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Re: [ns] Question on Error Model



> 	a)      When using the Uniform distribution for the Error Model in
> NS, can we specify the unit as byte ?
> 	        i.e.
> 				    	set myEM  [new ErrorModel/Uniform
> 0.2 byte]

I think you can because that uniform thing is just a simple derivation of
error model and it does not add much. 

> 		  When i looked through the ns-errmodel.tcl, there is only
> definition for the unit packet and no definition for the unit byte.

See ~ns/errmodel.{h,cc}

> 	    	  If the unit is in pkt, what does 0.2 means ? does it mean
> that 20% of the packets sent by the sender would be dropped ?

Yes.

> 	 b.   Does the Uniform ErrorModel suppose to distribute the error
> evenly ?

If you read ErrorModel code in errmodel.cc, you'll think that it should.
I'd be interested if it does not.

> 	      however, from the tracefile, i do not seem to see that 20% of
> the packets are dropped. The tracefile shows that about 13% of packets 
> 	are dropped.  Is that correct ?

Did you run it long enough?

- Haobo