LLN Fragment Forwarding and Recovery
Jonathan W. Hui, Pascal Thubert · 2018
Considering that an LLN frame can have a MAC payload below 100 bytes, an IPv6 packet might be fragmented into more than 10 fragments at the 6LoWPAN layer. In a 6LoWPAN mesh-under network, the fragments can be forwarded individually across the mesh, whereas a route-over mesh network, a fragmented 6LoWPAN packet must be reassembled at every hop, which causes latency and congestion. This draft introduces a simple protocol to forward individual fragments across a route-over mesh network, and, regardless of the type of mesh, recover the loss of individual fragments across the mesh and protect the network against bloat with a minimal flow control.