Open SIP Server
OpenSIPS is an open source SIP proxy/server project providing high-performance signaling infrastructure for voice, video, IM, and presence, used by carriers, telecoms, and ITSPs globally for Class 4/5 platforms, SBC, and IMS deployments. Revenue comes from training, Summit tickets, and donations under a non-profit model.
- Company typePrivate
- Founded2008
- HeadquartersBucharest, Romania
- Headcount11–50
- GTM typeB2B
- OfferingSoftware
What Open SIP Server does
OpenSIPS is an open source SIP (Session Initiation Protocol) proxy/server project founded in 2008 and developed by a core team based in Bucharest, Romania, operating as a non-profit initiative under The OpenSIPS Software Foundation. The platform provides high-performance signaling infrastructure for voice, video, instant messaging, and presence services, delivering tens of thousands of call setups per second and supporting millions of simultaneous calls. Its modular architecture comprises over 120 modules covering SIP handling, database integration, media relay control, AAA (RADIUS/DIAMETER), monitoring (Prometheus, OpenTelemetry), and billing (CGRateS), with multi-protocol support across UDP/TCP/TLS/SCTP and IPv4/IPv6. The platform is used by carriers, telecoms, ITSPs, and UCaaS/IMS providers globally for Class 4/5 residential platforms, trunking/wholesale, enterprise PBX, session border controllers, application servers, load balancers, and IMS deployments.
The product portfolio spans the core OpenSIPS platform, four Docker-based Community Edition turn-key solutions (SBC, SoftSwitch, AI Voice Connector, IMS CSCF), the OpenSIPS Control Panel for web-based administration, and training programs (QuickStart, Bootcamp, Corporate Training). OpenSIPS generates no direct software licensing revenue under its GPLv2 distribution; instead, it monetizes through training program fees, Summit ticket sales (with the 12th annual Summit held in Bucharest in 2026), donations managed by the Foundation, and ecosystem sponsorship. Commercial support and enterprise services are provided by third-party companies, notably SIPhub and SIPfront, whose principals overlap with the core development team. The project follows a release policy alternating between standard releases (1.5-year support) and Long-Term Supported releases (3-year support), with version 4.0.0 (June 2026) representing a major architectural overhaul of the TCP/TLS framework, introduction of OpenTelemetry profiling, cluster-bridge replication, and Web3-based authentication.
Open SIP Server firmographics
Firmographics- Name
- Open SIP Server
- Legal name
- OpenSIPS Project
- Website
- https://opensips.org
- Company type
- Private
- Founded year
- 2008
- Operating status
- Operating
- Headcount range
- 11–50 employees
- Short description
- OpenSIPS is an open source SIP proxy/server project providing high-performance signaling infrastructure for voice, video, IM, and presence, used by carriers, telecoms, and ITSPs globally for Class 4/5 platforms, SBC, and IMS deployments. Revenue comes from training, Summit tickets, and donations under a non-profit model.
- Ownership category
- akta.pro rank
Open SIP Server industry classification
Industry- Product category
- Open Source SIP Server Software
- NAICS
- Computer Systems Design and Related Services (54151), Computing Infrastructure Providers, Data Processing, Web Hosting, and Related Services (518)
- SIC
- Services-Telephone Interconnect Systems (7385), Services-Computer Programming, Data Processing, Etc. (7370), Services-Prepackaged Software (7372)
- akta.pro primary industry
- VoIP Access & ITSP Services (HDAIAHAD)
Keywords
Where Open SIP Server is headquartered
LocationHeadquarters
- HQ city
- Bucharest
- HQ country
- Romania
- HQ region
- Europe
Offices1 record
Markets served
Open SIP Server business model
Business model- GTM type
- B2B
- Offering type
- Software
- Cost components
- Technology or R&D, Personnel, Operations, Marketing or Sales, Infrastructure
Revenue model
- Open Source Software Distribution: OpenSIPS core software is distributed as free open source under GPLv2. No direct revenue from software licensing. The project accepts donations via PayPal to support generic efforts, servers, hosting, code development, and events.
- Training Programs: Revenue generated through official training programs: OpenSIPS QuickStart (online recorded beginner training), OpenSIPS Bootcamp (in-class/online intensive training), and Corporate Training (custom on-premises sessions).
- Donations & Sponsorship: Financial donations managed transparently by The OpenSIPS Software Foundation. Sponsorship of the annual OpenSIPS Summit provides visibility for companies in the VoIP/ RTC ecosystem.
