US mobile operator Sprint has extended the availability of its SIP Trunking solution to 12 European countries, in an attempt to meet the needs of enterprises with distributed branch offices.

Session Initiative Protocol (SIP) Trunking is a Voice over Internet Protocol (VoIP) that allows businesses to replace expensive “physical trunks” that connect a private branch exchange (PBX) to a service provider network with “virtual trunks” over a single IP connection. It is used mainly for the delivery of telephony services.

Sprint’s solution allows multiple locations to connect over the same set of SIP trunks while preserving local telephone numbers, calling plans and emergency services. This reduces the overall number of trunks needed, thereby streamlining the network and reducing operating costs.

SIP Trunking from Sprint is now available in Austria, Belgium, Denmark, France, Germany, Ireland, Italy, Netherlands, Spain, Sweden, Switzerland and the United Kingdom.

“Flexibility and scalability are key advantages of SIP Trunking and we are pleased to extend these benefits to businesses with operations in Europe,” said Tim Donahue, vice president of International and Solutions Sales at Sprint.

“Sprint’s simple and flexible MPLS solution is the foundation for SIP Trunking and allows IP PBXs to deliver the features and functionality businesses are accustomed to using for voice calling along with Class of Service support of other real-time data.”

US furniture rental company CORT was an early adopter of Sprint SIP Trunking in the United States. It now has 145 domestic and international locations – primarily retail stores – so business continuity is key to its success.

“Sprint SIP Trunking has helped CORT eliminate redundant telephone and data networks and reduce the number of PBXs, bringing us significant cost savings, quality of service and helping to ensure business continuity,” said Tom Mattingly, project manager for IT and Product Development at CORT.

“Sprint not only makes it easy for us to implement the solutions, but it also simplifies adoption for our employees so they can quickly learn how to use and benefit from the new solutions.”

In a recent survey of 300 North American businesses by Infonetics Research, 58 percent said they plan to use at least some SIP trunks by 2015, compared to 38 percent today. Meanwhile, the percentage using T1 lines is expected to decline from 71 percent now to 55 percent in 2015.

Diane Myers, principal analyst for VoIP, UC, and IMS at Infonetics Research, said that SIP trunking adoption is growing as businesses seek to improve the reliability and lower the cost of communication services, but added that it is far from being ubiquitous.

"T1 lines are still the most commonly used trunking service today, and while their use is declining, our survey shows that North American businesses are using a combination of services,” said Myers.

“There isn’t going to be a 100 percent cutover from T1 to SIP. Companies are using SIP trunking for only a portion of their call capacity.”