This better describes what is going on here (as they are created by
coap_session_delay_pdu() and are only released off this queue when
either the session becomes established, or the outstanding CON requests
falls below COAP_DEFAULT_NSTART (a value of 1).
This is to remove confusion with the use of coap_context_t sendqueue
which is used for retransmitting data after no response detected for a
CON request.
include/coap/coap_session.h
src/coap_io.c
src/coap_session.c
src/net.c