[Ns-developers] aodv extension - new header problem

Cenker Demir cdemir at stevens.edu
Tue Apr 18 07:09:04 PDT 2006


Hello Vincent, thank you for your reply.

What I did was; I added a header to aodv_a (i named the extended 
version aodv as aodv_a) a packet header, in aodv_a_packet.h:

#define HDR_AODV_A_PAYMENT(P)      ((struct 
hdr_aodv_a_payment*)hdr_aodv_a::access(p))

and I also put the struct for my new header in the same file 
(aodv_a_packet.h).

Than, in aodv_a.cc, I used this header putting a metric value in it. 

My problem is; 

when recv(Packet *p, Handler*) function in aodv_a.cc calls 
rt_resolve(Packet *p) function to find a route for the packet, 
rt_resolve(Packet *p) checks if there is a known route for the packet. 
If there is not, then it puts the packet into its queue by calling 
rqueue.enque(p).

Then, as soon as the node gets a route reply for this packet's 
destination, it dequeues all the packets to this destination by calling 
rqueue.deque(rt->rt_dst). Then it calls the forward function, which is:
void
AODV_A::forward(aodv_a_rt_entry *rt, Packet *p, double delay). Then, 
all these packets are scheduled.

My question is: when I change my payment header's value in 
rt_resolve(Packet *p) and call the forward function, the value is still 
there. However, when I change the value in recvReply(), after dequeuing 
the packet, the value in my header becomes 0. 

I can get the info for my metric (payment value) only after getting 
route replies, so there is no way for me to set the value in 
rt_resolve(Packet *p) when I do not have a route. So, I have to set my 
value in recvReply(), after the packets are dequeued.

I will really appreciate if anyone has an idea...

Best regards
Cenker 

  


Vincent Nauwelaers wrote:


>to me it already is unclear what the forward function is, 
>I suspect a function of the AODV Agent, please specify
>your question with relevant code. Maybe some default values
>are used ...
>
>good luck
>
>----- Original Message ----- 
>From: "Cenker Demir" <cdemir at stevens.edu>
>To: <ns-developers at ISI.EDU>
>Sent: Monday, April 17, 2006 8:30 PM
>Subject: [Ns-developers] aodv extension - new header problem
>
>
>> Dear ns developers,
>> 
>> I am trying to write an extension code which uses aodv - with 
auctions. 
>> In order to do that, I added a new header type to other aodv header 
>> types. However, I use this header with data packets cbr/udp, and I put 
>> the header into data packets. The problem that I experienced is; when 
I 
>> change a value in this new header in -for instance- recvReply function 
>> to something non-zero, the value becomes "0" when forward function 
>> receives the packet. 
>> 
>> I sent the question to ns-users first, after looking for the answer in 
>> ns-archive, however could not get any response. Then I thought someone 
>> maybe able to answer the question in ns-developers list. I will really 
>> appreciate if anyone answers my question. 
>> 
>> Best regards
>> Cenker
>> 
>> 
>
>


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