Configuring Security, Quality, and Network Features
Setting Security Features
Cisco SPA and Wireless IP Phone Administration Guide
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6
SRTP and Securing Calls
Secure Real-Time Transport Protocol (SRTP) is a secure protocol for transporting
real-time data over networks. SPA9X2 phones use SRTP to securely send and
receive real-time voice traffic from other phones and gateways. Security
Description (RFC 4568) is supported.
SRTP provides media encryption to ensure that media streams between devices
are secure and that only the intended devices receive and read the data.
When a call is secure, the voice conversation is encrypted so that others cannot
eavesdrop on the conversation. To enable this feature the SPA9X2 phone must
have a mini-certificate installed.
The supplementary service Secure All Calls (*16)—Defaults to prefer to use
encrypted media (voice codecs). Audio packets in both directions of outbound
calls are encrypted using SRTP.
To use Secure Call on an extension, you must configure
Mini Certificate
and
SRTP
Private Key
for that extension. These parameters appear on the
Ext
tabs.
Secure Call Service activates secure encryption of RTP streams between the two
endpoints. You can disable this if the other endpoint (or gateway) does not
support this proprietary method.
To enable the secure call service:
STEP 1
Log in to the web administration interface.
STEP 2
Click Admin Login and advanced.
STEP 3
Click the Phone tab.
STEP 4
In the Supplementary Services section, under Secure Call Serv, choose yes.
STEP 5
Click Submit All Changes.
NOTE
This feature can also be configured from the User tab, under Supplementary
Services.
Users can enter *18 to Secure Next Call—Uses encrypted media for the next
outbound call (on this call appearance only). This star code is redundant if all
outbound calls are secure by default.
