Yealink T21PE2 User Manual

Security Features
387
Default 0
Parameter
phone_setting.reserve_certs_config.enable
[3]
<y0000000000xx>.cfg
Description
It enables or disables the IP phone to reserve the trusted and server certificates settings after the phone
reset to factory defaults.
Permitted
Values
0-Disabled, “static.security.trust_certificates”, “static.security.ca_cert”, “static.security.cn_validation” and
“static.security.dev_cert” will be reset.
1-Enabled, “static.security.trust_certificates”, “static.security.ca_cert”, “static.security.cn_validation”, “stat-
ic.security.dev_cert” and “phone_setting.reserve_certs_config.enable” will not be reset.
Default 0
[1]
X is the account ID. For T54S/T48S/T48G/T46S/T46G/T29G, X=1-16; for T52S/T42G/T42S, X=1-12; for T41P/T41S/T27G,
X=1-6; for T40P/T40G/T23P/T23G, X=1-3; for T21(P) E2, X=1-2; for T19(P) E2/CP920, X=1.
[2]
Y is the server ID. Y=1-2.
[3]
If you change this parameter, the IP phone will reboot to make the change take effect.
Secure Real-Time Transport Protocol (SRTP)
Secure Real-Time Transport Protocol (SRTP) encrypts the audio streams during VoIP phone calls to avoid interception
and eavesdropping. The parties participating in the call must enable SRTP feature simultaneously. When this feature is
enabled on both phones, the type of encryption to use for the session is negotiated between the IP phones. This nego-
tiation process is compliant with RFC 4568.
When you place a call on the enabled SRTP phone, the IP phone sends an INVITE message with the RTP/RTCP encryp-
tion algorithm to the destination phone. As described in RFC 3711, RTP/RTCP streams may be encrypted 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

Yealink T21PE2 Specifications

General

Brand	Yealink
Model	T21PE2
Category	IP Phone
Language	English