[ns] Timestamp trouble

[Andrea Josi <mr_josi@yahoo.it>]

Dear Felix Ko,

i am encountering the same large simulation memory and
time problems you quoted in 

http://www.isi.edu/nsnam/archive/ns-users/webarch/current/msg01836.html

I need to calculate the packets' end to end delay of a
multicast traffic. I have tried to apply the same
solution you suggested in that 
mail,  but i am encountering this problem:

i have added a field and a corresponding method in the
common header, "my_ts_"  and  "my_timestamp()"  

struct hdr_cmn {
..............
.............
 double ts_;  // timestamp: for q-delay measurement
 double my_ts_;   <---   this is mine
..... 
............
inline double& timestamp() { return (ts_); }
inline double& my_timestamp() { return (my_ts_); } 
<-- this is mine

I've also added a line in udp.cc in the places where
the original timestamp is used

hdr_cmn::access(p)->timestamp() = 
      (u_int32_t)(SAMPLERATE*local_time);
            
hdr_cmn::access(p)->my_timestamp() =
local_time;<--this is mine

I have implemented a receiver similar to
Agent/LossMonitor; in the recv function i have put
these lines

hdr_rtp* p = hdr_rtp::access(pkt);
start_time_ = hdr_cmn::access(pkt)->my_timestamp();

The simulation reports an error, which should concern
multicast forwarding; if i comment the lines i wrote
before, i get no error !
It seems like udp timestamp is used to identify
something ...?!!!
What was your solution ? (i don't really care to make
mine work, what i really need is a way to get the
packets departure times!)
Thanks for your help,
                                                
                Andrea Josi.


ns: _o29 new-group 2 -2147483648 0 wrong-iif: can't
read "protocols_(0)": no such element in array
    while executing
"$protocols_($iface) upcall $code $source $group
$iface"
    (procedure "_o30" line 9)
    (mrtObject upcall line 9)
    invoked from within
"$mrtObject_ upcall $code $src $group $iface"
    (procedure "_o24" line 3)
    (Node new-group line 3)
    invoked from within
"$node_ new-group $src $group $iface $code"
    (procedure "_o29" line 3)
    (Classifier/Multicast new-group line 3)
    invoked from within
"_o29 new-group 2 -2147483648 0 wrong-iif"  

______________________________________________________________________
Do You Yahoo!?
Il tuo indirizzo gratis e per sempre @yahoo.it su http://mail.yahoo.it