I haven&#x27;t really bench-marked the trafic on RasPi. Only just sent and received some messages. I know it works.<p>The only problem is when in your RapidSMS (Django framework for SMS) app you need to perform some calculations on each incoming message,... Celery will have to be used to schedule tasks  and that can take much RAM ,...including the RAM used by Kannel.<p>For us working in third-word countries where even Visa cards are not well available, using Kannel is an alternative to Twilio.