Yes, The PSTN Is Still the Core

Since AT&T filed a “comment” to the FCC at the end of 2009, calling for a definite timeline to “sunset” the PSTN, there’s been much discussion over the future of the old legacy Ma Bell network. Over at Squawkbox, Alec Saunders posted that mostly people are asking the wrong question; the real issue is not “whether VoIP will finally triumph over the PSTN,” Saunders maintained.

“That’s kind of a loopy question, as the core networks are already VoIP and have been for a long time. The ‘PSTN’ is really the user interface by which the customer accesses the network.”

That’s an interesting perspective because most people, or at least I, think of the typical VoIP user as someone who uses Skype or a provider like Alteva or SimpleSignal to access the voice network, but whose calls outside their network must at some point traverse the PSTN, leading to the inevitable degradation and latency that dog legacy networks. As evidence, in a subsequent post, he cited two recent developments: XConnect’s announcement that their IP traffic nearly doubled in 2009 and that they added 64 new interconnect customers, while doubling their revenue; and a Telegeography study showing that Skype carried 54 billion international voice minutes, nearly 12 percent of global voice traffic.

Those are certainly epochal signposts, and Alec’s assertion is as usual keen and provocative, but I don’t buy it. In fact, I’d argue that those two factoids actually argue the reverse: people are flocking to interconnection providers like XConnect, and over-the-top providers like Skype, because they can’t get what they want at a comparable price from traditional operators, because most of the traditional operators’ traffic still travels over the bad old PSTN.

Why else would we be seeing a groundswell of interest in IP peering and interconnection, as I reported earlier this week? For that matter, why else would AT&T Inc. (T) be petitioning the federal government for relief from the burden of maintaining a dying business over the PSTN?

“Congress’s goal of universal access to broadband will not be met in a timely or efficient manner if providers are forced to continue to invest in and to maintain two networks,” AT&T pointed out. If, as Saunders claimed, “The PSTN is simply the average person’s experience of an all-VoIP network,” the major carriers wouldn’t need the FCC’s help; they’d just continue their rollout of U-Verse, FIoS, and other fiber-to-the-home initiatives. And Mzima Networks, acquired last month by Packet Exchange, wouldn’t be creating a sizable business based on what CTO Grant Kirkwood calls “doughnut peering” – multi-hop connections via VoIP providers that, you guessed, it, bypass the core PSTN.