Subject: [netlmm] draft-singh-netlmm-protocol-02.txt

From: "Singh Ajoy-ASINGH1" <[email-masked]>
Date: Mon, 5 Mar 2007 16:23:01 -0500

Hi, All, 

We have submitted today an updated version of PMIPv6 draft.
We have made few editorial changes in this draft.    
Please review and provide your feedback. 

Regards,
Ajoy 
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From: Ashutosh Dutta <[email-masked]>
Date: Sun, 18 Mar 2007 09:17:22 -0400

Ajoy,

      Please allow me to ask few clarification on the recent 
draft-singh-netlmm-protocol-02.txt draft.

    What is the relationship between LMA and GMA? Both are claimed to 
behave like HAs? I realize that GMA is more useful when the mobile is 
MIPv6 capable and moves between the LMDs. The description of GMA and its 
  interaction with LMAs are somewhat not very clear in the current 
version of the draft except for GMA can communicate with AAA server.

Separation of PMIP client that will have a centralized control maybe a 
good idea. Also, as it appears, even if PMIP client may co-exist it will 
not co-exist with each MAG but only with the first MAG where the mobile 
starts the communication. How do you decide whether PMIP client should 
coexist with the MAG or stay as a separate entity?

Also, do you assume Inter-LMA movement to be same as inter-LMD movement? 
Section 4.4. says that the client maybe under the same MAG but can still 
move between the LMAs and thus, may change the LMD.

As it appears from your draft, multiple MAGs can share the same PMIP 
client for a given MN. However, in case of inter LMA (Inter-LMD?) 
movement, the draft says MN may or may not change the PMIP client. What 
is the policy for deciding that?

In case PMIP client does not co-exist with the MAG, the draft suggests 
to use SCTP as a transport protocol between MAG and PMIP client, is it 
mostly for reliability? Are there any deployment consideration, issues 
thereof, if SCTP is used between a MAG and a PMIP client in real world?

Regards
Ashutosh

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From: "Singh Ajoy-ASINGH1" <[email-masked]>
Date: Sun, 18 Mar 2007 11:30:11 -0400

Hi,  Ashutosh, 

Thanks for reviewing the draft. I appreciate your objective comments. 
Please find inline response. 

Regards,
Ajoy 

-----Original Message-----
From: Ashutosh Dutta [mailto:[email-masked]] 
Sent: Sunday, March 18, 2007 8:17 AM
To: Singh Ajoy-ASINGH1
Cc: [email-masked]
Subject: Few clarification on [netlmm]
draft-singh-netlmm-protocol-02.txt

Ajoy,

behave like HAs? 

Ajoy-> That is correct. We have shown an use case scenario where we can
use LMA (derived from HA)
for local mobility and GMA (standard MIPv6 HA) for local mobility.   

I realize that GMA is more useful when the mobile is
MIPv6 capable and moves between the LMDs. 

Ajoy-> This is correct. GMA is needed for inter-LMD handoff. 

The description of GMA and its
  interaction with LMAs are somewhat not very clear in the current
version of the draft except for GMA can communicate with AAA server.

Ajoy-> Agreed. This is still an open issue and we are working to make
this clearer. 
There was some discussion on the list about this, but that did not
converge so 
we have kept the interaction between GMM and LMM at conceptual level. 
Please see below some of my thoughts: 
(1) Global mobility management protocol need not be aware of underlying
local mobility management protocol. 
(2) All MAG of a given LMD will advertise same prefix that will ensure
that client based global 
mobility management protocol need not be aware of local mobility
management protocol till mobile  
moves inside a given domain. Advertised prefix will change after mobile
moves from one LMD to other. 
The change of prefix will trigger mobile to initiate client MIPv6 based
binding update for global 
mobility management. 
(3) Although client MIPv6 is better solution for global mobility, it is
likely that some SDOs 
might like to use NETLMM solution for global mobility management also. I
think, in that case, SDO will have to make 
some adaptation to NETLMM protocol for global mobility management
purpose.  

good idea.

Ajoy-> Agreed. This simplifies NETLMM protocol significantly. 

Also, as it appears, even if PMIP client may co-exist it will not
co-exist with each MAG but only with the first MAG where the mobile
starts the communication. 

Ajoy-> We do allow co-existence of PMIP client on MAG as well. 

How do you decide whether PMIP client should coexist with the MAG or
stay as a separate entity?

Ajoy-> This depends upon implementation. As long as we define a clean
separation between 
PMIP client and MAG bearer plane, we can implement this either on a MAG
or a separate entity. 
PMIP client will be an independent process running on MAG.  Note that
NETLMM protocol will have to provide
following two supports: 
(1) Allow a scenario for PMIP client anchoring.   
(2) Define a protocol between PMIP client and MAG data plane. 

Ajoy-> Yes, but in some deployment you want to change LMA without
changing LMD. This can be for load balancing purpose. 
Note, this will require PMIP client to establish security association
with new LMA.    

