Why Traditional Network CNAM Does Not Work Anymore
Why does traditional network CNAM not work anymore? One of the questions we often get is how the Phone APIs provided by Trestle differ from traditional network CNAM (Caller ID Name), the industry standard 15-character name data provided by subscribers to phone carriers and aggregated by a few providers. Before we begin, let us cover all the parties involved and their definitions in the CNAM ecosystem.
- Subscriber: The consumer buying the carrier service and whose name is displayed as the caller’s name when they call someone.
- Carrier: The carrier providing the phone/messaging services to the subscriber.
- CNAM Data Repositories: The 12 or so CNAM repositories in the U.S. that host the CNAM data from the participating carriers and who are the original sources of CNAM data providing it to terminating carriers and businesses.
- Number Portability Administration Center (NPAC): Number portability administration center, which can determine if the number has been ported and which carrier currently ‘owns’ the number.
- Calling Name Access Routing Guide (CNARG): The Caller Name Routing Guide determines the CNAM repository housing the CNAM data for a non-ported phone number.
- CNAM Providers: CNAM data resellers who query the CNAM data repositories to get the CNAM data.
- Terminating Carrier: A telecommunications carrier upon whose network telecommunications traffic terminates.
- Business: Enterprises looking for CNAM data for business purposes.
Over the years, this ecosystem has neglected CNAM, resulting in a substandard product that businesses can no longer rely on. Let’s look at the data flow through this ecosystem to understand the reasons.
As shown in the diagram above, it starts with a subscriber providing the 15-character CNAM name that should appear on the caller ID when they make a call. The carriers then pass this to CNAM data repositories. These repositories exist so carriers do not have to do all the work to host the data on their side or provide their subscriber data to every business or consumer for caller ID purposes in real-time. This way, the carrier can outsource the work to the data repositories, from hosting the data to serving the CNAM queries for the numbers they own. In the U.S., there are about a dozen repositories used by the majority of the carriers for the hosting and aggregation of this data. This CNAM data is then passed on to other ‘CNAM Providers’ who essentially query these repositories and provide the data to large businesses.
When a terminating carrier or a business queries for CNAM, the process involves several steps. First, the query is directed to the Number Portability Administration Center (NPAC) to determine if the number is ported and which CNAM repository holds the data for this number. If the number is not ported, the query is then sent to CNARG to identify the CNAM repository that houses the data for the specific carrier. NPAC/CNARG is also responsible for ensuring that the data is only available for legitimate use cases and is granted to select carriers and businesses. While businesses can navigate this process, they typically opt to directly query a CNAM provider to obtain the associated name for the phone number.
Now, anyone using the CNAM data knows that the typical coverage for actual non-junk (i.e., real/valid) data is around 50%, with an accuracy of around 80% for the name provided. Non-junk means the returned data is not ‘Wireless Caller’ or ‘Seattle WA,’ etc. Why is there such low coverage and accuracy from these ‘authoritative’ sources? There are a few reasons for this.
First and foremost, it is entirely up to the subscriber if they want their name to be published within the CNAM directory. Also, barring a few restrictions from the carriers, the subscriber can put in anything they want as their CNAM name. Next, over the years, these carrier data repositories have had lax rules in refreshing this name data, including not purging old names when carriers stop providing them updates. The result is that this old data continues to be in place for a phone number, resulting in inaccuracies. Further, due to the NPAC/CNARG use case restrictions, these data repositories and the CNAM data providers ‘co-mingle’ the carrier data with other non-authoritative data sources so that they can sell it to a larger customer base. In addition, they also use caching at times to save on costs. As you can imagine, all these things add up, compounding the inaccuracies.
Similarly, many of these entities have been focusing on other areas like Branded Caller ID, where businesses pay carriers to display their names to consumers when they call. This diversion of resources from the existing CNAM ecosystem to Branded Caller ID is significant, given the bigger potential revenue opportunity. This shift in focus directly impacts the resources available to maintain the accuracy and coverage of CNAM data.
Finally, the subscribers who are getting the CNAM caller ID on their phones might not pay for the service as the carrier typically charges an additional fee. This additional fee acts as a barrier to adoption, further widening the alignment gap among everyone to keep this data up-to-date.
All of these inefficiencies across the ecosystem result in the 50% coverage and 80% accuracy we mentioned above. So, what should businesses who are looking for ‘authoritative’ name data really do?
- Outbound dialers struggling with inaccurate CNAM data: Businesses looking to get their names updated within appropriate CNAM repositories so that their names are accurately displayed when they dial their customers have no choice but to work with their phone carrier and their hosting data repositories to get it updated appropriately. As mentioned above, if they are getting the data from specific CNAM data providers, it might be worth working with them to publish the updates, as they are easier to access and work with. As you can see, all of this is not as straightforward given the multiple parties involved and for the data to be propagated across the entire ecosystem quickly, and some of the entry-level VoIP providers do not even offer the ability to make CNAM updates. Still, there really is no other choice.
- Businesses handling inbound calls: Terminating phone carriers looking for CNAM caller ID data that they can provide to their customers should, of course, use their own subscriber data and combine that with other identity data sources, such as Trestle’s Smart CNAM API, to maximize coverage and accuracy.
- Phone Verification: Businesses looking at CNAM data for verification purposes, such as right-party contact verification or fraud prevention, should rely on data providers like Trestle’s Reverse Phone API, which assimilates the data from various authoritative and public sources to maximize coverage and accuracy. From the tests we have done, our coverage and accuracy of above 90+% provide the best identity verification solution for these use cases.
Do you have any questions? Is there anything we missed in this flow? If you would like to work with us to test one of our Phone APIs, please contact us at support@trestleiq.com. We would love to chat.
