VoIP suffers identity crisis

No fall-back

You don't have anyone you can call if Skype doesn't work, apart from the handful of guys that work at Skype. With an enterprise VoIP set-up you can have someone look at your routers, do an examination of your network, check for incompatibilities between your SIP (session initiation protocol) clients, and your firewall or NAT server.

Your Softswitch, a server which acts like a VoIP PBX, might need configuring and you may have interference from outside your network and perhaps the policy on your session boarder controller, a multi Gigabits per second device, might need adjustment.

The corporate version of voice over IP, and all the digital additions to telephony that can be added around VoIP, is indeed complex. It needs to be secure from attack. For instance what's the difference between an unsolicited email, and a phone call? And yet not only do you want an unsolicited phone call from a new prospect to get into the network, you want it treated with priority.

But how does your network know that a voice call on VoIP doesn't contain a virus if it bypasses the firewall, hence the border controllers that are becoming fashionable from companies like Nortel, but also Netrake, ACME, 3Com, Sonus and a host of others that are all members of the SIP way of doing things in the corporate world. And similarly how do you bridge in and out of an enterprise that still has legacy telephony systems side by side with new VoIP systems, and here more gateways are needed.

Zennstrom says he has the answer, don't use SIP at all, "Because it is a badly written protocol and it just doesn't work." Well that's a bit strong given that the entire VoIP industry has been built around it. What Zennstrom really means is that SIP doesn't work first time on every network and has trouble traversing firewalls and especially NAT servers.

In other words someone that understands networks has to make sure that your network is set up to recognise and receive VoIP packets and route them appropriately. And that, for the most part, includes more expensive, specialised hardware.

In fact this is really part of the Nortel message to operators everywhere, replace declining voice revenues, and those being lost to wireless telephony by offering managed and hosted services. Day says he has seen ARPU (average revenue per user) figures as high as $300 to $600, and on this basis the systems that he was pushing show a payback in under 18 months. Effectively he sees his role as helping to stop the operators go out of business.

The revenue pie

Zennstrom sees the situation differently. In the end he believes that pure voice will only be around a $10bn slice at the top of the revenue pie. The rest will be data, but included in that is voice data.

The interesting thing about the VON community was that Zennstrom's Skype, in the 10 short months that it has been in existence, has made it onto virtually every set of slides that were presented at the event. Skype was always in the corner, at the bottom, described as low end and not doing very much.

The next most frequent thing mentioned at the show was the Yahoo! Broadband service in Japan, where it has amassed 4 million VoIP subscribers across the broadband lines it sells there. An Alcatel spokesman described how Yahoo! employed people to give away home gateways for nothing, outside underground train stations. But no-one from Yahoo! was present to explain just what the economic model for it was.