Chapter 10 The VoIP Account Screens
WiMAX Device Configuration User’s Guide
164
1st Codec, 2nd
Codec, 3rd
Codec
Select the WiMAX Device’s first, second, and third choices of the type of voice
coder/decoder (codec) that you want the phone line to use when
communicating with the SIP server. The following codecs (shown in highest
quality to lowest quality order) are supported by the WiMAX Device:
• G.711 aLaw (typically used in Europe)
• G.711 muLaw (typically used in North America and Japan)
• G.729
You can also select NONE for the 2nd and 3rd codecs if your VoIP service
provider only gave you one or two codec settings.
When two SIP devices start a SIP session, they must agree on a codec.
Session Timer
Min Session
Timer
Enter the minimum session expiry time in seconds. The allowable range is
90~65535 seconds.
When an incoming call requests a session expiry time that is lower than this
value, the WiMAX Device will respond with a "423 session timer too small"
message and tell the peer to use this value as the minimum bound.
Session Timer
Enter the session expiry time in seconds for all phone connections on this
trunk. The allowable range is 120~65535 seconds. This value cannot be lower
than the Min Session Timer.
The WiMAX Device will use INVITE or UPDATE method to keep alive a session
every half of the session expiry time during a call.
If the keep-alive action is successful, the WiMAX Device will re-start the timer
and do another keep-alive action after it reaches half of the session expiry
time.
If the keep-alive action failed, the call will terminate automatically.
See Section 9.4 on page 155 to configure the Refresh Method with the INVITE
or UPDATE method.
Table 72 SIP (continued)
LABEL DESCRIPTION
