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Re: Using TC to simulate wireless channels



On Wed, 16 Aug 2000, christian.benven wrote:
> it depends on what you mean by bits/s (I do not know what is a 3G 
> channel). Do you mean 300, 1200, 9600, ...?
> To smaller you want it to be, the worse it becames the simulation.

Yes, that's only because shaping is not the correct way to emulate 
bandwidth. Let's use ping as an example. It sends one packet per
second. If the granularity of the shaper is second, the traffic is
never shaped and each packet is passed as it is. This is exactly
how nistnet does it and why it doesn't also work. In reality you have
to calculate the transmission delay (e.g. how long would this packet
occupy the virtual bit-pipe) of the given packet and delay each packet 
accordingly.

-- 
D.