Re: [ns] question about tree computation and RP resetting inCentralized multicast

[Haobo Yu <haoboy@isi.edu>]

>       1. about multicast tree construction
> 
>           what is the tree construction method from RP to receivers? Is it Reverse Path       Forwading ? 
> 
>           and If I will construct tree from RP through intermediate several nodes to Receivers as I want to, How and what can I modify ? 

If you are using centralized mcast, see tcl/ctr-mcast. 

>       2. about RP reset 
> 
>       I modify tcl example.
>       After setting up a RP as below, I want to change the RP to another one.
>       How can I do that in same tcl script?
> 
>       ---------------------------------------
>       if {$mrthandle != ""} {
>       $ns at 0.5 "$mrthandle set_c_rp [list $n1]"
>       }
>       ----------------------------------------
> 
>       When I inserted something as below. ns starts RP from $n6, not $n1.
>       I want to simulate first RP $n1 and second RP $n2.
>       I saw the nam siwtch the simulation from RPT to SPT by using switch-tree procedure in example file. 

switch-treetype is in tcl/ctr-mcast/CtrMcastComp.tcl

>       How can I do that?
>       -----------------------------------------
>       if {$mrthandle != ""} {
>       $ns at 0.90 "$mrthandle set_c_rp [list $n6]"
>       $ns at 0.90 "$mrthandle compute-mroutes" 
>       }
>       ------------------------------------------
>       I am looking forward to your reply.
>       Thanks a lot. 
> 
> 
> from ns beginner.....
>