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 layer. The TCP framework, in the form we have known it so far, has stayed largely the same since it … Continue reading TCP/TLS rework in OpenSIPS 4.0
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, putting on the Summit map new locations like Houston, Athens and Valencia. This year is Bucharest! And there are … Continue reading OpenSIPS Summit 2026 Bucharest
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. In IMS-heavy networks, RFC 3262 support is often assumed. That means 100rel, RSeq, RAck and PRACK are not optional extras anymore, but part of normal call establishment. On the … Continue reading SIP PRACK/UPDATE Interworking Support 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 picking / setting an outbound OpenSIPS socket for the handled call. But there are cases where such simple approach simply does not work: reaching … Continue reading Bond sockets 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 are extremely useful, they often hide the original source address of the client from the backend SIP infrastructure. Starting with OpenSIPS 4.0, we are introducing support for the Proxy … Continue reading Proxy Protocol support in OpenSIPS 4.0
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 forking means creating more and more branches (destinations) for a transaction, as the following real life scenarios demonstrate: Multi-level hunt groups in class V VPBX systems … Continue reading Big scale SIP forking
The upcoming OpenSIPS 4.0 release already includes a new feature for the clusterer module dubbed "Cluster-Bridge Replication". It mainly targets setups with multiple, geo-distributed data centers which make use of WAN links to exchange clustering data. Re-organizing the nodes into islands connected by bridges allows considerable bandwidth savings, especially if the WAN links are over … Continue reading Scaling Geo-Distributed OpenSIPS Clusters with Bridge Replication
Last week, I had the great honor of representing the OpenSIPS Project in the ClueCon 2025 IT & Telephony conference: The ClueCon 2025 leaflet, pretty smooth! As always, the event took place in the "windy" city of Chicago, this time returning to the Swissôtel. Fun fact: "windy" isn't related to the city's weather, rather to … Continue reading We’re Back From #ClueCon25, and it was AI-mazing!
As already mentioned, the 3.6 major release will end the 3.x family of OpenSIPS releases. They stretch over 7 years of work, 7 major releases, each with its own philosophy. The 3.x legacy The 3.x OpenSIPS family addressed a large spectrum of topics. The most representative was the DevOps area (3.0 and 3.6) bringing awesome … Continue reading OpenSIPS 4.x, the next evolution step
Some time ago, we demonstrated how to dynamically tune OpenSIPS' runtime configuration using the OpenSIPS Control Panel in combination with the SQL Cacher module. While effective, that approach involved a certain level of configuration overhead to set up and maintain the SQL Cacher infrastructure. To address this, we’ve taken a significant step forward with the … Continue reading Dynamic Runtime Configuration using OpenSIPS 3.6 – continuation
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