The Post PSTN Telco Cloud

I will be moderating a panel on this topic at ITExpo East 2012 in Miami at 3:00pm on Thursday, February 2nd.

The panelists are Brian Donaghy of Appcore, LLC, Jan Lindén of Google, Hugh Goldstein of Voxbone and Danielle Morrill of Twilio.

The pitch for the panel is:

The FCC has proposed a date of 2018 to sunset the Public Service Telephone Network (PSTN) and move the nation to an all IP network for voice services. This session will explore the emerging trends in the Telco Cloud with case studies. Learn how traditional telephone companies are adapting to compete, and new opportunities for service providers, including leveraging cloud computing and Infrastructure as a Service (IaaS) systems that are being deployed with scalable commodity hardware to deliver voice and video services including IVR, IVVR, conferencing plus Video on Demand and local CDNs.

In related news, a group of industry experts is collaborating on a plan for this transition. The draft can be found here. I volunteered as the editor for one of the chapters, so the current outline roughs out some of my opinions on this topic. This is a collaborative project, so please contact me if you can help to write it.

ITExpo West — The State of VoIP Peering

I will be moderating a session at ITExpo West on Monday 4th October at 2:15 pm: “The State of VoIP Peering,” will be held in room 304C.

Here’s the session description:

VoIP is a fact – it is here, and it is here to stay. That fact is undeniable. To date, the cost savings associated with VoIP have largely been enough to drive adoption. However, the true benefits of VoIP will only be realized through the continued growth of peering, which will keep calls on IP backbones rather than moving them onto the PSTN. Not only will increased peering continue to reduce costs, it will increase voice call quality – HD voice, for instance, can only be delivered on all-IP calls.

Of course, while there are benefits to peering, traditional carriers have traditionally not taken kindly to losing their PSTN traffic, for which they are able to bill by the minute. But, as the adoption of IP communications continues to increase – and of course the debate continues over when we will witness the true obsolescence of the PSTN – carriers will have little choice but to engage in peering relationships.

This session will offer an market update on the status of VoIP peering and its growth, as well as trends and technologies that will drive its growth going forward, including wideband audio and video calling.

The panelists are:

This is shaping up to be a fascinating session. Rico can tell us about the hardware technologies that are enabling IP end-to-end for phone calls, and Mark and Grant will give us a real-world assessment of the state of deployment, the motivations of the early adopters, and the likely fate of the PSTN.

HD Voice, Peering and ENUM

The most convenient route between telephone service providers is through the PSTN, since you can’t offer phone service without connecting to it. Because of this convenience telephone service providers tend to consider PSTN connectivity adequate, and don’t take the additional step of delivering IP connectivity. This is unfortunate because it inhibits the spread of high quality wideband (HD Voice) phone calls. For HD voice to happen, the two endpoints must be connected by an all-IP path, without the media stream crossing into the PSTN.

For example, OnSIP is my voice service provider. Any calls I make to another OnSIP subscriber complete in HD Voice (G.722 codec), because I have provisioned my phones to prefer this codec. Calls I make to phone numbers (E.164 numbers) that don’t belong to OnSIP complete in narrowband (G.711 codec), because OnSIP has to route them over the PSTN. If OnSIP was able to use an IP address for these calls instead of an E.164 number, it could avoid the PSTN and keep the call in G.722.

Xconnect has just announced an HD Voice Peering initiative, where multiple voice service providers share their numbers in a common directory called an ENUM directory. When a subscriber places a call, the service provider looks up the destination number in the ENUM directory; if is there, it returns a SIP address (URI) to substitute for the phone number, and the call can complete without going over the PSTN. About half the participants in the Xconnect trial go a step further than ENUM pooling: they interconnect (“peer”) their networks directly through an Xconnect router, so the traffic doesn’t need to traverse the public Internet. [See correction in comments below]

There are other voice peering services that support this kind of HD connection, notably the VPF (Voice Peering Fabric). The VPF has an ENUM directory, but as the name suggests, it does not offer ENUM-only service; all the member companies interconnect their networks on a VPF router.

Some experts maintain that for business-grade call quality, it is essential to peer networks rather than route over the public Internet. Packets that traverse the public Internet are prone to delay and loss, while properly peered networks deliver packets quickly and reliably. In my experience, this has not been an issue. My access to OnSIP and to Vonage is over the public Internet, and I have never had any quality issues with either provider. From this I am inclined to conclude that explicit peering of voice networks is overkill, and that if you have a VoIP connection all that is needed for HD voice communication is to list your phone number in an ENUM directory. Presumably the voice service providers in Xconnect’s trial that are not peering share this opinion.

Xconnect’s ENUM directory is enormous, partly because it is pooled with Pathfinder – the GSMA ENUM directory administered by Neustar. Xconnect’s ENUM directory had over 120 million numbers in it as of 2007.

Xconnect and the VPN only add to their ENUM directories the numbers owned by their members. But even if you are not a customer of one of their members, you can still list your number in an ENUM directory, This way, anybody who checks for your number in the directory can route the call over the Internet. Calls made this way don’t need to use SIP trunks, and they can complete in HD voice.

If you happen to have an Asterisk PBX, you can easily provision it to check in a list of ENUM directories before it places a call.