[ns] attach-agent failure

[Patrick Simen <psimen@eecs.umich.edu>]

I need a traffic generating agent like Application/Traffic/CBR which sends
out a packet through a UDP agent when a TCPSink agent at the same node
receives a packet (to simulate a received TCP packet being forwarded
on over UDP multicast).  I created a modified cbr_traffic.cc file called
bridge_traffic.cc, and I also modified tcp-sink.cc and tcp-sink.h.  It
turns out I needed to separate out the class definition for Bridge_Traffic
from the file bridge_traffic.cc, so I created a header called
bridge_traffic.h.  I added bridge_traffic.o to the list of
dependencies in the makefile variable OBJ_CC.  I then did makedepend and
make, and compilation was fine.  When running a script with the following
commands to attach the bridge agent to a UDP agent:

$ns attach-agent $udp($i) $bridge($i)

I get the following error:

trace: can't attach _o1376 for writing
    (_o1348 cmd line 1)
    invoked from within
"_o1348 cmd attach _o1376"
    invoked from within
"catch "$self cmd $args" ret"
    (procedure "_o1348" line 2)
    (SplitObject unknown line 2)
    invoked from within
"$node attach $agent"
    (procedure "_o3" line 2)
    (Simulator attach-agent line 2)
    invoked from within
"$ns attach-agent $udp($i) $bridge($i)"
    (file "/home/psimen/TclScripts/uni-to-edge-multi-to-net.tcl" line 166)


Any ideas?  Application/Traffic/Bridge is just like
Application/Traffic/CBR, except that timeout() doesn't cause a packet to
be sent unless a new member variable called trigger_ is also set.

Thanks for any help. --Pat.