Re: RE: AD request / L2 Triggers Chapter Statement

Phil Neumiller wrote:
>>>Right, but many routing systems are built ON IP and below transport.
>>>Take MIP, any MANET protocol, ICMP itself, OSPF, BGP4, etc.  All of
>>>these systems that reside at the IP layer in routers CAN INDEED make
>>>extremely good use of this information.
>>
>>Which of these operates on millisecond decisions?
> 
> 
> Oh, this is a trick question....  NONE because they CAN'T.  YOU can NOT
> convince me that they WOULD NOT if they COULD!!!!

OK - so we agree to disagree on whether anyone would use this 
information.  My concern is that no existing protocol does anything 
anywhere near this fast in the Internet; the simple variability in paths 
is enough to kill most 'hard realtime' guarantees on timing. As a 
result, it isn't clear that they COULD (perhaps not enough to convince 
you, but can you convince me??).

>>What I'm asserting is:
>>
>>if it's within two links of the same type, a meta-link can do it
> 
> 
> Yeah, and where is this defined in ANY commercial IP stack???

No. And rightly so. That would be inside the link layer.

>>if it's between two different links, IP routing has to do it,
>>and that doesn't care about millisecond events
> 
> Baloney!  Policy based routing most certainly does. 

Can you be more specific (and less inflammatory, please?)?
E.g., a policy based-routing that would _change_ what it does on a 
millisecond timescale. Granted that policy routing operates on those 
timescales, but it isn't clear that anything it does would change on 
those timescales.

> Especially with respect to
> wireless handovers which is the MAIN purpose of this discussion.

Wireless handovers is a link-layer issue, not necessarily an IP-layer issue.

>>Again, if you want to do this on a single box, you don't need an L2 
>>trigger. It's not that you're talking to IP in general, but that you're 
>>talking to a particular stack implementation.
> 
> Wrong.  We absolutely NEED IP to change so that there is a standard 
> mechanism for ALL future L2s to communicate with IP from the bottom up.

So what you're saying is:

	- we NEED L2 triggers

	- we NEED all of IP to change to be realtime to USE L2 triggers

	- everyone NEEDS all of this to support one link type for
	certain applications

Sounds a lot like optimizations.

> Imagine yourself as an L2.  How on earth are you going to send any kind
> of link quality assesment to IP? 

Better - _why_ am I sending link quality assessment to IP? What would IP 
do differently? The routing protocol already sends route advertisements; 
they get there or they do not; if they do not, the routing changes (on 
the timescales of seconds).

IP is not a realtime system. You're asserting it should be; that sounds 
like a job larger than a single WG can handle.

---

Does anyone else have a position to share on this?? I'm not claiming 
that this group should not move forward; it would be better, IMO, if 
there were a clearer reason, however...

Joe



_______________________________________________
pilc mailing list
[email protected]
https://www1.ietf.org/mailman/listinfo/pilc
http://www.ietf.org/html.charters/pilc-charter.html
http://pilc.grc.nasa.gov/