* If there are packets on the fastq, they are sent FIFO, before
* everything else. Otherwise we choose the first packet from the
* batchq and send it. the next packet chosen will be from the session
* If there are packets on the fastq, they are sent FIFO, before
* everything else. Otherwise we choose the first packet from the
* batchq and send it. the next packet chosen will be from the session