Subject: [nemo] Questions about draft-kniveton-nemo-prefix-delegation-01

From: Romain KUNTZ <[email-masked]>
Date: Mon, 25 Jul 2005 19:58:13 +0900

Hello,

I have read draft-kniveton-nemo-prefix-delegation-01 and have some
questions about it.

- In section 5.2, it is said:
    When setting the Prefix Status bit, the HA also
    lists all the prefixes associated to that Mobile Router using Mobile
    Network Prefix Confirmation options.

But in section 8, it is said:
    If the Binding Update contains an S bit, the Home Agent includes a
    Mobile Network Prefix Option for each prefix the Home Agent believes
    is assigned to the Mobile Route

So which one of the MNP Option or the MNP Confirmation Option should be
used to list all the MNPs ?

- Also, I don't understand well the utility of the I flag in the Mobile
Network Prefix Option:
       Implicit (I): The (I) bit is set if the prefix is assigned to and
       routed via the MR even if the prefix is not listed in explicit
       mode BU.

No MNP options are used when the MR uses Implicit mode. So this bit is
never used. Or does the HA has to use the MNP option and set this bit
when listing all the prefixes owned by the MR ?

- Once the prefix delegation is finished, does the MR and HA have to set the
bit relative to prefix delegation in the MNP Option?  Or should they
just operate NEMO BS (unless they send/receive MNP request or
confirmation option)?

Regards,

-- 
Romain KUNTZ
[email-masked]

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From: "T.J. Kniveton" <[email-masked]>
Date: Tue, 26 Jul 2005 17:14:28 -0700

> I have read draft-kniveton-nemo-prefix-delegation-01 and have some

Should I take it that you're implementing the draft? :-D

> used to list all the MNPs ?

This is something we need to think about further -- I believe that they 
should be MNPOs, and MNPCOs are reserved for a request-response of a 
delegation event. But I would also like to hear others' opinions on 
this.

> when listing all the prefixes owned by the MR ?

That's correct. The idea is to be able to explicitly list *all* 
prefixes assigned, including ones that are bound using implicit BUs.

> just operate NEMO BS (unless they send/receive MNP request or

Should be orthagonal, so that you can just use regular NEMO BS.

TJ

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From: Romain KUNTZ <[email-masked]>
Date: Wed, 27 Jul 2005 09:30:10 +0900

Hello,

Thank you for your reply. More comments below:

> Should I take it that you're implementing the draft? :-D

Let's say I am interested in :)

> delegation event. But I would also like to hear others' opinions on this.

The problem is that if you use MNPOs, then in the case where the MR 
sends a registration BU with MNP Request Options + the S bit set, then 
the HA will have to reply with MNPCO and MNPO for the same prefixes, 
right ? It might be a big overhead.

> That's correct. The idea is to be able to explicitly list *all* prefixes 
> assigned, including ones that are bound using implicit BUs.

Ok, but if the HA uses MNPO to list all the prefixes, see my comment above.

> Should be orthagonal, so that you can just use regular NEMO BS.

Ok, it seems coherent.

Thanks,

Romain

---

From: "T.J. Kniveton" <[email-masked]>
Date: Fri, 29 Jul 2005 16:24:31 -0700

> Let's say I am interested in :)

Good
>> This is something we need to think about further -- I believe that  
>> they should be MNPOs, and MNPCOs are reserved for a request- 
>> response of a delegation event. But I would also like to hear  
>> others' opinions on this.
>>
>
> sends a registration BU with MNP Request Options + the S bit set,  
> then the HA will have to reply with MNPCO and MNPO for the same  
> prefixes, right ? It might be a big overhead.

I would imagine that you would process the request, put an MNPCO at  
the end of the BAck, then process the S bit and put MNPO for all  
prefixes (including the one assigned). I suppose we should discuss  
this more in person, next week.

> Ok, but if the HA uses MNPO to list all the prefixes, see my  

How does it relate to implicit prefixes?