Re: [Mipshop] AD review of draft-ietf-mipshop-pfmipv6

[Hidetoshi Yokota <[e-mail]>]

Hi Rajeev and Ahmad,

Thanks Rajeev for your input. It seems that all of the questions and
ambiguity pointed out by Ahmad lead to one issue: PMIPv6 defines
multiple encapsulation methods; therefore the inter-MAG tunnel must
specify which method should be used. If Rajeev's input is acceptable.
I'll come up with some text along that line.

Regards,
-- 
Hidetoshi

Koodli, Rajeev wrote:
>  
> Hi Ahmad,
> 
> Let me see if I could understand your concern.
> 
> RFC 5568 assumes that tunneling is IPv6-in-IPv6 based on RFC 3775. So,
> it does not need to specify how/which encapsulation mode is used.
> 
> PFMIP6, on the other hand, is for PMIP6 which does support multiple
> encapsulation modes. Hence, PFMIP6 needs to specify how/which
> encapsulation mode is used. Is this right?
> 
> If so, here is my input. PFMIP6 must state what encapsulation modes MUST
> be supported. The encapsulation modes should be configurable. Which
> particular mode is used is dependent on the particular deployment. There
> must be text stating that deployments MUST configure the encapsulation
> modes on MAGs to be the same, and it is recommended to use the same
> encapsulation modes as in MAG-LMA communication whenever feasible for
> operational uniformity. If the deployments fail to configure the
> encapsulation modes to be the same across all MAGs, then the protocol
> will not work correctly. 
> 
> How does this sound?
> 
> Regards,
> 
> -Rajeev
> 
> 
>> -----Original Message-----
>> From: Ahmad Muhanna [mailto:[e-mail]] 
>> Sent: Tuesday, September 22, 2009 10:58 PM
>> To: Hidetoshi Yokota
>> Cc: Mipshop; [e-mail]
>> Subject: RE: [Mipshop] AD review of draft-ietf-mipshop-pfmipv6
>>
>> Hi Hidetoshi,
>>
>> Thanks for your thoughts on this. 
>> I expected a little more serious ones:), but please see some 
>> more of the same thoughts inline! :)
>>
>> Regards,
>> Ahmad
>>> -----Original Message-----
>>> From: Hidetoshi Yokota [mailto:[e-mail]]
>>> Sent: Tuesday, September 22, 2009 6:20 AM
>>> To: Muhanna, Ahmad (RICH1:2H10)
>>> Cc: Mipshop; [e-mail]
>>> Subject: Re: [Mipshop] AD review of draft-ietf-mipshop-pfmipv6
>>>
>>> Hi Ahmad,
>>>
>>> Thanks for your detailed thoughts. Below, we try to answer your 
>>> questions as best we can.
>>>
>>> Ahmad Muhanna wrote:
>>>> Hi Hidetoshi,
>>>>
>>>> Looking one more time into the draft I found the following under 
>>>> section
>>>> 4.1:
>>>>
>>>> "
>>>>    The encapsulation type for these user packets SHOULD
>>> follow that used
>>>>    in the tunnel between the LMA and MAG (IPv6-in-IPv6 as
>>> specified in
>>>>    [RFC2473], IPv6-in-IPv4, IPv6-in-IPv4-UDP as specified in
>>>>    [IPv4PMIPv6], TLV-header UDP tunneling as specified in
>>> [GREKEY] or
>>>>    any new method defined in the future).
>>>> "
>>> The intention here is that the inter-MAG tunnel should 
>> support all the 
>>> encapsulation types that are mentioned in RFC5213.
>> [Ahmad]
>> Well, whatever it is this document supports, it needs to make 
>> it clear and ensure that it works. My question is the 
>> following: Does this document support ONLY IPv6-in-IPv6 
>> tunneling between the MAG and the LMA? or it also supports 
>> the different tunneling that the document claims to support 
>> as quoted above?
>>
>> If it only supports IPv6-in-IPv6, this document MUST document 
>> that clearly. On the other hand, if it supports the above 
>> listed tunneling protocols, it MUST document how forwarding 
>> these packets over the inter-MAG tunnel works.
>>
>>>> IMO, this is a very broad statement that underestimates its
>>> content. 
>>>> It is way underspecified how these tunneling protocols will
>>> be used to
>>>> successfully map the traffic from the MAG-LMA tunnel to 
>> the MAG-MAG 
>>>> tunnel. In this regard, I have the following questions:
>>>>
>>>> 1. Is it documented any where how this mapping would work
>>> for all of
>>>> these tunneling/encapsulation mechanisms?
>>> It seems that the mapping of these flows is rather implementation 
>>> specific. Is there anything that should be considered in 
>> addition to 
>>> RFC5568?
>> [Ahmad]
>> Of course. I guess you need to get out of the mode that this 
>> document is nothing but few tweaks to make FMIP6 works for 
>> PMIPv6. In RFC5568, it clearly assumes that protocol is used 
>> for fast handover when IP Mobility based on MIP6 as described 
>> in RFC3775. In that sense, only IPv6-in-IPv6 is assumed. 
>>
>> Again, the above claim of supporting all these tunneling 
>> mechanisms should either be removed and clearly document that 
>> this protocol works ONLY when the tunneling between the MAG 
>> and LMA is IPv6-in-IPv6 or explain how they will work.....
>>
>>>> 2. Is the tunneling mode (between the PMAG and the LMA) 
>>>> negotiated/communicated between the PMAG-MAGs?
>>> If the tunneling mode is determined between the LMA and 
>> PMAG, which is 
>>> in the scope of RFC5213, that of the inter-MAG tunnel should follow 
>>> it.
>>> It is also assumed that the same type of tunneling will be used 
>>> between the LMA and NMAG.
>> [Ahmad]
>> Sure, but your document claim that it supports all of these 
>> tunneling mechanisms (as per the quoted text from section 
>> 4.1) and at the same time documents nothing about how these 
>> should work across the inter-MAG tunnel.
