Preferred
Codec
The IPPH 202 supports up to 7 different Codec types including G.711 G.723.1, G.726, G.728,
G.729A/B, iLBC. Users can configure Codecs in a preference list that will be included with the same
preference order in SDP message. The first Codec in this list can be entered by choosing the
appropriate option in “Choice 1”. Similarly, the last Codec in this list can be entered by choosing the
appropriate option in “Choice 7”.
G723 Rate:
This defines the encoding rate for G723 codec. By default, 6.3kbps rate is chosen.
iLBC Frame
Size:
This defines the size of the iLBC codec frame. The default setting is
20ms.
iLBC Payload
Type:
This defines payload time for iLBC. Default value is 97.
Voice Frames
per TX
This field contains the number of voice frames to be transmitted in a single packet. When setting this
value, the user should be aware of the requested packet time (used in SDP message) as a result of
configuring this parameter. This parameter is associated with the first codec in the above codec
Preference List or the actual used payload type negotiated between the 2 conversation parties at run
time. For example, if the first codec is configured as G723 and the “Voice Frames per TX” is set to be
2, then the “ptime” value in the SDP message of an INVITE request will be 60ms because each G723
voice frame contains 30ms of audio. Similarly, if this field is set to be 2 and if the first codec chosen
is G729 or G711 or G726, then the “ptime” value in the SDP message of an INVITE request will be
20ms. If the configured voice frames per TX exceeds the maximum allowed value, the IPPH 202 will
use and save the maximum allowed value for the corresponding first codec choice. The maximum
value for PCM is 10(x10ms) frames; for G726, it is 20 (x10ms) frames; for G723, it is 32 (x30ms)
frames; for G729/G728, 64 (x10ms) and 64 (x2.5ms) frames, respectively.
Layer 3 QoS
This field defines the layer 3 QoS parameter, which can be the value used for IP Precedence or Diff-
Serv or MPLS. Default value is 48.
Layer 2 QoS
This contains the value used for layer 2 VLAN tag. Default setting is 0.
Silence
Suppression
This controls the silence suppression/VAD feature of G723 and G729. If set to “Yes”, when a silence
is detected, small quantity of VAD packets (instead of audio packets) will be sent during the period of
no talking to make the connection feel more "natural". If set to “No”, this feature is disabled.
Phone Features Settings:
Phone Features Settings
