MQTT Now uses MQTT over TCP/IP. MQTT Anywhere is the one for MQTT-SN over UDP for cellular devices with our Thingstream SIM.
All of the plans are based on using MQTT protocol-level messages (CONNECT, PUBLISH, SUBSCRIBE, etc.). The MQTT Now plans are tailored for Enterprise clients where a customer only has one or two for their back-end systems, but we can provide custom plans if you need multiple clients in the field.