IP-PBX P-CSCF | | |<---(1) INVITE---------------------------------| | (SDP) a=3ge2ae:applied | | (SDP) a=crypto:1 AES_CM_128_HMAC_SHA1_80 inline:EpcgtOdT5qd... | | |----(2) 100 TRYING---------------------------->| | | |----(3) 180 RINGING--------------------------->| | | |----(4) 200 OK ------------------------------->| | (SDP) a=3ge2ae:requested | | (SDP) a=crypto:1 AES_CM_128_HMAC_SHA1_80 inline:lnfakjh2sd1... | |