Free phone service provider Skype is horning further in on the corporate market with new functionality that enables it to work with most existing corporate phone systems.

Skype for SIP, which the company has released in beta, works with SIP-based PBX systems to enable companies to receive calls from Skype users directly into their PBX system. This new functionality pushes Skype past the free computer-to-computer calling model that put the company on the map and into the more mainstream low-cost calling model using traditional telephony systems.

Companies using Skype for SIP can use the service to place calls to landlines and mobile phones worldwide from any connected SIP (session initiated protocol) enabled PBX at Skype’s global rate, which currently is 2.1 cents per minute. They also can connect with customers via a click-to-call icon on the company Website, and the calls will be received through their existing office system at no cost to the customer.

The Skype calls can be managed just as a regular call would, through a company’s existing hardware and system applications; no additional downloads or training are required, according to the company.

For solution providers, the Skype for SIP application can be one more way they can help their customers save money without costly hardware and software replacement or upgrades.

“It’s positive and negative in both aspects,” said Quy “Q” Nguyen, CEO of Allyance Communications, an Irvine, Calif.-based communications solution provider. “It’s definitely positive for the customers – especially in today’s economy, their No. 1 initiative is to cut cost.

“This is also great avenue for solution providers to get their feet in the door and talk to customers about helping them reduce their cost without significant upfront capital,” he added. “The last thing any solution provider wants to do is sell something that’s not going to help the customer's bottom line.”

However, he said, for solution providers already working with carriers such as Verizon, Qwest, AT&T and the like, the new Skype offering could cut their monthly long distance revenues dramatically. “With the Skype SIP platform, a customer’s monthly bill could decrease from $50,000 monthly, for example, in long distance charges to $20,000 to $40,000, depending on a number of factors [such as] their overall usage, their current rate plan, their international call destinations, who else is using Skype to call them.”

And, he said, despite the drop in call costs, customers could see other costs increase with Skype for SIP. “Customers need to be careful if they have a certain contractual volume commitment [with their service provider] or else they will be financially penalized. Also, customers will need to beef up their bandwidth to withstand the increase in VOIP traffic,” Nguyen said. “So on one end, they’ll need to pay more for bandwidth charges but they’ll save more on the long distance charges.”

Still, he noted, for a certain segment, Skype for SIP can be an attractive offering. “If the beta is proven to be effective and the call quality is up to par, I can see the immediate impact from a cost saving perspective to our customers.”

Skype for SIP will be fully released later this year, but companies interested in taking part in the beta program can sign up at www.skypeforsip.com. Applicants will need to be businesses and have an installed SIP-based IP-PBX system, as well as the ability to configure their system. Only a limited number of participants will be able to participate.