User's Manual

Chapter 21 Voice 168
Primary
Compression
Type
Secondary
Compression
Type
Third
Compression
Type
Select the type of voice coder/decoder (codec) that you want the Router to use.
G.711 provides high voice quality but requires more bandwidth (64 kbps). G.711 is
the default codec used by phone companies and digital handsets.
• G.711a is typically used in Europe.
• G.711u is typically used in North America and Japan.
• G.711a_VBD is used in fax transmission. If both sides support the Voice Band
Data (VBD) codec defined in ITU-T Recommendation V.152, they automatically
use it instead of T.38.
G.722 is a 7 KHz wideband voice codec that operates at 48, 56 and 64 kbps. By
using a sample rate of 16 kHz, G.722 can provide higher fidelity and better audio
quality than narrowband codecs like G.711, in which the voice signal is sampled at
8 KHz.
G.726 operates at 24 or 32 kbps.
The Router must use the same codec as the peer. When two SIP devices start a SIP
session, they must agree on a codec.
Select the Router’s first choice for voice coder/decoder.
Select the Router’s second choice for voice coder/decoder. Select None if you only
want the Router to accept the first choice.
Select the Router’s third choice for voice coder/decoder. Select None if you only
want the Router to accept the first or second choice.
Speaking Volume
Control
Enter the loudness that the Router uses for speech that it sends to the peer
device.
Minimum is the quietest, and Maximum is the loudest.
Listening Volume
Control
Enter the loudness that the Router uses for speech that it receives from the peer
device.
Minimum is the quietest, and Maximum is the loudest.
Enable G.168
(Echo
Cancellation)
Select this if you want to eliminate the echo caused by the sound of your voice
reverberating in the telephone receiver while you talk.
Enable VAD
(Voice Active
Detector)
Select this if the Router should stop transmitting when you are not speaking. This
reduces the bandwidth the Router uses.
Call Features
Send Caller ID Select this if you want to send identification when you make VoIP phone calls.
Clear this if you do not want to send identification.
Enable Call
Transfer
Select this to enable call transfer on the Router. This allows you to transfer an
incoming call (that you have answered) to another phone.
Call Waiting
Reject Timer
Specify a time of seconds that the Router waits before rejecting the second call if
you do not answer it.
Table 97 SIP Account (continued)
LABEL DESCRIPTION