Interoperability Now!

Before a new technology can become pervasive, industry standards must be established. VoIP doesn't have a standard, exactly, but it seems to have sprouted an acceptable substitute.

by Gerry Blackwell

Last month we met Britt Clark, president of World Presence Internet Services, a start-up ISP in Alabama. Clark was all revved up about offering long distance telephone service to his customers using VoIP.

His idea is to route his customers' voice calls over the Internet backbone to another VoIP-enabled ISP closer to the call's destination. That ISP would dump the call out onto the PSTN through its IP telephony gateway.

(PSTN: that's Public Switched Telephone Network. And an IP telephony (or VoIP) gateway is the device that turns an analog voice call from the PSTN into a stream of IP packets—or vice versa, depending on which end of the process it sits.)

Flaw in the ointment
The way Clark is talking about operating his service conforms to one of a few models ISPs could conceivably adopt to exploit the VoIP business opportunity. But it has one tiny flaw.

If you have a gateway made by Cisco and the ISP at the other end has a gateway made by 3Com, or Lucent, or VocalTec, you are SOL. (SOL: that's . . . well, never mind.)

Despite both vendors' products supposedly complying with the H.323 streaming multimedia standard from the International Telecommunications Union (ITU), they in fact cannot accept IP calls from each other.

You can still set up a network of ISPs to terminate each others' calls as Clark hopes to do. It's just that they will all have to use the same—or compatible—gateways.

This means it may not be possible to find ISP partners in every calling area. So either you won't be able to offer service to those areas, or you'll have to set up a billing system to record and settle long distance charges. Very messy.

Proto-solution
While it won't help ISPs attempting to do what Clark wants to do right now, an important ad hoc standards initiative may eventually solve the problem and make the Internet as open as the PSTN.

Inow—for interoperability Now —was launched last year by ITXC Corp., a global wholesaler of IP telephony services, and two of its gateway suppliers, Lucent Technologies and the Israeli firm, VocalTec Communications Ltd.

"Right now," says ITXC marketing vice president Mary Evslin, "each manufacturer has an island of gateways they have sold. You can only call within that island—and none of these firms has critical mass. If the [IP telephony] industry is to succeed, we need to have them all talking to each other."

ITXC challenged its two vendors to solve the compatibility problem. The company was surprised, Evslin says, when Lucent and VocalTec actually did it.

From a technical perspective, the problem is that H.323 is not really a standard yet. As Evslin puts it, it's more like a "moving continuum." Different vendors chose to implement it in their products at different points in its evolution. Result: they still can't talk to each other.

Bandwagon effect
iNow was formed after Lucent and VocalTec demonstrated the interoperability they had achieved at a conference last spring. Other vendors saw it and said they wanted to climb on the bandwagon and make their products interoperable too.

The result was the formation of the iNow consortium and the writing of the iNow profile. The profile essentially says, 'This is the version of H.323, these are the parts of the evolving standard that we will program to now.'

It doesn't mean the profile won't change in the future to reflect the evolving H.323 standard, Evslin points out, but putting a stake in the ground now was the only near-term hope for interoperability.

To date, over 30 companies, including virtually every major manufacturer of IP telephony gateways, have joined iNow, saying they will build their next product revisions to the specs in the iNow profile.

Getting from theory to reality
"Now," says Evslin, "we need to get them to really do it." None has so far, but in fairness, most only signed on two months ago and are targeting fall '99 for their first iNow-compliant products.

What can you do—now? Before you buy a gateway, make sure your vendor is part of iNow, and question the company closely about when it plans to actually deliver compliant product.

ITXC, Lucent, and VocalTec recently passed off the iNow initiative to the International Multimedia Teleconferencing Consortium Inc. (IMTC), a non-profit corporation comprising more than 150 companies worldwide. You'll find a list of vendors supporting iNow at the ITMC site.

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