Verizon seeks gateway provider deadline extensions

Verizon petitioned the FCC for a limited waiver of deadlines related to the Gateway Provider Order. Their request highlights the effort required to complete an IP transition. Here’s an overview.

Gateway provider rule and deadlines

The Gateway Provider Order included the following requirements and deadlines:

Verizon requested a limited waiver of deadlines for implementing DNO (Do-Not-Originate) blocking and for implementing STIR/SHAKEN signatures to incoming gateway traffic with U.S. calling numbers that it will exchange with another provider as a SIP call. (These items are highlighted in the table above.) Verizon asked that both deadlines be extended to December 31, 2023, so they can complete IP transition work in their gateway network.

We aren’t calling out Verizon for requesting an extension, and we have no opinion on whether the Commission should grant the petition. We think the petition illuminates the difficulties that providers face with an IP transition.

Network changes planned

Verizon is already doing DNO blocking and STIR/SHAKEN authentication and verification in their domestic network. In their petition, Verizon explained that they:

• Block thousands of calls each month that use calling numbers that appear on the Industry Traceback Group’s DNO list.
• Sign more than seven billion calls per month as an originating carrier
• Verify more than seven billion calls per month on the terminating side using STIR/SHAKEN.

Verizon does not have these capabilities in its gateway network. Most of the traffic to Verizon’s international gateways arrives at 1990s-era non-IP switches that are incapable of being configured for either blocking or STIR/SHAKEN.

Verizon considered replacing these legacy switches with newer ones that can handle both DNO blocking and STIR/SHAKEN. They concluded that this would take several years and impose costs in the eight-figure range (i.e., tens of millions of dollars).

Instead of this “rip and replace” approach, Verizon chose a “workaround” strategy. They will evolve an existing STIR/SHAKEN-capable network that has been used only for domestic traffic so that it can accept traffic from abroad.

Even this workaround approach involves many steps:

• Resize the domestic network
• Configure the billing system to accept international traffic
• Work through order entry and IT challenges
• Coordinate test calls with foreign carriers and analyze the results
• Do lab tests with the VoIP platform vendor to confirm switch trunk configurations
• Troubleshoot delays due to issues with new firewall support systems
• Reroute foreign traffic arriving at the domestic network back to legacy switches to handle additional billing and IT requirements (these processes will be migrated later after these initial compliance steps are completed).

Verizon explained that they have begun this project by prioritizing customers with the largest amount of traffic. With this approach, they expect to migrate a substantial majority of traffic early on, although it will take time to migrate all customers.

Verizon’s international partners must make investments on their side to convert their traffic from TDM to IP, which takes time and money.

Comparing notes

We noticed some similar themes in Verizon’s petition with comments of Iowa Network Services, Inc. (d/b/a Aureon) in the Commission’s non-IP inquiry.

In their comments, Aureon explained that they have been working on replacing a legacy tandem switch in their network since 2015. Aureon procured and deployed a new IP-capable switch. The new switch began operating alongside the old switch in 2020. This timeline seems to corroborate Verizon’s estimate of the time required for a rip-and-replace approach. (Aureon did not have a workaround option available to them.)

As with Verizon, Aureon’s timeline is dependent on their interexchange partners. Those partners must convert their networks to IP. (Aureon is a Centralized Equal Access provider with small LECs serving subscribers on one side and interexchange carriers (IXCs) on the other.)

Aureon estimates that LEC IP transitions will take 24 months. However, Aureon has no control over IXC IP transitions, which could cause further delays. Aureon noted that their “conversion to IP will be for naught if IXCs are not also required to send their traffic to Aureon as SIP rather than TDM traffic.”

Verizon anticipates that its international exchange partners will complete their IP transitions in 12 months.

This is a recurring dilemma in the IP transition saga:

1. IP transition is a costly, complex, time-consuming process.
2. IP transition won’t produce the expected benefits if interexchange partners don’t agree to exchange traffic over IP.

What can a provider do if they transition to IP but some of their interexchange partners won’t exchange traffic with them over IP?

• Verizon wrote that they would jettison traffic that cannot be migrated to IP by the extended deadline they requested.
• Aureon can’t jettison traffic. They plan to continue to accept traffic over non-IP trunks and use Out-of-Band to transport call authentication information around non-IP barriers. This approach enables full STIR/SHAKEN coverage sooner while allowing time for the IP transition to complete later.

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