SIP routing
Programmable routing engine with a flexible C-like scripting language.
OpenSIPS — The new breed of communication engine
v4.0.0 in beta · See the full release history
The SIP server that
The SIP server that
powers real networks
From startup VoIP platforms to Tier-1 operators — OpenSIPS handles the signaling.
$ apt install opensips
120+
Modules
18+
Years in production
LTS + yearly
Release cadence
1.6k★
on GitHub
Trusted by
What it does
Built for production SIP at scale
Carrier security
TLS, SRTP, anti-flooding, fraud detection, blacklists.
Clustering
Geo-distributed deployments, replication, HA failover.
Voice, video, IM
Presence, B2BUA, registrar, SMS gateway, media handling.
Observability
Live profiling, metrics, tracing, MI and event interfaces.
Extensible
120+ modules, REST, MI, event interfaces, Perl/Java SDK.
Latest news
Profiling your OpenSIPS 4.0
Profiling with OpenSIPS 4.0 or the realtime X-ray of OpenSIPS, to answers to: what my OpenSIPS is doing, why is it slow or why not handling traffic.
OpenSIPS Summit 2026, 28 Apr – 1 May, Bucharest
The Summit is over, enriching us with presentations, recordings and photos, all gathered for you to review!
OpenSIPS SBC Community Edition
We are proud to announce the latest Community Edition project: the OpenSIPS Session Border Controller.
Minor releases: OpenSIPS 3.6.5, 3.4.18
A new round of minor versions for all stable releases.
OpenSIPS 4.0 beta release is out
The 4.0 version is a turning point in the OpenSIPS evolution, opening the way to radically change and improve legacy concepts and code.
TCP/TLS rework in OpenSIPS 4.0
OpenSIPS 4.0 brings a full TCP/TLS redesign, from multi-process connection handling to a centralized, multi-threaded I/O model.
PRACK/UPDATE Interworking in OpenSIPS 4.0
Bridge IMS and legacy SIP networks using either simple built-in enablement or full scripting control.
Bond sockets in OpenSIPS 4.0
The bond sockets make possible the proper selection of the outbound socket based on the last-minute discovered (DNS based) properties of the destination.
Proxy Protocol support for OpenSIPS 4.0
Check out the HAProxy Proxy Protocol implementation in OpenSIPS 4.0 in our latest blog post!
OpenSIPS Control Panel 9.3.6 has been released!
OpenSIPS Control Panel 9.3.6, compatible with OpenSIPS 3.6.x versions has just been released!
Minor releases: OpenSIPS 3.6.4 and 3.4.17
Two new minor versions of our stable releases are out!
Big scaling SIP forking
OpenSIPS 4.0 brings dynamic allocation of high number of branches per transaction, without any memory or processing penalties.
Minor releases: OpenSIPS 3.6.3, 3.5.9, 3.4.16
A new round of minor versions for all stable releases.
Minor releases: OpenSIPS 3.6.2, 3.5.8, 3.4.15
Two new minor versions of our stable releases are out!
Minor releases: OpenSIPS 3.6.1, 3.5.7, 3.4.14
A new round of minor versions for all stable releases.
Stable release: OpenSIPS 3.6.0
OpenSIPS 3.6 is now stable, as beta testing phase is complete!
Minor releases: OpenSIPS 3.5.6, 3.4.13
We just released two new minor versions, one for each stable OpenSIPS release!
From the blog
All →OpenSIPS APT and YUM Repositories Are Moving to GitHub Actions
We are pleased to announce a major refresh of the official OpenSIPS package repository infrastructure. The repositories available at: are now served by a completely new repository and package-building…
The re-design of the OpenSIPS Documentation
The OpenSIPS documentation was designed and structured more than 15 years ago. The documentation covers a vast area – the generic manual, core documentation, module’s documentation, tutorials, migrati…
Recent Security Fixes in OpenSIPS
Security has always been an important part of the OpenSIPS development process. As a project used in production SIP infrastructures, OpenSIPS needs to remain stable, reliable and secure across a wide …
Profiling your OpenSIPS 4.0
A key aspect of operating production systems is to be able to understand what your OpenSIPS is doing, why behaving in certain ways or what is the performance of it. And of course, you want to do all t…
TCP/TLS rework in OpenSIPS 4.0
OpenSIPS 4.0 is not only about adding new features, but also about rethinking parts of the engine that have remained unchanged for a very long time. One of the most important examples is the TCP/TLS l…
OpenSIPS Summit 2026 Bucharest
The OpenSIPS Summits have a 10 + years of history behind them. Started as an Amsterdam based event, the pandemic made us go and visit different cities each year – the community is the one voting, putt…
SIP PRACK/UPDATE Interworking Support in OpenSIPS 4.0
Introduction One of the more stubborn SIP interop problems in modern networks is reliable provisional response handling, especially when bridging classic SIP deployments with IMS-oriented environments…
Bond sockets in OpenSIPS 4.0
In real-life scenarios, the SIP routing is done across multiple IP interfaces (like public or private, different VPN’s, IPv4 versus IPv6 or different protocols). Usually this is handled in OpenSIPS by…
Proxy Protocol support in OpenSIPS 4.0
Modern SIP infrastructures increasingly rely on load balancers, reverse proxies and cloud edge services in order to provide scalability, security and geographic distribution. While these components ar…
Big scale SIP forking
SIP forking is an important feature. It helps with parallel ringing, with class V features (like Hunt Groups), but also with failover (like multi-gateway/carrier failover). SIP parallel and serial for…