Nobody likes delays, especially when they have a problem that requires urgent assistance. So what happens when a customer attempts to ring your organization, and they are impacted by post dial delay (PDD)?
This PDD could mean that they don’t hear a ring tone until ten or twenty seconds after dialing? At the very least, PDD can cause confusion for the listener, particularly when silence is all that can be heard at the other end of the phone.
Post dial delay (PDD) is the time that elapses from when a phone number has been dialed until the caller or called party hears ringing.
Key facts about post dial delay
- Definition: The time from when a number is dialed until the caller hears ringing
- Acceptable threshold: Under 7 seconds per ITU industry standards
- Common causes: Carrier acknowledgment time, network hops, intermediary routing delays
- Customer impact: Confusion, frustration, and potential call abandonment when delays exceed acceptable thresholds
What is post dial delay?
The standard definition of PDD is:
“The time or delay that occurs from the time when a number has been dialed, until the caller or called party hears ringing.”
Bandwidth, a leading US carrier who offers communication application programming interfaces (APIs) which allow organizations to embed voice calling and messaging capability into their applications, describes that “PDD occurs because each carrier can take a few seconds to acknowledge their ability to complete the call.”
Most carriers in the telecommunications industry consider a PDD under seven seconds to be acceptable. As such, they generally don’t troubleshoot anything below this threshold. However, while seven seconds may not appear lengthy on paper, for someone requiring an immediate response, it will be. Imagine trying to make an urgent call to an emergency helpline and being faced with this delay; each second would feel like an eternity.
What causes post dial delay?
Several technical factors contribute to PDD:
- Carrier acknowledgment time: Each carrier in the call path takes time to confirm their ability to complete the call.
- Network hops: Calls routed through multiple networks experience cumulative delays.
- Intermediary routing: Third-party carriers and routing decisions add processing time.
- Signal processing: Time required for networks to establish and verify connections.
PDD vs. latency: understanding the difference
While both metrics relate to call quality, PDD and latency measure different aspects of the calling experience. PDD specifically measures the time from dialing until hearing a ring tone, which is the pre-connection delay. Latency, on the other hand, measures the delay in voice transmission during an active call. High PDD affects whether customers wait for or abandon a call attempt, while latency impacts conversation quality once connected.
The challenge
In contrast to a typical call scenario where a phone may ring before being answered, many of our customers’ numbers are set to answer immediately. Upon answering, an IVR welcome message automatically greets the caller, aiming to minimize wait times and provide a smoother customer experience.
Consequently, PDD, by its definition, doesn’t align with the requirements of these customers. For this reason, Cyara uses a specialized approach to calculating PDD which aligns better with the specific needs of our customers.
How does Cyara measure post dial delay?
Cyara’s tests replicate the exact flow of your customer’s calling experience. We place a number of test calls which are configured to automatically answer. This means, in a typical test call flow, ringing won’t be heard. Let’s take a look at a typical Cyara call test flow:
- Cyara initiates the call.
- The provider (or multiple providers, if applicable) establishes the connection.
- The call reaches the called party and the caller hears ringing.
- The called party answers (picks up) the call. As noted above, these calls are generally automatically answered by our customers’ systems.
- The call then ends.
- The test results are presented back to the customers for problem identification, resolution and benchmarking purposes.
In summary, the Cyara PDD test serves as a ‘call answer time’ metric, which better includes any delays introduced by your intermediary networks and carriers. It also allows for the identification of delays that go beyond those identifiable by the industry-standard PDD calculation.
Benefits of Cyara’s PDD testing
Cyara’s PDD testing solution provides comprehensive monitoring and measurement capabilities that help organizations maintain optimal call connection performance:
- Identifies connectivity issues associated with high post dial delay.
- Provides a reliable, robust, and comparable benchmark for call answer times.
- Enables identification and reporting of potential issues before they affect your customers, safeguarding your brand reputation and customer loyalty.
- Accurately measures the delay between dialing the number and the call answering.
- Presents essential data for identifying necessary changes to reduce your organization’s PDD, thereby enhancing the customer experience.
- Reduces your troubleshooting time by enabling more proactive carrier management and ensuring their adherence to their service-level agreements (SLAs).
Frequently Asked Questions
Most carriers consider a PDD under 7 seconds to be acceptable per ITU industry standards. Delays exceeding this threshold typically warrant troubleshooting and investigation.
PDD is measured as the elapsed time from when a phone number is dialed until the caller hears a ring tone or the call is answered. Cyara measures this as ‘call answer time’ to account for auto-answer systems.
When PDD exceeds acceptable thresholds (10-20 seconds or more), callers experience confusion and frustration due to prolonged silence. This can lead to call abandonment, negative customer experiences, and potential damage to brand reputation.
Post dial delay is the time that occurs from when a number has been dialed until the caller or called party hears ringing. Even a delay of seven seconds, which most carriers consider acceptable, can feel significant to someone needing urgent assistance.
PDD occurs because each carrier in the call path takes time to acknowledge their ability to complete the call. The more intermediary networks involved, the greater the potential for delay.
Most carriers in the telecommunications industry consider a PDD under seven seconds to be acceptable and generally will not troubleshoot issues below this threshold.
Many organizations use systems that answer calls immediately with an IVR welcome message rather than allowing the phone to ring. In these cases, the standard definition of PDD does not align with their actual call experience or requirements.
Cyara places test calls configured to automatically answer, treating PDD as a “call answer time” metric. This approach captures delays introduced by intermediary networks and carriers that standard PDD calculations may miss.
Cyara’s PDD testing identifies connectivity issues, benchmarks call answer times, and surfaces potential problems before they affect customers. It also helps reduce troubleshooting time through proactive carrier management and SLA adherence monitoring.
Yes, even brief delays can cause confusion for callers, particularly when silence is all that is heard after dialing. For customers contacting urgent helplines, each additional second of delay can feel significant.
