Yealink VC Series Administrator's Guide

Configuring Security Features
141
2. Click Browse to locate the certificate (*.pem or *.cer) from your local system.
3. Click Upload to upload the certificate.
Secure Real-Time Transport Protocol (SRTP) encrypts RTP streams during calls to avoid
interception and eavesdropping. To use SRTP encryption for SIP calls, the participants in
the call must enable SRTP simultaneously. When this feature is enabled on both systems,
the encryption algorithm utilized for the session is negotiated between the systems. This
negotiation process is compliant with RFC 4568.
When a site places a call on the SRTP enabled system, the system sends an INVITE
message with the RTP encryption algorithm to the destination system.
The following is an 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

Yealink VC Series Specifications

General

Brand	Yealink
Model	VC Series
Category	Conference System
Language	English