Re: Setting link up & down in your agent code

[Cheng Lin TAN <chenglin@acm.org>]

hi kannan,

thanks for the quick answer.  If that's case, does it mean that i have to call my agent in the test script as follows :

$myagent BringDown"
$ns at 0.8 "$myagent BringUp"


At 10:09 AM 6/10/98 PDT, Kannan Varadhan wrote:
>> From: ChengLin TAN <chenglin@acm.org>
>> Date: Wed, 10 Jun 1998 18:56:16 +0200
>
>ChengLin,
>
>In connection with bringing a link down, you also have to
>
>	a) update unicast routing at the incident nodes
>	b) update multicast routing at the incident nodes
>	c) drop all packets queued for transmission on that
>		link
>	d) drop all packets in transit
>
>Conversely, when bringing a link up, you have to do steps (a) and (b)
>above only.
>
>The rtmodel APIs do all of that automatically.  If you choose to
>control the links directly through your agent, then you'd likely
>want to do the work of the rtmodel code yourself.  
>
>All of this is in the documentation
>(http://www-mash.cs.berkeley.edu/ns/nsDoc.ps.gz),
>and, of course, the source code.
>
>
>Kannan
>
>
>
>> hi,
>> 
>> To set link up & down, i know i can use
>> $ns rtmodel-at 0.2 down $n0 $n1
>> $ns rtmodel-at 0.8 up $n0 $n1
>> 
>> However, if i want to use the following in my agent code procedures
>> (called BringUp and BringDown) instead :
>> 
>> [$ns link $n0 $n1] down ---> in BringDown
>> [$ns link $n0 $n1] up -----> in BringUp
>> 
>> I have declared both links to be dynamic using
>> [$ns link $n0 $n1] dynamic
>> [$ns link $n0 $n1] dynamic
>> 
>> in my test script, i called the procedures as follows:
>> 
>> $ns at 0.2 "$myagent BringDown"
>> $ns at 0.8 "$myagent BringUp"
>> 
>> After i bring up the link, the link does not seems to be working
>> (although NAM shows the link turns fr red to black).  Is it that the
>> routes are not updated yet?  How do i solve this problem?
>> 
>> Thanks in advance for any clue.
>> regards,
>> chenglin
>> 
>
>--
>kannan@isi.edu
>http://www.isi.edu/~kannan
>
>
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Cheng Lin TAN


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