Administrator’s Guide for SIP-T2 Series/T4 Series/T5 Series/CP920 IP Phones
115
Description It configures whether to use audio encryption service.
Permitted
Values
0-Disabled
1-Optional, the phone will negotiate with the other phone what type of encryption to use for the ses-
sion.
2-Compulsory, the phone must use SRTP during a call.
Default
0
Web UI
Account > Advanced > RTP Encryption (SRTP)
Parameter account.X.srtp_lifetime
[1]
<MAC>.cfg
Description
It configures the lifetime of the master key used for the cryptographic parameter in SDP. The value spe-
cified is the number of SRTP packets.
When the lifetime is set, a re-invite with a new key is sent when the number of SRTP packets 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 the phone. It works
only if “account.X.srtp_encryption” is set to 1 (Optional) or 2 (Compulsory).
Permitted
Values
Integer greater than or equal to 0
0-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 2^ 48-the master key lifetime is 2^48.
Default
0
Parameter account.X.srtp.unencrypted_rtp.enable
[1]
<MAC>.cfg
Description
It enables or disables the phone’s capability to include unencrypted RTP streams in SDP offers when
using SRTP.
Note: It works only if “account.X.srtp_encryption” is set to 1 (Optional) or 2 (Compulsory).
Permitted
Values
0-Disabled
1-Enabled, the phone offers both encrypted and unencrypted RTP streams (Unencrypted RTP
streams carry UNENCRYPTED_SRTP session parameters) in SDP offers. After a successful nego-
tiation, whether the RTP stream is encrypted or not depends on the SDP answer.
Default
0
Parameter account.X.srtp.unencrypted_rtcp.enable
[1]
<MAC>.cfg
Description
It enables or disables the phone’s capability to include unencrypted RTCP streams in SDP offers
when using SRTP.
Note: It works only if “account.X.srtp_encryption” is set to 1 (Optional) or 2 (Compulsory).
Permitted
Values
0-Disabled
1-Enabled, the phone offers both encrypted and unencrypted RTCP streams (Unencrypted RTCP
streams carry UNENCRYPTED_SRTCP session parameters) in SDP offers. After a successful nego-
tiation, whether the RTCP stream is encrypted or not depends on the SDP answer.
Default
0
