Subject: RE: [nemo] RE: about the Home Network Models WG item

From: "Pascal Thubert \(pthubert\)" <[email-masked]>
Date: Wed, 5 Jan 2005 17:55:38 +0100

| -----Original Message-----
| From: Alexandru Petrescu [mailto:[email-masked]]
| Sent: Wednesday, January 05, 2005 4:51 PM
| To: Pascal Thubert (pthubert)
| Cc: [email-masked]
| Subject: Re: [nemo] RE: about the Home Network Models WG item
| 
| Pascal Thubert (pthubert) wrote:
| > Hi Alex:
| >
| > | Then, in the current description of the "Aggregated Home Network"
| > | section 5, there are very many things unclear to me:
| > |
| > | section 5:
| > | > A node on the Home Link computes that the Aggregated Home
Network is
| > | > actually a subnet on the Home Link and may use it for
| > | > autoconfiguration purposes.
| > |
| > | It would be more readable to say: "use the prefix on the Home Link
to
| > | autoconfigure a Home Address".
| > |
| >
| > I agree with you here. I made the change as issue 1.
| 
| Ok.  I hope having an issues list helps advancing this draft WG item.
| 
| What about the other issues I raised by email to you and authors of
| draft?  They don't appear in the issues list.
| 

My understanding is that we had already discussed the other items (name
for extended, order in the doc between aggregated and extended, /64 in
the examples) in the ML itself and done the changes we agreed upon at
the time (in particular, say that 64 as a prefix length is an example,
and use a different value in the aggregated case). 

But if you wish to change something more, please present on this list at
this time, and if you get enough support, I'll do the changes as
required.

You might want to consult the WIP for 02 at:
http://mobilenetworks.org/~pthubert/draft-ietf-nemo-home-network-models-
xx.html

Pascal

---

From: Alexandru Petrescu <[email-masked]>
Date: Wed, 05 Jan 2005 18:58:20 +0100

Pascal Thubert (pthubert) wrote:
[...]
> please present on this list at this time, and if you get enough 
> support, I'll do the changes as required.

I do not think in the simplest Home Network configuration the MR may use
a Home Address derived from the prefix assigned on its moving network
link, the MNP.  In the simplest cases, the MR Home Address is derived
from the prefix valid on the Home Link.

Or, section 4.1 Extended Home Network configuration has a last item saying:
> Alternatively, a Mobile Router could also form a Home Address from
> one of its prefixes and use it to register[...]

I think this kind of item should belong to other more complex Home 
Network configurations.

Besides, I think that a useful informational document on the types of 
home networks should describe several such networks - in the order of 
simplicity - starting first from the most simple and basic and obvious 
and only later to the most exotic.

Or, while the current document does describe three such networks, there 
does not seem to be an order from basic to complex.  The first described 
is already "Extended" and the other two are "Aggregated" and "Virtual". 
  The "Aggregated" is a little more complex than the "Extended" in that 
the MR looks up its MNNs via ND on the Home Link, which is a little 
exotic feature.  The "Virtual" model is the most exotic in that there is 
no returning home procedure for example.

So, I understand there is a form of scale on differentiation, from the 
most basic up to the most complex, but the most basic is still called 
"Extended" and allows MR HoA from MNP.

Hence my proposal to call the basic model just "Basic Home Network" and 
this model not to use MR Home Address from the MNP.  Alternatively, I 
propose to introduce a 4th model, called "Basic Home Network Model", 
that would come before the other three models, and in which MR would 
only construct its Home Address from the prefix on the home link, that 
would perform ND for that address, that would implement the NEMO 
Returning Home procedure and for which address the HA performs proxy ND 
when MR not at home, according to Mobile IPv6.

What do you think Pascal?  What do the others think?

Alex

---

From: Daniel Shell <[email-masked]>
Date: Wed, 05 Jan 2005 13:23:44 -0500

Sounds good to have the sections labelled

Basic
Extended
Aggregated
Virtual

Would like to see what Pascal says though.

