Subject: [DMM] comments on draft-ietf-dmm-best-practices-gap-analysis-01

From: Jouni Korhonen <[email-masked]>
Date: Wed, 24 Jul 2013 15:54:36 +0300

Authors,

I finally read the draft and below are some comments to hopefully help
completing and improving the draft.

In Section 4.2. it is stated:

  "view using common and standardized protocols.  Since WiFi is the most
   widely deployed wireless access technology nowadays, we take it as"

Do you have some data/reference to backup your claim?

In Section 4.2.1. it is stated:

  "at different point of attachment.  However there is no mechanism
   specified to enable an efficient dynamic discovery of available"

I would add a clarification here that there is no such mechanism 
available within IETF specifications. Other SDOs do have such mechanism
(e.g. 3GPP).

Furthermore, around the bulleted list for the MIPv6 RO discussion, I would
mention that nothing prevents a MN to use its CoA directly when communicating
CNs on the same link or anywhere in the internet. Of course there is no
mobility in that case but it is a valid scenario to mention IMHO (and also
part of our charter). I recon the HMIPv6 text mentions at least the use of
RCoA already.

In Section 4.2.2. where the text describes RFC6463, I would also reference to
RFC6097 since that has quite a bit of text regarding the discovery procedure
of the LMA.

While I found Section 4.2. good in general I was somehow expecting to see 
text regarding MOBIKE (RFC4555). We can safely assume MOBIKE is probably
the most deployed client mobility enabling technology out there today.

In Section 4.3. it says:

  "GPRS Tunnelling Protocol (GTP) [3GPP.29.060] is a network-based
   mobility protocol specified for 3GPP networks (S2a, S2b, S5 and S8
   interfaces)."

While 29.060 is about GTP, for the above referenced interfaces 29.281
and 29.274 are probably more appropriate.

  "A Local IP Access (LIPA) and Selected IP Traffic Offload (SIPTO)
   enabled network [3GPP.23.829] allows offloading some IP services at"

I would say referencing to e.g. 23.401 on LIPA/SIPTO is more appropriate
these days, since the TR23.829 is somewhat left behind and the LIPA/SIPTO
functionality is part of the main stage-2 specs already.

I found Section 4 in general quite nice. However, I was somehow expecting
to see a bit of text of WiMAX. Or can we safely state that no IPv6 deployments
ever took place in WiMAX? Anyway, at least a reference to WiMAX would be
nice, since they spent quite a bit of time developing both CMIPv6 and
PMIPv6 functionality into their architecture.

In Section 4.3. I would reference to 3GPP TS29.303 and say something
about 3GPP's heavy use of DNS as the "gateway location database" and
how that is used to discover gateways with both topological and gateway
collocation in mind

In Section 5. it is stated:

  "o  The dynamic anchor relocation needs to ensure that IP address
      continuity is guaranteed for sessions that need it at the
      relocated anchor.  This for example implies having the knowledge"

Since our charter _allows_ solutions where mobility is used "when needed"
that fact should be reflected above. Even if there is mobility supported
only locally within a limited area, it might meet the requirements from 
the MN or the application point of view i.e. when the MN or the application
does not care about a "full longstanding mobility" to be provided.

  "o  Dynamic discovery and selection of anchors.  There might be more
      than one available anchor for a mobile node to use.  Currently,
      there is no efficient mechanism that allows to dynamically
      discover the presence of nodes that can play the role of anchor,
      discover their capabilities and allow the selection of the most
      suitable one."

Within 3GPP TS29.303 makes that possible and is deployed.

In general the draft is heading to a good direction IMHO! Just complete
it fast ;-)

- Jouni

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From: Liu Dapeng <[email-masked]>
Date: Tue, 30 Jul 2013 16:45:19 +0800

Hi Jouni,

Thanks for the comments.

2013/7/24 Jouni Korhonen <[email-masked]>

> Do you have some data/reference to backup your claim?

[Dapeng] Maybe we can change the wording a little bit. e.g. remove 'most'.

> available within IETF specifications. Other SDOs do have such mechanism

[Dapeng] OK.

> [Dapeng] Agree.

> RFC6097 since that has quite a bit of text regarding the discovery

[Dapeng] OK.

> the most deployed client mobility enabling technology out there today.

[Dapeng] We can add MOBIKE there.

> and 29.274 are probably more appropriate.

[Dapeng] We will  add those reference.

> functionality is part of the main stage-2 specs already.

[Dapeng] We will update this reference.

> PMIPv6 functionality into their architecture.

[Dapeng] OK.

> how that is used to discover gateways with both topological and gateway

[Dapeng] OK.

> does not care about a "full longstanding mobility" to be provided.

[Dapeng] We can change the wording here.

> [Dapeng] We can scope the statement in IETF?

> In general the draft is heading to a good direction IMHO! Just complete

[Dapeng] Thanks for the valuable comments. We will update the draft
according to the comments soon.

Dapeng

- Jouni
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-- 

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Best Regards,
Dapeng Liu