Configuring Security Features7092. Click Upload File to select and upload the certificate (*.pem and *.cer) from your localsystem.Secure Real-Time Transport Protocol (SRTP)Secure Real-Time Transport Protocol (SRTP) encrypts the RTP during VoIP phone calls to avoidinterception and eavesdropping. The parties participating in the call must enable SRTP featuresimultaneously. When this feature is enabled on both phones, the type of encryption to utilizefor the session is negotiated between the IP phones. This negotiation process is compliant withRFC 4568.When a user places a call on the enabled SRTP phone, the IP phone sends an INVITE messagewith the RTP encryption algorithm to the destination phone. As described in RFC 3711, RTPstreams may be encrypted using an AES (Advanced Encryption Standard) algorithm.Example of the RTP encryption algorithm carried in the SDP of the INVITE message:m=audio 50020 RTP/AVP 118 9 0 8 18 101a=rtpmap:118 opus/48000/2a=fmtp:118 sprop-maxcapturerate=48000; maxaveragebitrate=40000;a=rtpmap:9 G722/8000a=rtpmap:0 PCMU/8000a=rtpmap:8 PCMA/8000a=rtpmap:18 G729/8000a=fmtp:18 annexb=noa=ptime:20a=sendrecva=rtpmap:101 telephone-event/8000a=fmtp:101 0-15a=crypto:1 AES_CM_128_HMAC_SHA1_80 inline:NWM5YmZkZDk5YjI1OTg2MDgwOTM5ZjIxNmJkNTY5a=crypto:2 AES_CM_128_HMAC_SHA1_32 inline:N2M1NmMzZTI2MGFkZjY5YWYzMGE5MWViYTljNzg4a=crypto:3 F8_128_HMAC_SHA1_80 inline:NjMxYmIzMDIxNGExM2JkYWQxZTMyODQ1MThkYzg0m=video 50022 RTP/AVP 97 98 99 117
