B Timer
An extension of PDD, B-Timer moves a call to the next trunk or trunk group if no response is received from the vendor. The portal activates B-Timer when the INVITE sent to the outgoing trunk does not receive a 100 Trying within the allocated time. If the allocated time exceeds the portal limit, the call rolls over to the next Trunk or Trunk Group if available.
The B-Timer value should be:
between 1-10 and
smaller than the PDD value.
The default setting is an empty field. That means B-Timer is not considered unless the field contains an integer value between 1 to 10.
Example
Set PDD to 10 seconds and B Timer to 3 seconds.