Layers stack on a link and are configured on its packet_interface entry.
Each layer type registers itself with its kind, so a new type needs only
a new module. The first is a reliability layer in the style of HDLC
asynchronous balanced mode, with go-back-N retransmission.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Each packet is one UDP datagram, using the settings of the udp component.
The udp component now reports whether a packet was sent, and an ENOMEM
refusal from lwIP is logged at verbose level as the packet can be sent
again.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
A packet interface moves packets over a channel, with a uart link and a
packet_transport platform that uses any packet interface. Later layers
stack on the same base class.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
