A method and arrangement for determining the expiry time for a period during which the re-establishment of lost radio bearers is allowable. There is determined a first expiry time (206, 207) for a period during which the re-establishment of lost radio bearers used to provide services of a first category, like real time services, is allowable. Additionally there is determined a second expiry time (208, 209) for a period during which the re-establishment of lost radio bearers used to provide services of a second category, like non-real time services, is allowable.