Re: RE: questions about draft-wen-ipv6-rsra-opt-multihoming-00

[Greg Daley <Greg.Daley@eng.monash.edu.au>]

Hi Wen, 

----- Original Message -----
From: CTO WEN Haibo <Haibo.WEN@alcatel-sbell.com.cn>
Date: Tuesday, June 6, 2006 9:34 pm
Subject: RE: questions about draft-wen-ipv6-rsra-opt-multihoming-00
To: Lawrence Zou <zou.rong@huawei.com>
Cc: multi6@ops.ietf.org, shim6@psg.com

> Please see below.
> 
> 
> > -----Original Message-----
> > From: Lawrence Zou [mailto:zou.rong@huawei.com]
> > Sent: 2006?6?6? 17:33
> > To: CTO WEN Haibo
> > Cc: multi6@ops.ietf.org; shim6@psg.com
> 
> > >In current IPv6 multihoming site, each hosts in this site can 
> > >have multiple prefixes from different exit routers. It cannot 
> > >identify which ISP assignes 
> > >the exact prefix, because there is no extra information in 
> > >prefix information option.
> > >
> > >The multi-homing information defined in this draft is used 
> > >along with prefix information option. It will provide extra 
> > >information for host to do selection. Host only selects the 
> > >prefix from the desired ISP to form its IPv6 address, of 
> > >course, the corresponding exit router will be cached. Other 
> > >prefixes from other routers will not be used to form IP 
> > >address. For example, STB may only want services from IPTV 
> > >service provider. Other prefixes from other service providers 
> > >are useless for itself.
> > 
> > yes,i think you point out the most important thing:the host only 
> > form IP adress it will use it .
> > so i guess that:
> > 1)ISP1 and ISP2 send RA with prefix information and multi-homing
> > information.
> > 2)if host can decide whitch ISP it will select,for example ,it 
> select> ISP1,the host will form address with
> >  the prefix in the RA of ISP1 and ignore  the RA of ISP2.
> > 
> > >
> > >Host knows which ISP it will got its service, and it also 
> > >knows its exit router is the edge router of the desired ISP. 
> > >But it doesn't know the network topology, it doesn't know the 
> > >exact exit router either, unless multi-homing informaiton 
> > >option is used along the prefix information option.
> > 
> > i do not agree with this point of "Host knows which ISP it will 
> got its
> > service" in the scenario of  stateless address auto-configure,in 
> the SAAC,
> > we should assume that No manual configuration 
> > of individual machines  before connecting them to the network, 
> but if
> > you do not do some manual configuration,
> > how can you know which ISP the host will got its service?One 
> available> method the host can do this is it ask "who
> > can provide the service of......?" and if someone  anwer it 
> > "i can do it ",then the host select this ISP.
> 
> The core of this multi-homing information option is that to provide 
> someextra information along with prefix information option to help 
> host do 
> selection, and the host uses the prefix once it finds the matching 
> information in multi-homing information option. 
> ISP name is a sub-option, ISP name is a generalized name, the IPTV 
> service provider can name itself as "IPTV", Internet service provider
> can name itself as "HSI", these names also indicates their service 
> type.Maybe I haven't made this very clear in the draft. Of course, 
> any other option can be also defined under this architecture, for 
> example, what 
> kind of service the isp can provide, the qos parameter, etc. 
> Currently,only a few suboption have been defined.
> 
> Using this multi-homing option, router can priodically advertises 
> the 
> ISP's ability and related information.
>

I think it's a much better fit to provide this (changeable) operator
related information using 802.21 media independent information services.

With respect to access network related configuration information,
we already have DHCPv6 for that, and more specific route options
for Router Discovery.

Router Discovery is for prefix and next hop determination.  Let's not
make it complicated for other reasons.

Greg