Hi Mohamed, Thanks for the reply and many thanks for the link to the paper. The paper you mentioned offers a very lucid and clear explanation of 802.11 implementation in NS.
So, I guess the simulation is indeed correct since with the current implementation of 802.11 MAC and with RTS/CTS turned on, we will probably face this problem even in real networks. Thanks again. Regards, Kanthi > The problem is originated in the MAC layer due to the problems of > hidden/exposed nodes. When the MAC layer fails in delivering the packet > after the several transmissions, it will stop its trials and alerts the > network layer. The network layer will consider this as a route failure > -although the route always exists- and restarts its route calculation. You > can find more details in this paper: "Revealing the problems with 802.11 > medium access control protocol in multi-hop wireless ad hoc networks" for > Shugong Xua and Tarek Saadawi. > > Regards, > > Mohamed Youssef > Université de Sherbrooke > > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf > Of Kanthi > Sent: Monday, February 27, 2006 7:48 AM > To: ns-users@ISI.EDU > Subject: [ns] Link Layer Reports Route Failed - AODV > > > Hi All, > > I am using NS-2.28 and default AODV implementation on it. During some > simulations, when number of nodes are high, there are a lot of dropped > packets and repeated RREQ packets. > > The reason logged indicates that the link layer reports that a route > failed. > > Although, routes are again found, this seriously hampers the throughput. I > am not sure that this is "correct" simulation. > > My scenario has static nodes (no mobility and no change in topology during > the simulation), no error model and a simple two-ray ground propogation > model. > > Why should link layer conditions change at all in such a scenario and why > should there be drops due to that ? > > It would be really great if somebody could provide some insight. > > Thanks and Regards, > Kanthi > > -- > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.1.375 / Virus Database: 268.1.0/269 - Release Date: 2/24/2006 > > > -- > No virus found in this outgoing message. > Checked by AVG Free Edition. > Version: 7.1.375 / Virus Database: 268.1.0/269 - Release Date: 2/24/2006 > > > -- " I gave my life to become the person I am right now. Was it worth it? " - Richard Bach
