RE: Problem with Mac/Csma/Cd

[Jeff Donahoo <Jeff_Donahoo@baylor.edu>]

There was a thread (w/ subject Csma/Cd in ns) just last week that answered
this question.  Basically, the CSMA/CD code has been commented out due to
"glitches" [Haobo Yu 1999].  You can use the Mac/802_3 agents which
implement CSMA/CD; however, we have had some problems with 802_3 agents that
have not been addressed to my knowledge.  (See posting by Jason Todoroff on
9/18/99.)

Good Luck

> Hi!
>
> I wrote a script to simulate a LAN containing 5 nodes. It begins with
> these lines :
>
> set ns [new Simulator]
>
> set n0 [$ns node]
> set n1 [$ns node]
> set n2 [$ns node]
> set n3 [$ns node]
> set n4 [$ns node]
> set n5 [$ns node]
>
> $ns make-lan "$n0 $n1 $n2 $n3" 10Mb 10ms LL Queue/DropTail Mac/Csma/Cd
>
> ...
>
>
> whene I start ns, I get the following error :
>
>
> invalid command name "Mac/Csma/Cd"
>     while executing
> "Mac/Csma/Cd create _o30 "
>     invoked from within
> "catch "$className create $o $args" msg"
>     (procedure "new" line 3)
>     invoked from within
> "new $macType_"
>     (procedure "_o27" line 14)
>     (LanIface init line 14)
>     invoked from within
> "_o27 init _o10 _o22 -ifqType Queue/DropTail -llType LL -macType
> Mac/Csma/Cd -phyType Phy/WiredPhy"
>     (Class create line 1)
>     invoked from within
> "LanIface create _o27 _o10 _o22 -ifqType Queue/DropTail -llType
> LL -macType Mac/Csma/Cd -phyType Phy/WiredPhy"
>     invoked from within
> "catch "$className create $o $args" msg"
>     (procedure "new" line 3)
>     invoked from within
> "new LanIface $src $self  -ifqType $ifqType  -llType  $llType
> -macType $macType
>   -phyType $phyType"
>     (procedure "_o22" line 14)
>     (LanNode addNode line 14)
>     invoked from within
> "$lan addNode $nodelist $bw $delay $llType $ifqType $macType  $phyType"
>     (procedure "_o3" line 3)
>     (Simulator make-lan line 3)
>     invoked from within
> "$ns make-lan "$n0 $n1 $n2 $n3" 10Mb 10ms LL Queue/DropTail Mac/Csma/Cd"
>     (file "lan-1.tcl" line 10)