Security Features423SRTP ConfigurationThe following table lists the parameters you can use to configure the SRTP.Parameter account.X.srtp_encryption[1] <MAC>.cfgDescription It configures whether to use voice encryption service.PermittedValues0-Disabled1-Optional, the IP phone will negotiate with the other IP phone what type ofencryption to use for the session.2-Compulsory, the IP phone must use SRTP during a call.Default 0Web UI Account->Advanced->RTP Encryption(SRTP)Parameter account.X.srtp_lifetime[1] <MAC>.cfgDescriptionIt configures the lifetime of the master key used for the cryptographic parameter inSDP. The value specified is the number of SRTP packets.When the lifetime is set, a re-invite with a new key is sent when the number or SRTPpackets sent for an outgoing call exceeds half the value of the master key lifetime.Note: Setting this parameter to a non-zero value may affect the performance of thephone. It works only if “account.X.srtp_encryption” is set to 1 (Optional) or 2(Compulsory).PermittedValuesInteger greater than or equal to 00-the master key lifetime is not set.1 to 1024-the master key lifetime is 1024.1025 to 2^48-the master key lifetime is the configured value.A value greater than 2048-the master key lifetime is 2048.Default 0Parameter account.X.srtp.unencrypted_rtp.enable[1] <MAC>.cfgDescriptionIt enables or disables the phone’s capability to include unencrypted RTP streams inSDP offers when using SRTP.Note: It works only if “account.X.srtp_encryption” is set to 1 (Optional) or 2(Compulsory). After successful negotiation, whether the RTP stream is encrypted ornot depends on SDP answer.PermittedValues0-Disabled1-Enabled, the phone offers both encrypted and unencrypted RTP streams(Unencrypted RTP streams carry UNENCRYPTED_SRTP session parameters) in SDPoffers
