Chapter1 An Overview of the Cisco Unified IP Phone
Understanding Security Features for CiscoUnified IP Phones
1-16
Cisco Unified IP Phone 7906G and 7911G Administration Guide for Cisco Unified CallManager
OL-10008-01
In an authenticated call, all devices participating in the establishment of the call
are authenticated by the Cisco Unified CallManager. When a call in progress is
authenticated end-to-end, 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 CiscoUnified CallManager. 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:
Note If the call is routed through a non-IP call leg, for example, PSTN, the call will be
nonsecure even though it is encrypted within the IP network and has a lock icon
associated with it.
Related Topic
•Understanding Security Features for CiscoUnified IP Phones, page 1-10
•Security Restrictions, page 1-16
Security Restrictions
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 barge initiator's phone.
If the initiator phone is configured for encryption, the barge initiator can barge
into an authenticated or nonsecure call from the encrypted phone. After the barge
occurs, Cisco Unified CallManager classifies the call as nonsecure.
If the initiator phone is configured for encryption, the barge initiator can barge
into an encrypted call, and the phone indicates that the call is encrypted.