SIP – Session Initiation Protocol – is a standards-based signaling technique that establishes, controls and ends Internet Protocol sessions. SIP trunking is the use of the protocol to carry, or backhaul, signals from the field (generally, the corporate site) to carriers or the Internet. SIP trunking, Lemelin says, will increasingly be used to connect formerly isolated islands of UC.
SIP is a pretty hot topic in UC, as evidenced by Lemelin's work and a study by Strategic Network Group President Lisa Pierce that I blogged about at the beginning of the month. It doesn't take an engineering degree to see the benefits of the ability to seamlessly knit together isolated pockets of UC-enabled users, such as headquarters and branch offices.
The fact that this can be done within the context of cutting costs by replacing traditional back haul approaches – the main driver of SIP – is an added bonus. Lemelin told me that there are a couple of benefits:
One, it gives you the ability to escalate calls into video and collaborative sessions, an ability that you just don't have today with the PSTN. It allows for UC outside of closed corporate networks without having to touch the public Internet�SIP trunking really provides enterprise UC capabilities�in as well as outside the enterprise.
Lemelin's study also suggests that the increasing bandwidth brought by smartphones is mobilizing UC. He told me that mobility is a bit of a longer-term play, but one that is potentially a big money saver:
It deals with moving UC and collaborative abilities outside of the mobile usage domain into data channels. You are eliminating mobile billing minutes by using mobile VoIP. It makes using mobility for UC independent of the mobile service provider.
Andrew Borg, a senior research analyst for the Aberdeen Group, concurs. Borg blogged at TMCnet on UC and mobility. He quoted from an Aberdeen report published last autumn that looked at both the promise and challenge of highly mobilized UC:
Because UC is ultimately about uniting today's disparate communication modes into an integrated whole, mobility always plays an enabling role. In fact, mobility is the one common denominator in every UC initiative. The recent emergence of the mobile device as the most reliable point of contact for an individual, along with the need to integrate the device into the organization's communications infrastructure, has become one of the primary drivers for increased UC adoption.
The message is a strong one: UC is in essence a mobile set of applications, despite the fact that until now it generally happened between stationary devices. With the advent of higher-bandwidth wireless and cellular networks and devices, the mobilizing of UC can begin realizing its full potential.
The bottom line, according to the In-Stat study, is that SIP trunking and mobilization will drive UC service revenues to more than $17 billion by 2013 and that equipment revenues will triple between last year and 2013.