3Com NBX 100 Administrator's Manual - page 40
40
C
HAPTER
2: S
YSTEM
S
ETTINGS
When the system negotiates which codec to choose, the process starts
from the top of the list and queries devices to discover if they support the
codec. If the device is supported, the system chooses the codec;
otherwise, the system goes on to the next codec in the list and initiates
the query process.
Codecs and NBX
Devices
Codecs reside on the NBX devices — telephones, analog terminal
adapters, and so forth. Some older devices do not support the latest
codecs. Therefore, during call setup, NBX devices negotiate an encoding
scheme that both devices (or all devices on a conference call) support.
Table 11
lists each device that must encode or decode audio, and shows
how each device supports the available codecs. Certain devices are
marked “N/A” for the G.722 codecs because those codecs are for
wideband audio, which is not supported by wide area networks or across
the PSTN.
Table 11 Audio Encoding Supported by NBX Devices
Device
Part Number
G.729
ADPCM G.711
G.722
G.722.2 G.722.2LB
3Com 1102, 2102, and 2102-IR
Business Telephones
3C10121 3C10122
3C10226A
3C10228IRA
No
Yes
Yes
No
No
No
3C10226PE
3C10226B
3C10228IRPE
3C10228IRB
3C10281PE
3C10281B
Yes
Yes
Yes
No
No
No
3Com 2101 Basic Telephones
3C10248PE
3C10248B
Yes
Yes
Yes
No
No
No
3Com 3100 Entry Telephone
3C10399A
Yes
Yes
Yes
No
No
No
3Com 3101, and 3101SP Basic
Telephones
3C10401A
3C10401SPKRA
Yes
Yes
Yes
No
No
No
3Com 3101B Basic Telephone
3C10401B
Yes
Yes
Yes
Yes
Yes
Yes
3Com 3101SPB Basic Telephone
3C10401SPKRB
Yes
Yes
Yes
Yes
Yes
Yes
3Com 3102 Business Telephone
3C10402A
Yes
Yes
Yes
No
No
No
3Com 3102B Business Telephone 3C10402B
Yes
Yes
Yes
Yes
Yes
Yes
3Com 3103 Manager’s
Telephone
3C10403A
Yes
Yes
Yes
Yes
Yes
Yes
3Com 3106C and 3107C
Cordless Telephones
3C10406C
3C10407C
Yes
Yes
Yes
No
No
No