Hi Neels,
On Fri, Feb 23, 2018 at 12:58:15AM +0100, Neels Hofmeyr wrote:
Yes, handover can be initiated in any mode of lchan and we saw handovers for lchans in GSM48_CMODE_SIGN mode. So I think we should be able to cover this case because I didn't find any mention in the specs that this case is prohibited for HO. I don't know if HO is allowed for CSD (GSM48_CMODE_DATA_*), it should be checked. But if it is prohibited for CSD, I think we should check and block it on the stage of bsc_handover_start or earlier.
So, what is CMODE_DATA, is it for PDCH / GPRS data?
It is, ad Ivan stated, for CSD (circuit switched data). Which was never fully implemented in OsmoBSC at all, only very partially and only with nanoBTS. None f the OsmoBTS code / PHYs support it, and not our TRAU frame handling for the E1/T1 BTSs.
So basically, it is unsupported :)