LAPD timers completely broken
The T200 timer must be started at the moment the related frame (e.g. SABM, I, ...) is pulled out by L1 at the bottom of LAPD.
However, looking at the code, it seems to be doing it completely wrong: It starts the timer when it receives e.g. an ESTABLISH REQUEST from the L3. There can be any amount of time between that (L3 running asynchronous of the L1 of the underlying TDM) and the actual transmission.
In the end, the current behavior means that T200 is started way too early, and hence times out way too soon.