I wouldn't want to run an alarm system over UDP, which provides none of the reliability guarantees of TCP, so I'd have to implement it myself. XMPP classically

I wouldn't want to run an alarm system over UDP, which provides none of the reliability guarantees of TCP, so I'd have to implement it myself. XMPP classically runs over raw TCP, but can also run over HTTP, and there's a newish proposal for XMPP-over-websocket. Protobuf, bson, json, etc. are all good building blocks that nonetheless require you to reinvent message/framing semantics. Why not use a premade protocol that already has that figured out, like XMPP, or AQMP, or MQTT? The vendor in the example had the right idea by picking a protocol designed for this kind of thing, instead of trying to roll their own. They could've used it better (hence the blog post), ie. more idiomatically and over TLS.