3Com NBX 100 Administrator's Manual - page 259
System Settings
259
Silence Suppression Overview
Silence suppression is a method of reducing the number of packets
transmitted during a conversation. Silence suppression can help you avoid
dropped packets on a congested network. During a conversation there
are periods of silence. A packet of silence takes up as much bandwidth as
a packet with audio data. If you enable Silence Suppression, the phone
sends a 'silence indicator' when it senses the start of a silent period and it
suppresses all subsequent voiceless frames. When another NBX device
receives this indicator, it generates and inserts white noise until it receives
the next frame that contains audio data. If you enable Silence
3Com 3102 Business
Telephone
3C10402A
Yes
Yes
Yes
3Com 3103 Manager’s
Telephone
3C10403A
Yes
Yes
Yes
3Com 3100 Entry
Telephone
3C10399A
Yes
Yes
Yes
3Com 3106C and 3107C
Cordless Telephones
3C10406C
3C10407C
Yes
Yes
Yes
3Com 3101, and 3101SP
Basic Telephones
3C10401A
3C10401SPKRA
Yes
Yes
Yes
NBX Analog Terminal
Adapter
3C10120
3C10120B
No
Yes
Yes
3C10400
Yes
Yes
Yes
NBX Analog Terminal Card 3C10117
3C10117B-INT
No
Yes
Yes
3C10117C
Yes
Yes
Yes
NBX Analog Line Card
3C10114
3C10114-ANZ
No
Yes
Yes
3C10114C
Yes
Yes
Yes
NBX Digital Line Card
3C10116,
3C10116B
3C10116C
3C10164-ST (BRI)
3C10164C-ST (BRI)
3C10165
3C10165C
No
Yes
Yes
3C10116D
3C10165D
Yes
Yes
Yes
Table 35 Audio Encoding Supported by NBX Devices (continued)
Device
Part Number
G.729
ADPCM
G.711