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Re: RE : [DNA] [Announce] DNA in IPv6 Goals I-D Update
Dear Njedjou
Thanks for your kind comments. Kindly find my inline comments.
> SECTION 1 Introduction
> "Today a link change necessitates an IP configuration change.
> Whenever the host detects that it has remained at the same link, it
> can usually assume its IP configuration is still valid. Otherwise,
> the existing one is no longer valid and a new configuration must be
> acquired. Hence a host only needs to check for link change to
> examine the validity of its IP configuration."
>
> Comment: I am surprised at such an assumption. When a 802.22 STA
> reassociates to a new AP, the IP subnet behind could possibly be the
> same as that of the previous AP. Unless you define a link change
> differently from the way people generally think of it.
We have different opinions about the link definition. We define link as of RFC 2461,
a communication facility or medium over which nodes can communicate at
the link layer. Then there is no link change in the above example.
We discussed about the term 'link' in DNA ML for a while ago. Though we were
not entirely happy with the term, we could not find a better term.
Kindly find my presentation at 58th IETF meeting in which I tried to clarify the
notion of link there.
> SECTION 2 DNA in existing IPv6 systems
> "When a host changes its attachment point, for efficiency, a host
> should examine whether its IP configuration is still valid before
> initiating the process of acquiring a new IP configuration."
>
> Comment: It should be precised that change of attachmment here refers
> to change of link-layer attachment for clarity purpose
In the discussion concerning terms, L2 link and L3 link, we decided to use 'link'
for 'L3 link' and 'attachment point' for 'L2 link'. You can find more details in
Feb DNA ML.
> SECTION2 DNA in existing IPv6 systems
> "Link-layer hints are indications from lower
> layers that IP connectivity may have changed. With suitable
> hysteresis, these hints may be used to initiate IP based
> reachability checks."
>
> Comment:
> I do not agree with this definition of a link layer hint.
> Link layer hints could just indicate that a new link is present without
> the IP configuration on current link being no more valid. I think there
> is a confusion throughout this document between presence of a new link
> and IP connectivity change. The first does not necessarily implies the
> second.
I guess what you mean by 'link' is L2 link, or attachment point.
We may clarify this in Terminology draft which Carl is preparing.
Best Regards
JinHyeock Choi
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