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FirstHand Technologies - http://www.firsthandtech.com/
Client and server software developer for service providers and telecom equipment vendors, to address enterprise mobility markets. |
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Tech Invite - http://www.tech-invite.com
Portal containing links to technical information and RFC documentation. |
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VoIP User - http://www.voipuser.org
Consumer guide and forum. Also has software phone downloads and links to service providers. |
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Voice System - http://www.voice-sistem.ro
Design, consultancy and development for SIP Express Router (SER) servers. |
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Session Initiation Protocol (SIP) - http://www.cs.columbia.edu/sip/
FAQs, background materials and lists of current work in this field. |