>>
>>>> 3. If the tunneling between the PMAG-LMA is
>>> IPv6-in-IPv4-UDP, Does it
>>>> mean the tunneling between the PMAG-NMAG is also going to
>>> use the same
>>>> encapsulation?
>>> Yes, that is the basic idea.
>> [Ahmad]
>> Good. Then How that should work?
>> Is there anything in your document which specify that? I am 
>> all ears, just point me to the text.
>>
>>>> 4. If the UDP tunneling between the two MAGs is not needed,
>>> what kind
>>>> of tunneling will be used between the two MAGs to correctly
>>> map the MN
>>>> traffic and successfully deliver it to the MN?
>>> That mode has not been considered. It will be possible, but 
>> is there 
>>> any reason that a different type of tunneling should be used?
>> [Ahmad]
>> I am not suggesting to use a different tunneling mechanism 
>> between the PMAG and the NMAG; However, You are saying that, 
>> e.g., IPv6-in-IPv4-UDP is naturally extended over the 
>> PMAG-NMAG tunnel without saying how it should work. That what 
>> I was speculating that you probably use a specific tunneling, 
>> of course, other than IPv6-in-IPv6 to make it work.
>>
>> So, again, if PMAG-NMAG interface does support all these 
>> tunneling mechanisms, then we need to know how it works? That is all.
>>
>>>> 5. Do these tunneling mechanisms include plain GRE
>>> Encapsulation with
>>>> GRE keys or only GRE with TLV-header UDP tunneling?
>>> <draft-ietf-netlmm-grekey-option> supports both modes, so
>>> PFMIPv6 should also support them.
>> [Ahmad]
>> That is a clear answer. Thanks.
>> Could you please make sure that your document clarify and 
>> clearly document it.
>>
>>>> 5.1. If plain GRE encapsulation with keys is used, then the
>>> document
>>>> needs to clearly specify if there are two sets of GRE 
>> keys for the 
>>>> same mobility session or only one set? i.e., GRE Keys between the 
>>>> PMAG-LMA, GRE Keys for PMAG-NMAG or one set is used. It is
>>> not clear
>>>> in the current document.
>>> PFMIPv6 describes only GRE keys for the inter-MAG tunnel 
>> (PMAG-NMAG), 
>>> which I think is clarified in Section 4.2. As far as GRE 
>> Key Option is 
>>> used, it is difficult to transport multiple sets of keys at 
>> one time.
>> [Ahmad]
>> Well,
>> 1. It is not clarified nor clear under section 4.2. but, 
>> could you please point me to the text you are talking about?
>> 2. As far as of multiple GRE keys exchange, currently that is 
>> a limitation of the PMIPv6 protocol. Right? Then, when you 
>> need multiple GRE keys, how these GRE keys are communicated? 
>> Is that explained in the document?
>>
>>>> 5.2. same question as in 4, if there is GRE with TLV-header UDP 
>>>> tunneling between the PMAG and the LMA, Is that needed 
>> between the 
>>>> PMAG-NMAG? If NOT, what encapsulation mechanism is being
>>> used and how
>>>> is the mapping works?
>>> The working assumption is "yes".
>> [Ahmad]
>> That is a huge CLAIM that is NOT backed by any technical 
>> data! How that should work? Can you document that some where 
>> in the specification? If it is already document, please point 
>> me to the text.
>>
>>>> 6. Is the assumption here that the NMAG and the PMAG have 
>> the same 
>>>> transport with the LMA?
>>> For the sake of simplicity, the answer should be "yes".
>>> If not, the network between MAGs should provide the transparent 
>>> environment (e.g., by another tunneling).
>>>
>>>> 7. with respect to "any new method defined in the future" 
>>> what is the
>>>> constraints on this statement? It seems to me an
>>> overstatement of the
>>>> capabilities of this protocol and an underestimate of the future 
>>>> tunneling mechanism. May be you need to make sure that the
>>> wording is
>>>> correct by having some conditional restrictions.
>>> The intention here is that if a new tunneling mechanism is 
>> specified 
>>> for  PMIPv6, PFMIPv6 should also support it. If this is too 
>> vague, it 
>>> could be removed.
>> [Ahmad]
>> Sure, please remove it. Unless, you propose a dynamic 
>> tunneling mechanism that is forward compatible and capable to 
>> address future tunneling between the PMAG and LMA.
>>
>>>> In addition,
>>>> ============
>>>> IMO and based on a quick review of this draft, I find it 
>> very vague 
>>>> and does not have the details for an Interoperable
>>> protocol. I believe
>>>> the draft SHOULD CLEARLY address the following points:
>>>>
>>>> Decide whether it needs to specify/support a single tunneling 
>>>> encapsulation mechanism between the PMAG-NMAG or more than one.
>>>>
>>>>
>>>> SINGLE tunneling and encapsulation mechanism between PMAG-NMAG:
>>>> ===============================================================
>>>> 1. This *protocol* needs to specify the exact details of how this 
>>>> tunneling mechanism is dynamically established to address
>>> the nature
>>>> of the problem being address in this *handover optimization
>>> protocol*.
>>>
>>> The nature of the specification and its performance is based on 
>>> RFC5568.
>> [Ahmad]
>> That is part of the problem not to be sited here as a 
>> supporting argument!
>> As I said earlier, RFC5568 assumes that there is always 
>> IPv6-in-IPv6 tunneling between the mobile node and the home 
>> agent. In the case of
>> PMIPv6 that assumption is INVALID.
>>
>>> Whether the establishment of the tunneling mechanism is dynamic or 
>>> static is operation-specific.
>> [Ahmad]
>> That is NOT true. This document is supposedly offering a fast 
>> handover mechanism for PMIPv6 which dynamically does 
>> (implicitly or explicitly) negotiates tunneling between the 
>> MAG and the LMA. So, how a statically configured tunnel 
>> between the PMAG and the NMAG tunnels a mobile node traffics 
>> when the mobile node traffic between the PMAG and LMA for the 
>> same mobile node was dynamically negotiated?
