Changes between Version 21 and Version 22 of UsersGuide


Ignore:
Timestamp:
Oct 24, 2012 4:04:12 PM (11 years ago)
Author:
Ted Faber
Comment:

--

Legend:

Unmodified
Added
Removed
Modified
  • UsersGuide

    v21 v22  
    371371In return for the greater control on packing, there is a price.  When a set of containers is packed, the containers system takes into account both the nodes to be packed and their interconnections.  When subsets of containers are packed, the system cannot consider the interconnections between subsets.  In some cases, the packing of subsets can lead to a DETER experiment that cannot be created successfully.  This danger is mitigated by the fact that containers that are packed together are often related in ways that limit the number of connections between that set and another.
    372372
    373 
     373To explore packing, we need a [attachment:example6.tcl larger topology]:
     374
     375{{{
     376source tb_compat.tcl
     377set ns [new Simulator]
     378
     379set center [$ns node]
     380tb-add-node-attribute $center "containers:PartitionPass" 0
     381
     382
     383for { set i 1} { $i < 4 } { incr i} {
     384    set lanlist $center
     385    for { set j 0 } { $j < 20} { incr j } {
     386        set idx [expr $i * 20 + $j]
     387        set n($idx) [$ns node]
     388        tb-add-node-attribute $n($idx) "containers:PartitionPass" $i
     389        lappend lanlist $n($idx)
     390    }
     391    $ns make-lan [join $lanlist " "] 100Mb 0
     392}
     393
     394# Creation boilerplate
     395$ns rtptoto Static
     396$ns run
     397}}}
     398
     399This creates 3 20-node subnetworks attached to a single central router.  It looks like this:
     400
     401[[Image(packing-small.png)]]
     402
     403Each node in the topology is assigned a {{{containers::PackingPass}}} attribute that groups them into subsets.  The {{{conatiners:PackingPass}}} attribute must be assigned an integer value.  The nodes in each packing pass are considered together when packing.  Each pass can be assigned different parameters.  The passes are carried out in order, though that is rarely important.
     404
     405Our topology assigns
    374406
    375407== Further Reading ==