3.1.5.8 Handling Out-of-Sequence Packets

The process for handling out-of-sequence packets is described in [RFC2637] section 4.3. The PAC/PNS SHOULD attempt to reorder packets before sending them to the higher layer.<7> However, when reordering is not possible, the packets SHOULD continue to be sent to the higher layer even though the packets might be sent out of order.

Packets with duplicate sequence numbers SHOULD never occur, as specified in [RFC2637] section 4.3. However, the PAC/PNS SHOULD continue to send packets to the higher layer even though packets with duplicate sequence numbers might exist.

Note Sending out-of-sequence packets to the higher layer is in direct contravention of [RFC2637] section 4.3, which states that such behavior could cause problems because proper PPP protocol operation is premised upon receiving packets in sequence.