Subject: RE: [nemo] About section 2.5 in ro-problem-statement

From: "Pascal Thubert \(pthubert\)" <[email-masked]>
Date: Wed, 6 Jul 2005 16:59:34 +0200

>>
>> What this sentence tries to illustrate is that mobile routers may
wish
>> to relay each others packets to the Internet.  Remembering they are
>> mobile, there may be times when MR3 is attached to MR2, and times
when
>> MR2 is attached to MR3.  So when MR3 is attached to MR2, should MR2
>> prove to refuse to provide connectivity to MR3, when the times comes
to
>> MR2 attaching to MR3, MR3 may refuse to help.
>
> how MR2 knows that it is forwarding traffic for MR3 and not from a
> MNNs ? I mean that your text implies that the MR2 is able to detect
> that MR3 is a Mobile Router and not a MNN.
>
> (maybe by inspecting BUs sent from ingress network ?)
>
[<PT>] This might depend on the RO solution :) Also, there might be some
minimal handshake between routers when the form a mesh. All to be
defined.

Pascal

---

From: Thierry Ernst <[email-masked]>
Date: Thu, 7 Jul 2005 10:42:18 +0900

> [<PT>] This might depend on the RO solution :) Also, there might be
> some minimal handshake between routers when the form a mesh. All to be
> defined.

A scenario where MR2 is providing access to MR3 and later MR3 providing
access to MR2 seems to suggest an ad-hoc netsted NEMO. Is this
intentional ? Isn't this crossing a boundary between MANET and NEMO that
we should better avoid crossing ? 

In the general case, there would be a MR in a bus and then a passenger
with a MR. The MR in the bus would always provide connectivity to the MR
carried by the passenger, never the other way round. 

Thierry

---

From: Chan-Wah Ng <[email-masked]>
Date: Thu, 07 Jul 2005 10:28:09 +0800

> we should better avoid crossing ? 

Not entirely.  Think of a PAN with a laptop and phone, and other geezmo
gadgets you have nowadays.  At times the laptop provides Internet
connectivity through its built-in WLAN or even good old traditional
Ethernet, at others, the phone provides Internet connectivity through
its 3G access. 

> carried by the passenger, never the other way round. 
Of-course, and the point of the sub-section is still there (although I
can't fathom why a company that deploys a MR on a train would have
security policy to forbid traffic from visiting nodes to be tunneled
back to its home network).  

But, train is just one of the countless examples of NEMO, a fleet of
ships on the sea is yet another.  Even in the train situation, suppose
the MR is using 802.11.  Alice with a bluetooth gadget handphone would
not be able to connect through the train MR.  Bob may comes along with a
personal MR allowing Alice to connect through.  When the train go into
blind-spots  where connection is lost for the train MR, Alice might wish
to return the favor for Bob to connect through her phone.

/rgds
/cwng

---

From: Thierry Ernst <[email-masked]>
Date: Thu, 7 Jul 2005 12:41:10 +0900

> > 
> > A scenario where MR2 is providing access to MR3 and later MR3
> > providing access to MR2 seems to suggest an ad-hoc netsted NEMO. Is
> > this intentional ? Isn't this crossing a boundary between MANET and
> > NEMO that we should better avoid crossing ? 
> > 
> 
> Not entirely.  Think of a PAN with a laptop and phone, and other
> geezmo gadgets you have nowadays.  At times the laptop provides
> Internet connectivity through its built-in WLAN or even good old
> traditional Ethernet, at others, the phone provides Internet
> connectivity through its 3G access. 

I don't call this a nested NEMO, but a multihomed NEMO. I would rather
since this as a PAN with 2 MRs. 1 MR may be the default router at a
time, and the other one at another time. 

> > In the general case, there would be a MR in a bus and then a
> > passenger with a MR. The MR in the bus would always provide
> > connectivity to the MR carried by the passenger, never the other way
> > round. 
> > 
> not be able to connect through the train MR.  Bob may comes along with
> a personal MR allowing Alice to connect through.  When the train go
> into blind-spots  where connection is lost for the train MR, Alice
> might wish to return the favor for Bob to connect through her phone.

I think your scenario is better solved by a MANET routing protocol
running in the NEMO train between Alice and Bob. Of course, a nested
NEMO could also do the job, but I can see this solution as "walking on
the path of MANET". I'm not saying this is bad, but that MANET protocols
are just designed for this kind of example. However, I do think it's
better to let MANET taking care of this, as I don't see why Bob would
provide Alice a CoA when it could simply operate his WIFI in adhoc mode.

This should push us to consider inter-operability between MANET and
NEMO. 

Thierry.

---

From: Chan-Wah Ng <[email-masked]>
Date: Thu, 07 Jul 2005 13:52:38 +0800

> time, and the other one at another time. 

True, it is not nested, but it illustrates the case where MR2 and MR3
may use each other as default router alternatively. 

> This should push us to consider inter-operability between MANET and

Point taken, but I just wish to probe this further.  The concern you
have is just with the example given in sect 2.5, right?  Or do you think
that the problem illustrated by sect 2.5 is non-existent once the
inter-operability between MANET and NEMO is clear?

/rgds
/cwng

---

From: Thierry Ernst <[email-masked]>
Date: Thu, 7 Jul 2005 14:52:53 +0900

> have is just with the example given in sect 2.5, right?  Or do you
> think that the problem illustrated by sect 2.5 is non-existent once
> the inter-operability between MANET and NEMO is clear?

Hi,

I don't have a concern with the content in the draft, just about the
example given in this thread. 

Thierry