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OpenSIPS is an Open Source SIP proxy/server for voice, video, IM, presence and any other SIP extensions.

OpenSIPS is a multi-functional, multi-purpose signaling SIP server used by carriers, telecoms or ITSPs for solutions like Class4/5 Residential Platforms, Trunking / Wholesale, Enterprise / Virtual PBX Solutions, Session Border Controllers, Application Servers, Front-End Load Balancers, IMS Platforms, Call Centers, and many others - see the full Set of Features.

OpenSIPS is recommended for any kind of SIP scenario / service by:

• the high throughput - tens of thousands of CPS, millions of ‏simultaneous calls (see official tests)
• the flexibility of routing and integration - routing script for implementing custom routing logics, several interfacing APIs (see the Manual)
• the effective application building - more than 120 modules to provide features, for SIP handling, for backend operations, for integration, for routing logics (see List of Modules)

OpenSIPS 3.2 release was subject of a security audit, making everything safer and more secure for everybody.

Latest News...

OpenSIPS new Config module
20th of May 2025 Check out how you can easily tune OpenSIPS configuration at runtime using the new Config module. Read more...

Unified branches, or SIP branches before and after SIP relaying
19th of May 2025 OpenSIPS 3.6 - how to correlate branches before and after the SIP signalling, to attach custom data to branches or to do inter-branch data access. Read more...

Structured SDP Manipulation in OpenSIPS 3.6
15th of May 2025 OpenSIPS 3.6 introduces new ways to access, edit and replace the SIP message SDP body. All in real-time. Read more...

SIP Sockets Management at runtime in OpenSIPS 3.6
13rd of May 2025 Configure SIP Sockets dynamically at runtime using the new Sockets Management module in OpenSIPS 3.6. Read more...

Mastering Custom Tables with OpenSIPS Control Panel
26th of February 2025 Discover how easy it is to provision custom tables with the OpenSIPS Control Panel's powerful tviewer tool! Read more...

High Availability for VoIP in Microsoft Azure
06th of February 2025 Discover how to implement high availability in Microsoft Azure in our latest blog post! Read more...

Defend Against SIP Flood Attacks with OpenSIPS Pike Module
19th of December 2024 Dealing with SIP traffic from open Internet is always challenging due to the exposure to DoS flood attacks. Read more...

OpenSIPS Cluster Hardening in Large Dataset Scenarios
19th of December 2024 We've recently pushed several stability improvements to the clusterer module, when working with large datasets. Read more...

Releases...

Minor releases: OpenSIPS 3.5.5, 3.4.12
23rd of April 2025 A new round of minor versions for all stable releases. Read more...

Minor releases: OpenSIPS 3.5.4, 3.4.11
19th of February 2025 Two new minor versions of our stable releases are out! Read more...

Minor releases: OpenSIPS 3.5.3, 3.4.10
18th of December 2024 A new round of minor versions for all stable releases. Read more...

Minor releases: OpenSIPS 3.5.2, 3.4.9
23rd of October 2024 Two new minor versions of our stable releases are out! Read more...

Minor releases: OpenSIPS 3.5.1, 3.4.8
21st of August 2024 A new round of minor versions for all stable releases. Read more...

Minor releases: OpenSIPS 3.5.0-rc1, 3.4.6 and 3.2.19
19th of June 2024 New minor releases for all versions. EOL for OpenSIPS 3.2! Read more...

Minor releases: OpenSIPS 3.4.5, 3.2.18
18th of April 2024 A new round of minor versions for all stable releases. Read more...