>>
>>
>>>> 1.1. for example, if GRE with Keys is being used, then it MUST be 
>>>> clear how the GRE keys are exchanged between the PMAG-NMGA,
>>> similar to PMIPv6.
>>>
>>> The current text proposal for Section 4.2 tries to clarify it 
>>> regarding who selects the key and how it is transferred.
>> [Ahmad]
>> Hmmm.. Tries to clarify ... I guess we need a clear 
>> specification that documents an Interoperable solution. We 
>> can not just propose a standard track document that is some 
>> what clear in the mind of some. Right?
>>
>>>> 2. How the chosen PMAG-NMAG tunneling protocol is able to 
>> interwork 
>>>> with all tunneling mechanisms that are currently supported
>>> by PMIPv6,
>>>> e.g., IPv6-in-IPv6, IPv6-in-IPv4, IPv6-in-IPv4 UDP, etc. 
>>> between the
>>>> PMAG-LMA as is being claimed under section 4.2 of this draft.
>>> Basically, it is supposed that the same tunneling protocol as that 
>>> between the LMA and MAG is used. The tunneling type between the LMA 
>>> and MAG should be determined in advance.
>> [Ahmad]
>> I guess this answer is more confusing .... One time you said 
>> that the tunnel can be static and can be dynamic. Now, you 
>> just said that the tunnel should be STATIC? I mean what is 
>> it? It needs clarification......
>>
>>
>>>> 3. This *protocol* needs to clearly specify how the
>>> different mobility
>>>> sessions are being mapped between the PMAG-LMA tunneling to the 
>>>> PMAG-NMAG tunneling? Somewhat similar to 2 above.
>>> The basic mechanism is the same as in RFC5568. 
>> [Ahmad]
>> Again, in the case of RFC5568 it is straight forward. Only 
>> IPv6-in-IPv6 is supported as per RFC3775. Not the case for PMIPv6.
>>
>>> If a GRE
>>> tunnel further differentiates the session, the GRE key will be used.
>> [Ahmad]
>> Good. Which GRE Key then?
>> 1. Is that a statically configured GRE key?
>> 2. Is it the same set of GRE keys between the PMAG and LMA?
>> 3. If none of the above, how these GRE keys are generated and 
>> exchanged between the PMAG and the NMAG?
>>
>>>> Multiple Tunneling and encapsulation mechanisms between the
>>> PMAG-NMAG:
>> ======================================================================
>>>> If the choice as being claimed under section 4.1, is to
>>> support all of
>>>> the current tunneling mechanisms between PMAG-LMA on the 
>> PMAG-NMAG 
>>>> interface, then the protocol needs to address the following:
>>>>
>>>> 1. Provide a good analysis why that option is the best 
>> option? What 
>>>> are the advantages and the disadvantages?
>>> I think that is the most workable solution. 
>> {Ahmad]
>> What do you have to technically back up this statement. 
>> Otherwise, it is just another statement.
>>
>>> Since the
>>> tunneling mechanism selected for the PMIPv6 tunnel is supported by 
>>> both the PMAG and NMAG, no extra capability is required for the 
>>> inter-MAG tunnel.
>> [Ahmad]
>> OK. I am not disputing that the PMAG and the NMAG supports 
>> the same sets of tunneling mechanisms or not. It is more of 
>> which tunnel to use for which mobile node session and what 
>> parameter is needed for this inter-MAG tunnel to correctly 
>> tunnel the mobile node traffic and deliver it to the end of 
>> the tunnel in a non ambiguous way.
>>
>> For example:
>> Tunneling Case 1:
>> =================
>> 1. PMAG and the LMA negotiates the GRE encapsulation and the 
>> GRE keys using the PBU and PBA for each applicable mobility session.
>> 2. It is very well understood that both the PMAG and the NMAG 
>> support GRE tunneling with GRE keys + GRE keys exchange using 
>> PMIPv6 signaling with the LMA.
>> 3. Now: for the inter-MAG tunnel and for the same mobility 
>> session, how GRE tunneling and GRE keys are negotiated 
>> between the PMAG and NMAG? Of course, using HI and HAck, right?
>> 4. Okay, we need the exact details for this specific case.
>>
>> Tunneling Case 2:
>> =================
>> 1. Let us assume IPv6-in-IPv4 UDP is used for MN1. Okay 2. 
>> That tunneling is implicitly negotiated between the PMAG and 
>> LMA during the PBU/PBA exchange, right?
>> 3. How that is negotiated between the PMAG and the NMAG? We 
>> need the details..
>>
>> And so on....
>>
>>> Also, I don't see any specific reason to use a special tunneling 
>>> mechanism for the inter-MAG tunnel.
>> [Ahmad]
>> Good. This means you would use the same tunneling between the 
>> PMAG and LMA over inter-MAG tunneling. In this case, we need 
>> the details for negotiating that tunneling mechanism between 
>> the PMAG and the NMAG.
>>
>>>> 2. How this *protocol* dynamically negotiates the tunneling
>>> mechanism
>>>> type?
>>> If the tunneling mechanism between the LMA and MAG is determined in 
>>> advance, the same mechanism is used for the inter-MAG 
>> tunnel. So, it 
>>> is not on-demand and no negotiation is assumed. If the tunneling 
>>> mechanism between the LMA and MAG is determined on demand, 
>> then that 
>>> is a different story...
>> [Ahmad]
>> Well, what do you mean? The tunneling between the PMAG and 
>> the LMA is NOT on demand?
>> I believe IPv4 support for PMIPv6 and GRE key for PMIPv6 
>> drafts will be helpful in answering this question.
>>  
>>>> 3. How that should work, for example if the tunneling mechanism 
>>>> between the PMAG-LMA is IPv6 in IPv4 UDP, how that
>>> tunneling will be
>>>> extended to go over the PMAG-NMAG interface and how it is
>>> supposed to work.
