Srtp Configuration - Yealink SIP-T5 Series Administrator's Manual

When you place a call on the enabled SRTP phone, the phone sends an INVITE message with the RTP/RTCP
encryption algorithm to the destination phone. As described in
using an AES (Advanced Encryption Standard) algorithm.
Example of the RTP encryption algorithm carried in the SDP of the INVITE message:
m=audio 11780 RTP/SAVP 0 8 18 9 101
a=crypto:1 AES_CM_128_HMAC_SHA1_80 > inline:NzFlNTUwZDk2OGVlOTc3YzNkYTkwZWVkMTM1YWFj
a=crypto:2 AES_CM_128_HMAC_SHA1_32 > inline:NzkyM2FjNzQ2ZDgxYjg0MzQwMGVmMGUxMzdmNWFm
a=crypto:3 F8_128_HMAC_SHA1_80 inline:NDliMWIzZGE1ZTAwZjA5ZGFhNjQ5YmEANTMzYzA0
a=rtpmap:0 PCMU/8000
a=rtpmap:8 PCMA/8000
a=rtpmap:18 G729/8000
a=fmtp:18 annexb=no
a=rtpmap:9 G722/8000
a=fmtp:101 0-15
a=rtpmap:101 telephone-event/8000
a=ptime:20
a=sendrecv
The callee receives the INVITE message with the RTP encryption algorithm and then answers the call by respond-
ing with a 200 OK message which carries the negotiated RTP encryption algorithm.
Example of the RTP encryption algorithm carried in the SDP of the 200 OK message:
m=audio 11780 RTP/SAVP 0 101
a=rtpmap:0 PCMU/8000
a=rtpmap:101 telephone-event/8000
a=crypto:1 AES_CM_128_HMAC_SHA1_80 inline:NGY4OGViMDYzZjQzYTNiOTNkOWRiYzRlMjM0Yzcz
a=sendrecv
a=ptime:20
a=fmtp:101 0-15
When SRTP is enabled on both phones, RTP streams will be encrypted, and a lock icon appears on the LCD
screen of each IP phone after a successful negotiation.
Note : If you enable SRTP, then you should also enable TLS. This ensures the security of SRTP encryption. For more inform-
Transport Layer Security (TLS)
ation on TLS, refer to
streams in SDP offers by "account.X.srtp.unencrypted_rtp.enable"/"account.X.srtp.unencrypted_rtcp.enable".
Topic

SRTP Configuration

SRTP Configuration
The following table lists the parameters you can use to configure the SRTP.
Parameter account.X.srtp_encryption
RFC
. You can configure the IP phone to include unencrypted RTP/RTCP
[1]
<MAC>.cfg
3711, RTP/RTCP streams may be encrypted
Security Features
114