Feature #2724: Improve default timers
T3101 default is way too large at 10s
As can be found in literature, 1.5s to 3s is a reasonable default, far away from our 10s.
the result is that we use the radio interface quite inefficiently, particularly in presence of RACH.One problem is that the BSC doesn't really know when exactly to start T3101, as it doesn't know about
- the propagation delay on Abis to the BTS
- the queueing delay inside the BTS (due to queue length, AGCH load)
- the queueing delay inside the PHY/L1 (e.g. the OsmoTRX TRX/UDP protocol)
In order to cover at least the top two items, we could introduce a vendor-specific RSL message indicating when exactly the IMM.ASS had been sent on the radio interface.
Until such a non-3GPP solution is implemented, T3101 should have some reservation for the above delays. But for sure, 10s is completely over the top