OsmoBSC - lchan allocation failed in state WAIT_RLL_RTP_ESTABLISH

Hello guys,

I found an interesting issue. After I place a call to a number which is not existent in HLR DB I am not able to make a call to an existing one anymore. Seems the timeslot is not released properly. If I am doing a BSC config adjustment like channel allocator mode assignment to descending (assuming it was ascending before) I am able to make a call again (until i call a wrong number and the lchan gets stucked).

Im using an ipaccess nanoBTS (fw version 168d502_v206b17d0) as hardware and latest versions of Osmocom packages (BSC, MSC, HLR, MGW and STP) with minimal changes of example configuration (from /etc/osmocom).

Do you have any idea if could be an issue related to nanoBTS firmware?

Regards, Cristian