[ns] bugs/errors in ns-2.27?
alexh at telecom.lth.se
Tue May 11 10:51:59 PDT 2004
I havn't been an active user for a long time now. However, recently I
installed the latest version ns-allinone-2.27.
I was glad to notice that the installation process was really easy in my
Linux Red Hat 7.2. However, there are some small bugs (or whatever you
can call them) which still remain from very old versions although they
have been pointed out several times by people in this list (when I was
active). I think it's a pity and hope they will not reappear in the next
release! Here they are:
couldn't read file "../mobility/scene/scen-3-test": no such file or
set opt(sc) "../mobility/scene/scen-3-test" ;# node movement file.
set opt(sc) "../../tcl/mobility/scene/scen-3-test";# node
Nam syntax has changed: v -t 0 set_rate_ext 0.01 1
Please use this format in the future.
v -t <time> -e <tcl expression>
$self puts-nam-config "v -t [$self now] set_rate_ext $r 1"
$self puts-nam-config "v -t [$self now] -e set_rate_ext $r 1"
My comments: No error message displayed, but the expanding ring search
algorithm is broken. This bug causes a RREQ message to be broadcasted with
TTL=30 at the first attempt of route discovery instead of using the
ring search algorithm.
See AODV::sendRequest(nsaddr_t dst) in aodv.cc line
"rt->rt_req_last_ttl = max(rt->rt_req_last_ttl,rt->rt_last_hop_count);"
rt_hops = rt_last_hop_count = INFINITY2;
rt_hops = INFINITY2;
rt_last_hop_count = 0;
My comments: No error message displayed. But is this file used at all?
the function of this file? I've been discussing this issue before.
If aodv.tcl is not used at all, it should be removed since it causes
users think it is an normal tcl script for a simulation and try to run it!
(null) - invalid packet type (exp).
ADD TO "void CMUTrace::format(Packet* p, const char *why)"
[alexh at lisa19 cmu-scen-gen]$ ns cbrgen.tcl -type cbr -nn 10 -seed 1 -mc
8 -rate 4
invalid sending rate 4
set opt(interval) [expr 1 / $opt(rate)]
set opt(interval) [expr 1.0 / $opt(rate)]
[alexh at lisa19 edu]$ ns B3-sliding-window.tcl
using backward compatible Agent/CBR; use Application/Traffic/CBR instead
My comments: But the NAM window does not pop up and it is not executable!
$node_(r1) shape "rectangular"
$node_(r1) shape "box"
There are some minor bugs in aodv.cc which I've been discussing with Riadh
Marrakchi; e.g. regarding rp->rp_src = index; in sendReply(). But now
tired and I have to go home :-) If anyone knows more about this, please
If any of my points is wrong please correct me; otherwise please fix the
problems! I don't receive the emails sent to the list so please send
your replies to my address also.
NOTE! It took me pretty long time to write this email so I really hope I
havn't written it in vain, i.e. I hope I can see the changes in the next
Thanks for a good simulator and for your time,
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