Post Dial Delay (PDD) measures the amount of time that passes before a caller hears a ring tone or busy signal. PDD starts counting time as soon as the caller enters the last digit of a phone number (the SIP Invite is received) and ends when ring tone is heard (a SIP provisional response 18x or final response 200OK is received.)
The default time frame is 15 seconds for Max PDD when the value field is left empty.
B-Timer acts as an extension of PDD and is designed to work as a smaller subset timer to roll over to the next trunk if no response is received from the vendor. The B-timer is activated when the INVITE is sent to the outgoing trunk, and if no 100 Trying is received within the allocated time it will expire and roll over to the next Trunk or Trunk Group if available. B-timer values can be between 1-10 and must always be smaller than the PDD value. The default value entry field for B-timer is empty, which means it will not be considered unless an integer value between 1 to 10 is set for it.
The Ports field indicates the port limit for the trunk group.
CPS allows you to indicate the CPS limit for the trunk group. We suggest a 10 to 1 ratio.
Max Call Duration defaults to 14,400 seconds (4 hours) if left empty. Configure this in seconds to accommodate your needs.
PDD = (sum of all PDDs from CDRs) / (sum of all completions)
where PDD is the defined above.