Re: [ns] Why the message is not delivered (ARP requests lost?)

[Chalermek Intanagonwiwat <intanago@ISI.EDU>]

Does this happen in every round of positive reinforcement ?

-- Chalermek

On Fri, 14 Sep 2001, YY YY wrote:

> Hi, there:
> 
> I am using ns2 to simulate the ad hoc network and the routing protocol is 
> directed diffusion. The scenario is simple enough with only three nodes, one 
> sink and three sources(one node has both a sink and a source). When two 
> nodes unicast positive reinforcement messages to the third one 
> simultaneously, only one message is delivered. I checked the trace file and 
> found that both nodes sended an ARP request first, but only one is received 
> by the destination. So only one ARP reply message is generated. The network 
> is far from overload and the lost positive message is critical to the 
> protocol. I don't understand why only the ARP Requests are dropped. Is it 
> because of confict? But all data messages are delivered successfully.
> 
> Thanks a lot.
> 
> Yong
> 
> 
> Node 1 sends Pos to 0; (Generate ARP request)
> Node 2 sends Pos to 0; (Generate ARP request)
> 
> 0 receivs 1's request and replies;
> 0 doesn't receive the ARP request from 2;
> 
> r 0.117095713 _2_ AGT  --- 16 diffusion 36 [0 0 0 0] [energy 9999.994047] 
> ------- [2:255 2:0 32 0]
> s 0.117150647 _1_ MAC  --- 0 ARP 80 [0 ffffffff 1 806] [energy 9999.994017] 
> ------- [REQUEST 1/1 0/0]
> s 0.117150713 _2_ MAC  --- 0 ARP 80 [0 ffffffff 2 806] [energy 9999.994047] 
> ------- [REQUEST 2/2 0/0]
> r 0.117470668 _0_ MAC  --- 0 ARP 28 [0 ffffffff 1 806] [energy 9999.994070] 
> ------- [REQUEST 1/1 0/0]
> s 0.118329800 _0_ MAC  --- 0 MAC 44 [28f 1 0 0] [energy 9999.994070]
> r 0.118505821 _1_ MAC  --- 0 MAC 44 [28f 1 0 0] [energy 9999.993703]
> s 0.118515821 _1_ MAC  --- 0 MAC 38 [1ed 0 0 0] [energy 9999.993703]
> r 0.118667841 _0_ MAC  --- 0 MAC 38 [1ed 0 0 0] [energy 9999.993863]
> s 0.118717841 _0_ MAC  --- 0 ARP 80 [a2 1 0 806] [energy 9999.993863] 
> ------- [REPLY 0/0 1/1]
> r 0.119037862 _1_ MAC  --- 0 ARP 28 [a2 1 0 806] [energy 9999.993475] 
> ------- [REPLY 0/0 1/1]
> s 0.119047862 _1_ MAC  --- 0 MAC 38 [0 0 0 0] [energy 9999.993475]
> r 0.119199883 _0_ MAC  --- 0 MAC 38 [0 0 0 0] [energy 9999.993590]
> 
> _________________________________________________________________
> Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp
>