SIP Trunking Provider

Digium makes Asterisk available to the open source community under the GNU General Public License (GPL) and uses business-class Asterisk to power a broad family of products for small, medium and large businesses. The company’s product line also includes a wide range of hardware to enable resellers and customers to design their own voice over IP (VoIP) systems. www.digium.com

Switchvox is a leading provider of PBX and VoIP phone systems for small- to medium-sized businesses (SMBs). The company's SOHO product enables small and home offices to easily and affordably create and manage their phone system, using traditional analog lines, as well as VoIP services. The Switchvox SMB product is a full-featured, more advanced IP PBX system for larger organizations. www.switchvox.com

Fonality is a leader in open source, Asterisk-based IP telephony systems. PBXtra, Fonality's IP-PBX product line for small and medium-sized businesses, includes a hardened and improved version of the popular open source Asterisk code base which has been modified to add reliability, stability and enterprise-class features. www.fonality.com

trixbox, with a lowercase 't', is an IP-PBX software solution designed for small and medium-sized businesses. trixbox comes in two flavors: the open-source community edition and a hybrid-hosted, commercially-proven solution. www.trixbox.com

3CX Phone System for Windows is an award-winning software-based IP PBX that replaces traditional proprietary hardware PBX / PABX. It is entirely SIP standard based, and therefore interoperates with most popular SIP phones, SIP VOIP Gateways and SIP VOIP providers. It is intended to completely replace a traditional PBX, be easily manageable by system administrators and to integrate well with Windows Network infrastructure.. www.3cx.com

Grandstream's IP-PBX product segment consists of the GXE5024 and GXE5028. The GXE502x appliance is a powerful all-in-one voice + video + fax + data communication solution for the small to medium sized business. The GXE502x product family optimally integrates legacy PSTN trunk and telephone interfaces for fail-safe hybrid communication needs in all circumstances including power or network loss. www.grandstream.com

Epygi Technologies designs, manufactures and distributes globally feature-rich IP PBXs, voice over IP gateways and cost-saving conference servers. The privately held U.S. corporation was founded in 2000. www.epygi.com

Pbxnsip makes SIP-based Private Branch Exchange (PBX) telephone system. Customers may run the PBX on Microsoft Windows and Linux-based servers as well as in embedded appliances like our CS410. The pbxnsip solution is ideal for small to medium size businesses, enterprises, hosted environments, call centers, and the hospitality industry. www.pbxnsip.com/

Allworx develops award winning, phone & network systems for small-to-medium sized businesses. The product line includes the Allworx 6x and 24x systems. By combining the advanced features of today's VoIP systems with the key system features SMBs have grown to rely on, Allworx systems are ideal replacements for the millions of aging (TDM) PBX and key phone systems in use today.www.allworx.com