Re: [Hipsec] Comment on VIA_RVS parameter - 5204 & 06 -bis

[Miika Komu <[e-mail]>]

Hi,

On 09/16/2016 02:45 PM, Robert Moskowitz wrote:
>
>
> On 09/16/2016 06:57 AM, Tom Henderson wrote:
>>
>>
>>
>> On Thu, 15 Sep 2016, Robert Moskowitz wrote:
>>
>>> 5206-bis specifies how to user RVS for the 'double-jump' mobility
>>> problem.
>>>
>>> 3.2.3 1) says:
>>>
>>> 1. The mobile host sending an UPDATE to the peer, and not receiving
>>> an ACK, MAY resend the UPDATE to a rendezvous server (RVS) of the
>>> peer, if such a server is known.
>>>
>>> But it DOES know there is an RVS IF the I1 had FROM and RVS_HMAC
>>> parameters and it had created a VIA_RVS parameter to send in the R1.
>>
>> Yes, but the responder may not know the initiator's RVS even if the
>> the responder's RVS was used, and it also may be the case that neither
>> host's RVS was involved in the session setup.
>
> I see now.  As currently speced, R has no way of learning I's RVS. The
> 'easy' way to fix this is for I to include a VIA_RVS in the I2 packet
> for mobility support.
>
> "If you every want to get back to me, I can always be reached at this
> number".

do you actually need the initiator's RVS for double jump? I think the 
responder's RVS is enough.

>>> This VIA_RVS provides the knowledge and locator of the peer's RVS.
>>>
>>> In fact an aggressive mobility UPDATE would be sent simultaneously to
>>> the host and its RVS.  If the host had not moved itself, it gets both
>>> and drops the one from the RVS.
>>
>> I believe that Baris Boyvat on the InfraHIP project was looking a
>> while back at such an approach to fast mobility; it was called
>> 'shotgun' approach to mobility and multihoming (try all candidates
>> simultaneously), if I remember correctly.

Yes, the idea was to send I1 (or UPDATE) through all the available 
address pairs, but I think the idea is now achieved in a more controlled 
way in draft-ietf-hip-native-nat-traversal-13