>>>
>>> In this case, both the PMAG and NMAG should be dual-stack 
>> and the IP 
>>> addresses in the IPv4 outer header are those of the PMAG and NMAG. 
>>> IPv6 inner header should be kept intact.
>>>
>> Okay..... Then if the NMAG sends the first packet over the 
>> NMAG-PMAG tunnel! Which encapsulation mechanism is going to 
>> use to encapsulate that packet?
>>
>> Also, Do you agree that there is a specific reason for the 
>> traffic between the PMAG and the LMA to be IPv6-in-IPv4-UDP. 
>> Right? That reason may NOT be VALID between the PMAG and the 
>> NMAG. Right?
>> Then why to use the same tunneling here? Just out of curiosity!
>>
>>>> Finally, the draft could have some restrictions and define the 
>>>> PMAG-NMAG tunneling/encapsulation mechanism and could
>>> define a set of
>>>> PMAG-LMA tunneling mechanism that are being
>>> supported/interwork over
>>>> the PMAG-NMAG tunneling/encapsulation.
>>> What kind of restrictions do you foresee? Do you also have any 
>>> specific mechanism for the inter-MAG tunnel in mind?
>> [Ahmad]
>> I guess, you need to answer many of the above comments before 
>> we talk about this. A clear understanding of this tunneling 
>> is needed and I do not see it documented in this draft.
>>
>> BTW: Under section 4, this specification says:
>>
>> "
>>    In order to further improve the performance during the 
>> handover, the
>>    PFMIPv6 protocol in this document specifies a bi-directional tunnel
>>    between the Previous MAG (PMAG) and the New MAG (NMAG) to tunnel
>>    packets meant for the mobile node.  
>> "
>>
>> Which bi-directional tunnel? Where? What are the details?
>>
>>>> One more note: I found defining and describing a protocol
>>> based on a
>>>> call flow, is not the most easy to follow. But, that could
>>> just be me.
>>>
>>> What do you think could improve the readability of the document?
>> [Ahmad]
>> Quite some of them... But I gave up after a while....
>>
>>> Regards,
>>> --
>>> Hidetoshi
>>>
>>>> Regards,
>>>> Ahmad
>>>>  
>>>>
>>>>> -----Original Message-----
>>>>> From: [e-mail]
>>>>> [mailto:[e-mail]] On Behalf Of Muhanna, Ahmad
>>>>> (RICH1:2H10)
>>>>> Sent: Thursday, September 17, 2009 9:23 PM
>>>>> To: Hidetoshi Yokota
>>>>> Cc: Mipshop; [e-mail]
>>>>> Subject: Re: [Mipshop] AD review of draft-ietf-mipshop-pfmipv6
>>>>>
>>>>> Hi Hidetoshi,
>>>>> Please see inline.
>>>>>
>>>>> Regards,
>>>>> Ahmad
>>>>>
>>>>>> -----Original Message-----
>>>>>> From: Hidetoshi Yokota [mailto:[e-mail]]
>>>>>> Sent: Thursday, September 17, 2009 4:48 PM
>>>>>> To: Muhanna, Ahmad (RICH1:2H10)
>>>>>> Cc: Mipshop; [e-mail]; 
>> Jari Arkko
>>>>>> Subject: Re: [Mipshop] AD review of draft-ietf-mipshop-pfmipv6
>>>>>>
>>>>>> Hi Ahmad,
>>>>>>
>>>>>> Here is the proposed revision:
>>>>>>
>>>>>> In Section 4.2:
>>>>>>       [... message with the same sequence number.] The necessary
>>>>>>    information MUST be transferred in the HI/HAck messages to
>>>>>>    distinguish MN's packets for forwarding in advance or at
>>>>> this time.
>>>>>>    Such information includes the MN ID and/or GRE key(s).  
>>>>> Typically,
>>>>>>    the NMAG selects the GRE key for the downlink packets
>>>>> and the PMAG
>>>>>>    selects that for the uplink packets.  Each key is 
>> conveyed in 
>>>>>> either
>>>>>>    the HI or HAck message separately when GRE Key Option
>>> [GREKEY] is
>>>>>>    used. [For the downlink ...]
>>>>>>
>>>>> [Ahmad]
>>>>> In addition to what Vijay mentioned with respect to
>>> Typically (which
>>>>> should be removed), I believe the draft needs to be clear on the 
>>>>> mechanism that is used for exchanging the GRE keys. When you say 
>>>>> "...when the GRE Key Option [GREKEY] is used." What 
>> happens if the 
>>>>> GRE key option is NOT used. Is there another mechanism?
>>>>>
>>>>> Since the GRE keys are necessary to establish the lateral
>>> tunnel and
>>>>> identify the MN traffic, the draft must specify a default
>>> mechanism.
>>>>> Other mechanisms can be used or specified some where else
>>> if needed,
>>>>> but we need a default one here. Right?
>>>>>
>>>>> Also, you replaced the **HoA of the MN** with the **MN ID**. 
>>>>> What is the reason for this change?
>>>>> And how this should work NOW while you have ".. and/or GRE Keys"?
>>>>>
>>>>>> If the above description is acceptable, I will submit 
>> the revised 
>>>>>> version by the end of the week.
>>>>>>
>>>>>> Regards,
>>>>>> --
>>>>>> Hidetoshi
>>>>>>
>>>>>> Ahmad Muhanna wrote:
>>>>>>> Hi Hidetoshi,
>>>>>>>
>>>>>>>> -----Original Message-----
>>>>>>>> From: Hidetoshi Yokota [mailto:[e-mail]]
>>>>>>>> Sent: Monday, September 14, 2009 7:37 AM
>>>>>>>> To: Muhanna, Ahmad (RICH1:2H10)
>>>>>>>> Cc: Mipshop; [e-mail];
>>>>> Jari Arkko
>>>>>>>> Subject: Re: [Mipshop] AD review of draft-ietf-mipshop-pfmipv6
>>>>>>>>
>>>>>>>> Hi Ahmad,
>>>>>>>>
>>>>>>>> Thanks for your comment. I'm glad to hear an opinion from
>>>>>> a GRE key
>>>>>>>> expert. Please see inline:
>>>>>>>>
>>>>>>>> Ahmad Muhanna wrote:
>>>>>>>>> Hi Hidetoshi,
>>>>>>>>>
>>>>>>>>> I just have one quick comment and question.
