Snoop

[Ingela Anderton <ingela@docs.uu.se>]

Hello every one!

Before I asked if anyone hade any clues why I didn't get any better
throughput with snoop than with out it. Yes it was really strange. But
now I found out why by myself, well sort of anyway.
I still have some question marks, see below. 

When adding the base station to the lan I used the following command:
	
   $lan	addNode [list $node($newnode)]  $opt(bw) $opt(delay)
	LL/LLSnoop $opt(ifq) $opt(mac) 

This however seems to just add the LL/LLSnoop in one direction so to speak.
My simulation kind of snooped only in one direction. (Well that is
what I gathered from the debug messages I put in snoop.cc)

So now I use the command: 

   $lan	addNode [list $node($newnode)]  $opt(bw) $opt(delay)
	LL/LLSnoop $opt(ifq) $opt(mac) LL/LLSnoop

                                       ^^^^^^^^^^
			              This is the difference		


However I am a bit confused though, because if I change the first appearance of
LL/LLSnoop above to LL and only have LL/LLSnoop as the last argument
it still seems to work the same way.  


The definition of addNode is:

LanLink instproc addNode {nodes bw delay {sllType ""} \
		{ifqType ""} {macType ""} {dllType ""}}


So what does sllType and dllType stand for? I don't think these are
optimal variable names. I gather ll = link layer but what does s and d stand
for? If I knew that for sure I could understand why the behaviour of
my simulations.

 
This is my simulation scenario:
    -----
   |     |  
   |  0	 |--|
   |	 |  |
    -----   |
            |
            |
    -----   |
   |     |  |
   |  1	 |--| LAN
   |     |  |
    -----   |
            |
            |
    -----   |          -----
   |     |  |         |     |
   |  2	 |--|         |  3  |
   |	 |------------|     |
    -----  Wireless    -----	 
           link
  


I use node 0 as an FTP server and node 2 is a basstation and node 3 is
the mobile host. At the time beeing I only have on traffic flow, a FTP
transfer from node 0 to node 3. The wireless link I have made lossy
using the errormodel. 

-- 
/m.v.h. Ingela

//The highway of life is always under construction. //

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