PCT No. PCT/SE93/00237 Sec. 371 Date Nov. 14, 1994 Sec. 102(e) Date Nov. 14, 1994 PCT Filed Mar. 22, 1993 PCT Pub. No. WO93/19551 PCT Pub. Date Sep. 30, 1993Methods and devices for handling a buffer in packet networks, particularly in regard of loss and delay of packets, which belong to predetermined or implicitly given loss priority classes and delay priority classes. When a packet arrives at the buffer, its loss priority and delay priority classes are determined. For each loss priority class, there is a predetermined threshold value, and a total filling level of the buffer, i.e., the total number of packets stored, is compared to the threshold value of the packet's loss priority class. If the threshold value is larger than the total filling level, the packet is buffered in order to be forwarded; otherwise, the packet is lost. In determining whether a packet is to be buffered or lost, the packet's delay priority is not taken into account. In forwarding packets from the buffer, those packets that belong to higher delay priority classes are chosen in the usual way before packets belonging to lower delay priority classes. This is done such that packets belonging to all delay priority classes can be warranted a specific minimum service level by associating each such class with a maximum time period, within which at least one packet of the delay class considered will be forwarded if such a packet is available in the buffer.