Anybody not involved in the telephone business will probably be surprised to find that the old TDM telephone networks are still very much alive and in place. The old technologies were supposed to be phased out and replaced by digital technologies. The FCC started talking about this before 2010. In 2013, Tom Wheeler, the FCC Chairman at the time, announced an effort to force the needed changes, which was dubbed the IP Transition. The goal of the transition was to upgrade and replace the public switched telephone network that was used by every telco, CLEC, and cable company for exchanging voice traffic.

The FCC made good on the promise and released an order in 2015 that described the process for telcos to retire copper networks, and that also discontinued the requirement that big telcos offer wholesale TDM services. In 2016 the FCC released that full IP Transition Plan that was aimed at replacing the TDM voice infrastructure with an all-IP network.

But somewhere along the line, AT&T and Verizon highjacked the IP Transition. AT&T announced a few trials to eliminate the TDM network, but then the transition process stopped and was never discussed again. Industry insiders speculated that all the big telcos really wanted from the IP Transition was the ability to retire copper telephone networks, and once they won that issue, they lost interest in the costly process of replacing or upgrading legacy systems. The FCC didn’t help when it poured billions of dollars into upgrading the old copper networks of the big telcos through the CAF II subsidy program.

The problem is that all of the problems that were identified with old TDM technology in 2013 are still around today. Any telephone company or CLEC that wants to exchange traffic with the big telephone companies must still do so using TDM technology (technology based on T1s). Telephone features like caller ID still rely on the SS7 network, which is a separate network used to exchange data associated with a telephone call.

Small carriers have been begging for years for the big telcos like AT&T, Verizon, and CenturyLink to allow digital SIP connections instead of TDM connections—but the big companies are deaf to these pleas. There are big parts of the national telephone networks that have been upgraded—for example, large cellular companies have digital SIP connections to the big telcos. It’s interesting how something that benefits AT&T and Verizon was upgraded, just not the connections used by everybody else.

It’s getting more costly every year for traditional carriers to keep using the TDM networks. The prices being charged for T1s have steadily climbed since the 2015 order that eliminated mandatory wholesale T1 prices. The cost of ancillary services needed to support voice, like the SS7 network, is climbing even faster. A handful of large companies that provide most of the SS7 services have squeezed smaller providers out of the market. The cost to access to the databases that include things like the name of calling parties needed for Caller ID has skyrocketed.

Meanwhile, smaller telcos have done everything suggested by the original IP Transition order. Most of them have replaced or are in the process of replacing copper networks with fiber. These companies have modernized everything except for the legacy connections, which are still the only option for completing local calls with neighboring carriers.

What is probably most amazing (or maybe not amazing at all) is how the FCC ordered the IP Transition and then just let the biggest telcos walk away from the process with no repercussions. This is partly due to the big telcos that just stopped working on the issue, but also on the Ajit Pai FCC that entered the picture in 2017 with the agenda of not regulating big companies. It’s time for the FCC to pick this back up and finally make this happen.

My consulting firm is still highly attuned to these issues. Anybody having a problem with TDM trunking, or access to SS7 or SS7 databases should contact me. I will be the first to tell you that I never expected to be still talking about these issues in 2024.