Subject: [nemo] Questions about <draft-ng-nemo-multihoming-issue-03.txt>..

From: "Shine Choi" <[email-masked]>
Date: Fri, 28 May 2004 10:20:54 +0900

Hello! everybody concerned with the draft, 
<draft-ng-nemo-multihoming-issue-03.txt> or interested in my question.

I'm Shine who's been studying multihoming in NEMO. 
By the way, something in the draft has made me feel wonder.
If there's someone who can help me understand it clearly, please help me.
My question is...

In brief, I don't understand why there must be "the number of HAs" 
as one of the 3-tuple in the multihoming classification.

To let me understand why~, I need to know these things first...

1) Are there some cases or scenarios that show an ISP has multiple HAs?
2) If so, could you give me the examples of those..? 
I would like someone, who made the number of HAs as one of the 3-tuple in
the classification, to show me why there could be multiple HAs with
examples.
3) I think, such multiple HAs could be logically viewed as the one HA in the
ISP 
even if they are physically many in there. 

The "logically" term means multiple HAs would act like one HA.
Even though there were multiple HAs in an ISP, the HAs would be like only
distributed system.
If that's right, bidirectional tunnel between HAs in the ISP and a MR would
be also made on the same route.
In addition, I think, MRs and CNs outside the ISP cannot help regarding the
HAs as just one HA acting.

I'm waiting someone to reply for my questions asap. 

Cheers,
Shine

---

From: Chan-Wah Ng <[email-masked]>
Date: Fri, 28 May 2004 11:04:08 +0800

Hello Shine,

The deployment scenarios has been illustrated in previous versions,
however, due to the introduction of multihoming-goals-and-benefits
draft, to reduce duplication, deployment scenarios has been removed.

Anyway, consider a multi-mode mobile router.   When it subscribe to
Wi-Fi, GPRS or even satellite through different service providers, it is
likely for each service provider assign different HA to the mobile
router.

If all HA are assigned to a single ISP, I agree with your statement that
they can be "logically viewed as one".

/rgds
/cwng

---

From: Thierry Ernst <[email-masked]>
Date: Fri, 28 May 2004 12:07:46 +0900

Hi,

On Fri, 28 May 2004 10:20:54 +0900

> 2) If so, could you give me the examples of those..? 

This has been discussed at length on the mailing list. First, HAs may
not belong to the same ISPs. Take a PAN-like scenario. My NEMO-PAN has
sevelal egress interfaces.  One is a WLAN 802.11b, the HA is at my
office. The second one is a cellular link, the HA is in my cellular
provided's network.

> even if they are physically many in there. 

Not valid if HAs belong to distinct ISPs.

> I'm waiting someone to reply for my questions asap.

Thierry.

---

From: Thierry Ernst <[email-masked]>
Date: Fri, 28 May 2004 12:35:42 +0900

> draft, to reduce duplication, deployment scenarios has been removed.

Well, indeed, the idea was to remove what ever was general, but to keep
NEMO-specific **configurations** in the draft (like one example with multple HAs,
and multiple MRs.). We shall consider this for next revision (which
should be a WG document draft-ietf-nemo0-multihoming-problem-statement.txt).

Also, the draft will have to discuss the configurations that are useful
to handle.

Thierry.