I've gotten accustomed to the hot issues in our industry being about things other than, strictly speaking, technology: What's the future of Nortel? What's the future of Unified Communications? Will Microsoft beat out Cisco? Are the "legacy" vendors doomed?I gauge these issues' "hotness" by how many people attend VoiceCon sessions on these topics, how many people read NoJitter.com articles and blogs about them, and how many comments we get from the audience in these forums.

Saying that these issues aren't about technology isn't the same thing as saying they aren't important. Nothing's more critical to a Nortel customer than what happens to their primary vendor as it goes through Chapter 11. And choosing a primary vendor for Unified Communications-be it Cisco, Microsoft, or an Avaya/Nortel/Siemens/NEC-type company-is a move with career implications for our audience. Furthermore, understanding what the vendors are saying about these topics- wading through the marketing hype, to be blunt about it-is vital to making the right decisions.

But still, we like to think that this is a technology industry we're in, so we expect that at least some of the hot issues will overtly deal with technology. And right now, there's a very hot technology issue: SIP Trunking. In fact, I don't even feel that I'm going out on a limb very far when I declare that SIP Trunking is the hottest issue in enterprise communications right now.

It's a stealth issue for a few reasons: For one thing, SIP Trunks involve the carriers, and it's my observation that too often, we like to keep the carriers as far off in the periphery of our discussions as we can. Maybe it comes from the old Bell System days when the "demarc" was a legal concept as well as a bright line dividing which individuals ought to get fingers pointed at them when troubles crop up in an end user's system. Or maybe it's just that the two worlds, carrier and enterprise, tend to view each other with (often-justified) suspicion that breeds less than perfect understanding.

Whatever the reason, SIP Trunks haven't gotten as much attention as some of these "bigger" issues, but we're seeing an explosion of interest in the topic nevertheless. Our breakout session on SIP Trunking drew the largest crowd of any breakout at VoiceCon, and this week's VoiceCon Webinar on SIP Trunking (register here) is already our biggest webinar in more than a year, with a few more days of registration to go. Clearly, something s going on here.

If you look at the Comments section to this blog I wrote last week, my concerns about ubiquitous availability seem to be outnumbered by several commenters' concerns about implementation. Likewise, in his excellent synopsis of that VoiceCon SIP trunking panel, David Rohde of TechCaliber Consulting (who moderated the session) paints a picture of a user community with several concerns still to be put to rest, namely: Can you trust the interoperability certifications of either the equipment vendors or the carriers? How will my traffic perform on plain-vanilla IP trunks (in other words, what are the implications for QoS on my network)? And will these challenges drive up my real cost of implementation and management such that the promised cost savings on WAN service charges get eaten up by the attendant problems? Those cost savings are, of course, a big part of what's drawing interest to SIP trunks at this moment in time.

Everybody is doing everything he or she can to slash the costs of the network without hindering service quality or, if they can help it, IT staffing levels. If SIP trunks can deliver service that's equivalent to PRIs at lower cost, they're a winner.

But that's a big "if," and one our audience is hungry for answers on.If SIP trunks can deliver service that's equivalent to PRIs at lower cost, they're a winner. But that's a big "if."