Configuring Security Features
949
2.
Click
Browse
to select the certificate (*.pem and *.cer) from your local system.
3.
Click
Upload
to upload the certificate.
Secure Real-Time Transport Protocol (SRTP)
Secure Real-Time Transport Protocol (SRTP) encrypts the RTP 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 utilize
for the session is negotiated between the IP phones. This negotiation process is compliant with
When a user places a call on the enabled SRTP phone, the IP phone sends an INVITE message
with the RTP encryption algorithm to the destination phone. As described in
, RTP
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
The callee receives the INVITE message with the RTP encryption algorithm, and then answers
the call by responding with a 200 OK message which carries the negotiated RTP encryption
algorithm.
Summary of Contents for CP860 SERIES
Page 1: ...63 ...
Page 51: ...Getting Started 25 For SIP T46G S Desk Mount Method Wall Mount Method Optional ...
Page 53: ...Getting Started 27 For SIP T42S T41S Desk Mount Method Wall Mount Method Optional ...
Page 55: ...Getting Started 29 For SIP T23P T23G Desk Mount Method Wall Mount Method Optional ...
Page 70: ...Administrator s Guide for SIP T2 Series T19 P E2 T4 Series T5 Series CP860 CP920 IP Phones 44 ...