Compare FusionPBX vs. Kamailio

FusionPBX serves as a versatile solution for both single and domain-based multi-tenant PBX setups, functioning as a carrier-grade switch, call center system, fax server, VoIP server, voicemail server, conference server, and voice application server, among other roles. Meanwhile, FreeSWITCH™ stands out as a highly adaptable and scalable communication platform that operates across multiple threads and platforms. It boasts an impressive array of features, including unlimited extensions, voicemail-to-email, music on hold, call parking, call center capabilities, call queues, and phone provisioning, catering to businesses of all sizes. By delivering corporate-level phone system functionalities, it meets the diverse needs of small, medium, and large enterprises alike. Significant efforts have been invested in enhancing security, resolving issues, and refining the codebase. Furthermore, ongoing advancements are being made in preparation for an upcoming release, with notable progress achieved; the master branch has outpaced the current version in several respects. As the team works meticulously to finalize the essential updates, anticipation builds for the enhancements that will accompany this release. The commitment to continuous improvement ensures that the platform will remain competitive and relevant in the rapidly evolving telecommunication landscape.

Kamailio® is an open-source SIP server, which evolved from the earlier OpenSER and SER, and is distributed under GPLv2+, capable of managing thousands of call setups each second. This robust platform can be utilized for constructing extensive systems for VoIP, real-time communication, presence, WebRTC, instant messaging, and various other applications. Additionally, Kamailio is well-suited for scaling SIP-to-PSTN gateways, PBX systems, or media servers such as Asterisk™, FreeSWITCH™, or SEMS with ease. Its extensive feature set includes support for asynchronous TCP, UDP, and SCTP, secure communication through TLS for voice, video, and text, as well as WebSocket compatibility for WebRTC. The server supports both IPv4 and IPv6, offers simple instant messaging and presence capabilities with an integrated XCAP server and MSRP relay, and enables asynchronous operations. Furthermore, it includes IMS extensions for VoLTE, ENUM functionality, DID and least cost routing, load balancing, and routing failover. Kamailio also provides comprehensive accounting, authentication, and authorization features, while supporting a variety of backend systems, including MySQL, Postgres, Oracle, Radius, LDAP, Redis, Cassandra, MongoDB, and Memcached. All these capabilities make Kamailio a versatile choice for modern communication infrastructures.