Re: Questions on draft-matsushima-stateless-uplane-vepc-02

Hi Satoru,

It seems most issues are resolved, except one below.

Regards,

Behcet

On Fri, May 23, 2014 at 3:39 AM, Satoru Matsushima
<[email protected]> wrote:
> Behcet, thanks for clarifying more clearly. :)
>
>
> On Fri, May 23, 2014 at 4:15 AM, Behcet Sarikaya <[email protected]>
> wrote:
> -- snip --
>
>>
>> >
>>
>> > Ah, I see what you mean. Yes, I'm sure that RR/RS just only know about
>> > routes, nor whole mobility information exists. When I see a node which
>> > plays
>> > MME role, the node could also be a BGP speaker to export the mobility
>> > info
>> > transformed to the routes.
>> >
>>
>> So MME should be BGP speaker?
>> If not then what would happen?
>>
>
> Precisely, say MME, which 3GPP defined mobility management entity, doesn't
> have the BGP function. IMO, If the entity can be coexist with BGP in a
> single node, an interface for exposing/retrieving mobility information would
> be required between them.
>
>
>>
>> > What do you mean by "topologically incorrect"?
>> > Is that the assigned prefixes are disordered to be aggregated?
>> >
>>
>> Yes. UE moves to another EPC-E which supports a different prefix than UE
>> has?
>> You need to keep host-based prefixes as routes, is there another way?
>>
>
> In the draft, as long as an UE keeps same prefix during hand-over among
> EPC-E routers, those routers belong to a same group that is expected to
> preserve same prefix for the UE. It should be initial attach when the UE is
> attached to different EPC-E and assigned different prefix from previous one.
> Please read section 3.3 and 3.4 of the draft.
>

Attach is OK but I am talking about handover. In Section 3.4 you say:
Thus, UE's address
   is unchanged even after handover.

I don't understand your statement
those routers belong to a same group that is expected to
 preserve same prefix for the UE.

I think you mentioned this before in another conversation that EPC-E's
will be assigned prefixes based on geographical division. If a UE
moves to a different region, how could the routers preserve the same
prefix for the UE without host routes or host prefixes?

Regards,

Behcet
> cheers,
> --satoru