SIP trunking is bubbling up from the bottom

A growing number of large enterprises are reporting various experiences in sounding out and testing AT&T and Verizon on SIP trunking services. The big carriers are moving at sometimes uncertain speeds to completely leap into the market with aggressive proposals that actually leverage the replacement of legacy elements in their own incumbent infrastructure.

But there's no question about the speed of SIP trunking's ramp-up at the other end of the carrier market -- the small-business CLECs and alternative carriers. One after another they are jumping head-first into the SIP trunking pool. And if past experience with new carrier products is any guide, you'll be hearing about sales calls from these companies to your business units and branch offices, no matter how many protections you have in place for who's authorized to buy telecom services.

A key point came in early December with the announcement of SIP trunking from XO Communications. XO is a fixture in the telecom industry that's hung on through Chapter 11, mergers, technology migrations and strategy shifts. It's primarily seen in the small business market, although it has a clear strategy to move substantially into the middle market and occasionally provides circuits or hosting to large enterprises (and would like to do more).

But XO is hardly alone. Individual companies with no particular play (yet) in the enterprise market, and much less of a legacy in the 1990s CLEC boom and bust, are clearly putting SIP trunking front and center.

Speakeasy out of Seattle, which began as an Internet cafe company and is now actually part of Best Buy, offers an "Integrated Voice" package that neatly offers SIP trunking provided you have an IP PBX at a centralized voice location (or old-fashioned PRIs if you don't).

Cbeyond out of Atlanta offers what it calls its BeyondVoice with SIP service, boasting its early role in helping develop the "SIPconnect" standard. SIPconnect, as we've previously discussed, is a kind of global certification label that IP PBX makers and carriers can use to specify that they adhere to a certain approved subset of SIP procedures, and may be appropriate for locations without large-enterprise, mission-critical requirements (like full-featured contact centers) or strict testing requirements.

And our friends at Network World just reported on the new "Dynamic Office" service from Windstream Communications based on SIP trunking. This one is particularly intriguing because Windstream is actually an independent ILEC -- an incumbent, not alternative, local carrier based in North Carolina that serves areas that the big incumbents either never served or offloaded.

Clearly there are some cautionary items with regard to these new services. Most small SIP trunking carriers will in fact rely on SIPconnect or other methods to ensure compliance rather than engage in individual carrier-PBX certification tests. Some of them don't offer MPLS, so what you're basically buying is integrated voice-data access over dedicated Internet lines to bring voice streams from branch offices to the SIP trunking core and out to the public network.

And you have to be aware of any alternative carrier's financial status -- XO, for example, has an odd set-up where it's 89% owned by Carl Icahn and his affiliated companies. It's still not really profitable and probably not independently viable without this single backer, which doesn't need to be a large concern until you start using them strategically rather than tactically.

But all of these SIP trunking carriers are leveraging the now solid penetration of pure IP PBXs from Cisco, Avaya, ShoreTel and others. And they're certainly less beholden than the big carriers to separate voice trunks, unconverged dedicated access lines, and old ISDN infrastructure. It's great to see them pressuring the market from below, and that can only bode well for the acceleration of SIP trunking into the large enterprise market in a truly competitive, financially compelling way.