[LARTC] tbf token help

[LARTC] tbf token help

[mknific]

Hi all!

I just started to experiment with bandwidth management using tbf.
I have the folowing problems with token understanding:

1) What unit is token? Is "1 token = 1 byte" ?
    If this is so, then with rate=0.5mbit and HZ\x100 the bucket gets filled
    with 0,64kb (655 tokens) every 10ms?

2) How much tokens are used for one packet (1500)?

3) And token unrelated question. Does packet droping alway ocurrs or 
    it happens because of bad settings?
    
    I have applied this settings on 10mbit ethernet card:
    tc qdisc add dev eth1 root tbf rate 0.5mbit burst 5kb latency 70ms /
    peakrate 1mbit minburst 1540
   
   Result:
   qdisc tbf 8007: dev eth1 rate 512Kbit burst 5Kb/8 mpu 0b peakrate 1Mbit mtu
   1539b/8 mpu 0b lat 68.4ms 
   Sent 1284481 bytes 852 pkts (dropped 48, overlimits 1743)


Thanks!

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Re: [LARTC] tbf token help

[Damion de Soto]

Have you fully read:
http://lartc.org/howto/lartc.qdisc.classless.html#AEN691
?
most of it is explained in there.

> 1) What unit is token? Is "1 token = 1 byte" ?
>     If this is so, then with rate=0.5mbit and HZ\x100 the bucket gets filled
>     with 0,64kb (655 tokens) every 10ms?
1 token is one packet.

> 2) How much tokens are used for one packet (1500)?
1

> 3) And token unrelated question. Does packet droping alway ocurrs or 
>     it happens because of bad settings?
>     
>     I have applied this settings on 10mbit ethernet card:
>     tc qdisc add dev eth1 root tbf rate 0.5mbit burst 5kb latency 70ms /
>     peakrate 1mbit minburst 1540
>    
>    Result:
>    qdisc tbf 8007: dev eth1 rate 512Kbit burst 5Kb/8 mpu 0b peakrate 1Mbit mtu
>    1539b/8 mpu 0b lat 68.4ms 
>    Sent 1284481 bytes 852 pkts (dropped 48, overlimits 1743)
Packet dropping happens when too much data is coming in.
See the explanation in the link above.

regards,

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