At 06:58 PM 1/5/2005 +0100, Alexandru Petrescu wrote:
>>please present on this list at this time, and if you get enough support, 
>>I'll do the changes as required.
>
>I think this kind of item should belong to other more complex Home Network 
>configurations.
>
>Besides, I think that a useful informational document on the types of home 
>networks should describe several such networks - in the order of 
>simplicity - starting first from the most simple and basic and obvious and 
>only later to the most exotic.
>
>is already "Extended" and the other two are "Aggregated" and 
>"Virtual".  The "Aggregated" is a little more complex than the "Extended" 
>in that the MR looks up its MNNs via ND on the Home Link, which is a 
>little exotic feature.  The "Virtual" model is the most exotic in that 
>there is no returning home procedure for example.
>
>propose to introduce a 4th model, called "Basic Home Network Model", that 
>would come before the other three models, and in which MR would only 
>construct its Home Address from the prefix on the home link, that would 
>perform ND for that address, that would implement the NEMO Returning Home 
>procedure and for which address the HA performs proxy ND when MR not at 
>home, according to Mobile IPv6.
>

Dan Shell
Government Service Unit
CISCO Systems
IP mobility/Wireless/Satellite
440 331 5663

---

From: Ryuji Wakikawa <[email-masked]>
Date: Thu, 06 Jan 2005 04:02:36 +0900

Hello Alex.

Happy New Year!

I agree.
Since the draft title is "home network models", it is fare to have the
basic configuration.

regards,
ryuji

At Wed, 05 Jan 2005 18:58:20 +0100,

---

From: Vijay Devarapalli <[email-masked]>
Date: Sun, 09 Jan 2005 20:44:19 -0800

I have to disagree. this draft is primariy about Home Network
Configuration. in every model (extended, aggregated and virtual),
the Mobile Router is free to configure a HoA from the MNP at
any time and use that for Home Registration. there is no way a
Home Agent can force the Mobile Router to only use a HoA from
the home link. lets assume a particular home link as configured
as a "Basic Home Link" (as described by Alex below). if the MR
chooses to configure a HoA from the MNP, the HA can't prevent
it. and I dont think we need to provide a way for the HA to
prevent it.

I dont see the need for a "Basic Home Link" model.

Vijay

---

From: Alexandru Petrescu <[email-masked]>
Date: Mon, 10 Jan 2005 12:16:30 +0100

Vijay Devarapalli wrote:
> if the MR chooses to configure a HoA from the MNP, the HA can't 
> prevent it. and I dont think we need to provide a way for the HA to 
> prevent it.

Vijay, true HA can't prevent MR do whatever it wants with its addresses.
  But in order for HA to do proxy-ND for Home Address that Home Address
must be valid on the Home Link.  If it's from MNP then it's not valid on
the Home Link.

Alex

---

From: Vijay Devarapalli <[email-masked]>
Date: Tue, 11 Jan 2005 15:43:52 -0800

> must be valid on the Home Link.  If it's from MNP then it's not valid on

if the HoA does not belong to the home link and belongs to the MNP,
the Home Agent treats the address as any other address in the MNP.
it does not treat it as an address on the home link. if the HA is
using a route for the MNP (pointing to the MR's current
location/tunnel interface) to do routing for addresses in the MNP,
it does the same for the HoA.if the HA using proxy ND to do routing
for addresses in the MNP, it does the same for the HoA.

Vijay

---

From: Alexandru Petrescu <[email-masked]>
Date: Wed, 12 Jan 2005 04:10:20 +0100

I'm trying to follow you...

Vijay Devarapalli wrote:
>>> prevent it. and I dont think we need to provide a way for the HA
>>>  to prevent it.
>> 
>> Vijay, true HA can't prevent MR do whatever it wants with its 
>> addresses. But in order for HA to do proxy-ND for Home Address that
>>  Home Address must be valid on the Home Link.  If it's from MNP 
>> then it's not valid on the Home Link.
> 
> the Home Agent treats the address as any other address in the MNP. it
>  does not treat it as an address on the home link. if the HA is using
>  a route for the MNP (pointing to the MR's current location/tunnel 
> interface) to do routing for addresses in the MNP, it does the same 
> for the HoA.

Kind of agree, but I don't understand exactly what you mean.  Do you 
mean that wherever the HoA is coming from (MNP or home link) packets to 
it will actually get routed to the MR?  I agree with it.  I do have the 
picture of a R1 (MR) and R2 (HA) holding a route towards R1's ingress 
interface (and not R1's egress).  Is it this you mean?

Also I'm confused you saying "if HA uses a route towards MNP" because HA 
must always have a route to MNP, be MR at home or away, right?

> if the HA using proxy ND to do routing for addresses in the MNP, it
> does the same for the HoA.

First, HA can't do proxy-ND for an address that is not valid on its 
link, and all addresses derived from MNP aren't valid on the home link. 
  If HA can't do proxy-ND for the HoA from MNP then HA can't receive 
packets addressed to HoA when MR not at home, do you agree?

Alex