Subject: [manet] scalable wireless simulation (was: Scalalbe DSDV code in ns-2?)

From: Rimon Barr <[email-masked]>
Date: Fri, 7 Nov 2003 11:33:07 -0500 (EST)

Dear Jangeun Jun and others,

As Naoumov already mentioned, the problem is first the simulator and
then (possibly) the network protocol being simulated. I'm currently
building a simulation system called JiST (for Java in Simulation Time)
and a wireless network simulator on top of this system called SWANS (for
Scalable Wireless Ad hoc Network Simulator), explicitly to tackle this
problem of scalability. This work is a project at Cornell's Wireless
Networking Lab: http://wnl.ece.cornell.edu. Based on my results, I
believe that 100,000 nodes is a *very* realistic number and can it be
simulated with accuracy in just a few hours even with a sequential
simulator. My preliminary results show that JiST out-performs Glomosim,
ns2 and even raw Parsec code by 2x-10x just in terms of event
throughput. More importantly for this group, I have also run full
wireless simulations in SWANS. SWANS uses an effective algorithm to
simulate signal propagation similar to Naoumov's idea presented at
MSWiM. It is improved to be insensitive to bin size. The result of
efficient signal propagation, combined with the time and memory saving
of the JiST approach, is that the total time to run a wireless
simulation is linear with respect to the number of nodes (for fixed
density and proportional traffic load) and I am running simulations with
100,000 nodes on commodity hardware (2.0GHz processor with less than 1Gb
of RAM) within a few hours. I've also recently been able to show
1,000,000 nodes. We're currently working on more simulation components
and hope to release the software in a few months. So, 100,000 nodes and
up is certainly possible, even with a sequential simulator on commodity
hardware -- you just need to do things efficiently.

All the best,
Rimon.
-- 
Rimon Barr -  Ph.D. candidate, Computer Science, Cornell University
rimon-AT-acm.org - http://www.cs.cornell.edu/barr - Y!IM: batripler

On Thu, 30 Oct 2003, Kenneth Brayer wrote:

>Jangeun
>
>You have another problem. Mario Gerla of UCLA, CS Dept., gave a talk in
>a panel discussion at Milcom 2002 pointing out that ns-2 is very slow
>above a few hundred nodes. He suggested Qualnet as a simulator for large
>networks and ran a 1000 node example of I think LANMAR above AODV(?). It
>took minutes. He said ns-2 would run for like days(?). Mario can
>probably give you better info.
>Ken
>
>Jangeun Jun wrote:
>
>>Hi,
>>Thank you Peter, thank you Mehran, I appreciate your prompt reponses.
>>I agree that 100K is somewhat unrealistic number.
>>Then, how about 1K? (or hopefully 10K?)
>>
>>I need to compare the performance of a new algorithm with existing ones
>>(DSDV, DSR, AODV, TORA and so on...). And I don't think it's a good idea
>>to compare the performance only up to 100 nodes because of DSDV. (Other
>>models seem to be OK... Why only DSDV?)
>>
>>I agree that DSDV is not scalable by its nature. But that's what we want
>>to simulate. The restriction of 100 nodes is really painful. I mean it
>>can be difficult to tell the difference with only 100 nodes.
>>
>>Can anyone please let me know if there is *any* version of DSDV model
>>written in ns-2 that overcame the 100-node limit?
>>Or, has anyone tried to modify the ns-2's "dsdv.cc" code to enable
>>multiple packets per update?
>>
>>Regards,
>>
>>-Jangeun Jun
>>
>>>Hi
>>>I dont think that you can manage to run such scenario realistically.
>>>If anyone did, I am really interested to know.
>>>BTW, I heard someone has run a network of 10000 nodes using AODV...
>>>
>>>Cheers
>>>Peter Pham
>>
>>On Thu, 30 Oct 2003 [email-masked] wrote:
>>
>>>Hi Jangeun,
>>>
>>>I am not sure why you want run such a large number of nodes.
>>>I dont think DSDV or any other proactive routing protocol
>>>would scale to such a large number of nodes, as the number of
>>>update packets would overwelm the network, not mension that
>>>your simulator would crash or run for a very very long time
>>>regardless of what simulation tool you use (NS, glomosim..etc).
>>>
>>>I dont know of any proposed MANET routing protocol
>>>proven to run such a large network.
>>>
>>>Regards,
>>>Mehran
>>>--------------------------------
>>>
>>>Dear sir or madam,
>>>
>>>I am a Ph.D. student at NC State University.
>>>As it's clearly shown in ns-2's DSDV source code (dsdv.cc),
>>>the current
>>>ns-2 DSDV protocol is not scalable. The maximum number of
>>>entries in an
>>>update packet is around 100 and nodes cannot generate multiple
>>>packets for one update.
>>>
>>>Since I need to run very large DSDV scenario (100,000 nodes), I am
>>>looking for a *scalable* DSDV model written in ns-2.
>>>Your tip will be greatly appreciated.
>>>
>>>(I posted this question on ns-2 mailing list but no answer. I hope
>>>that there is an improved DSDV model done by an expert in this
>>>manet
>>>circle.)
>>>
>>>Regards,
>>>
>>>-Jangeun Jun

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From: "iman elghandour" <[email-masked]>
Date: Fri, 07 Nov 2003 16:39:30 -0500

Hi,
woow. It ‘s really amazing to simulate a 1,000,000 node and so it encouraged me to ask this question.. my question is what about the reality, can I have this number of nodes connected in an ad hoc network, I think there is no real life implementation but theoretically is it possible??!!
I was thinking of another thing too, what about simulating the network to be composed of smaller separated sub-networks,. Have any one considered this simulation in his work. I think it will be important to consider it in service discovery or file sharing scenarios.
Kind regards,
Iman.

----- Original Message -----
From: Rimon Barr <[email-masked]>
Date: Fri, 7 Nov 2003 11:33:07 -0500 (EST)
To: [email-masked]
Subject: [manet] scalable wireless simulation (was: Scalalbe DSDV code in ns-2?)

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