Subject: Re: [DMM] Comment on Req2 transparency for DMM

From: h chan <[email-masked]>
Date: Thu, 2 Aug 2012 06:35:25 +0000

How about changing to the following:

The DMM solutions MUST provide transparency above the IP layer when needed, such as upon change of point of attachment to the Internet, for the application flows that cannot cope with a change of IP address. Otherwise the support to maintain a stable home IP address or prefix during handover may be declined.

Original was:
The DMM solutions MUST provide transparency above the IP layer when needed. Such transparency is needed, when the mobile hosts or entire mobile networks [RFC3963] change their point of attachment to the Internet, for the application flows that cannot cope with a change of IP address. Otherwise the support to maintain a stable home IP address or prefix during handover may be declined.

H Anthony Chan

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf Of Alexandru Petrescu
Sent: Tuesday, July 31, 2012 4:18 PM
To: [email-masked]
Subject: [DMM] Comment on Req2 transparency for DMM

DMM coleagues,

I would like to comment on the REQ2 "Transparency to Upper Layers when
Needed".  The slide 4 of slides-84-dmm-1.pptx at
https://datatracker.ietf.org/meeting/84/materials.html says:

> The DMM solutions MUST provide transparency above the IP layer when
> needed. Such transparency is needed, when the mobile hosts or entire
> mobile networks [RFC3963] change their point of attachment to the
> Internet, for the application flows that cannot cope with a change
> of IP address. Otherwise the support to maintain a stable home IP
> address or prefix during handover may be declined.

Such transparency is needed indeed.  But I suggest moving the part "when
the mobile hosts or entire mobile networks" outside of this paragraph -
maybe as a common denominator as part somewhere earlier in the draft.

Most if not all requirements of DMM would be good to deal with mobile
hosts as well as groupings of computers (mobile networks).

This transparency aspect we discuss here is about the stack - its
effects are within the stack of a single computer.  When this
transparency is offered it means the existing applications which are
unaware of mobility events (changes in IP address) do not need to be
modified in order to deal with these mobility events.

There is another transparency aspect when we discuss outside a single
computer's stack - the mobility management performed by a Mobile Router
on behalf of LFNs in a moving network is also transparency - the LFNs
are not implementing any mobility software - the world looks fixed to them.

So this would require both transparency1 and transparency2.  I wonder
what happens in cases when only transparency1 or only transparency2 are
required and the other is relaxed - maybe a new scheme pops up.
Or maybe it doesnt make any sense...

Alex
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---

From: Alexandru Petrescu <[email-masked]>
Date: Thu, 02 Aug 2012 11:38:50 -0700

H Anthony,

Yes, this reflects Sri's and my suggestion about removal of MN/MR
qualifier.  I agree with the idea of the new text as you put it.

Then, if I re-read just like that, there still seems to be some
difficulty to my brain to understand:

Le 01/08/2012 23:35, h chan a écrit :
> needed, such as upon change of point of attachment to the Internet,
> for the application flows that cannot cope with a change of IP
> address. Otherwise the support to maintain a stable home IP address
> or prefix during handover may be declined.

I don't understand the last phrase - the 'otherwise' relates to the
first MUST?  Or to the latter 'cannot'?

But this may be just nitpicking on the use of language.  I agree with
the direction of the idea and thank you for having provided the
modification.

Alex

---

From: h chan <[email-masked]>
Date: Fri, 3 Aug 2012 17:07:48 +0000

How about the following:

The DMM solutions MUST provide transparency above the IP layer when needed. Such transparency is needed, for example, upon change of point of attachment to the Internet for the application flows that cannot cope with a change of IP address. Otherwise the support to maintain a stable home IP address or prefix during handover may be declined.

Or

The DMM solutions MUST enable transparency above the IP layer. Such transparency is needed, for example, upon change of point of attachment to the Internet for the application flows that cannot cope with a change of IP address. Otherwise the support to maintain a stable home IP address or prefix during handover may be declined.

H Anthony Chan

-----Original Message-----
From: Alexandru Petrescu [mailto:[email-masked]] 
Sent: Thursday, August 02, 2012 11:39 AM
To: h chan
Cc: [email-masked]
Subject: Re: [DMM] Comment on Req2 transparency for DMM

H Anthony,

Alex

---

From: [email-masked]
Date: Mon, 6 Aug 2012 17:07:02 -0700

Dear Anthony and Alex, 

I believe Anthony has pointed out that, maintaining IP session continuity 
is just "an example" of maintaining upper layer transparency.   It should 
be fundamental to maintain the upper layer transparency even though upper 
layer may be able to cope with changing IP address, e.g. maintaining the 
QoS performance or location context for the service layer.  Hence, the 
clause of the "Otherwise" portion is not very clear as Alex has pointed 
out. 

Hence, I would like to suggest a friendly amendment to Anthony's latest 
proposal as follows: 
The DMM solutions MUST provide transparency above the IP layer when 
needed. Such transparency is needed, for example, upon change of point of 
attachment to the Internet for the application flows that cannot cope with 
a change of IP address may trigger the application to decline the handover 
request.

Would this be acceptable to both of you?  Thanks.
Tricci 

h chan <[email-masked]> 
Sent by: [email-masked]
08/03/2012 10:07 AM

To
Alexandru Petrescu <[email-masked]>
cc
"[email-masked]" <[email-masked]>
Subject
Re: [DMM] Comment on Req2 transparency for DMM

How about the following:

The DMM solutions MUST provide transparency above the IP layer when 
needed. Such transparency is needed, for example, upon change of point of 
attachment to the Internet for the application flows that cannot cope with 
a change of IP address. Otherwise the support to maintain a stable home IP 
address or prefix during handover may be declined.

Or

The DMM solutions MUST enable transparency above the IP layer. Such 
transparency is needed, for example, upon change of point of attachment to 
the Internet for the application flows that cannot cope with a change of 
IP address. Otherwise the support to maintain a stable home IP address or 
prefix during handover may be declined.

H Anthony Chan

-----Original Message-----
From: Alexandru Petrescu [mailto:[email-masked]] 
Sent: Thursday, August 02, 2012 11:39 AM
To: h chan
Cc: [email-masked]
Subject: Re: [DMM] Comment on Req2 transparency for DMM

H Anthony,

Alex

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