New to TC and qdisc

Hi everyone,

I just need a little help understanding an example traffic shaping
script does.

$TC qdisc add dev eth0 root handle 11: cbq bandwidth 100Mbit avpkt
1000 mpu 64
$TC class add dev eth0 parent 11:0 classid 11:1 cbq rate $DNLD weight
$DWEIGHT allot 1514 prio 1 avpkt 1000 bounded
$TC filter add dev eth0 parent 11:0 protocol ip handle 4 fw flowid
11:1

In the first line, it uses 'root handle 11'.
1, What is the root handle?
2, Does 11 mean anything, or will any number do?
3, why does root handle change to parent in the second line?


Thanks for any help you may provide