- Community Editions: Pre-configured open source SIP platforms (SBC, SoftSwitch, IMS CSCF, AI Voice Connector) provided free as Docker-based turn-key solutions. Commercial support available from third-party providers.
Pricing tiers
| Model | Billing | Price |
|---|---|---|
| Freemium | Pay-as-you-go | OpenSIPS Core Software - Free Open Source |
| Subscription | Pay-as-you-go | Conference Pass - $399 |
| Subscription | Pay-as-you-go | Conf & Training Pass - $699 |
| Subscription | Pay-as-you-go | Corporate Pass (3+ Tickets) - 15% discount |
Go-to-market motion1 record
Distribution channels7 records
Marketing channels8 records
Open SIP Server product offering
Product offeringCore offering
OpenSIPS is an open-source SIP proxy/server (RFC3261) for voice, video, IM, presence, and SIP extensions, used by carriers, telecoms, and ITSPs to build Class4/5 residential platforms, trunking/wholesale, enterprise/Virtual PBX, SBC, application servers, load balancers, IMS platforms, and call centers. The platform ships as a modular core engine with 120+ modules, a C-like routing scripting language, and a portfolio of Docker-based Community Edition turn-key solutions (SBC, SoftSwitch, IMS CSCF, AI Voice Connector) plus a web-based Control Panel, training programs, and an annual Summit.
Product overview
OpenSIPS is an Open Source multi-functional SIP proxy/server platform for voice, video, IM, and presence services, used by carriers, telecoms, and ITSPs. The product portfolio consists of a modular core platform (OpenSIPS Core) supporting 120+ modules with high throughput (tens of thousands CPS), complemented by Community Edition turn-key solutions including the OpenSIPS SBC (Session Border Controller), SoftSwitch, AI Voice Connector, and IMS CSCF (all Docker-based ready-to-run platforms). Additional offerings include the OpenSIPS Control Panel web administration interface, menuconfig graphical configuration tool, training programs (QuickStart, Bootcamp, Corporate), and the annual OpenSIPS Summit conference. The platform supports multiple database backends, media relays, caching systems, and integrates with billing engines like CGRateS.
Differentiator
Problem solved
Functional benefit
Brands
- OpenSIPS SBC: Session Border Controller - Open Source turn-key solution covering NAT, mid-register, media handling, topo hiding, carrier support.
- OpenSIPS SoftSwitch
- OpenSIPS IMS CSCF
- OpenSIPS AI Voice Connector
Products and services
- OpenSIPS Core Platform Open-source SIP proxy/server (RFC3261) for voice, video, IM, presence and SIP extensions, with a modular architecture (120+ modules), C-like custom routing scripting language, UDP/TCP/TLS/SCTP and IPv4/IPv6 transport support, and integrations with databases, media relays, and monitoring stacks. Used by carriers, telecoms, and ITSPs for Class4/5 residential, trunking/wholesale, enterprise/Virtual PBX, SBC, application servers, load balancers, IMS platforms, and call centers.
- OpenSIPS SBC Community Edition Open-source Session Border Controller (SBC) turn-key solution covering NAT traversal, mid-register, media handling, topology hiding, and carrier support, delivered as a Docker-based ready-to-run platform.
- OpenSIPS SoftSwitch Community Edition Open-source VoIP SoftSwitch platform for residential, trunking, and carrier-grade deployments, delivered as a Docker-based ready-to-run solution for Class 4/5 VoIP services.
- OpenSIPS AI Voice Connector Community Edition Open-source AI Voice Connector for integrating AI voice services with OpenSIPS infrastructure, delivered as a Docker-based solution for voice AI and conversational AI deployments.
- OpenSIPS IMS CSCF Community Edition Open-source IMS (IP Multimedia Subsystem) CSCF (Call Session Control Function) turn-key solution covering Core Network, IMS Core, and Application Server layers, delivered as a Docker-based ready-to-run platform for IMS deployments.
- OpenSIPS Control Panel Web-based administration and provisioning interface for OpenSIPS, with DB-based configuration, per-tool settings, a new charting engine, dashboard with multi-panel views, and tools for user management, dispatcher, dialplan, and SIPP monitoring.
- OpenSIPS Bootcamp Training Intensive in-class or online training program targeting beginners and medium-skilled users, providing hands-on SIP and OpenSIPS knowledge in a 40-hour, ten-day format.
