[ns] control flow thru 802.11 mac
Tue Apr 16 12:40:04 2002
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
On Tue, 16 Apr 2002, Sorav Bansal wrote:
> 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).
> Krishna" To: ns-users@ISI.EDU
> <firstname.lastname@example.org cc:
> .ernet.in> Subject: [ns] control flow thru 802.11 mac
> Sent by:
> 04/16/02 04:16
> Please respond
> to "M.Gopi
> 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
> Is this true?