Running the client
Cisco TelePresence Movi Administrator Guide (4.1)
Page 23 of 29
Encryption
For a call to be encrypted, both the SIP and the media communication must be encrypted, and all parties
must support encryption. Encrypted media communication is sent using the Secure Real-time Transport
Protocol (SRTP) with a 128-bit Advanced Encryption Standard (AES).
The Encryption policy setting is provisioned0 to the client as configured in
Systems > Provisioning >
Directory
in Cisco TMS.
n
Force TLS/TCP
determines whether the SIP communication is encrypted (TLS) or not (TCP).
n
Force/No Srtp
determines whether the media communication is encrypted or not.
n
Auto
means the Movi client will try to have an encrypted call, but if not possible, it will allow the call to
be unencrypted.
If no provisioning is supplied, the
Transport
field in the
Advanced
settings determines the encryption
policy. The mapping is as follows:
n
Auto
is equivalent to the
Auto provisioning
option
n
TLS
is equivalent to the
ForceTlsAutoSrtp
provisioning option
n
TCP
is equivalent to the
ForceTcpNoSrtp
provisioning option
Note:
Users can tell whether their current call is encrypted by the icon in the information bar at the top of
the video window.
means the call is encrypted,
means it is unencrypted.
Sent and received bandwidth
During call setup Movi signals the maximum bandwidth it would like to receive according to the settings
in the client. It is up to the system on the other end of the call to respect this signaling.
Both the maximum bandwidth to be sent during call and the bandwidth sent at the start of the call are
determined at call setup.
During the call, Movi can change and send more or less bandwidth, but never more than the maximum
bandwidth decided during call setup.
Maximum bandwidth sent
To determine the maximum bandwidth to be sent, Movi chooses the lowest of these two values:
n
Max outgoing bandwidth, configured in the Movi client’s settings
n
Max incoming bandwidth restriction from the far end
Bandwidth sent at the start of the call
To determine the initial bandwidth for a new call, Movi uses its traffic data history, pulled from a database
of your last 250 calls. The calls are indexed by the network locations from which the calls were made.
Based on what Movi knows about the network and the far end SIP URI, a "safe" initial bandwidth is
chosen.
The database resides in the Windows user profile:
n
Windows XP: %userprofile%\Local Settings\Application Data\Cisco\Movi\2.0
n
Windows Vista and Windows 7: %userprofile%\AppData\Local\Cisco\Movi\2.0