- OpenSIPS QuickStart Training Online recorded beginner training providing SIP and OpenSIPS basics and common ground knowledge, sold via voip.school.
- OpenSIPS Corporate Training Private on-premises training with custom content and duration tailored to organizational needs.
- OpenSIPS Summit Annual international conference bringing together OpenSIPS developers, VoIP experts, and users for presentations, design clinics, interactive demos, advanced training, and networking.
Quantifiable outcome
- Tens of thousands CPS throughput
- +4 more outcomes
Companies that use Open SIP Server
Customer profileSegments4 records
Ideal customer profiles3 records
Open SIP Server technology and API
TechnologyTechnology focussed Yes
API detail
- Has API
- Yes
- API docs
- API detail
Core technology
AI maturity
App detail
Integration33 records
AI capability6 records
Feature12 records
Open SIP Server partnerships and signals
Strategic signalPartnerships
Eleven partnerships are on record, tiered diamond sponsor, platinum sponsor, gold sponsor, silver sponsor and organizer.
- SIPhubdiamond sponsorSIPhub is the Diamond sponsor of OpenSIPS Summit 2026. SIPhub appears to be a company closely associated with OpenSIPS development, with core team members Razvan Crainea and Vlad Paiu affiliated with SIPhub according to summit speaker listings.
- Five9platinum sponsorFive9 is a Platinum sponsor of OpenSIPS Summit 2026, providing Open Source Lunch sponsorship. Summit speaker Nuno Ferreira is listed as Sr Staff Software Engineer at Five9.
- SIPfrontplatinum sponsorSIPfront is a Platinum sponsor of OpenSIPS Summit 2026, providing Open Source Lunch sponsorship. Speaker Andreas Granig is from Sipfront, presenting on Voice AI deployment.
- Genesysgold sponsorGenesys is a Gold sponsor of OpenSIPS Summit 2026, providing Coffee Break sponsorship. Speaker David Trihy is Lead Software Engineer at Genesys Cloud Voice, presenting on topology hiding modifications.
- 46Labsgold sponsor46Labs is a Gold sponsor of OpenSIPS Summit 2026, providing Coffee Break sponsorship. Speaker Jarrod Baumann is VP of Technology at 46Labs, presenting on Kubernetes CRAP integration.
- Ecosmobsilver sponsorEcosmob is a Silver sponsor of OpenSIPS Summit 2026. Speaker Sagar Malam is Chief Innovation Officer at Ecosmob, presenting on 6G signaling infrastructure.
- ConnexCSsilver sponsorConnexCS is a Silver sponsor of OpenSIPS Summit 2026.
- SipPulsesilver sponsorSipPulse is a Silver sponsor of OpenSIPS Summit 2026. Speaker Flavio Goncalves is CEO at SipPulse, presenting on troubleshooting SIP.
- Inextrixsilver sponsorInextrix is a Silver sponsor of OpenSIPS Summit 2026. Speaker Pratik Patel is Technical Lead at Inextrix Technologies, presenting on scaling ASTPP with OpenSIPS.
- Voyssilver sponsorVoys is a Silver sponsor of OpenSIPS Summit 2026.
- VoicenterorganizerVoicenter is co-organizer of OpenSIPS Summit 2026 alongside OpenSIPS Project. Speaker Shlomi Gutman is CTO at Voicenter Ltd.
Scale indicators6 records
Recent moves6 records
Expansion highlights6 records
Open SIP Server competitors and assessment
Company assessmentBroad incumbents
- Cisco (Webex Calling / CUCM): Incumbent enterprise UC vendor offering CUCM, Webex Calling, and dedicated SBCs. Represents the proprietary incumbent alternative that OpenSIPS often displaces in cost-sensitive carrier and ITSP builds.
- Twilio: Cloud CPaaS/UCaaS leader abstracting SIP via APIs. Competes indirectly by reducing developer demand for raw SIP server infrastructure, but also consumes OpenSIPS-compatible SIP trunks at the carrier edge.
- Avaya: Legacy UC and contact-center vendor with proprietary SBC and session manager products. Competes with OpenSIPS in large enterprise and carrier SIP routing where Avaya Aura/Session Manager is deployed.
- Genesys: Major CCaaS/UC platform and Gold Summit sponsor with speaker presentations on topology hiding. Uses SIP infrastructure at scale and is both a deployment target for OpenSIPS-based carriers and a competitor in the broader enterprise communications stack.