>>>>>>>>>
>>>>>>>>> Reading the draft, it seems to me that the GRE keys are
>>>>>>>> somehow sent
>>>>>>>>> from the NAR to PAR in the HI (section 4.2). Is that the
>>>>>> case? This
>>>>>>>>> means both the DL and UP GRE keys for the bilateral
>>>>>> tunnels between
>>>>>>>>> the two AR(s). Is my understanding correct? It also
>>>>>>>> mentions that the
>>>>>>>>> format
>>>>>>>> In terms of the GRE keys for the bilateral tunnel, 
>> the working 
>>>>>>>> assumption is that the DL key is selected by the NAR and
>>>>>> the UL key
>>>>>>>> is selected by the PAR. Depending on the fast handover
>>>>> mode, those
>>>>>>>> keys are transferred to the other MAG via either the 
>> HI or Hack.
>>>>>>>>> of these keys are based on the GRE keys for PMIPv6
>>>>> draft (section
>>>>>>>>> 6.2.6).
>>>>>>>> Correct.
>>>>>>>>
>>>>>>>>> It seems to me that there should be more text to define
>>>>>> which keys
>>>>>>>>> exchange in the HI and which in the HaCK
>>>>>>>> If the above assumption works, I would like to add more
>>>>> text along
>>>>>>>> that line.
>>>>>>> [Ahmad]
>>>>>>> That is great. Please add some clarification text to
>>>>>> clearly indicate
>>>>>>> that only one key in the HI and the other in the HACK.
>>>>>>> Since some specification in 3GPP2 depends on this draft, I
>>>>>> appreciate
>>>>>>> if you can publish an updated version before the end of
>>> the week. 
>>>>>>> Thanks in advance!
>>>>>>>
>>>>>>>>> If both keys are exchanged in the same HI, How these 
>> keys are 
>>>>>>>>> identified at the pAR?
>>>>>>>>> In GRE keys for PMIPv6 draft, downlink GRE key is included
>>>>>>>> in the PBU
>>>>>>>>> and the uplink GRE key in included in the PBA. They never
>>>>>>>> exist in the
>>>>>>>>> same message and that way there is no confusing.
>>>>>>>> So far, each key is conveyed by either the HI or HAck. 
>>>>>>>> However, I haven't explored all of the possibilities. 
>>> If you can
>>>>>>>> think of any case that two keys must be conveyed in one
>>> message,
>>>>>>>> please let me know.
>>>>>>> [Ahmad]
>>>>>>> I do not see any reason for this case (one key per
>>>>> message) not to
>>>>>>> work for all implementation.
>>>>>>>  
>>>>>>>>> In addition, DL and UP GRE keys are generated by NAR and
>>>>>>>> sent inside
>>>>>>>>> the HI, my question: Is there any specific reason for
>>>>> the NAR to
>>>>>>>>> specify both GRE keys for the bilateral tunnels?
>>>>>>>> It would be more problematic that the NAR determines the
>>>>> both keys
>>>>>>>> and I would rather like to avoid it.
>>>>>>>>
>>>>>>>>> Sorry for this comment to be so late but hope that you have
>>>>>>>> the chance
>>>>>>>>> to take a look at it.
>>>>>>>> That's ok. The draft is under the review process. Your
>>>>> comment is
>>>>>>>> highly appreciated.
>>>>>>>>
>>>>>>>> Regards,
>>>>>>>> --
>>>>>>>> Hidetoshi
>>>>>>>>
>>>>>>>>
>>>>>>>>> Thanks!
>>>>>>>>>
>>>>>>>>> Regards,
>>>>>>>>> Ahmad
>>>>>>>>>  
>>>>>>>>>
>>>>>>>>>> -----Original Message-----
>>>>>>>>>> From: [e-mail] 
>>>>>>>>>> [mailto:[e-mail]] On Behalf Of
>>> Hidetoshi Yokota
>>>>>>>>>> Sent: Wednesday, September 02, 2009 11:12 PM
>>>>>>>>>> To: Jari Arkko
>>>>>>>>>> Cc: Mipshop; [e-mail]
>>>>>>>>>> Subject: Re: [Mipshop] AD review of 
>> draft-ietf-mipshop-pfmipv6
>>>>>>>>>> Hi Jari,
>>>>>>>>>>
>>>>>>>>>> Thanks for your patience. The attached revised document is
>>>>>>>> supposed to
>>>>>>>>>> reflect the rest of your comments. Please also see inline,
>>>>>>>> where the
>>>>>>>>>> revised part is explained item by item. If there is no
>>>>>> outstanding
>>>>>>>>>> issue there, we will upload it shortly.
>>>>>>>>>>
>>>>>>>>>> [Apologize if you received it twice. Since the size just
>>>>>>>> exceeded the
>>>>>>>>>> limit of this ML, this mail is reposted without the
>>>>> attachment.]
>>>>>>>>>> Hidetoshi Yokota wrote:
>>>>>>>>>>> Hi Jari,
>>>>>>>>>>>
>>>>>>>>>>> Appreciate your detailed review. The editorial corrections
>>>>>>>>>> are mostly
>>>>>>>>>>> done and the revised version is attached to this mail. 
