using dummynet to simulate modem, dsl, etc

[Mark Hannon]

Luigi Rizzo wrote:

>>  # add serilization of 40 octet ACK to upsteam delay
>>  $us_serial_delay = (40 * 8 ) / $$this{us_bw};
>>    
>>
>...
>  
>
>>  # add serilization of MTU octet data to downstream delay
>>  $ds_serial_delay = ($$this{mtu} * 8 ) / $$this{ds_bw};
>>    
>>
>
>why are you adding this extra delay ? dummynet already does that --
>a packet only comes out of a pipe after what you call the "serialization"
>delay (of the packet itself and any other packet queued in front of
>it).
>
Thanks for clarifying that - for some (probably stupid) reason I thought 
that dummynet
simply limited the maximum bandwidth used by a pipe but that it was 
still clocked at the
line rate of the original interface.  That should improve the results a bit.

Regards/Mark