sip:a.b.c.d:5060 SIP/2.0 Max-Forwards: 70 To: <sip:ping@a.b.c.d:5080> From: NMS <sip:x.y.z.t> Call-ID: 83185420572 CSeq: 8764 OPTIONS Allow: ACK,CANCEL Accept: application/sdp Content-Length: 0 BR