SIP2SIP is free to use and supports audio/video, presence, chat and file transfers depending on the client capabilities. To try out video conferencing without creating an account, choose a room and click Go:


To experience all features offered by SIP2SIP, like receiving incoming calls, you will need to sign up for an account.

Desktop and mobile clients

Optimized for audio/video conferencing

Classic VoIP Clients

Optimized for audio calls

There are many SIP software and hardware devices on the market that you can use with For configuring them with your SIP2SIP account setting, please consult the manual or instructions from their vendor.


  • Internet SIP address (e.g.
  • WebRTC interface
  • Audio and Video (RTP media)
  • Chat and File transfer (MSRP media)
  • Presence (SIP SIMPLE)
  • Contacts Management (XCAP)
  • Directory Services (LDAP)
  • Multi-party Conferencing (WebRTC)
  • XMPP Gateway (Audio, Video, Chat)


SIP2SIP is a service provided by AG Projects, a company based in the Netherlands. We've made Open Source software since 2002 which is actively used in thousands of deployments world-wide.


SIP2SIP service runs on SIP Thor platform build by AG Projects. The platform implements several Internet Open Standards: SIP, WebRTC and XMPP. WebRTC functionality is provide by SylkServer.