Also known as: 6LoWPAN, IPv6 over 802.15.4
6LoWPAN (IPv6 over Low-Power Wireless Personal Area Networks) is an IETF adaptation layer that lets full IPv6 packets travel over the tiny, low-power frames of IEEE 802.15.4 radios.1 It sits between the 802.15.4 link and the IP stack, compressing headers and fragmenting packets so that internet addressing reaches even the smallest battery-powered IoT devices — the foundation on which Thread is built.
Overview
An 802.15.4 frame is at most 127 bytes, yet a bare IPv6 header alone is 40 bytes and IPv6 requires links to carry packets of 1280 bytes. 6LoWPAN bridges that gap with two core mechanisms. Header compression exploits shared context — the link already knows the addresses and many fields are predictable — to squeeze a 40-byte IPv6 header (plus UDP) down to a handful of bytes. Fragmentation and reassembly splits a larger IP packet across several link frames and rebuilds it at the far end. A mesh-forwarding sublayer and stateless address autoconfiguration round out the design, letting devices derive IPv6 addresses from their 802.15.4 identifiers.
Technical characteristics
| Property | Value |
|---|---|
| Defined by | IETF RFC 4944, updated by RFC 6282/6775 |
| Carried protocol | IPv6 (with UDP compression) |
| Underlying link | IEEE 802.15.4 (also BLE, sub-GHz) |
| Header compression | 40 B → as few as ~4 B |
| Fragmentation | IPv6 ≥1280 B over 127 B frames |
| Addressing | Stateless autoconfiguration from EUI-64 |
Although born for 802.15.4, the same adaptation ideas were later applied over other constrained links, including Bluetooth LE.
History
The IETF 6LoWPAN working group published the base specification, RFC 4944, in 2007, with improved compression (RFC 6282) and neighbour discovery (RFC 6775) following. Its design directly shaped Thread and other IP-based IoT stacks.
Deployment
6LoWPAN is rarely a consumer-facing brand; it lives inside stacks like Thread and some industrial and metering systems. Its significance is architectural: it made “IP all the way to the sensor” practical on power- and bandwidth-starved radios.
Decoding it with GopherTrunk
GopherTrunk does not decode 6LoWPAN. It is a networking adaptation layer above an 802.15.4 (or similar) radio that GopherTrunk cannot demodulate in the first place, and its traffic is typically encrypted within Thread. It has no bearing on GopherTrunk’s land-mobile and aeronautical decode chain.