This helper provide TCP reassembly and reordering. It means that it will buffer packets that are received out of order and pass the in the right order to the rule processor. This way, the targets or any subsequent match don't have to care about the order of TCP packets since this helper ensure that packets are in the right order and not duplicate. This helper has two parameters :

• pkt_timeout

This parameter specifies the number of seconds to wait between out of order packets.
Default : 30 seconds

• conn_buffer

This parameter specifies the maximum amount of data that will be saved by connection while waiting for a missing packet. If the limit is reached, the missing packet is ignored and the rest of the packets are processed.
Default : 64 Kbytes

• fill_gaps

This parameter specifies if helper_tcp should try to fill gaps of missing packets. If set to yes, it will generate packets with zero filled payload.
Default : yes