[ns] control flow thru 802.11 mac

[M.Gopi Krishna]

Hi,
Thanks for the reply. I think you are correct.
So what happens when a mac packet is pending due to backoff and another
mac packet comes? Can this happen? If so, won't it corrupt the pktRTS_ and
pktDATA_ variables?

Thanks,
Gopi

 On Tue, 16 Apr 2002, Sorav Bansal wrote:

> 
> Hi,
>     No I dont think thats true. The RTS packet is stored in pktRTS_ until
> it gets a chance to be sent on the channel. The RTS packet is created only
> once and once it is sent successfully (after multiple retransmits), it is
> deleted. Till then it is stored in pktRTS_.
>     On sensing the carrier to be busy, the backoff is started and the
> backoffHandler when backoff expires (and hence the pktRTS_ is safe).
> regards,
> --sorav
> 
> 
> 
>                                                                                                  
>                     "M.Gopi                                                                      
>                     Krishna"              To:     ns-users@ISI.EDU                               
>                     <mgopi@csa.iisc       cc:                                                    
>                     .ernet.in>            Subject:     [ns] control flow thru 802.11 mac         
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>                     04/16/02 04:16                                                               
>                     PM                                                                           
>                     Please respond                                                               
>                     to "M.Gopi                                                                   
>                     Krishna"                                                                     
>                                                                                                  
>                                                                                                  
> 
> 
> 
> 
> Hello,
> I've some doubt reg packet flow thru 802.11 mac.
> According to me, link layer schedules the packet handler of mac using some
> delay. After this delay, mac handler is activated and recv(Packet *p) of
> 802_11 mac is called. This checks whether is call is upcall or
> downcall. Let's assume this is downcall, this calls
> Mac802_11::send(...). This initializes mac header and creates (allocs) an
> RTS pkt. It then checks for medium busy. If the medium is busy, it does
> the same as done by link layer (schedule handler).
> But where does it free the RTSpacket alloc'd.
> 
> 
> Since this may happen multiple times, this may create multiple RTS packets
> unfreed.
> Is this true?
> 
> Thanks,
> Gopi
> 
> 
> 
> 
>