Avaya 1110 Fundamentals page 331

Operating parameters
The Media Security feature has the following operating parameters
• During a firmware upgrade, the Media security is automatically disabled.
• Media security does not support duplicate media streams encryption, such as IP Call
Recording.
• Pre-Shared key (PSK) SRTP media encryption negotiates after the call is setup. The first
few seconds of the call can sometimes be unsecured; after the lock icon displays the call
is secure. UNIStim key (USK) SRTP media encryption is negotiated before the call is
setup so no delays occur. In both versions of SRTP the call is secure when the lock
displays.
When USK SRTP negotiates, an outlined lock icon and Encrypted appears on the display.
When PSK SRTP negotiates, a solid lock icon displays but Encrypted does not display.
Important:
A maximum of 24 characters for a name in the Personal Directory, Callers List, or Redial
List can appear in the display area. If PSK SRTP is enabled and the name has the
maximum of 24 characters, the last character in the name truncates to display the
secure lock icon.
• SRTP PSK does not negotiate if you use 10ms G.729, due to the small payload size. The
call remains in RTP. All other payloads are supported for PSK SRTP. USK SRTP supports
all payloads.
Important:
The Avaya 1210 IP Deskphone, Avaya 1220 IP Deskphone, and Avaya 1230 IP Deskphone
do not support 10ms G.729.
Configuration
For Avaya Communication Server 1000 Release 5.0 or later, you can configure a system-wide
configuration setting (USK SRTP), which controls whether or not the CS 1000 system is
capable of providing Media Security.
It is possible to enable both PSK SRTP on the IP Phone and configure USK SRTP at the Call
Server. If USK SRTP does not negotiate for a call, PSK SRTP attempts to negotiate during a
call. If the two endpoints for the call have PSK SRTP enabled, the call is encrypted using PSK
SRTP.
By default, Media Security is enabled on the system. To configure USK SRTP, see
configuration
configuration
IP Deskphones Fundamentals
on page 332. To configure PSK SRTP on the IP Phone, see
on page 332.
Telephony features
USK SRTP
PSK SRTP
February 2013 331