>>>>>>>> Regarding the
>>>>>>>>>>> technical comments, only the policies for the correction
>>>>>>>>>> are listed for
>>>>>>>>>>> now. The complete correction will be posted as soon as
>>>>>>>>>> possible. Please
>>>>>>>>>>> see inline for the responses to your questions and 
>> comments:
>>>>>>>>>>> Jari Arkko wrote:
>>>>>>>>>>>> I have reviewed this document. It was generally in good
>>>>>>>>>> shape and easy
>>>>>>>>>>>> to read. I did find a number of issues though. Please
>>>>>>>>>> discuss them with
>>>>>>>>>>>> me on this thread and/or revise the draft accordingly.
>>>>>>>>>>>>
>>>>>>>>>>>> Technical:
>>>>>>>>>>>>
>>>>>>>>>>>> I do not understand the IP host aspects of the
>>>>>> handover. For an
>>>>>>>>>>>> unmodified host, what kind of interfaces exist on the
>>>>>> host, what
>>>>>>>>>>>> addresses they have, and at what time are interfaces
>>>>>>>>>> removed or added? 
>>>>>>>>>>>> Is this exactly the same as in RFC 5213, or does PFMIPv6
>>>>>>>>>> introduce some
>>>>>>>>>>>> change here?
>>>>>>>>>>> The basic principle would be that this specification does
>>>>>>>>>> not require
>>>>>>>>>>> any additional IP-level function to the MN running in the
>>>>>>>>>> PMIPv6 domain.
>>>>>>>>>>> This MN should therefore be the same as defined in RFC5213.
>>>>>>>>>>>
>>>>>>>>>>> A typical network interface would be one with the
>>>>>>>> cellular network,
>>>>>>>>>>> where the network basically controls the movement of the
>>>>>>>>>> MN. Different
>>>>>>>>>>> types of interfaces could be involved such as different
>>>>>>>>>> generations (3G
>>>>>>>>>>> and 3.9G) or different radio access systems. Any type of
>>>>>>>> IP address
>>>>>>>>>>> could be assigned (IPv4/v6 or global/private), but the
>>>>>>>>>> assigned address
>>>>>>>>>>> must be preserved before and after the handover. PFMIPv6
>>>>>>>>>> should be able
>>>>>>>>>>> to handle the single radio situation, where only one
>>>>>>>>>> interface is active
>>>>>>>>>>> at any given time. This is a tougher situation in terms of
>>>>>>>>>> packet loss
>>>>>>>>>>> and delay.
>>>>>>>>>>>
>>>>>>>>>>>> I would like to see a new section on manageability
>>>>>>>>>> considerations. For
>>>>>>>>>>>> instance, Section 5 talks about some 
>> configuration issues. 
>>>>>>>>>> These should
>>>>>>>>>>>> be mentioned, and there should be a description of what
>>>>>>>>>> the operator
>>>>>>>>>>>> needs to configure in order to set up a PFMIPv6 network.
>>>>>>>>>>> We will add a new section for manageability considerations
>>>>>>>>>> to clarify
>>>>>>>>>>> the above and to reflect your suggestion.
>>>>>>>>>> A new subsection is added in Section 5 describing the
>>>>>>>> above aspects:
>>>>>>>>>> -------------------
>>>>>>>>>> 5.  PMIPv6-related Fast Handover Issues
>>>>>>>>>>
>>>>>>>>>> 5.1.  Manageability Considerations
>>>>>>>>>>
>>>>>>>>>>    This specification does not require any 
>> additional IP-level
>>>>>>>>>>    functionality on the LMA and the MN running in 
>> the PMIPv6 
>>>>>>>>>> domain.  A
>>>>>>>>>>    typical network interface that the MN could be
>>>>>> assumed to have
>>>>>>>>>> is one
>>>>>>>>>>    with the cellular network, where the network 
>> controls the 
>>>>>>>>>> movement of
>>>>>>>>>>    the MN.  Different types of interfaces could be
>>>>>> involved such as
>>>>>>>>>>    different generations (3G and 3.9G) or different
>>>>> radio access
>>>>>>>>>>    systems.  This specification supports a MN with the
>>>>>> single radio
>>>>>>>>>>    mode, where only one interface is active at any given
>>>>>> time.  The
>>>>>>>>>>    assigned IP address is preserved whether the physical
>>>>>> interface
>>>>>>>>>>    changes or not and the MN can identify which
>>>>>> interface should be
>>>>>>>>>> used
>>>>>>>>>>    if there are multiple ones.
>>>>>>>>>> --------------------
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>>>> If the new router's interface is configured to 
>> respond to 
>>>>>>>>>>>>> queries sent to link-layer addresses than its
>>>>>>>>>> own (e.g.,
>>>>>>>>>>>>> set to promiscuous mode), then it can respond to the
>>>>>> NUD probe,
>>>>>>>>>>>>> providing its link-layer address in the 
>> solicited Neighbor 
>>>>>>>>>>>>> Advertisement.
>>>>>>>>>>>> Is this according to RFC 5213? I seem to recall that RFC
>>>>>>>>>> 5213 operated
>>>>>>>>>>>> on the same link layer addresses.
>>>>>>>>>>> I think your observation is correct... I'll check with the
>>>>>>>>>> other authors
>>>>>>>>>>> to see if it is ok to rewrite it.
>>>>>>>>>> The new text doesn't mention the promiscuous mode and
>>>>>>>> emphasizes the
>>>>>>>>>> common link-layer address among all MAGs in the 
>> PMIPv6 domain:
>>>>>>>>>> ---------------
>>>>>>>>>> 5.2.  Expedited Packet Transmission
>>>>>>>>>>
>>>>>>>>>>    [...]
>>>>>>>>>>
>>>>>>>>>>    The protocol specified in this document is applicable
>>>>>>>> regardless of
>>>>>>>>>>    whether link-layer addresses are used between a MN and
>>>>>>>> its access
>>>>>>>>>>    router.  A MN should be able to continue sending
>>>>>> packets on the
>>>>>>>>>>    uplink even when it changes link.  When link-layer
>>>>>> addresses are
>>>>>>>>>>    used, the MN performs Neighbor Unreachability
>>>>> Detection (NUD)
>>>>>>>>>>    [RFC4861], after attaching to a new link, probing the 
>>>>>>>>>> reachability of
>>>>>>>>>>    its default router.  The new router should respond
>>>>> to the NUD
>>>>>>>>>> probe,
>>>>>>>>>>    providing its link-layer address in the 
>> solicited Neighbor
>>>>>>>>>>    Advertisement, which is common in the PMIPv6 domain.  
