Cisco Systems 7940G Manual De Usuario

When security is implemented for a phone, you can identify authenticated or encrypted phone calls by 
icons on the screen on the phone.

In an authenticated call, all devices participating in the establishment of the call are authenticated by the 
Cisco Unified Communications Manager. When a call in progress is authenticated, the call progress icon 
to the right of the call duration timer in the phone LCD screen changes to the following icon:

In an encrypted call, all devices participating in the establishment of the call are authenticated by the 
Cisco Unified Communications Manager. In addition, call signaling and media streams are encrypted. 
An encrypted call offers the highest level of security, providing integrity and privacy to the call. When 
a call in progress is being encrypted, the call progress icon to the right of the call duration timer in the 
phone LCD screen changes to the following icon:

If the call is routed through non-IP call legs, for example, PSTN, the call may be nonsecure even though 
it is encrypted within the IP network and has a lock icon associated with it.

The following restrictions apply to encrypted calls:

When establishing an encrypted call on a phone that is configured for encryption and associated with 
a wideband codec region, Cisco Unified Communications Manager ignores the wideband codec and 
chooses another supported codec from the codec list that the phone presents. If the other devices in 
the call are not configured for encryption, Cisco Unified Communications Manager may establish 
the authenticated/nonsecure call by using the wideband codec.

A user cannot barge into an encrypted call if the phone that is used to barge is not configured for 
encryption. When barge fails in this case, a reorder tone (fast busy tone) plays on the phone on which 
the user initiated the barge.