Re: [spring] [DMM] How Encoded SID should be placed in SL (SRv6-mobile-uplane)

["Kentaro Ebisawa" <[e-mail]>]

Hi Satoru,

Thank you for the email replies and taking time for offline discussion.

Your explanation in the emails clarified my questions, and leaving a few 
notes below to share clarification made during the offline chat for 
others on the list.

* In the draft, SRv6-mobile-uplane, IPv4 client packets will use Encap 
and IPv6 packets will use Insert while traversing SRv6 network.
* For UL, Encoded SID will be SL[1]
     * Exist side of SRv6 and not on the interworking node in DL.
     * SL[0] is an end host on external network who MN is communicating 
with.
* "Locater of interwork" differes for UL and DL. (as mentioned in the 
draft)

Regards,
--
Kentaro Ebisawa <[e-mail]>

------ Original Message ------
From: "Satoru Matsushima" <[e-mail]>
To: "Kentaro Ebisawa" <[e-mail]>
Cc: "dmm" <[e-mail]>; [e-mail]; "Matsushima Satoru" 
<[e-mail]>
Sent: 2017/08/29 10:44:16
Subject: Re: [DMM] How Encoded SID should be placed in SL 
(SRv6-mobile-uplane)

>Hi Kentaro,
>
>I've replied to your previous mail that I hope it would answer to your 
>questions.
>
>On Tue, Aug 29, 2017 at 12:44 AM, Kentaro Ebisawa <[e-mail]> 
>wrote:
>>Hi,
>>
>> > Q2) Down Link packet (SRv6 to existing network)
>> > > When the endpoint receives packet and the active segment of the
>> > > packet indicates the SID, the endpoint pop the SRH of the SID, and
>> > ...
>> >
>> > IPv6 Src: Origin Host
>> > IPv6 Dst: SL[n]
>> > Segment Left = n
>> > SL[m] = Encoded SID
>> > SL[m+1] = Segment m+1
>> > SL[n] = Segment n
>>
>>Actually I think this differs for T.Insert case, where MN user packet 
>>is IPv6.
>># Unless I missed description that Stateless Interworking will always 
>>use encapsulation mode even if user packet is IPv6.
>
>In DL, Stateless Interworking uses encapsulation for original IPv6 
>packet with IPv4 and tunnel header.
>
>
>>
>>
>>IPv6 Src: Origin Host
>>IPv6 Dst: SL[n]
>>Segment Left = n
>>SL[0] = MN address
>>SL[1] = Encoded SID
>>SL[n] = Segment n
>>
>
>As I mentioned in the previous mail, SL indicates SL[1] at the 
>interworking node.
>
>
>>And interworking segment should behave like below.
>>
>>When the endpoint receives packet and the active segment of the
>>packet indicates the SID, the endpoint pop the SRH of the SID,
>> >> Set IPv6 destination address as SL[0] (MN's address), and
>>then the endpoint encaps the payload with the encoded information in
>>the SID which are tunnel identifier of tunnel header, source and
>>destination IPv4 address of IPv4 header described in Figure 3.
>
>
>Right, it looks more precise description to it. Thanks!
>
>
>>
>>Maybe having example packet headers described for each cases 
>>(encap/insert, User Packet = IPv4/IPv6) will help this makes more 
>>easier to understand.
>>
>
>Absolutely yes, it's helpful to understand. I'll update the I-D with 
>that example in next revision.
>
>Thanks,
>--satoru
>