Post Dial Delay (PDD)
Post Dial Delay (PDD) is the time or delay that occurs from the time a number has been dialed until the caller or called party hears ringing.
Post dial delay is more common on wholesale termination (LCR) products, which provide aggressive rating as a product of having multiple carriers to attempt to complete the call. This occurs because each carrier can take a few seconds to acknowledge their ability to complete the call. Most carriers within the telecommunications industry consider anything under 7 seconds as an acceptable amount of PDD, and most will not troubleshoot PDD that is less than 7 seconds.