Diomerc for smartphones and tablets

Diomerc is one of the most famous open source softphones in the world. It is fully SIP-based, for all calling, presence and IM features.

Use Diomerc for free, and enjoy its intuitive interface and advanced features with our free SIP service or with an existing SIP account.


Easy-to-use graphical interface :

– Account creation assistant
– Smart contact list, with address book synchronisation for smartphones
– Call history
– “Invite your friends” option
– Remote provisioning from a QR Code or a URL

Advanced calling features :

– HD video calls with video preview (H.264, H.265 and VP8 codecs supported)
– Audio conference calls
– Call transfer and multi-call management (pause and resume)
– Call recording and replay (audio only)

Increased audio and video quality :

– State-of-the-art adaptive jitter buffer algorithm
– Innovative adaptive bitrate control
– HD voice (Opus support) and echo cancellation
– Call quality indicator and display of advanced call statistics

Enhanced Instant Messaging experience :

– One-to-one and multi-participant conversations
– Intuitive message delivery status (IMDN)
– Picture and file sharing
– Multi-device support
– Advanced IM notifications, with “reply to” and “mark as read” options

Secure communications :

– SIP TLS with state-of-the-art cypher algorithms
– Audio and video encryption with SRTP and ZRTP
– End-to-end encryption for 1-to-1 and group messaging


App Diomerc

Encrypted videocalls and calls.

ZRTP – Ultra High Security
NSA Suite B “TOP-SECRET” security level. AES-256 Encryption, 80-bit HMAC-SHA1, Elliptical curve DH P-384
Videocalls using VP8, H263 & H264 codecs. H264 for iOS
Incoming calls via PUSH notifications.
G.729 codec Audio data compression algorithm for voice that compresses voice audio into 10 millisecond bits.

Encrypted instant messaging.

Chat encrypted to communicate between our users, instant messages without a trace.


It is a web application to communicate with your account, which runs from the browser and desktop applications for Mac OS X and Windows.


We charge a fee for the account, so we don’t need to sell your data or your privacy, as all the “free” services found online. Our server does not keep data of calls that pass through it, in addition the information passes completely encrypted and free of metadata.


We offer you applications to use with our secure server, applications that have been reviewed by us, with the best and safest encryption systems. Our applications come preconfigured and ready for you without complex configurations.

Diomerc for desktop platforms

Diomerc Desktop, the brand new version of Diomerc for desktop platforms, is perfectly suited for both standard users with no specific knowledge of VoIP/SIP and for advanced audio/video calling use cases in a professional environment.
It is fully SIP-based, for all calling, presence and IM features.

Use Diomerc Desktop for free, and enjoy its modern look and feel and its many advanced features with our free SIP service or with an existing SIP account.


Complete, intuitive User Interface :

– Simplified user experience with swift access to major features
– Intelligent search bar for ease of communicating
– Contact list with presence status
– Unified call and chat history
– Quick access to your recent events
– Multi-account and multi-device support

Enhanced Instant Messaging Experience :

– Instant messaging with file sharing
– Access to chat views during calls
– Intuitive message delivery status (IMDN)

Advanced calling features :

– HD video calls in full screen mode (H.264, H.265 and VP8 codecs supported)
– Optimised audio/video quality, thanks to our new jitter buffer and bitrate adaptation algorithms
– HD voice (Opus support) and echo cancellation
– Audio conference calls with up to eight participants
– Multiple call management (pause and resume)
– Call transfer, auto-answer, DTMF support
– Call quality indicator and display of advanced call statistics
– Secure communications with SIP/TLS, SRTP and ZRTP

Diosip Server

Diosip is a complete, modular and scalable SIP server suite that includes proxy, presence, and group chat functions.

Diosip offers an easy-to-install SIP server solution, offering all the features required to deploy your own SIP service tuned for mobile or desktop applications, « out of the box ».

The free sip.diomerc.org SIP service has run on Diosip since 2011, and enables Diomerc users to create their own SIP addresses to connect with each other.


Proxy :

– NAT-aware with built-in media relay module and ICE/STUN support
– Interconnected with push notification systems
– High availability and cluster mode for large deployments
– High-level event logging for activity monitoring
– Digest and TLS client certificate authentication

Diosip manages SIP SUBSCRIBE and PUBLISH from client applications, in order to :

– Identify users of the service within the address book
– Provide users with real-time presence status
Group chat :
– Entirely SIP-based solution
– Efficient management of groups and participants
– Multi-device support
– Notification of group events (users joining or leaving, new admins etc.)
Diosip can be integrated into your SIP infrastructure for various purposes, for example IN THE CLOUD in order to run your own VoIP service, EMBEDDED in small hardware systems or in its PUSH GATEWAY mode of operation.