Linphone: free SIP telephony, no proprietary PBX
An open source softphone that speaks SIP natively, on desktop and mobile, without depending on a proprietary PBX or a mandated carrier.
Linphone has been developed since 2001 by Belledonne Communications and remains one of the few open source softphones covering desktop and mobile with the same SIP codebase.
Why SIP instead of a proprietary standard
SIP (Session Initiation Protocol) is an open standard: any compatible carrier or server can route your calls, without depending on a proprietary box locked to a single vendor. That's what lets you switch telecom carriers without replacing the company's entire phone system.
What we set up
A SIP server (usually Asterisk or FreeSWITCH) hosted on a Trustinstance instance, with Linphone as the client on workstations and mobiles — business numbers, voicemail, call hold and transfer, with no per-user license.
What it changes day to day
Teams keep a single professional number, reachable from any desk phone or a personal mobile through the app, without exposing a personal number or depending on an aging physical phone system.
A question about your situation?
Request a free audit, we'll look at your specific case.