What makes Voice-over-Internet (VoIP) potentially disruptive this time around, compared to all prior attempts, is really that there is now a standard allowing VoIP services to interoperate over the Internet directly, without ever hitting the traditional telephone network (PSTN). This standard is called SIP, Session Initiation Protocol. It’s not important to know technically what SIP is. It is only important to know that it enables the kind of interoperability and interconnectivity we have come to expect from the Internet.
In the past, VoIP services where characterized as PC-to-PC or PC-to-Phone. In those days, PC-to-PC meant users on VoIP service A could call other users on VoIP service A. If another user was on VoIP service B, there was no way for the two to talk, unless they both upgraded to a PC-to-Phone service, essentially using the PSTN as the interconnect. Today, using the SIP standard, users on VoIP provider A can communicate with users on VoIP provider B, directly over the Internet. The media has not yet grasped the significance of this and they still report about VoIP in the same old terms, still considering the traditional PSTN as the means to interconnect.
Because of standards, users on Internet service A can communicate via email with users on Internet service B. Likewise, now that interoperable standards exists for VoIP, users on VoIP provider A can place calls to users on VoIP provider B, if both provider A and B operate interoperable SIP-based VoIP services. This is as it should be. That’s how we expect the Internet to work. We don’t need the PSTN to communicate with each other if we are both using VoIP services. Would we sign up for an Internet service provider that only allowed us to exchange email with other users on the same service, or charged extra for sending such email? I don’t think so. And there will come a day when we will not use VoIP services that only let us call other users on the same service, or charge extra to call other users on other VoIP services.
But the media doesn’t get it yet. They should be telling us which services are based on SIP-standards, which ones support standard SIP hardware/software as opposed to requiring propriety hardware/software, which ones support inter-provider calling, which ones support future standards like ENUM, and, just as importantly, which ones are closed systems with no inter-provider connectivity like the services of days gone by.
Below is a list of free services that support SIP-standards:
- Free World Dialup (FWD) sip:email@example.com
- IPTEL.ORG sip:firstname.lastname@example.org
- SIPPhone sip:email@example.com
Using any of the above VoIP services, allows you to call anyone on the same service as well as people on any of the other VoIP services listed above, and even anyone on the Internet with a SIP address/number, which includes a rapidly growing number of corporations, universities, and smaller service providers not listed above.
Other so-called VoIP services, such as Skype and Voiceglo, DO NOT allow calling to anyone outside their service over the Internet. For example, a Skype or Voiceglo user cannot call a SIPPhone, IPTEL.ORG, or FWD user, but IPTEL.ORG, SIPPHONE, and FWD users can call everyone except a Skype or Voiceglo user. Skype and other non-standards-based services are essentially VoIP islands, excluded from the open SIP VoIP community.
When picking a VoIP provider, be sure to ask if they support the SIP standard, whether they use standard SIP hardware/software (soon to be available at your local Bestbuy), and whether they interoperate with other SIP-based VoIP providers. It may not matter to you that much right now, but it will matter a great deal in the not so distant future.