kannel

Kannel is an open-source software package that functions as a WAP and SMS gateway, providing a bridge between Internet applications and mobile networks. It handles WAP content delivery and push messaging to mobile devices, while also routing SMS messages to and from SMS centers (SMSC). The project is commonly used to build on-premises messaging gateways and to provide bulk messaging capabilities.

Design and features: Kannel uses a modular architecture with separate components for the HTTP/SMPP interfaces, message queuing, and connections to SMSCs. It supports multiple SMSC connections using SMPP as well as legacy protocols such as CIMD and UCP/EMI. It exposes HTTP-based interfaces for sending messages, receiving delivery reports, and querying status. The system can serve as a gateway for bulk messaging, and can integrate with backend systems via standard protocols and databases.

Implementation and license: Kannel is implemented in C and designed to run on Unix-like systems, including Linux and BSD variants. It is distributed under a free software license (GPL), reflecting its open-source nature and community-driven development.

History and usage: The project originated in the late 1990s and has since been maintained by an international community of contributors. It has been adopted by various mobile operators, MVNOs, and message aggregators as an economical gateway solution for private or on-premises deployments, particularly where flexible protocol support and control over routing are important.

See also: WAP gateway, SMS gateway, SMPP, open-source messaging software.