Is the End of the TDM PSTN Coming?Is the End of the TDM PSTN Coming?

AT&T is again pressing the FCC to sunset the legacy public network. Enterprises need to be prepared for the possible consequences.

Is the end of the TDM based PSTN in sight?

On August 30, AT&T sent a letter outlining a request for the FCC to consider a clear sun setting of the TDM network. In the letter, AT&T clearly requests that the FCC essentially vacate any federal and state requirements to deliver TDM based telephony trunk services and related 911, as well as to relieve the inter-exchange carriers from providing TDM-based interconnections services. While there is not a specific date mentioned in the letter, the language used by AT&T in their filing makes it clear they believe the time is imminent: "...steps the Commission (FCC) should undertake without delay to begin the transition as well as additional steps that would facilitate completion of that transition (elimination of TDM)."

Here is a link to the AT&T letter and suggestions: http://apps.fcc.gov/ecfs/document/view?id=7022008762

A critical area that AT&T references is the relief from providing TDM services, including the termination of ETC (Eligible Telecom Carrier) designations that currently require carriers to provide certain services, along with removal of the requirements to provide bundled local services to other carriers. Also, the AT&T TDM sunset proposal suggests that carrier interconnection should be limited to VoIP (assumed this would be SIP based), and that TDM interconnects would be eliminated.

For enterprise IT and Telecom organizations, this looming transition could potentially eliminate TDM circuits and associated trunks, requiring movement to SIP Trunking. So now core sites and branches could not use local analog trunks but would need SIP connectivity.

While AT&T does not propose to ban TDM, it would remove its obligation to provide it, and even goes so far as to propose how an end user who does not migrate on their own would be forced to migrate. Also, with this new capability, the 911 services will need to change, and this is suggested as a requirement in the letter.

As users consider their Unified Communications options and how the next generation of technology will come into their systems, this potential elimination of the TDM PSTN is definitely something that should be considered. Understanding how to implement SIP trunking and SIP connectivity will be critical. Also, as your customers move to VoIP, clear consideration needs to be given to how Contact Centers will change.