CounterPath Bria Professional 2.5 Configuration Guide - Manual (Page 16)

CounterPath Corporation
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2.7 DTMF
This group of settings configures Bria Professional to handle DTMF.
DTMF will be sent using either:
• Out-of-band, using 2833 DTMF packets
• Out-of-band, using INFO DTMF.
• In-band, by encoding the DTMF signal in the audio stream.
The preferred method is out-of-band. In-band is used only to deal with specific network situations, as described
in the reference section for these settings.
You must configure Bria Professional to use either in-band or out-of-band. If you configure it to use out-of-
band, it will use 2833 packets if 2833 is available. Otherwise, it will use the fallback you configured:
• INFO, or
• in-band.
2.8 Encryption (Call Security)
About Encryption
Bria Professional can be configured to support specific combinations of signaling and media encryption
(security) for phone calls.
• Signaling encryption is only possible using TLS as the transport; UDP and TCP do not support signaling
encryption.
• Media encryption, which is performed using SRTP, can only be supported if signaling encryption is in
place, in other words, if TLS is used for the transport.
Setting up for Security outside of Bria Professional
When using TLS, the user must have the root certificate that signs the proxy’s chain of certificates. In most
cases, the root certification will already be installed. Procedures for exchange of certificates are outside the
scope of this documentation. The certificates must be stored on the Bria Professional computer, in the root
certificate store.
Setting up the root certificate on the Bria Professional user’s computer ensures that the connection to the proxy
is TLS secure (the first hop). Any proxy in the chain (between the user and the other party) that does not support
TLS may cause an insecure link in the chain. Therefore, if the other party is outside your domain, you cannot be
completely sure that the call is secured at the signaling level, which means that you cannot be sure that it is
secured at the media level.
When a call with both signaling and media encryption is established, Bria Professional displays the encryption
icon. This icon indicates that the call is secure between each caller and their proxy (the first and last hops); the
call may or may not be secure for other hops.