[ns] bugs/errors in ns-2.27?

[Ali Hamidian]

Hi ns-users!

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:


===========================================================
1. ~ns-2.27/ns-tutorial/wireless2.tcl

Error message:
couldn't read file "../mobility/scene/scen-3-test": no such file or 
directory
    while executing
"source.orig ../mobility/scene/scen-3-test"

Solution:
CHANGE FROM
   set opt(sc)     "../mobility/scene/scen-3-test"    ;# node movement file.
TO 
   set opt(sc)     "../../tcl/mobility/scene/scen-3-test";# node 
movement file.
===========================================================

2. ~ns-2.27/tcl/lib/ns-namsupp.tcl:set-animation-rate

Error message:
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>

Solution:
CHANGE FROM
   $self puts-nam-config "v -t [$self now] set_rate_ext $r 1"
TO
   $self puts-nam-config "v -t [$self now] -e set_rate_ext $r 1"
===========================================================

3. ~ns-2.27/aodv/aodv_rtable.cc

Error message:
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 
expanding
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);"

Solution:
CHANGE FROM
rt_hops = rt_last_hop_count = INFINITY2;
TO
rt_hops = INFINITY2;
rt_last_hop_count = 0;
===========================================================

4. ~ns-2.27/aodv/aodv.tcl

Error message:
My comments: No error message displayed. But is this file used at all? 
What is
the function of this file? I've been discussing this issue before.

Solution:
If aodv.tcl is not used at all, it should be removed since it causes 
confusion. New
users think it is an normal tcl script for a simulation and try to run it!
===========================================================

5. ~ns-2.27/trace/cmu-trace.cc

Error message:
(null) - invalid packet type (exp).

Solution:
ADD TO "void CMUTrace::format(Packet* p, const char *why)"
   case PT_EXP:
        format_msg(p, offset);
        break;
===========================================================

6. ~ns-2.27/indep-utils/cmu-scen-gen/cbrgen.tcl

Error message:
[alexh at lisa19 cmu-scen-gen]$ ns cbrgen.tcl -type cbr -nn 10 -seed 1 -mc 
8 -rate 4 

invalid sending rate 4

Solution:
CHANGE FROM
set opt(interval) [expr 1 / $opt(rate)]
TO
set opt(interval) [expr 1.0 / $opt(rate)]
===========================================================

7. ~/nam-1.10/edu/B*.tcl

Error message:
[alexh at lisa19 edu]$ ns B3-sliding-window.tcl
using backward compatible Agent/CBR; use Application/Traffic/CBR instead
running nam...

My comments: But the NAM window does not pop up and it is not executable!

Solution:
CHANGE FROM
$node_(r1) shape "rectangular"
TO
$node_(r1) shape "box"
===========================================================

8. ~ns-2.27/aodv/aodv.cc

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 
I'm very
tired and I have to go home  :-) If anyone knows more about this, please 
tell us!
===========================================================

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 
release.

Thanks for a good simulator and for your time,
Ali Hamidian