when a MS is in a call it misses the network-initiated Location Area Update procedure(s). This inconvenience can lead (if the call ends after the expire_lu time) to having an attached (and active) subscriber marked as expired in the HLR. Furthermore if at this point the MS initiates a new call, the call will be dropped and (as expected) a new Location Area Update procedure will be initiated by the BSC.

I find this behavior annoying mostly in scenarios where the T3212 (LAU timer) has been setup to a low value.

To tackle this issue I thought of triggering a subscriber update when a call get released (either by the network or by the MS) for each of the MS involved in the call.

The code can also be optimized by checking whether the subscriber is expired before performing the update.

I can provide a patch if you also consider the above as a misbehavior of OpenBSC.

cheers

luca