Subject: definition of large ad hoc networks

From: MEDDOUR Djamal Eddine thesard FTRD/DAC/LAN <[email-masked]>
Date: Wed, 13 Feb 2002 14:00:17 +0100

any comments ?

-----Message d'origine-----
De : Kilian Weniger [mailto:[email-masked]]
Envoyé : mercredi 13 février 2002 13:58
À : Bruno Husson
Cc : MEDDOUR Djamal Eddine thesard FTRD/DAC/LAN; CARLINET Yannick
FTRD/DAC/LAN
Objet : Re: Address Allocation with IPV6

From my point of view a large network is a couple of hundred nodes. You
might have as many nodes in conferences, at exhibitions, on highways etc.

For example kids in the back of a car want to play multiplayer-games with
other kids in another car, or you want to exchange files with other
people in a train.... This would be too expensive und not free from
interruptions (tunnels,...), if you would use cellular networks.

Kilian

On Wed, 13 Feb 2002, Bruno Husson wrote:

> Hello Kilian,
>
> What are the use cases of large ad-hoc networks  you consider as possible
?
> Large ad-hoc networks for which kind of community :
> - Companies ?
> - public sites like airports, railway stations, hospitals ?
> - public networks ?
> Have you some example where large ad-hoc networks would be an interesting
solution compared to
> cellular based networks ?
>
>
> Kilian Weniger a écrit :
>
> > Hi Bruno,
> >
> > yes, we are also interested in large networks. We want a system, that
> > scales to a large number of nodes.
> >
> > We claim, that our system can do that. Of course it also works for small
> > networks. E.g. If the network is so small, that it has the radius equal
> > or less to the radius of a scope, there is only one subnet with one
leader node.
> > This is equivalent to a simple, flat address scheme.
> >
> > If nodes also would have unique IPv6 address, this could be used as
global
> > routable address in conjunction with Mobile IP to connect the ad hoc
> > network to the internet. The site-local addresses constructed by the
IPv6
> > SAA could than be used for the communication within the ad hoc network
> > (with the benefit of route aggregation).
> >
> > regards,
> >
> > Kilian Weniger
> >
> > On Tue, 12 Feb 2002, Bruno Husson wrote:
> >
> > > Hello Kilian and Djamal,
> > >
> > > Kilian Weniger a écrit :
> > >
> > > > Hello Djamal,
> > > >
> > > > I have two comments on that:
> > > >
> > > > Firstly, in your scenario routing would only work if every existing
> > > > device has an unique IPv6 address assigned by the manufacturer.
> > >
> > > IPv6 shall not be defined by the manufacturer. It should be
auto-configured or configured by
> > > administrator of the network.
> > >
> > > > This is not the case today and even
> > > > if EVERY manufacturer would start doing so at some point of time in
the
> > > > future (I don't see any such effort, yet), there are still
> > > > thousands of devices without addresses, that were sold before.
> > > > Furthermore, you would need some sort of central registration, as
there is
> > > > for IEEE MAC-addresses. And even the MAC-addresses are not unique
today
> > > > (some manufacturers sell devices with unregistered MAC-addresses;
you can change
> > > > the MAC-address of some devices,...). So even in the case you would
have
> > > > this central registry, you probably want to have a backup solution
to
> > > > guarantee unique addresses.
> > >
> > > Yes. IPv6 adress may be built based on MAC address (EUI-64 solution).
In that case it has a
> > > good probability to be unique, except that some devices may have non
unique MAC adress for
> > > the reasons you indicate.
> > > So, some detection of duplicate address (DAD) should be recommanded,
except if you work in a
> > > closed environment where your are sure it is unnecessary (this is not
the IETF philosophy).
> > >
> > > >
> > > > By the way, if you argue against IPv6 SAA in ad hoc networks, you
> > > > could also argue against IPv6 SAA in general (in wired LANs). You
> > > > wouldn't need that, too, if all (wired) network devices would have
unique,
