Re: [6tisch] Question on draft-ietf-6lo-routing-dispatch-00

[Tengfei Chang <[e-mail]>]

Yes, I see. Thanks for the explanation!

Tengfei

On Wed, Jan 6, 2016 at 5:16 PM, Pascal Thubert (pthubert) <
[e-mail]> wrote:

> I see TengFei:
>
>
>
> The text means a header that is used for the purpose of routing, not
> necessarily a source route header like an IPv6 RH…
>
>
>
> Take care,
>
>
>
> Pascal
>
>
>
> *From:* Tengfei Chang [mailto:[e-mail]]
> *Sent:* mercredi 6 janvier 2016 16:43
> *To:* Pascal Thubert (pthubert) <[e-mail]>
> *Cc:* [e-mail]; [e-mail]
> *Subject:* Re: Question on draft-ietf-6lo-routing-dispatch-00
>
>
>
> Hi Pascal,
>
>
>
> Thanks for the replies! And thanks a lot for the slides! That's exactly
> the thing what we are looking for!
>
>
>
> The IPv6ExT is IPv6 Extension Header with the value of 7 of EID which
> indicate the following IPv6 Header(IPHC).
>
>
>
> I misunderstood IPinIP-6LoRH since I saw the first sentence of section 8
> where it says: *The IP-in-IP 6LoRH (IPinIP-6LoRH) is an Elective 6LoWPAN *
> *Routing Heade**r **that provides** a compressed form for the
> encapsulating IPv6 Header **in the case of an IP-in-IP encapsulation.*
>
>
>
> This confused me a little bit since it was called Routing Header (I was
> thinking the source routing header) but, yes, it explained that it's being
> used for compressing form for encapsulating IPv6 Header. Is here any
> different concept for routing header?
>
>
>
> Anyway, with the reply we are understanding now what IPinIP 6LoRH stands
> for. Thanks a lot for the answering!
>
>
>
> Cheer,
>
> Tengfei
>
>
>
>
>
> On Wed, Jan 6, 2016 at 3:46 PM, Pascal Thubert (pthubert) <
> [e-mail]> wrote:
>
> Hello TengFei : )
>
>
>
> I hope you’re doing good!
>
>
>
> Please see below:
>
> 1. in section 4.2, second paragraph:
>
> *One or more 6LoRHs MAY be placed in a 6LoWPAN packet and MUST always*
>
> *be placed before the LOWPAN_IPHC [RFC6282].*
>
>
>
> What's the situation when Ip-in-Ip encapsulation structure was used?
>
>
>
> <pascal>
>
> The idea is that the original IPv6 packet that may eventually fly over the
> internet or has come from the Internet should be encoded using RFC6282.
> There may be IP in IP in there but then the RPL routers would not see the
> inner IP.
>
> When that packet traverses the RPL network, headers may need to be added
> or removed. If so, anything that needs to be added or removed in the life
> of the packet by a node that is not source or destination must be placed in
> an IP in IP using 6LoRH
> https://tools.ietf.org/html/draft-ietf-6lo-routing-dispatch-00#section-8,
> and the 6LoRH must be placed before the IPHC. There’s no a comprehensive
> study of that here
> https://tools.ietf.org/html/draft-robles-roll-useofrplinfo-02 thanks to
> the efforts of the RPL chairs.
>
> </pascal>
>
>
>
>
>
> 2. section 8: IP-in-IP 6LoRH first paragraph:
>
> *The IP-in-IP 6LoRH (IPinIP-6LoRH) is an Elective 6LoWPAN Routing*
>
> *Header that provides a compressed form for the encapsulating IPv6*
>
> *Header in the case of an IP-in-IP encapsulation.*
>
>
>
> According to the description, it the IPinIP-6LoRH is a combination of
> IPHC+RH3 but in a compressed format?
>
> <pascal>
>
> No, TengFei. The IP in IP 6lorh encodes the outer IP header that must be
> placed to encapsulate. RH3 is encoded as a series of 6Lorhs as described in
> https://tools.ietf.org/html/draft-ietf-6lo-routing-dispatch-00#section-6
>
> </pascal>
>
>
>
> For example: following is the format of packet containing routing header
> which defined in old draft using an Ip-in-Ip encapsulation:
>
> MACheader + IPHC + RH3 + IPv6ExT + IPHC + ICMPv6
>
>
>
> If we are using the 6LoRH, will it turns to :
>
> MACheader + Paging Dispatch(page 1) + IPinIP-6LoRH + IPv6ExT + IPHC +
> ICMPv6
>
>
>
> Is this correct? If not, what it should be? Thanks!
>
>
>
>
>
> <pascal>
>
> Not really:
>
> 1)      The RH3 is expressed as a series of 6LoRH after the IP in IP, one
> 6LoRH per group of contiguous addresses that are compressed to the same
> size Please look at slide 10 in
> https://www.ietf.org/proceedings/94/slides/slides-94-6lo-2.pdf
>
> 2)      What is the IPv6Ext? The only header that RPL may add there is
> RPI in HbH, compressed by 6loRH. And Actually I’d place it before the RH.
> Anything that is not compressed by 6LoRH has to be compressed by RFC 6282
> and must be placed after the IPHC
>
>
>
> <pascal>
>
>
>
> You two take care,
>
>
>
> Pascal
>
>
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