Matter-over-Thread devices are designed to operate locally, with hubs handling internet communication. But when direct internet access is needed for telemetry or custom cloud services, Thread Border Routers can bridge the gap via NAT64. The post explains the networking stack (Thread, IPv6, NAT64, UDP), walks through a working UDP echo example on the nRF54LM20 DK using OpenThread's DNS client and UDP APIs, and covers practical constraints like payload size limits and the absence of TCP/TLS. For production use, CoAP over DTLS is recommended as a lightweight, encrypted protocol layer that runs over UDP.
Table of contents
Table of ContentsA Brief Introduction to MatterThe Hub Does Most of the WorkReaching the InternetnRF54LM20 Example: UDP EchoDoing something usefulConclusionReferences116 Impressions