Yealink T48G, Administrator'S Manual

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Security Features
423
SRTP Configuration
The following table lists the parameters you can use to configure the SRTP.
Parameter account.X.srtp_encryption
[1]
<MAC>.cfg
Description It configures whether to use voice encryption service.
Permitted
Values
0-Disabled
1-Optional, the IP phone will negotiate with the other IP phone what type of
encryption to use for the session.
2-Compulsory, the IP 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 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 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 2048-the master key lifetime is 2048.
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). After successful negotiation, whether the RTP stream is encrypted or
not depends on SDP answer.
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