[16NG] Re: some thoughts on IPv6-over-IPv6CS

[Alexandru Petrescu <alexandru.petrescu at motorola.com>]

Dear JinHyeock, thanks for your reply.

Just one comment, I will not insist on this.

JinHyeock Choi wrote:
> Dear Alex
>
> Kindly find my in-line comments.
>
> > > > > IEEE 802.16 also defines a secondary management connection 
> > > > > that can be used for host configuration.  However support for
> > > > >  secondary management connections is not mandatory.  A 
> > > > > transport connection has the advantage of it being used for 
> > > > > host configuration as well as for user data.
> > > > Are you specifying something about the use of the management 
> > > > connections? If not, take it out.
> > >
> > > Not really specifying anything w.r.t the management connection. 
> > > This came up during discussion with Alex Petrescu and I added it 
> > > just for the sake of completeness. Within the scope of this I-D, 
> > > the management connection has no relevance. I can take it out.
> >
> > Yes, the issue is that 802.16 recommends the RS/RA to happen on a 
> > Secondary Management Connection (instead of on a Transport 
> > Connection). Clarifications on the list suggested that probably 
> > nobody uses a SMC. But that doesn't mean that the IEEE spec isn't 
> > saying so.
>
> As of my knowledge, 802.16 doesn't mandate which connection to use 
> for RS/RA.

Well I thought that mentioning of sl address autoconf happening on the
SMC, check citation below.

> Actually in the beginning of IPv6 over 802.16 IP CS work, we gave 
> much thought on which connection to use for Neighbor Discovery 
> messages such as RS/ RA or NS/ NA. (because those messages can carry 
> multicast destination address and unspecified source address, special
> features are required for the connection.)

What came out of the discussion?

> Unfortunately 802.16 spec is not perfectly clear about this. While 
> there are a few vague statements which may be interpreted to 
> recommend the Secondary Management Connection, upon discussing with 
> 802.16 & WiMAX people, we found out that neither the statements were 
> written with that intention nor the actual 802.16 SS and BS were 
> implemented that way. Transport Connection (especially Initial 
> Service Flow for WiMAX case) is universally agreed as long as our 
> experience & knowledge goes. If there is something missing or wrong, 
> kindly let me know.

Look.  Let's ignore WiMax for a very short moment.  All we're left with
is the 802.16-2005 spec:

> IPv6 Stateless Address Autoconfiguration [IETF RFC 2462] based on the
>  value of a TLV tuple in REG-RSP. Establishment of IP connectivity 
> shall be performed on the SS’s Secondary Management Connection (see 
> Table 110).

First issue is the use of SMC for RS/RA.

The second item is the value in REG-RSP.  That value is equivalent to
the M-bit in RA.

Both issues can be solved directly and solely in the IETF draft, until
the IEEE spec is updated.

I agree discussion and clarification happened, at least on the list, but
its results should be documented.  I agree that IEEE 802.16 may be fed
back and modified suggestions.  I would like that to happen.  If that
happens then some coherency is gained.

Remark we can't put deadlines on IEEE document advancement, so maybe
just hold on for a while.

Alex


> Thanks for your kind consideration.
>
> Best Regards
>
> JinHyeock

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