Re: [netext] Update on flow mobility following discussion with ADs

[Julien Laganier <[e-mail]>]

Hi Rajeev,

I've been under the impression that correctness is only achievable to
the extent that the network offers flow-mobility / inter-access
handoffs only to the MN that indicates their support for the feature
(e.g., via the logical interface construct, or any other.) If that
holds, since the MN can' t indicate this at layer 3, this has to be
done at layer 2, thus you need this extended L2 signaling in all
cases.

Am I missing something?

--julien

On Thu, Mar 3, 2011 at 9:40 PM, Rajeev Koodli <[e-mail]> wrote:
>
> Hi Julien,
>
> I don't believe I suggested sacrificing correctness and robustness; in fact,
> I suggested robustness of protocol operation to cover all cases.
>
> More to the point, I think relying _only_ on extended L2 signaling is one of
> the cases the protocol needs to cover. We need to include the case when
> either new L2 signaling is unavailable or is not considered reliable.
>
> I am proposing an inclusive approach for providing flow mobility when the
> desired aspects of L2 signaling are available (HI=Flow Mobility) _and_
> consider the case when we they are not available (HI=Unknown). I should be
> able to move flows across interfaces regardless of whether the LMA maintains
> a single session or multiple sessions (all created according to the baseline
> PMIP6 model).
>
> Making use of 3GPP as a customer is great, but I do not want to be limited
> only to it.
>
> Thanks,
>
> -Rajeev
>
>
>
> On 3/3/11 11:44 AM, "Julien Laganier" <[e-mail]> wrote:
>
>> Hi Rajeev,
>>
>> On Wed, Mar 2, 2011 at 12:39 PM, Rajeev Koodli <[e-mail]> wrote:
>>>
>>>
>>> On 3/2/11 11:49 AM, "Jari Arkko" <[e-mail]> wrote:
>>>
>>>> Sri:
>>>>
>>>> What Basavaraj said. I don't think the number of specifications is a big
>>>> concern either now or later. Split the documents the way you like. Lets
>>>> discuss functionality, robustness, assumptions instead -- those are
>>>> important.
>>>
>>>
>>> I agree that the spec should be robust, and should work under conditions
>>> assuming existing & new L2 signaling, as well as under conditions when new
>>> L2 signaling is unavailable.
>>
>> I have expressed doubts about the feasibility of a robust flow
>> mobility / inter-access handover solution that relies on existing,
>> unmodified L2 signaling (this is discussed in a different thread.) We
>> should not sacrifice correctness and robustness for the sake of
>> working around unmodified L2 signaling. As I've said earlier, one of
>> the potential customer for this (3GPP) owns two L2 that are used to
>> access their system (PMIP based S5 for 3GPP accesses, and PMIP based
>> S2b for no-3GPP accesses.)
>>
>>> It's a question of whether we agree that LMA-MAG signaling could also be
>>> used in addition to relying only on L2 signaling for flow mobility.
>>
>> At this stage the question is rather, is it possible to provide a
>> correct and robust system without modified L2 signaling. If it is,
>> then we can go ahead with the question you laid above. Would you
>> agree?
>>
>>>> (And of course, splitting to different specifications should not be
>>>> misused to hide a technical omission or a problem.)
>>>
>>> I would focus on getting a protocol that works under different cases and not
>>> just under continued reliance on (existing and new) L2 signaling. (I am not
>>> referring to new IP signaling between MN and MAG).
>>
>> See above. The focus you propose is only appropriate insofar we've
>> come up with a positive answer to the question I asked above, and that
>> we' re discussing with Carlos, Hesham, et al.
>>
>> --julien
>
>