>>>>>>>>>> Implementations
>>>>>>>>>>    should allow the MN to continue to send uplink packets
>>>>>>>> while it is
>>>>>>>>>>    performing NUD.
>>>>>>>>>> ----------------
>>>>>>>>>>
>>>>>>>>>>>>> At least one mobility option MUST uniquely identify
>>>>>> the target
>>>>>>>>>>>>> MN (e.g., the Mobile Node
>>>>>>>> Identifier
>>>>>>>>>>>>> Option defined in RFC4283
>>>>>>>>>> <http://tools.ietf.org/html/rfc4283>) and
>>>>>>>>>>>>> the transferred context MUST be for one MN per message.
>>>>>>>>>>>>>   
>>>>>>>>>>>> I would like the required options to be specified in more
>>>>>>>>>> detail. Which
>>>>>>>>>>>> identity options are sufficient to satisfy the MUST?
>>>>>>>>>>> The required option should be the MN Identifier in the
>>>>>> Mobile Node
>>>>>>>>>>> Identifier Option.
>>>>>>>>>> The above description is added in Section 6.1.1:
>>>>>>>>>>
>>>>>>>>>> ---------
>>>>>>>>>>    Requested option
>>>>>>>>>>              In order to uniquely identify the target
>>>>> MN, the MN
>>>>>>>>>>              Identifier MUST be contained in the 
>> Mobile Node 
>>>>>>>>>> Identifier
>>>>>>>>>>              Option.
>>>>>>>>>> ---------
>>>>>>>>>>
>>>>>>>>>>>>> If a default set of context information is defined
>>>>> and always
>>>>>>>>>>>>> sufficient, this option is not mandatory.  This
>>>>>>>>>> option is more
>>>>>>>>>>>>> useful to retrieve additional or dynamically
>>>>> selected context
>>>>>>>>>>>>> information.
>>>>>>>>>>>>>
>>>>>>>>>>>>> Context Request Option is typically used for the
>>>>>> reactive (NAR-
>>>>>>>>>>>>> initiated) fast handover mode to retrieve the context
>>>>>>>> information
>>>>>>>>>>>>> from the PAR.  When this option is included in the HI
>>>>>>>> message, all
>>>>>>>>>>>>> the requested context information SHOULD be included
>>>>>> in the HAck
>>>>>>>>>>>>> message in the corresponding mobility option(s) (e.g.,
>>>>>>>>>> HNP, LMAA or
>>>>>>>>>>>>> MN-IID mobility options).
>>>>>>>>>>>>>   
>>>>>>>>>>>> Please specify what the default set of context
>>>>>>>> information is, by
>>>>>>>>>>>> listing the required options when the CRO is not present.
>>>>>>>>>>> The default context information to request is the Home
>>>>>>>>>> Network Prefix
>>>>>>>>>>> Option. If the Mobile Node link-layer is available and
>>>>>>>>>> used, the Mobile
>>>>>>>>>>> Node Link-layer Identifier Option MUST also be requested. 
>>>>>>>>>> With these two
>>>>>>>>>>> options and the MN identifier, the NMAG can
>>> construct the PBU.
>>>>>>>>>> The above description is added in Section 6.2.1:
>>>>>>>>>>
>>>>>>>>>> ----------
>>>>>>>>>>    The default context information to request is the
>>>>>> Home Network
>>>>>>>>>> Prefix
>>>>>>>>>>    Option.  If the Mobile Node link-layer is available and
>>>>>>>> used, the
>>>>>>>>>>    Mobile Node Link-layer Identifier Option MUST also be
>>>>>> requested.
>>>>>>>>>> ----------
>>>>>>>>>>
>>>>>>>>>>>> Editorial:
>>>>>>>>>>>>
>>>>>>>>>>>>>    HO-Initiate:
>>>>>>>>>>>>>         A generic signaling message, sent from the P-AN
>>>>>>>>>> to the PMAG that
>>>>>>>>>>>>>         indicates a MN handover.  While this signaling is
>>>>>>>>>> dependent on
>>>>>>>>>>>>>         the access technology, it is assumed that
>>>>>>>>>> HO-Initiate can carry
>>>>>>>>>>>>>         the information to identify the MN and to
>>>>>>>> assist the PMAG
>>>>>>>>>>>>>         resolve the NMAG and the new access point or the
>>>>>>>>>> base station to
>>>>>>>>>>>>>         which the MN is moving to.  The details of this
>>>>>>>>>> message are
>>>>>>>>>>>>>         outside the scope of this document.
>>>>>>>>>>>>>
>>>>>>>>>>>>> 4. Proxy-based FMIPv6 Protocol Overview
>>>>>>>>>>>> Section 4 would probably benefit from an additional
>>>>>>>>>> paragraph at the
>>>>>>>>>>>> beginning to explain what assumptions there exist about
>>>>>>>>>> lower layer
>>>>>>>>>>>> functionality.
>>>>>>>>>>> Yes, the predictive fast handover relies on the 
>> lower layer 
>>>>>>>>>>> functionality to trigger to send the HI. A new paragraph
>>>>>>>>>> will be added
>>>>>>>>>>> to clarify it.
>>>>>>>>>> -------------
>>>>>>>>>> 4.  Proxy-based FMIPv6 Protocol Overview
>>>>>>>>>>
>>>>>>>>>>    If the MAGs can be informed of the detachment and/or
>>>>>>>> attachment of
>>>>>>>>>>    the MN in a timely manner via e.g. the lower layer
>>>>>> signaling, it
>>>>>>>>>> will
>>>>>>>>>>    become possible to optimize the handover procedure,
>>>>>>>> which involves
>>>>>>>>>>    establishing a connection on the new link and
>>>>>> signaling between
>>>>>>>>>>    mobility agents, compared to the baseline specification
>>>>>>>> of PMIPv6.
