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 is activated when the INVITE is sent to the outgoing trunk and if no 100 Trying is received within allocated time it will expire and roll over to the next Trunk or Trunk Group if available.
B-timer value can be between 1-10 and must always be smaller than PDD value. Default value for B-timer is empty which means it will not be considered unless integer value between 1 to 10 is set for it.
Example: PDD is set to 10 seconds; B Timer is set to 5 seconds