Re: [Gen-art] Gen-art review of draft-ietf-dime-pmip6-lr-07

[Qin Wu <[e-mail]>]

Hi,Elwyn:
Thank for your valuable review. please see our replies below.
----- Original Message ----- 
From: "Elwyn Davies" <[e-mail]>
To: "General Area Review Team" <[e-mail]>
Cc: <[e-mail]>
Sent: Thursday, February 02, 2012 9:06 PM
Subject: Gen-art review of draft-ietf-dime-pmip6-lr-07


>I am the assigned Gen-ART reviewer for this draft. For background on
> Gen-ART, please see the FAQ at
> < http://wiki.tools.ietf.org/area/gen/trac/wiki/GenArtfaq>.
> 
> Please wait for direction from your document shepherd
> or AD before posting a new version of the draft.
> 
> Document: draft-ietf-dime-pmip6-lr-07.txt
> Reviewer: Elwyn Davies
> Review Date: 2 February 2012
> IETF LC End Date: 24 January 2012
> IESG Telechat date: 16 February 2012
> 
> Summary:
> I have a couple of queries/minor issues regarding checking whether LMA1
> and LMA2 are the same node and some hand waving over the idea of
> 'localized routing setup/signaliing'.  There are also a few minor nits.
> Otherwise this is ready for the IESG.
> 
> [This document missed the normal gen-art last call allocation
> notification mechanism for some reason - so I didn't realize it was on
> my allocation till the end of last call and as a result the review is a
> bit late.]
> 
> Major issues:
> None
> 
> Minor issues:
> s5.1, para 3 and s5.2, last para:
> In s5.1:
>> MAG1 can verify
>>    whether both MAGs are under the same LMA by comparing the addresses
>>    of LMA1 and LMA2.
> Is this guaranteed to work?  Should we care? Or is this just too bad if
> the LMA has multiple addresses and the two MNs have different ideas?

[Qin]: In the example described in the s5.1, we don't consider one LMA has two LMA address.
LMA1 and LMA2 may represent two different mobility entities identified by LMA1 adress and LMA2 adress respectively.
If LMA1 address is LMA2 address, this just indicate LMA1 and LMA2 are the same mobility entity.
Even one LMA have more than one LMA address, this still work since MAG can know if these LMA addresses come from
the same mobility entity based on MN1 and MN2's binding update list.

> However in s5.2:
>> In the case where MNs share the same LMA, LR should be initiated by
>>    LMA1 (i.e.,LMA2) since only LMA1 knows that both MN1 and MN2 belong
>>    to itself by looking up the binding cache entries corresponding to
>>    MN1 and MN2. 
> I am unsure whether these two statements are talking about the same
> thing - and, if so, are they contradictory?
> 

[Qin]: No Confliction, See above.

> s5.1, last para:
>> Figure 4 shows another example scenario, similar to the example
>>    scenario illustrated in Figure 3, LMA1 does not respond to MAG1 with
>>    the address of LMA2, instead setting up a localized routing path
>>    directly between itself and LMA2 via localized routing signaling.
> I am unsure what 'localized routing signaliing' would involve.  What
> would the nodes do for this?  Appears to involve some waving of hands.

[Qin]: LMA1 and LMA2 exchange to trigger corresponding LMA to setup binding entries
on the correspoding MAG for localized routing and establish localized
routing path between MAG1 and MAG2.

> On a slightly broader point, there are a number of places where the
> phrase 'localized routing setup' (or similar) is used.  It would, I
> think, be useful to add a few words indicating what is thought to be
> involved although actually doing it is clearly out of scope of this
> document.

[Qin]: Okay.

> Nits/editorial comments:
> 
> s1, first sentence:
>> Proxy Mobile IPv6 (PMIPv6) [RFC5213] allows the Mobility Access
>>    Gateway to optimize media delivery by locally routing packets *within
>>    itself*, 
> Do you mean this? Shouldn't this be within the local network of the MAG?
> I have to admit that s9.2 of RFC 5213 is a bit ambiguous here as it is
> unclear whether 'locally connected' means a direct point-to-point
> connection or just locally routed.  Presumabnly a static node could be
> in the local net rather than actually directly connected.  Perhaps it
> might be worth copying a bit of the text from RFC 5213 here.

[Qin]: Yes,locally routing packets within itself means when MN1 and MN2 are attached 
to the same MAG, the packet sent from MN1 and destined for MN2 should not be forwarded from
MAG through tunnel (MAG->LMA) to LMA and then tunneled back to MAG and finally sent to the MN2
through the same MAG. Instead, the packet destined for MN2 should be intercepted by the MAG attached 
by both MN1 and MN2 and sent to the MN2 directly through this MAG.

> s4.2: Expand IPv4-MN-HoA.

[Qin]: Okay.

> s4.3: Expand MN-HNP and HAAA. 

[Qin]: Okay.
> 
> s5.1, para 3: Extraneous space in MIP6- Feature-Vector (MFV). (Might be
> good to use non-breaking hyphens in the various AVP titles to avoid
> splits across lines).

[Qin]: Okay.

> s5.1, para 3: s/indicating Direct routing/indicating direct routing/

[Qin]: Okay.

> 55.1, para 6 (bottom of page 9): s/anchored to different MAGs is
>   supported. .  LMA1/anchored to different MAGs is
>   supported. LMA1/

[Qin]: Okay.

> 
> Fig 5: Would improve readability to offset the 'Option 1' and 'Option 2'
> labels one space rightwards as the '1' blends into the vertical line at
> the moment.

[Qin]: Okay.
>