>>>>>>>>>>   [...]
>>>>>>>>>> -------------
>>>>>>>>>>
>>>>>>>>>> All the other corrections pointed out below have also been 
>>>>>>>>>> reflected in the revised document.
>>>>>>>>>>
>>>>>>>>>> Regards,
>>>>>>>>>> --
>>>>>>>>>> Hidetoshi
>>>>>>>>>>
>>>>>>>>>>>>> A new flag 'P' is defined for the HI and HAck 
>> messages to 
>>>>>>>>>>>>> distinguish from those in [RFC5268bis
>>>>>>>>>>>>>
>> <http://tools.ietf.org/html/draft-ietf-mipshop-pfmipv6-08#ref-
>>>>>>>>>> RFC5268bis>]
>>>>>>>>>>>>> and thus MUST
>>>>>>>>>>>>> be set in the entire document.
>>>>>>>>>>>>>   
>>>>>>>>>>>> This would be more readable as " ... those in
>>>>>>>>>> [RFC5268bis]. This flag
>>>>>>>>>>>> MUST be ..."
>>>>>>>>>>> Revised.
>>>>>>>>>>>
>>>>>>>>>>>>>    and the NAR creates a proxy NCE to receive those
>>>>>>>>>> packets for the NCoA
>>>>>>>>>>>> The term NCE has not been introduced at this stage yet.
>>>>>>>>>>> Spelled out as "Neighbor Cache Entry".
>>>>>>>>>>>
>>>>>>>>>>>>>    address that is used by the MN is MN-HoA.  Hence the
>>>>>>>>>> PAR forwards
>>>>>>>>>>>> The term MN-HOA has not been introduced before.
>>>>>>>>>>> Added the unabbreviated form "Mobile Node's Home Address" 
>>>>>>>> before it.
>>>>>>>>>>>>>         The access network to which the MN is attached
>>>>>>>>>> after handover.
>>>>>>>>>>>> New term MN, not introduced before.
>>>>>>>>>>>>
>>>>>>>>>>> Added "Mobile Node" before it.
>>>>>>>>>>>
>>>>>>>>>>>>> specifies forwarding when the MN uses HoA as its
>>>>>> on-link address
>>>>>>>>>>>> New term HoA...
>>>>>>>>>>> Changed to "Home Address".
>>>>>>>>>>>
>>>>>>>>>>>>>    as MN's NAI, Home Network Prefix (HNP), IPv4 Home
>>>>>>>> Address, are
>>>>>>>>>>>> New term NAI...
>>>>>>>>>>> Added "Network Access Identifier" before it.
>>>>>>>>>>>
>>>>>>>>>>>>>         flag set and include the MN ID, the MN-HNP, the
>>>>>>>>>> MN-IID and the
>>>>>>>>>>>> New terms MN-HNP and MN-IID (or at least they do not
>>>>>>>>>> appear in their
>>>>>>>>>>>> MN-XXX form before this point).
>>>>>>>>>>> Modified "MN-HNP" to "HNP" for consistency.
>>>>>>>>>>>
>>>>>>>>>>>>>         Inner destination address: HNP or IPv4-MN-HoA
>>>>>>>>>>>> IPv4-MN-HoA not defined earlier...
>>>>>>>>>>> Added "Mobile Node's IPv4 Home" before it.
>>>>>>>>>>>
>>>>>>>>>>>>>    between the PCoA and NCoA to forward packets for the
>>>>>>>>>> MN to the NAR,
>>>>>>>>>>>> New terms PCoA and NCoA... there's probably more undefined
>>>>>>>>>> terms in the
>>>>>>>>>>>> document, please check!
>>>>>>>>>>> Added "Previous Care-of Address" and "New Care-of 
>> Address". 
>>>>>>>>>> Will read
>>>>>>>>>>> through it to see if there is any other undefined acronym.
>>>>>>>>>>>
>>>>>>>>>>>>>    In (i),
>>>>>>>>>>>> In Step (i),
>>>>>>>>>>> Revised including other parts.
>>>>>>>>>>>
>>>>>>>>>>>>>           |(MN ID, Old AP ID) |     (MN ID, Old 
>> AP ID)    
>>>>>>>>>>  |        |
>>>>>>>>>>>> Old AP ID? AN ID? AR ID?
>>>>>>>>>>> AP ID stands for "Access Point Identifier", which is
>>>>>>>>>> defined in RFC5568.
>>>>>>>>>>> Added the unabbreviated form and citation.
>>>>>>>>>>>
>>>>>>>>>>> The rest of the part will be revised soon.
>>>>>>>>>>>
>>>>>>>>>>> Regards,
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>> --------------------------------------------------------------
>>>>>>>>>> ----------
>>>>>>>>>>> _______________________________________________
>>>>>>>>>>> Mipshop mailing list
>>>>>>>>>>> [e-mail]
>>>>>>>>>>> https://www.ietf.org/mailman/listinfo/mipshop
>>>>>>>>>> _______________________________________________
>>>>>>>>>> Mipshop mailing list
>>>>>>>>>> [e-mail]
>>>>>>>>>> https://www.ietf.org/mailman/listinfo/mipshop
>>>>>>>>>>
>>>>>>>
>>>>>> --
>>>>>> Hidetoshi Yokota
>>>>>>
>>>>>> Mobile Network Lab
>>>>>> KDDI R&D Laboratories, Inc.
>>>>>> e-mail:[e-mail]
>>>>>>
>>>>>>
>>>>> _______________________________________________
>>>>> Mipshop mailing list
>>>>> [e-mail]
>>>>> https://www.ietf.org/mailman/listinfo/mipshop
>>>>>
>>>>
>>>>
>>>
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