OpenSIPS

OpenSIPS
™ Kamailio Project · GPL · source
Name	OpenSIPS
Developer	OpenSIPS Project
Operating system	Linux
Genre	SIP proxy, SIP server, VoIP
License	GNU General Public License

OpenSIPS OpenSIPS is a high-performance telecommunication signaling platform used for Session Initiation Protocol switching, routing, and mediation. It interoperates with major telecom and internet projects, integrates with commercial vendors and open-source stacks, and is widely deployed across service provider, enterprise, and cloud environments.

Overview

OpenSIPS is a modular SIP proxy and application server that performs call control, registration, presence, and real-time signaling tasks. It coexists in ecosystems alongside projects and organizations such as Asterisk (PBX), FreeSWITCH, Kamailio, SIP (Session Initiation Protocol), 3GPP, IETF, and SIP Forum. The project interfaces with databases and middleware including MySQL, PostgreSQL, Redis, Memcached, MongoDB, and integrates with platforms like Kubernetes, Docker, OpenStack, and Amazon Web Services. OpenSIPS is used by carriers, enterprises, research institutions, and cloud providers that also adopt standards and tools from ETSI, ITU, GSMA, RFC 3261, and RFC 3581.

Features and Architecture

OpenSIPS implements SIP routing, registration, NAT traversal, load balancing, media proxying, and presence. Its architecture uses a multi-process core, dynamic modules, and event-driven I/O modeled after work in projects like Linux, epoll, kqueue, Nginx, and HAProxy. Modules provide integration with authentication systems and protocols such as SIP SIMPLE, XMPP, RADIUS, and Diameter used by carriers like Verizon, AT&T, and Vodafone in interoperability testing. Media handling often involves cooperation with media servers like Asterisk (PBX), FreeSWITCH, Jitsi, Kamailio-based setups, and media proxies like RTPEngine and SIPp. High-availability patterns employ clustering and replication concepts similar to Paxos, Raft, and database replication found in Galera Cluster and PostgreSQL streaming replication.

Configuration and Scripting

OpenSIPS configuration is rule-driven and scriptable via a domain-specific language that enables routing logic, authentication, billing hooks, and policy enforcement. Administrators create dialplans and scripts comparable to configurations in Asterisk (PBX), SIP Express Router (SER), and Kamailio while integrating with OSS/BSS stacks such as Odoo, Amdocs, Netcracker Technology, and billing engines used by operators like Deutsche Telekom and Orange S.A.. Hooks support databases like MySQL and PostgreSQL as well as directory services like OpenLDAP and Microsoft Active Directory. For observability, OpenSIPS exposes metrics compatible with Prometheus, logs parsable by ELK Stack and Grafana dashboards commonly used by teams at Google, Microsoft, and Facebook.

Deployment and Use Cases

OpenSIPS is deployed for SIP trunking, session border controller (SBC) functions, least-cost routing, number portability, and unified communications gateways. Service providers and enterprises use it in scenarios alongside vendors such as Cisco Systems, Ericsson, Nokia, Huawei, and cloud operators such as Google Cloud Platform, Microsoft Azure, and Amazon Web Services. Research deployments are seen at universities and labs associated with MIT, Stanford University, ETH Zurich, Tsinghua University, and Imperial College London. Typical use cases include integration with ENUM services driven by standards bodies like RIPE NCC and number portability databases used by regulators such as Ofcom and FCC.

Performance, Scalability, and Security

OpenSIPS focuses on low-latency signaling and high call-per-second throughput through optimizations inspired by high-performance systems like Redis, Nginx, and HAProxy. Scalability patterns incorporate horizontal scaling, stateless routing, and state synchronization compatible with distributed systems research from Google, Amazon, and Netflix. Security practices include TLS for SIP signaling influenced by IETF, SRTP integration consistent with work from ZRTP and IETF SRTP drafts, authentication via SIP Digest and external AAA using RADIUS and Diameter. Deployments follow security guidance from organizations like ENISA and implement mitigations for threats cataloged by CERT and guidelines from OWASP.

Development, Community, and Licensing

The OpenSIPS project is developed by a global community of contributors and companies, maintaining repositories and issue tracking practices similar to projects on GitHub, with continuous integration patterns used by organizations like Travis CI and Jenkins. The community collaborates through mailing lists, conferences, and events similar to FOSDEM, IETF Hackathons, SIPit, and carrier forums hosted by GSMA and ETSI. Licensing is under the GNU General Public License, paralleling licensing models of projects such as GNU Project and Linux kernel. Commercial support and professional services are offered by vendors and system integrators that also work with Accenture, Capgemini, IBM, and telecommunications operators worldwide.

Category:VoIP