[ns] in 802.11, ShortRetryLimit_ and LongRetryLimit_ "0" is same effect on simulation result as "1"?

[Sangho Lee]

I experiment on 802.11 wired-cum-wireless (wirelessLAN) with chanaging MAC
retransmission from 0 to 5 in NS-2.29.

The trace file of MAX retransmission "0" and "1" are completely same.

I change the value of MAX retransmission like below,

      set par(rtxMax)            0
       <...>
      Mac/802_11 set ShortRetryLimit_   $par(rtxMax)    ;# retransmittions
      Mac/802_11 set LongRetryLimit_    $par(rtxMax)    ;# retransmissions
       <...>


ns-2.29/mac/mac-802_11.cc
...
        if((u_int32_t) ch->size() <= macmib_.getRTSThreshold()) {
                rcount = &ssrc_;
               thresh = macmib_.getShortRetryLimit();
        } else {
                rcount = &slrc_;
               thresh = macmib_.getLongRetryLimit();
        }

        (*rcount)++;

        if(*rcount >= thresh) {
                /* IEEE Spec section 9.2.3.5 says this should be greater than
                   or equal */
                macmib_.FailedCount++;
....

if this pacekts try to send at first time,
rcount = 0 and increases to 1 by (*rocunt)++
then, "if (*rcount >= thresh)" check MAX retransmission threshold.
whenever thresh is 0 or 1, it can't try to retransmission more, right?

Is it normal results(IEEE 802.11 standard)? or not? (ns-2 implementation 
problem?)


please help me!


sincerely,
Sangho Lee