> > > > pre-assigned IPv6 addresses.
> > >
> > > This is not the solely objctive of SAA.
> > >
> > > >
> > > > Secondly, a hierarchy is established by the architecture described
in the
> > > > paper, which can be used by routing protocols to achieve an improved
> > > > scalability (route aggregation...). You wouldn't have this with
> > > > preassigned addresses.
> > > >
> > >
> > > That's the point. The site local or global IPv6 address is built to be
unique but also to
> > > enable integration of the node in a hierarchical address scheme.
> > > In a flat address scheme, a unique EUI-64 address would be sufficient
(except that we are
> > > not totally sure it is a unique address). However a flat address space
would imply great
> > > complexity in routing tables!  So hierarchy in the adress space is
needed and networs are
> > > pertitioned in subnetworks.
> > >
> > > Now, the problem is to define the notion of hierarchy and of
subnetwork in ad-hoc networks.
> > > There are several proposal but no unique answer to that question. In a
theoretical world,
> > > the mechanism proposed in the document seems interesting (hierarchy
depends on topology and
> > > may evolve with it). It answers large networks needs.
> > > Possibly there are more simple solutions that would answer smaller
topology cases where an
> > > a-dhoc network is a falt subnetwork to be integrated in a larger
network and adressing plan.
> > >
> > > Are you more interested in large scale networks ?
> > >
> > >
> > > >
> > > > Kilian Weniger
> > > >
> > > > On Tue, 12 Feb 2002, MEDDOUR Djamal Eddine thesard FTRD/DAC/LAN
wrote:
> > > >
> > > > > hi all
> > > > > I am reading a paper which talk about Address Allocation with IPV6
(IPv6
> > > > > Autoconfiguration in Large Scale Mobile Ad Hoc Networks). do you
think
> > > > > really that a same scheme is needed?. in IPV6 we have a huge
number of IP
> > > > > address, we can attribute statically one adresse by node (when we
buy a
> > > > > terminal we can buy an IP address with it).
> > > > > any comments ?
> > > > >
> > > > >
> > > >
> > > > --
> > > >
----------------------------------------------------------------------------
------------
> > > > Dipl.-Ing. Kilian Weniger           phone: (+49)(0)721-608 6415
> > > > Institute of Telematics             fax:   (+49)(0)721-388097
> > > > Department of Computer Science      email:
[email-masked]
> > > > University of Karlsruhe             homepage:
http://www.tm.uka.de/~weniger/
> > > > D-76128 Karlsruhe
> > >
> > > --
> > > Bruno HUSSON
> > > Tel : +33 1 46 08 61 92
> > > Fax : +33 1 46 08 61 10
> > > Standard : +33 1 46 08 61 00
> > > e-mail:[email-masked]
> > > -----------------
> > > SYCOMORE - Groupe EADS
> > > Immeuble l'Etendard
> > > 63 ter, Avenue Edouard VAILLANT
> > > 92517 BOULOGNE-BILLANCOURT
> > > http://www.sycomore.fr
> > > ------------------------------------------------------
> > >
> > >
> >
> > --
> >
----------------------------------------------------------------------------
------------
> > Dipl.-Ing. Kilian Weniger           phone: (+49)(0)721-608 6415
> > Institute of Telematics             fax:   (+49)(0)721-388097
> > Department of Computer Science      email: [email-masked]
> > University of Karlsruhe             homepage:
http://www.tm.uka.de/~weniger/
> > D-76128 Karlsruhe
>
> --
> Bruno HUSSON
> Tel : +33 1 46 08 61 92
> Fax : +33 1 46 08 61 10
> Standard : +33 1 46 08 61 00
> e-mail:[email-masked]
> -----------------
> SYCOMORE - Groupe EADS
> Immeuble l'Etendard
> 63 ter, Avenue Edouard VAILLANT
> 92517 BOULOGNE-BILLANCOURT
> http://www.sycomore.fr
> ------------------------------------------------------
>
>

-- 
----------------------------------------------------------------------------
------------
Dipl.-Ing. Kilian Weniger           phone: (+49)(0)721-608 6415
Institute of Telematics             fax:   (+49)(0)721-388097
Department of Computer Science      email: [email-masked]
University of Karlsruhe 	    homepage: http://www.tm.uka.de/~weniger/
D-76128 Karlsruhe