Date Added: Aug 2012
The security in Voice over IP using SIP initiated IPSec tunnel with the help of Multimedia Internet KEYing (MIKEY) protocol has been studied in this paper. Call establishment in SIP initiated IPSec deals with cryptographic processing at the caller and the recipient end. Cryptographic parameter negotiation for IPSec is done through the SIP INVITE message in the calling phase and 200OK response in the answering phase when the responder picks up his phone. This IPSec cryptographic processing at caller end makes it unable to send and receive the RTP media packets at the beginning of the RTP session. This situation is called as call clipping.