HELP: Multicast router link max?

[Jeff Donahoo <Jeff_Donahoo@baylor.edu>]

Hi.  Is there some limitations to the number of links on a multicast router?
In the script below, if I connect 128 nodes with receiver sinks to the
source node, I get the following error:

ns: _o2817 recv  255 0: no value given for parameter "m" to "_o2817"
    (Agent/Mcast/Control recv line 1)
    invoked from within
"_o2817 recv  255 0"

If I change it to 127 nodes, it works fine.  (Just change j assignment in
the script.)  If I change the routing scheme to CtrMcast, I get a core dump.
Any ideas on the problem?  I am running the allinone release with ns-2.1b5
under Linux (RH 5.2).

Thanks in advance for any and all help,
Jeff

PS I even tried connecting only 127 nodes to the source node and the 128th
node to the first of the 127 nodes with the same results.

set ns [new Simulator -multicast on]

$ns set-address-format expanded

# Allocate a few  nodes
set n0 [$ns node]
set j 128   # To make this script work, change this to 127 and comment out
            # the "set-address-format ..." line above.
puts "creating nodes ..."
for {set i 1} {$i <= $j} {incr i}

    set n($i) [$ns node]
}

puts "creating links .."
for {set i 1} {$i <= $j} {incr i}

    $ns duplex-link $n0 $n($i) 5Mb 2ms DropTail
}

#set mproto CtrMcast
#set mrthandle [$ns mrtproto $mproto {}]
set mproto DM
set mrthandle [$ns mrtproto $mproto {}]

set POLLSnd [new Agent/UDP]
$ns attach-agent $n0 $POLLSnd
set POLLSrc [new Application/Traffic/CBR]
$POLLSrc attach-agent $POLLSnd

puts "creating receivers..."
for {set i 1} {$i <= $j} {incr i} {
    set POLLRcv($i) [new Agent/Null]
    $ns attach-agent $n($i) $POLLRcv($i)
    $ns at 0.2 "$n($i) join-group $POLLRcv($i) 0x8000"
}

$POLLSnd set dst_ 0x8000

$ns at 0.3 "$POLLSrc start"

$ns at 10 "exit"

$ns run