Ajoy-> See above. Do you believe additional text will be needed to
clarify this behavior some more? 

client for a given MN. 

Ajoy-> yes 

However, in case of inter LMA (Inter-LMD?) movement, the draft says MN
may or may not change the PMIP client. What is the policy for deciding
that?

Ajoy-> We have left this to particular deployment. Do you see any need
to define such policies in NETLMM protocol itself? 

Ajoy-> Since SCTP is transport protocol for control message, we thought
it 
make sense to transport TRIGGER and NOTIFICATION messages using SCTP.
However, if there is consensus in IETF to choose some other transport
protocol, we are fine 
as well. However, I did not see any downside of using SCTP. Since
various SDOs are moving towards using SCTP as signaling transport
protocol, probably they might want SCTP for this as well.

Regards
Ashutosh

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From: Ashutosh Dutta <[email-masked]>
Date: Sun, 18 Mar 2007 12:24:48 -0400

Ajoy, thanks for clarifying many of my questions. I have one more 
specific query below. Please see inline.
> Ajoy-> We do allow co-existence of PMIP client on MAG as well. 

Right, but in Section 4.2 (Intra-LMD mobility)it says, the PMIP client 
if it has to coexist, can coexist with only one of the MAGs. This MAG 
could be the one where the mobile first obtains the IP address within an 
LMD. In that case, this MAG can also become the PMIP client anchor. 
Thus, you do not need to have instances of PMIP client running in each 
of the neighboring MAGs when the mobile moves between MAGs within an 
LMD? Is that correct?

Regards
Ashutosh

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From: "Singh Ajoy-ASINGH1" <[email-masked]>
Date: Sun, 18 Mar 2007 17:46:17 -0400

Hi, Ashutosh, 

Thanks. Please see inline. 

Regards,
Ajoy  

-----Original Message-----
From: Ashutosh Dutta [mailto:[email-masked]] 
Sent: Sunday, March 18, 2007 11:25 AM
To: Singh Ajoy-ASINGH1
Cc: [email-masked]
Subject: Re: Few clarification on [netlmm]

Right, but in Section 4.2 (Intra-LMD mobility)it says, the PMIP client
if it has to coexist, can coexist with only one of the MAGs. 

This MAG could be the one where the mobile first obtains the IP address
within an LMD. In that case, this MAG can also become the PMIP client
anchor. 

Ajoy-> Correct. 

Ajoy-> You need to have PMIP client functionality on neighboring MAG
because some other MN might end up attaching to neighboring MAG itself.
In this case neighboring MAG will become PMIP anchor for the new MN.
However, there is no need to have 
PMIP client instances on neighboring MAG for the MN whose PMIP client is
already anchored on a MAG. 
Hope this clarifies. 

Regards
Ashutosh

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From: qinxia <[email-masked]>
Date: Mon, 19 Mar 2007 10:24:54 +0800

If wimax prefers that MAG should be separated with PMA, the start point protocol  should have adequate concern on this point. Then it is easy to be adopted by industy.

> From: Singh Ajoy-ASINGH1 [mailto:[email-masked]]
> Sent: Monday, March 19, 2007 5:46 AM
> To: Ashutosh Dutta
> Cc: [email-masked]
> Subject: RE: Few clarification on [netlmm] draft-singh-netlmm-protocol-02.txt
> 
> Hi, Ashutosh,
>

---

From: "Singh Ajoy-ASINGH1" <[email-masked]>
Date: Mon, 19 Mar 2007 05:43:17 -0400

Hi, Alice, 

WIMAX NWG specification already defines PMIP client anchoring and also
supports complete re-use of MIPv4 HA functionality. 
What we have tried to show in our draft is that this is also possible in
PMIPv6 case.  So far most of the discussion has 
happened in context of draft-sgunave vs draft-singh. IMO, we should
discuss this idea from PMIP anchoring vs. 
PMIP relocation aspect and point out the key benefits of using PMIP
anchoring over PMIP relocation. I also see this idea very useful in 3GPP
so perhaps 3GPP also needs to discuss this in their context as well. We
should not ignore a good idea just because we need to prefer one draft
vs other draft. 

Regards,
Ajoy  

-----Original Message-----
From: qinxia [mailto:[email-masked]] 
Sent: Sunday, March 18, 2007 9:25 PM
To: Singh Ajoy-ASINGH1; 'Ashutosh Dutta'
Cc: [email-masked]
Subject: RE: Few clarification on [netlmm]

If wimax prefers that MAG should be separated with PMA, the start point
protocol  should have adequate concern on this point. Then it is easy to
be adopted by industy.

> This MAG could be the one where the mobile first obtains the IP 
> address within an LMD. In that case, this MAG can also become the PMIP

> client anchor.

> PMIP client instances on neighboring MAG for the MN whose PMIP client 
> is already anchored on a MAG.
> Hope this clarifies.
> 
> 
> Regards
> Ashutosh
>