Re: RE: AD request / L2 Triggers Chapter Statement

Hi JinHyyeock,

----- Original Message ----- 
From: "JinHyeock Choi" <[email protected]>



> Hi
> 
> Few will doubt that it is useful for the link layer to be able to send
> event notifications up to IP 
> layer, especially for fast handover in wireless environment. And if the
> link layer and the IP layer 
> reside in one system, we can implement the system to send suitable
> information upward. 
> 
> But what if the link layer and the IP layer are in separate systems?

If we use the "bits on the wire" philosophy elaborated on earlier, it should
not matter.  If the bits are defined, they can be sent over any interface to
IP.  The ideal interface would be a function call interface like the 
sockets interface but this is not absolutely necessary.

> What if the link layer in one 
> system wants to send notifications to the IP layer in another system?
> For example, is it possible 
> for an AP to send a notification to a mobile node or an access router? I
> think this kind of ability 
> is useful. We found some technical problem can be solved more easily
> with L2 and L3 
> cooperation. 
The L2 can put the info into a meta packet that is destined for IP rather than
through IP.  The IP layer can support a functional interface and a meta-packet
interface.  Either way, this WILL HAVE to be implementation specific.

> 
> This is an example. When a mobile node changes its point of attachment,
> it should find its new 
> access router as soon as possible. But there are some problem under
> current neighbor 
> discovery protocol. For more detail, confer 'Mobility Support in IPv6
> (draft-ietf-mobileip-ipv6-
> 17.txt)' 7.5 and 'IPv6 Fast Router Advertisement
> (draft-mkhalil-ipv6-fastra-00.txt)'. Because 
> of these, the standard (RFC 2461) change is suggested. But we can solve
> these problems more 
> easily if an AP caches suitable Router Advertisement message and sends
> it to an arriving mobile 
> node. For more detail, confer 'Fast Router Discovery with AP
> Notification (draft-jinchoi-
> l2trigger-fastrd-00.txt)'. 

In my heart of hearts, I believe in IP over everything.  If you are referring to 
the IEEE 802 style APs, I belive they are not properly designed.  They should
be IP routers, not simple bridging access points.  I am not out to change the
world.  I recall that IEEE 802 TG F has produced an IP based handover
recommenation that could perhaps be modified to support this in a more IP 
friendly way.
> 
> We believe that the above is not sole example. Moreover it will be nice
> for other standard body 
> (IEEE 802.11) to nofify them what kinds of triggers are needed to
> optimize IP 
> performance. Did IETF provide input for 3GPP? 

I will let somebody else answer this.  I believe so.
> 
> I guess the following questions are to be considered.
> 1) Is L2 trigger useful for Internet? 
> 2) Can we improve the current work on L2 trigger?
> 3) Is it appropriate to work on L2 trigger in IETF WG?

A more systemic question might be is IP mobility important to the Internet 
community?  Let's face it, mobile IP has seen scant deployment in its
years of existence.  Why?  Obviously its missing thing that would make it
commercially viable.  The 3G guys worked hard to add some of these,
but 3G is not necessarily moving that fast.  The hot spot, WLAN, WPAN,
ad hoc, mesh community is moving much faster.  There are many cheap
radios available here and much more can be done with them quickly.
L2 triggers are a win-win since they benefit 3G, 4G, WLAN, WPAN,
mobileip, and MANETs.  


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