- Sangoma Technologies: Commercial parent of Asterisk and a broad VoIP/UC vendor offering SBCs, gateways, and contact-center products. Competes in the same carrier/enterprise SIP infrastructure space with proprietary support and appliances layered on top of open source.
Direct peers
- 3CX: Commercial software PBX that ships its own SIP stack and SBC for SMB and enterprise customers. Directly comparable in the Virtual PBX / SIP trunking segment where OpenSIPS is used as a backbone signaling platform.
- Kamailio: Open-source SIP proxy/server forked from the same SER (SIP Express Router) lineage as OpenSIPS. Closest direct competitor, offering overlapping signaling features (clustering, TLS, multi-DB, RTP integration) for carriers and ITSPs.
- Asterisk: The dominant open-source PBX/softswitch, often used alongside OpenSIPS as a media server. Competes in overlapping telephony use cases (Class 4/5, trunking, enterprise PBX) and is the most-recognized OSS telephony brand.
- FreeSWITCH: Open-source telephony platform often paired with OpenSIPS as a media/IVR backend via the freeswitch ESL connector module. Competes on the application server / media plane side of the same SBC/PBX stack.
Emerging players
- Telnyx: Carrier-grade SIP trunking and communications platform with its own SBC and private IP backbone. Competes in the same ITSP/trunking segment OpenSIPS serves, with a more API-first commercial posture.
Market position
Strengths5 records
Weaknesses5 records
Competitive moat6 records
Key risks6 records
Key highlights7 records
Customer concentration
Open SIP Server social profiles
Digital presenceOpen SIP Server financial estimates
Financial estimateRevenue estimate
Valuation estimate
Open SIP Server leadership team
Management profileNumber of profiles
Profiles4 records
Open SIP Server funding detail
Funding detailFunding overview
Funding rounds
Investors
Funding detail is available on the Subscription and Enterprise plan.Contact sales →
Open SIP Server M&A and investment
M&A and investmentM&A
Investments
M&A and investment is available on the Subscription and Enterprise plan.Contact sales →
Frequently asked questions about Open SIP Server
What does Open SIP Server do?
OpenSIPS is an open-source SIP proxy/server (RFC3261) for voice, video, IM, presence, and SIP extensions, used by carriers, telecoms, and ITSPs to build Class4/5 residential platforms, trunking/wholesale, enterprise/Virtual PBX, SBC, application servers, load balancers, IMS platforms, and call centers. The platform ships as a modular core engine with 120+ modules, a C-like routing scripting language, and a portfolio of Docker-based Community Edition turn-key solutions (SBC, SoftSwitch, IMS CSCF, AI Voice Connector) plus a web-based Control Panel, training programs, and an annual Summit.
Is Open SIP Server a public or private company?
Open SIP Server is a private company. It is classified as nonprofit foundation owned and is currently operating.
When was Open SIP Server founded?
Open SIP Server was founded in 2008. It employs 11 to 50 people.
Where is Open SIP Server based?
Open SIP Server is headquartered in Bucharest, Romania, in the Europe region.
How does Open SIP Server make money?
Four revenue lines are on record. Open Source Software Distribution is the primary driver. The others are training Programs, donations & Sponsorship and community Editions.
Who are Open SIP Server's main competitors?
Broad incumbents on record are Cisco (Webex Calling / CUCM), Twilio, Avaya, Genesys and Sangoma Technologies. Direct peers are 3CX, Kamailio, Asterisk and FreeSWITCH. Telnyx is listed as an emerging player.
Does Open SIP Server have an API?
Yes. OpenSIPS provides multiple interfaces for external integration and control: Management Interface (MI) via FIFO, Unix sockets, UDP, HTTP, XMLRPC; Event Interface for notifications; Statistics Interface; Binary Internal Interface for inter-OpenSIPS communication; JSONRPC support; embedded HTTP server; REST client for HTTP API calls; Provisioning Interface (PI_HTTP). Additionally, an Ansible role is available (razvancrainea.opensips) for deployment automation. Developer documentation is at opensips.org/Documentation/Manual-4-1.
What industry is Open SIP Server in?
Open SIP Server's product category is Open Source SIP Server Software. Its primary akta.pro industry code is HDAIAHAD, VoIP Access & ITSP Services. Its NAICS code is 54151 and its SIC code is 7385.