Re: How to force a packet drop?

[Ahmed A-G Helmy <ahelmy@catarina.usc.edu>]

> Hi all,
> 
> what is the simplest way to force packet drop on an arbitrary
> link? I would like to control what packets are dropped, so I don't
> want to use TCP flows to saturate a link. I would also like deterministic
> and probablilistic drop. Is errormodel the right way to do it?
> How do you use it? I couldn't find any examples in the distribution.

I believe that error models are the right way.
There's support for lots of error models in NS, and there's a chapter in 
the ns documentation on it.
You can drop packets probabilistically, deterministically, or according to a 
trace file. 

You can drop per packet, byte, or specify what kind of 
packets to drop (e.g. SRM (check SRMErrorModel class), or PIM,Join (check 
MrouteErrormodel class)... etc) [but there's probably 
more work there if you want to specify new types, you can look in 
errmodel.cc for the C++ code].

The documentation is probably not up to date, but it's a good place to start,
http://www-mash.CS.Berkeley.EDU/ns/ns-documentation.html

Regards,
-A

> 
> Thanks,
> 
> Christos.
>