Local Number Portability (LNP) was mandated by Congress in the 1996 Telecommunications Act, and even though we’ve had 24 years to get used to the idea, LNP still creates many interesting challenges for those building switch translations. The idea of Nationwide Number Portability (NNP) has been around almost as long, but is gathering momentum, and threatens to provide a whole host of new challenges for service providers.
What is Nationwide Number Portability?
Whereas LNP allowed a subscriber to move their phone service from one service provider to another within the same LATA and keep the same phone number, Nationwide Number Portability would allow a subscriber to keep the same phone number even if they move across the country.
Consumers have become used to doing this with their cell phones. For cell phones every number works nationwide provided your carrier provides service (or has a roaming partner) in your location. But this is a new idea for wireline service.
How is that possible?
If you have any understanding of how the PSTN works, you’ll recognize that while NNP sounds good for consumers, it raises a lot of practical issues. To name just a few:
- How does the originating service provider know where to route the call?
- How is the call routed to the terminating service provider?
- Does my switch support this?
- Who is paying for a seemingly local call which ends up being long-distance?
I’ll address these questions and more in later articles, but for now suffice to say that those investigating this idea are aware of the issues and they’re trying to figure it all out.

Why should I care about this now?
Good question. The idea of Nationwide Number Portability has been floating around for a while, but one of our clients (thanks David) recently pointed out that there’s been more activity of late, and there are some important dates coming up.
- On May 13, 2019 the North American Numbering Council (NANC) released a report from their Nationwide Number Portability Issues Working Group to help “investigate the technical requirements necessary to support NNP and provide more detailed cost/benefit analyses of proposed solutions”. This report presented a couple of different options for how to implement NNP and was submitted to the FCC.
- On December 16, 2019 the FCC released a letter in response to that report asking for more detailed analysis of IPLRNs (IP-based LRNs which use SIP URIs to locate the host service provider).
- The NANC working group is working on this more detailed analysis, and the deadline for that response is June 28, 2020.
It therefore seems likely that in the second half of this year we’ll start seeing more activity on NNP once we have a concrete proposal in front of the FCC, which will likely result in requests for further input from the industry.
Now I’m not saying that anything concrete is going to happen this year – most likely not for several years – but I do believe that NNP will become a more prominent issue, and as an industry we’ll need to be educated on it so that we can engage with the FCC as they seek industry input.
I’ll do my best to educate you through these articles, but if there’s a particular topic or aspect of NNP that interests you please let me know.