Chapter 10 The VoIP Account Screens

Table 72 SIP (continued)

LABEL

DESCRIPTION

1st Codec, 2nd

Select the WiMAX Device’s first, second, and third choices of the type of voice

Codec, 3rd

coder/decoder (codec) that you want the phone line to use when

Codec

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

Enter the minimum session expiry time in seconds. The allowable range is

Timer

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.

 

 

164

 

WiMAX Device Configuration User’s Guide